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8 Recommended Flight Investigations and Supporting Ground-B ased AGtivities. 2003 -20 1 3 Earlier chapters present evidence of the dramatic scope of NASA's Solar System Exploration program' evidence of Me programs remarkable achievements as well as of id weaknesses' md descriptions of We remark- able breads of the flight md Earth-based opportunities ~~ currently exist to advance solar system science. Since it is ~ ineontes~ble feet of budgetary eonshain~ thy not all these opportunities em be Bead upon in the coming decade' ~ strategy is required ~~ integrates Me goals of Be diverse element of the program, moves to strengthen area of weakr~ess~ md accomplishes what em be done Trough opportunities win bow Be higher scientific merit md Ethnical readiness. JU[)GING MISSION AND RELATED PllIOllITIES The letter requesting this study called for the generation of ~ prioritized list of the most promising avenues for flight investigations md supporting ground-based activities. This chapter is devoid to that task. A prioritized lid implies ~~ the element of He list have been judged md ordered win respect to ~ set of relevant eri~ria. Equally the same eri~ria are used here ~~ were used in Chapter 7 to isolate key scientific questions for Be next decade: seientif~e merit, opportunity' md technological readiness. An assessment of all of these criteria together is Be essential eonsider~ion in determining mission priorities. For example' it would make little sense to have as ~ firm privily ~ flight mission or ground-based system that was awaiting some long-~rm technical development or for which no flight or budgetary opportunity existed, no mater how high He scientific merit was rend. I>DElIL YING PllOGllAMhIATIC llEQUIllEMENTS So far, priorities have been discussed in relationship to either scientific questions or speeif~e projects. However' programmatic requirements also need to be considered in building ~ Duly in~gra~d stringy. ~dividua1 flight projects recommended for the next decade red on the base of the long-term program. The top-level programmatic priorities provide the foundation for productivity md continued excellence in plenary exploration md build on the positive aspects of He Presidentts proposed FY 2003 budget for NASA.i These priorities are as follows: USE

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HEW FR0~ IN =E 50~R HIM I. Continue approved missions, such as ~e Cassini-Huygens mission to Saturn arid Tim arid those in ~e Mars Exploration Program (h~P) md the Discovery program of low-cost missions, arid ensure ~ 1~1 of funding thy is adequate bow for successful operations arid for ~e analysis of the dam arid publication of ~e results of them missions. Fundamental research programs, follow-on d~-~alysis programs, arid ~chnology-development programs thy support these missions should also ~ assured adequate funding. 2. Increase ~e fundamental research arid analysis grar~t programs ~ ~ ram above ir~fl~ion for ~ decade until they are ~ ~ 1~1 consistent win the round charge in character of the Solar System Exploration program thy is' chugs in the flight ram from ~ few large missions per decade to one or more small missions per year. 3. Establish the New Frontiers line of princip~-investig~or-led, competitively procured, medium-cost flight missions applicable to targets throughout ~e entire solar system md with ~ tom mission cost cap ~ $650 million. 4. Continue ~e development arid implementation of Flagship missions (~.g.. Viking' Voyager' Galileo' Cassini-Huygens) for the comprehensive exploration of extraordinary' high-priori science targets ~ ~ ram of roughly one per decade. S. Continue to support arid upgrade ~e technics expertise md the infrastructure in implementing orgar~iza- tions ~~ provide vital services to enable arid support solar system exploration missions. 6. Continue to encourage arid participate in international solar system exploration flight programs. Solar system exploration is art inherently intern~iona1 venture' md the U.S. program earl benefit from joint ventures. MISSION LINES ANN COMPETITION The success of He Discovery program, exemplified by the Near-Ear~ Asteroid llende~ous (NEAR) mission' Lunar Prospector' md Mars Pathfinders has convinced even He most hardened skeptic thy small, relatively low- eost missions em effectively address signif~e~t seientif~e goals. The discipline of Diseovery~s competitive selection process has been particularly effective in eliminating ill~oneeived concept md has resulted in richness of mission goals thy few would have thought possible ~ decade ago. The planetary science eommunity~s enthusiastic support for Discovery has led to calls for the competitive acquisition of all flight projects. The experience during the past decade in developing mission concept (i.e.' various Pluto flyby md Europa orbiter mission concepts) for which traditions procedures have led to eseal~ing cost estimates has amplified this call. The proposed line of New Frontiers missions is specifically intended to be competitively selected. Competition is seen as ~ vehicle to increase the seientif~e richness of flight missions md, perhaps of equal importance' as ~ device to constrain He large costs associated win flying robotic missions to the planets. Because of the positive experience with Discovery md also because of NASA's recent success in competing ~ outer solar system mission in the New Frontiers cost category, the SSE Survey strongly endorse the New Frontiers initiative. These spacecraft should he competitively procured and should have flights every ~ or 3 years' with the total mat capped at approximately twice that of ~ Discovery mission. Target selection should he guided hy the list in this report. While competitive selection has its advm~ges' id negative aspens should also be taken into consideration' md avoided if possible. They are as follows: . . . ~ c~ompet`~on ~ - to secrecy `n t~ concepts p - e of ~ To. For small missions having ~ adequate number of scientifically focused flight opportunities' this does not seem to be ~ demerit. However, with intrinsi- e ally expensive missions for which the flight opportunities may be singular md the scientific goals broad' it em be ~ problem. For New Frontiers missions' it does not seem advisable for conceptual scientific development to become He responsibility of ~ narrowly focused group in the eommunily, no matter how well motivated they are. The selection of New Frontiers missions needs to be ~ continuing process involving broad community input as has been accomplished by this deeada1 survey report. ~ Compet`~on for New Is moss may led to ~ s~! ~,`~e `n the of bosh I why conceptual! moron ~~iopm~t during t~ pros stage. As yet, the SSE Survey knows of no estimate or clearly identified source of funds for the development of proposals for New Frontiers missions. The cost of developing ~ Discovery proposal to Be final stage of ~ competition is not negligible. These costs em be expend

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RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED Al to increase with the sin md scope of the mission. The cost to develop ~ New Frontiers mission proposal will be considerably more Bars for Discovery missions. In Discovery, these funds come partly from ~e overhead charged on other projects ~ art implementing institution arid partly from NASA (particularly in the final stages of ~e competition). The SSE Survey r~mmencL an early study to determune the men for prodding the fund necessary to underwrite proposal competition in New Frontiers missions+ ~ Compet`~on may Bed to Sofa of 'nmrest at NASA In. There are areas of unique expertise resident in single NASA tenors ~~ must ~ supported md maintained ~ necessary arid required to carry outthe perry exploration enterprise fog., mission ar~alysis, navigation' arid deep-space communications). This expertise is often supported from institutional overhead on ongoing tenor missions. Since Base same centers may also wish to compete' particularly for large missions, the tenors will face ~ conflict of ingress when deciding whether to make such unique services available to their competitors. The SSE Survey recommend an early study to find ways to nvoitl the potentially adverse consequence of c~nBi~ of interest relating to' for example, Ned to unique expertise and infrnstru~ure nt NASA centers' DEFINITION OF MISSION COST CLASSES In the discussion of mission priorities thy follows, The SSE Survey, ~ NASA,s explicit request' divided missions into classes on the basis of ar~ticipa~d tom mission cost to completion But without extension). The mission cost classes adopted are as follows: Small less ~m $325 million' Medium between $325 million md $~50 million' md ~ Large more ~m $~50 million. For example, ~ Discovery or Mars Scout mission is ~ small mission by definition. New Frontier missions, as defined in the Presidentts proposed FY 2003 budget, are equivalent to Be Surveys medium-mission Oratory. Flagship missions' for example. Europa Geophysical Explorer or Mars Sample lleturn, are in He large-mission Gregory. The SSE Survey used the bed information available to it in assigning cost categories to Be mission concepts evaluated in this survey. Nevertheless, it must be emphasized that Be cost estimates' particularly for Be New Frontiers missions, are based on concept studies of limited scope. In order to confirm the residing of any New F=ntier minion concept prior to the issuance of an Announcement of Opportunity and to certify the minion concept's yu~lif'~ntion for this program' the SSE Survey recommend that after the first selection, an independent group Fondue n certiB'~ntion review of the mission concept to he solicited' prior to the issuance of any A_t of Opportunity+ SMALL MISSIONS The Discovery P - grain The Discovery line of small missions is reserved for competed missions responsive to discoveries md is outside Be donut of my long-term strategy. Over Be course of my 10-year period, Were are vermin to be new discoveries md high-seienee-~alue mission ideas that could not be discerned ~ the begirming of the strategic plying period. The Discovery program provides for the neeess~ flight program flexibility to cover these contingencies md to provide continuing new opportunities to Be planetary science eommunily for mission ideas nof provided in the long-term strategic plan. The Discovery program is fundamental md invaluable for planetary exploration' but it is outside the bounds of this long-~rm strategic plan. Therefore' the SSE Survey makes no specific flight mission recommendations for the Discovery program, but it is compelled to make ~ recommenda- tion on Be value of these missions to plme~ry exploration+ Given Discovery's highly su~sful start, the SSE Survey endorse the con tinuntion of this program' which relies on princip~l-investigntor leadership and

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HEW FR0~ IN =E 50~R HIM competition to obtain Me area - t science return within n cost cap+ A flight rate of no less In one launch every 18 months is recommended+ Flight Mission Extensions The SSE Survey rwogni~s mission extensions, even multiple extensions' as significar~t arid highly productive elements both of nominally successful missions arid of missions thy undergo charades of scope or time lines due to unpredictable events. The Voyager extensions to Neptune' Urmus, arid the outer heliosphere are examples of ~e former' arid the NEAR extension ~ Eros Id the Galileo Europa~ille~ium arid pep Space ~ extensions are highly productive examples of ~e lair. The Survey treats these extensions, which it assert will require Weir own funding arrangements, as independent, small-cl~s missions. The Discovery program cart make decisions on mission extensions within the Discovery program line by trading off Announcement of Opportunity release dams. As the examples Died above indicate' the productivity arid effectiveness of mission extensions in solar system exploration are unquestionable arid con~itu~ ~ importers part of ~e Surveys in~gra~d spongy. The SSE Survey support NASAL current Senior lleview proms for deciding the scientific merits of n propped minion extension and recommends that early planning he (lone to provide nileqante funding of mission extensions' particularly Flagship missions nnil missions with international partners+ PIlIOllITIZED FLIGHT MISSIONS FOR THE DECADE 2003-2013 The mission concepts proposed by He SSE Surveyor panels I see Part One) as future flight mission e~dida~s are compiled in Table 7.1 in Chapter 7. They encompass missions to ~ diverse set of targets' from Mercury to beyond the orbit of Pluto. These concept touch on ~ broad rime of questions that include He formation of He solar system, the evolution of habitable worlds, the origin of life, md the fate of Earth. Some of these missions em be flown win proven technology; others require sub~mtia1 technological development. It is clear ~~' given their cost implications, not all of the missions listed in Table 7.~ em be recommended for flight in the next decade, md therefore the SSE Survey prioritized them. To form ~ seientif~e basis for id integrated spongy (see Chapter 7~, He SSE Survey used He criteria of seientif~e merit opportunity' md technological readiness to Isolde 12 key scientific questions to be addressed during the next decade. It then showed how these questions relate to ~ small set of mission e~dida~s' highlighted in bold type in Table 7.~' which are He mission set from which He Survey creed its prioritized list of missions suitable for flight in He next 10 years. Overall program cost constraints are ~ feet of life. The SSE Survey restricted the number of missions in id prioritized list to ~ number ~~ it believes em be accommodated within He out-year budget profile in He Presidentts proposed FY 2003 budget: for large-class missions, He number is limited to one' md for medium- el~s, the number is limited to Tree; these are supplemented by two extra mission e~dida~s to account for uneer~inties' to encourage furler possible grown in He program, md also to give some indication of the possible direction for He program beyond He current decade. The SSE Survey, s recommendations for non-hIars missions' therefore' consist of ~ prioritized list of five medium-class missions for He New Frontiers program, the start of one large-class mission during He decade, md one small-class non-Dimovery mission extension. Mmy discoveries occur in the plme~ry sciences over the course of ~ decade' md for ~ deeada1 shaggy to maintain ~ course consistent win ongoing discoveries, the need to reconsider the priorities recommended by this Survey may arise. NASA should issue Armouneements of Opportunity for New Frontiers missions that are consistent with the priorities given in this Survey. Only in He ewe where ~ new discovery eh~ges He Surveys fundamental understanding should these priorities be reconsidered, in which ease the SSE Survey reco~en~ that the National llewnrch Council's Committee on Planetary and Lunar Exploration Fondue n review to confirm or modify dental survey recommendations and priorities for the New Frontiers flight program+ The number of Discovery missions is constrained only by the funding profile. llecognizing the Discovery progrnm's sumac, the SSE Survey recommend that ndeqante resource he provided to sustain an average flight rate of no less than one Inunch every 18 months+

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RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED Al While ~e Discovery program has resulted in grew success for small missions arid ~e New Frontiers program holds grew promise for modera~-cost missions' some high-priori~ science investigations will require higher-cost missions. The SSE Survey recommends Ant Flagship (~$650 million) minions he (1eveloped anal Down at n rate of Shout one per deende+ In addition' for large missions of such inclusive scientif'~ breadth, n broad cross Region of the community should he involved in the early planning stages+ Future survey committees should have ~ Weir disposal well-developed plying studies for missions in this class in order to make sensible decisions on prioritization. The SSE Survey reco~nends that NASA fondue n series of nd~nnced studies of Flagship mission concept with broad community participation over each 10-yenr period prior to deendal surveys. These and studies could ~ selected Trough ~ competitive process ar~alogous to the 21~ Century Mission Concepts for Astrophysics program run by NASA in the mid-~9Os `~to solicit i~ov~ive proposals for concept studies of new flight missions which cm Inhere capabilities for frontier research. . ., arid ``develop menu of po~ntia1 new mission concepts to be considered for the next decada1 survey commits. The rationale for the SSE Surveys prioritization within ~e Mars Exploration Program, which places ~ high priority on art early Mars Sample Return mission' is Dewed separately below. The final prioritized lid of flight- mission ear~dida~s is shown Tile ~ A. As indiea~d' Me raking reflects the Surveyor assessment of the scientific merit technological readiness' md special opportunities associated win each mission. Scientific lintion~le for Priorities in the l~edium-Cln~ New Frontier Line Kipper Bek Auto Explorer A mission to the Kuiper Belt' including Pluto-Charon, will provide the first exploration of this newly discovered domain in the solar system, provide importmt insights into Be physical nature of these planetary building blocks, md allow us to survey the organic muter md vol~iles ~~ they conning Collisions win objects such as these diverted into the irmer solar system may have imported Be basic volatile md molecular stock from which habitable environments were eons~ue~d in early planets history. Little is known of Be physical properties of Kuiper Belt objects (KBOs). However, what is known (several physically large objects with high rates of spin' several loosely bound binaries, md ~ wide range of color) indicates that they have diverse md unexpee~d properties. The value of this mission increases as it observes more KBOs md investigates Be diversity of their properties. The SSE Survey mlicipa~s that Be information returned from this mission might lead to ~ new paradigm for Be origin md evolution of these objects md their signifiemee in the evolution of objects in other park of the solar system. Comparison of Be eratering records on Pluto' Charon, md several smaller objects ~ ~ rude of heliocentric dimples will provide our first dam on Be eollisiona1 history of this region. Comparison of the surface eomposi- tions of objects in Be belt win Pluto md Charon md Triton may allow us to separate evolutionary surface processes from primordial surface properties in the outer solar system. The observations, if extended to small objects, may provide information on whether domed are eollisiona1 fragments from large KBOs or are themselves primordial bodies. The surface myriad on KBOs may not survive end into Be inner solar system. Investigation of the composition of this material' which is probably the most primitive in the solar system' will provide ~ important reference for comparison with the surface materials on relend bodies, including the Centaurs, the nuclei of comets' md certain near-E~h asteroids. The technic readiness of this mission is judged high' owing to Be ongoing development of ~ Ethnically equivalent mission concept. ~hlich~1 Kaplan NASA Headquarters' preserrt~ior1 to the N~iorla1 Research Council>s Tam Group or1 Spam Astronomy ~dA~rophysics' March' 1996' ba~groundm~erials compiled by Shobita Par~ar~hy arid David H. Smith.

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~4 HEW FR0~ IN =E SOLAR MOM TABLE 8.l An In~gra~d Strategy for Solar System Exploration: Prioritized List of Flight Missions for the Decade 2003-2013 Te chrlolo ~ =d h] Lion L in Skiers Opp ortur~ity Cou id Cou id Will Rank Create Charge Resu its Add to ire Cost New Existir~g Will Be Fa~u:~1 Technical Special Cons h~issior~ Concept Name Paradigm Paradigm Pivotal Ba~ Readir~s Opportunities SO LAB ~ YSTElYl FLI CHT lYlISSI O NS (non-lYlars) $~l ~ Cassini Extended x xx xxx xxx xxx MA Kuiper Belt-Pluto Explorer xxx xxx xxx xxx xxx ~ ~ South Pole-Aitker~ Basir~Sample Retum xx xx xxx xxx xx 3 3 Jupiter Polar Orbiter with Probes xx xxx xxx xxx x Venus Ir~Situ Explorer x xxx xxx xxx x ~ Comet Surfed Sample Return xxx xxx xxx xxx Argo ~ Europa Geophysical Explorer xxx xxx xxx xxx MARS FLI ~ HT lYlISSI O NS (beyond 2005) $~l hears Scout line x xx xxx xxx xxx ~ Mars Upper Atmosphere Orbiter x xx xxx xxx xx Mom hears Skiers L~or~ory x xx xxx xxx x ~ Mars Lor~g-Lived Lander Network xx xxx xxx xxx x Argo hears Sample Retum DISCOVERY FLI AT IVIISSI O NS Oral launch every ~ ~ months xxx xxx xxx xxx NOTE: Skiers Ad te~olo~ evalu~ior~ bomb: xxx' high; xx' medium; x' mown. Opportunity bomb: 1' approved missior~> operating spamoraft or Elegiac mechanics; 2' ir~m~ior~al; 3' te~olo~ opportur~i~. L=~r Some Po~-A'~= Bm`n Sample tom The goal of Me Soup Pole-Ailken Basin Sample Return (SPA-S1~) mission is to understand Me Azure of Me Moons upper mmile md to tie down early impact chronology by returning samples from Me South Pole-Ai~en Basin. This basin is Me larger known in the solar system md is str~igraphieally the oldest md deepest impact structure preserved on the Moon. This gist exertion penetrates the lunar crust md allows access to materials from the upper motley md so may have ~ subs~tia1 effect on our current paradigm for the differentiation process. Absolute dying of returned samples' which will include both soil md diverse rock chips, could also eke our understanding of the timing md intensity of the late heavy bombardment suffered by bow the early Earn md Moon. The emergence of life on Earn that was meesha1 to our eon~mpor~ biosphere could nof have occurred until after the last global' tom sterilization impact event which likely corresponds to Me end ofthe period of heavy bombardment. A sample-return mission such as SPA-S1l that is' one of moderate ~ehniea1 difficulty is ~ opportunity to gain relevant experience for much more complex sample-return missions from Mars md from Venus.

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RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED At Jumper Bomb Or6~r why proms ~5 There are five primp objectives for the Jupiter Polar Orbiter win Prows (JPOP) mission. Fired it will Carmine if Jupiter has ~ core' ~ question thy is key to gimt ply formation. One theory holds thy ~ rock-ice "seed,' of some 10 Earth masms is necessary to For act ~e lighter gases hydrogen arid helium. Another Emory says thy Jupi~r-si~d object cart form as stars do, attesting gas, ice' arid dust directly from ~e nebula. Second, JPOP will measure the wear abundar~e (hence' ~e O/H ratio)' which is uncertain by art order of magnitude even though oxygen is expected to be the third-most-~undar~t element after hydrogen arid helium. Wear plays art importmt role in diary ply formation. The OlH ratio Ells us how girt pits got Heir volatiles (H~O' CHIT NH ~ md HASP prods in particular, ~e ex~nt to which the volatiles were carried from beyond Neptune, orbit to ~e inner solar system on icy plar~simals. Third, JPOP will measure the deep winds to 100 bars arid will give some information about ~e winds to thousands of bars. The deep winds may be key to ~e extreme Lability of the weather systems observed ~ cloud top. Fourth' by virtue of its cloud-skimming orbit JPOP will measure the higher harmonics of the magnetic field' which is key to understanding how Jupi~r~s dynamo works. Fifth, JPOP will repeatedly visit ~e hitherto unexplored polar magnetosphere, where the current ~~ main- tain corot~ion (of the plasma win ~e ply pass into the ionosphere arid cause ~e Jovian aurorae. V=~ ~ ~m Explorer The Venus In Situ Explorer ~ISE) mission is ~ detailed exploration md study of the composition of Venusts atmosphere md surface materials. Venus md Earn may have had very similar surface conditions early in their histories' but~enusts subsequent evolution was differentirom Ear~'s, developing menvironmentunsui~ble for life. However' Venus is Fill ~ dynamic world win active geoehemiea1 cycles md nonequilibrium environments in the clouds md near surface ~~ are not understood. VISE will make compositional md isotopic measurements of the atmosphere on descent md of He surface on lading. A eve sample is obtained ~ He surface md lofted to altitude where furler geoehemie~ md mineralogical analyses are made. ~ situ measurement of winds md radiometry are obtained during descent md ~ He balloon station. Scientific dam obtained by this mission would help to constrain He history md stability of the Venus greenhouse md the recent geologic history' including resurfacing. The technology development achieved for this mission will pave the way for ~ potentially paradigm- al~ring sample-return mission in He following decade. Comet Surface Sample Chum A first sample from the near-surface layer of ~ comet' if Ken from ~ chive area Perhaps ~ sunrise when aetivily is low) will provide the first direct evidence on how comet aetivily is driven (whether He water is very close to the surface). The Comet Surface Sample lleturn (CASH) mission would provide He first real day on how small bodies peered (physical structure ~ scales from microscopic to centimeters)' chemical resolution of He org~ies in the wealth of large-mass molecules md fragments seen ~ Halley' md the first direct day on He selection effects that operas between the nucleus md the relatively well-studied material in come comae. CSS1l will also provide invaluable information on how the particles on ~ biometry nucleus are bound together: Is there ~ organic glue: Is there Sonnet welding: It will also provide He first direct information on He scales of physical md compositional heterogeneity: Is it microscopic as seen in meteorites' or is cometary ma~ria1 homogeneous ~ the microscopic scale: Finally, CSS1l will provide He first information on He macroscopic mineralogical md erys~lline structure md isotopic ratios in comet solids md also the first information on He physical relationships between vol~iles, ice' refractory material' md its porosity.

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HEW FR0~ IN =E 50~R HIM Scientific llation~le for Large-Cl=s Missions Outside the Mars Exploration Program e Flagship mission is recommended for this decade the Europa ~ophysica1 Explorer. Europa Copy Explorer Europa holds ~e mostpromise for increasing current understanding of the biological po~ntia1 of icy sa~lli~s. Convincing evidence exists for ~e presence of liquid wear within just lens of kilometers of the surfaced arid there is evidence for recent trar~sfer of myriad anthem ~e surface arid ~e wear layer. Europe oc~m is probably in direct contact win ~ rocky mmile below arid is potentially endowed win hydro~erma1 systems, so chemical disequilibrium may ~ able to nourish oceanic organisms. The first sup in understar~ding the po~ntia1 for icy sa~lli~s as abodes for life is ~ Europa mission with the goal of confirming the presence of art interior ocear~' characterizing the sullies ice shell' arid understanding id geological history. Europa is importers for addressing the issue of how far orgar~ic chemistry goes toward life in extreme environments arid ~e question of how tidal hewing cart affect ~e evolution of worlds. Europa is key to understanding ~e origin arid evolution of wa~r-rich environments in icy sa~lli~s. The SSE Survey endorses the current ~ndations for n minion to orbit Europa+ However, given the high cost of the Europa Geophysical Explorer mission, the Survey considers it essential that the minion address troth the Group 1 and Group ~ science objective described by the Europa Orbiter Science Definition Temn+ Them objectives are as follows: Group 1. Determine the presence or absence of ~ ocem; ehar~terize He ~ree-dimensiona1 distribution of my subsurface liquid wear md id overlying fee layer; md understand the formation of surface features' including sites of recent or current aetivi~, md identify candidate lading sins for future lander missions. ~ Group ). Characterize the surface composition' especially compounds of interest to prebiotie chemistry; map He distribution of impor~t constituents on the surface; md characterize the radiation environment in order to reduce the uncertainty for future missions' especially landers. Flagship missions have been ~ traditional mems for international cooperation in which NASA md other nations space agencies' including the Europem Space Agency (ESA), em leverage Heir resources to accomplish what might otherwise be difficult to achieve. Galileo md Cassini-Huygens provide good examples in this respect md the SSE Survey recommends that NASA engage prospective international partners in the planning and implementation of the Europa Geophysical Explorer+ llelative Priorities Between Mission Cat Calves The S SE Survey did not exempt to prioritize across mission cost classes so thy flexibility is preserved in order to address opportunities in the ~ua1 budget eyelet The opportunities to mount large~lass missions are very limited, md if ~ lower-cost mission em be woommoda~d in ~ new budget eyele, it should not be thwarted by requirement to wait for ~ opportunity to initiate ~ more expensive mission. Luther than compete large-ela~ minions with missions in other cost Moses, the SiSE Survey recommends flying large-c~s minions at an appropriate frequency (i+e+' roughly one per deadest independent of the issues facing new starts in other cost 1+ Since large-class missions represent ~ enormous investment md generally require ~ decade of study to mature in concept md design, the SSE Survey recommends that NASiA establish ~ procedure for reevaluating the candidate list of large~l=s minions for the decade 2013-2023+ Two possible men for this procedure include (1) the appointment of ~ Science Definition Temn every 3 years to define candidate minions or ~) ~ periodic competition for funds to support initial definition studies of minions concept+ Some large-class missions identified by He SSE Survey for the 2013-2023 decade' md which should be revisited in the near future' are listed in Box 8.~.

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RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED Al ~7 The Kuiper Belt-Pluto Explorer is the fire privily in He medium-cost class' md the Europa Geophysical Explorer (ECE) mission is Me firm priority in He large~ost elms. The Kuiper Belt-Pluto Explorer mission' win in potential for creating ~ new paradigm regarding primitive processes in the outer solar system md Heir effect on the evolution of bodies in over parts of He solar system' has scientific merit similar to ~~ of He ECE mission' which seeks primarily to define ~ possible habits for life by vastly expanding our current knowledge of ~ subsurface ocem. Win respect to technical readiness md special opportunities He Kuiper Belt-Pluto Explorer mission has clear advantages over ECE. Deferred High-Priority Missiom The prioritization process forces the SSE Survey to defer what would otherwise be excellent high-privily missions wormy of flight. Box 8.1 lisp mission concepts that are among the highest-r~ked by the SSE Surveys panels, but that did not make He final recommended priority list for He coming decade. Some of these missions are deferred because their mienee objectives em be more precisely defined after precursor missions are flown. The Europa Lander should follow as the next step after the Europa Geophysical Explorer. Similarly' ~ Titan Explorer mission should follow Cassini-Huygens. After having eondue~d orbiter missions to the two gas giants' Jupiter (Galileo) md Saturn (~assini), ~ orbiter mission to ~ fee Mint should follow He highest-ra~d being ~ Neptune orbiter mission carrying deep atmosphere (l OO-bar) probes win special attention to Triton exploration through flybys md perhaps ~ lamer. These outer-plmet missions will be enhanced md enabled by advanced nuclear power md propulsion. Venus sample return should fol low after experience win lunar md martim sample return, md ~ cryogenic comet sample return should follow experience with ~ non- eryogenie sample-return mission. The proposed set of medium-elassiNew Frontiers missions should be revisited on ~ appropriate time scale as new discoveries are made in the course of the solar system exploration enterprise.

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Ads HEW FR0~ IN =E 50~R HIM PlilOllITIES FOR THE MAItS EXPLORATION PllOGlIAM The exploration md scientific investigation of Mars have reached ~ importers same. Exciting discoveries from recent successful missions arid the ongoing research md m~ysis of dam from these missions arid martiar~ memories have established ~ broad underfunding of ~e plar~et arid id evolution. These developments have also raised ~ number of fundamental arid compelling questions relend to all aspects of Mars, from the outer Ionosphere arid space environment to ~e deep interior. The sheer number of questions presents ~ challenge to establishing ~ rationale arid ~ fiscally prudent plan the moves toward addressing the highest-priori~ question identified by numerous bodies (~.g., COMPLEX' REPAY, md this survey): Did life ever arise on Marsh No single measure- ment ~ ~ specific location on Mars will grower this question. Nor is the impor~ce of the question underwood without ~ broad under~ar~ding of Marsh current processes arid past evolution. It is imperative ~~ ~e exploration of Mars move aggressively to surface missions for in situ science investigations md ~~ it lay the foundation for sample return' the lamer irking early in ~e decade 2013-2023. In situ science is progressing rapidly, md such investigations will add substantially to our knowledge across broad rage of disciplines for Mars. However' the results thy will flow from ~e deviled investigations of martiar~ samples returned to Each using modern techniques arid sophisticated equipment will simply dwarf all previous results. It is importmt to be aware thy the first samples returned from Mars may not ~ definitive regarding ~e life question' no moor how carefully ~e samples are selected. However, the first returned samples would establish beyond ~ shadow of ~ doubt how ~e exploration of Mars must proceed md where to explore, using in situ measurement md additional returned samples. Equally importmily' Base samples will forever chugs our understanding of geologic md climate evolution' surface-~tmosphere interactions' md Mars as ~ abode of life. Table 8.l above contains the prioritized list of missions for the future Mars Exploration program, md Table 8.2 indigens ~ possible mission sequence for their implementation. lle~m~nded arm Missions Mars Sample Deem Observations by robotic orbiters md landers Cone are not likely to provide ~ unambiguous answer to He mod important questions regarding hears: whether life ever shred on ~~ planet, what the climate history of He plmet was' md why Mars evolved so differently from Earth. The definitive answers to these questions will require analysis in Earth-based laboratories of Mars samples returned to Earth from known provenances on Mars. Moreover' samples will provide the ultimate ground-tru~ for the wealth of dam returned from remote-sensing md in situ missions The SiSE Survey recommend that NASiA hewn its planning for Mars Sample Return minions so that their implementation On occur early in the decade 2013-2023 ~e Needfor S;`xmple Return to Search for Life. At our present sate of knowledge md ~ehnologiea1 expertise' it is unlikely that robotic in situ exploration will be Ale to prove to ~ acceptable level of certainty whether there TABLE 8.? A Possible Sequence for Future NASA Mars Science Missions with Early Sample lectern Year of Laurldh 2005 20 07 2009 2011 2014 h] ars Recor~r~aiss~e h] ars Scout ~ h] ars Skiers h] are Scout ~ h] are Samp 1e Retum Orbiter Laboratory with irtem~ior~1 pursers

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RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED Al once was or is now life on hears. Results obtained from life)~tion experiments carried out by robotic mems cm be challenged as ambiguous for ~e following reasons: ~ Result in~rpre~d as showing ~ absence of life will not be accepted because the experiments thy yielded them were too geocentric or otherwise inappropriately limited; Result consistent win but not definitive regarding the existence of life (em.' the detection of organic compounds of urn own, either biological or nonbiological, origin) will ~ regarded as incapable of providing clearcut mower; arid Result in~rpre~d as showing ~e existence of life will be regarded as necessarily suspect since Hey might reflect the presence of earthly contaminants rawer Bars of art indigenous martiar~ biota. ~e Needfor Sample Ream for Geochemist SO ~d Age Defog. Rocks contain ~ near-infini~ amount of information on ~ microscopic scale, some of it crucial to art understanding of the rocker origin arid history. The constituentminerals, fluid inclusions, md alteration produce cart be studied chemically arid isotopically, providing . . . ~ . - 1 ~ . - .d ~ . ~ .~ 1 ~ ~ . . - . . ~ . ~ ~ cry Mormon on me ages ctams of merma1 erect aqueous apron events, nature ot me source Argons aria history of magmatic processes. In situ inshumen~tion will always ~ limited to ~ fraction of ~e po~tia1 measurement ruin arid lower levels of precision md accuracy. ~form~ion about ~e Mars climax will ~ found in the layer of weathering products ~~ we expect to find on rock samples arid in the soils. These produce will almost certainly ~ very complex minerals or amorphous reaction products that will fax our best Earth-b~ed laboratory techniques to underhand. A critical urn own for Mars is the absolute chronology of the observed surface Unix. Prwise md accurate dying of surfaces win clearly defined fryer ages is best accomplished win returned samples. Me Need for Sample Re~m for Shades of Chime ~d C:oupled Aimosphere-Su~f~e-~ter~or Processes. Key measurements in modeling the relative loss of portions of the Exosphere to space md to surface reservoirs are surface mineral compositions md their isotopic systematic. Atmospheric loss processes (em., hydrodynamic escape' sputtering) leave characteristic isotopic signatures in certain elements. Loss to space md surface weather- ing (em.' C0~ to earbona~ minerals) are likelyto produce isotopic fraetion~ion in different directions. i5Nii4N in the martim Exosphere is understood to have evolved over the past 3.8 trillion years (it is currently I.6 times Me terreshia1 value), md ~ determination of this ratio in near-surface marries may constrain Me time of their formation. Compositional md isotopic analysis of surface minerals, weltering rinds' md sediments deposit will establish Me role of liquid water md processes such as weathering. The corresponding measurement on volatiles released from near-surface materials are likely to be more heterogeneous md may provide fossils of past atmospheric md chemical conditions that allow the past climax to be better understood. Me SNC:Meteorkes loo No! Olv~e the Need for Sample-Ret~crn Minions. SNC: meteorites have provided tm~lizing view of ~ few martim rocks md ~ demonsh~ion of how much em be leaned when samples em be examined in Earth-b~ed laboratories; however, Hey represent ~ highly selected subset of martim materials' specifically, very coherent rocks of largely igneous origin from ~ small number of urn own locations. Thus SNG meteorites are unhelpful in answering one of our outriding questions What is He absolute chronology of Mars: because although these meteorites em be accurately dandy He geologic Unix from which they are derived are up own. While returned samples are also ~ selected subset of martim materials we will know their geologic context md they will be from sites selected because Hey em provide particularly valuable information. Mars Scim~ ~oram~y The Mars Science Laboratory (MSL) is ~ important mission Song the paw of ``Seek' in situ, md sample.' The science goals are to fondue detailed in situ investigations of ~ site that is ~ wa~r-modified environment identified from orbital dam. As such' this mission will provide critical ground-bush for orbital dam md test hypotheses for He formation md composition of water-modified environments identified through morphological

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HEW FR0~ IN =E 50~R HIM arid spectroscopic investigations. The Ins of in situ measurements possible on howl are win retrying, including atmospheric sampling' mineralogy arid chemical composition' md Ash for ~e presence of orgar~ics. There currently is some Ibid as to whether this mission will have roving capability on the order of 10 km, or ~ more focused toward drilling to get Plow ~e surface' which is hostile to life. Both syzygies have merit in addressing high-priority science goals, Rough ~e drilling mission pub ~ much greater demar~d on precision larding. Regard- less of the ultimate design of the instrumentation' the SSE Survey recommend that while carrying out id science minions the Mars Science Laboratory minion shoulil - t nnil validate technology required for sample return (erg+' sample handling and storage in preparation for sample retrim and feed-forwnrd lander design, consistent with the future use of n l\Inrs Aseent Vehiele)+ ~ addition, ~e surfwe operations of the Mars Science Laboratory mission should feed forward to Mars Sample Retum. Mars Scout Program Mars Scout provides ~ excellent opportunity for NASA to address science priorities outside the principal objectives of Me Mars Exploration Program, arid for the broad science eommuni~ to respond to discoveries arid technological advar~eement. The SSE Survey reco~nen~ that the Mars Scout program he managed ns is the Discovery program' with princip~l-investigntor leadership and Repetitive Deletion of minions+ It is essential, therefore' thy Me measurement goals for the Mars Scout pro gram be directed toward the highest-priori~ science for Mars md be selected by peer review. The missions-of-opportunity element of the Scout program is also imported as it allows for p~icip~ion in foreign Mars missions. The SSE Survey strongly reco~en~ that the Mars Exploration Program commit equally ns strongly to the Scout program ns to sample retum+ While Mars sample-return missions will be expensive md consuming of the ideation of the MEP, Mere are sufficient resources in Me program as currently structured to achieve both ~ viable Se out program md sample return. As witnessed by Me response to Me recent call for Scout proposal ideas (over 40 submissions were received), tremendous enthusiasm has been stimulated by recent Mars discoveries Id scientific investigations not covered by the REP. Se out provides ~ mission eomponentth~ is highly flexible md responsive to discovery. The SSE Survey recommends that n Mars Scout mission he Down at every other launch opportunity+ Mars Long-lived ~~r Network The SSE Surveys Mars Panel considers ~~ ~ long-lived network of landed science investigations (hIL3N) should be ~ high-priority Mars mission. The principal experiment on these landed stations should be passive seismometers to determine interior structure Id aetivi~' Id malyzers of We ground-level atmosphere to address area of importune to maim Ionospheric science (meteorology' atmospheric origin Id evolution, chemical stability, Id atmospheric dynamics). Both We seismological Id atmospheric measurements must continue to record dam for ~ least ~ martim year to achieve Weir potential. NASA advisory panels have consistently recognized the importune of these experiments Id recommended their implementation.2 These questions are of particular interest for ~ broad eommunily of seienti~s' because useful comparisons with Earth em be made that may prove impor~t for understanding the atmospheric evolution of bow planets. Network science has been identified by the Europem Space Agency as ~ priority for hears (the NeLL~der mission). Mars [ripper Atmosphere 0~r The SSE Survey includes in id priority scheme ~ orbiter dedicated to studies of horses upper atmosphere Id plasma environment. Interactions win the solar wind are Nought to have played ~ signif~e~t role in the long-term evolution of the martim atmosphere, yet no measurements have been made to confirm or reject these ideas. A variety of atmospheric escape processes have been inferred from indirect measurement mdior predicted from theoretical models. This mission would provide qu~tit~ive information on the various po~nti~ escape fluxes md, thus' Justify eurrenteseape rams. Back extrapolation of such measurements might result in new underst~d-

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RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED Al 901 ing of the evolution of the Martian atmosphere arid maybe also provide imports clues to atmospheric evolution on Venus arid Earth. ~ carrying out these measurements, numerous other import=" questions of high scientific value associated with ~e middle arid upper atmosphere, exosphere, ionosphere, arid solar-wind interaction processes will also ~ addressed. No pliers exit in ~e current U.S. Mars Exploration Program to address arty of ~e scientific questions identified by previous parcels in this area. The Nozomi arid Mars Express missions will address Hem to some ex~nt but much more dam will ~ needed to meaningfully elucidate these issues. The measurements required for this mission could ~ accommodated as ~ science package on art in~rn~iona1 orbiter mission or as ~ star~d-alone mission in the Mars Scout program. Sowings Sequencing' Links to Other Mars Missions' and International Partnerships Enveloped in 1999 after ~e failures of Mars Polar Lander arid Mars Climax Orbiter' the Mars Exploration Program is founded on ~e pursuit of the highest-priority investigations along ~e path of ``Seek' in situ' arid sample.' The ``Seek', component consists of orbital investigations to identify sins with remotely sensed signatures indicative of wear. The ``in situ,' component involves gaping to the surface for detailed charac~riz~ion of specific sites arid providing ground-truth for orbital measurements. Finally' ~e "sample,' component concems ~e return to Earn of pieces of Mars thy will be imports for addressing the life question as well as all other aspects of martim science. The MEP plans for ~ mission to Mars ~ every launch window (approximately once every 2 years) md is eost- eonshained to some $700 million per opportunity. The program is designed to be flexible md responsive to discoveries' though mission design md implementation cycles require ~~ the wienee objectives md instrument suite for Me next opportunity be fixed prior to He results derived from the current opportunity. The Mars Exploration Program is currently reevaluating future missions, principally in response to the high cost of sample return. The program is being directed to develop discovery-driven investigation pathways win missions ~ every opportunity, unless compelling scientific justification em be developed for sample return. The SSE Survey believes ~~ sufficientresourees exist in the Mars Exploration Program to achieve the highest-privily mission identified by this md over panels (COMPLEX, MEPAG' md so on) while maintaining ~ flexible md dimovery-driven program of Mars exploration. Furthermore' this em be achieved to allow the first sample-return mission early in the next decade (2013-2023~. As ~ example, one possible pathway with ~ early sample return is outlined in Table 8.~. The interleaving of hears Scout with other MEP missions maintains He dimovery-driven aspects of He program. It is imports to recognize ~~ MS1l will be ~ long mission from development Trough launch' sample return' md sample analysis. It will take some time Her He samples return to Earth for the result of He analyses to be integrated win previous hears knowledge. Additionally' sample contingent md eur~ion facilities mud be operational before samples are returned, as was emphasized earlier in this report. The SSE Survey advocates ~~ MEL be structured to accomplished high-privily science goals md to achieve technological advances neeess~ for sample return. Sample-return technology em also be leveraged from developments in other missions, mod importantly He lunar Soup Pole-Aitken Basin Sample lleturn mission' recommended as ~ privily for the New Frontiers program. There are likely mmy common elements between this mission md Haley for example, He ascent vehicle' orbital rendezvous, lading systems' md sample handling md receiving. ~ feet the opportunity to test He Earth-return aspects of sample handling without the high-level plme~ry protection protocols required for Hall might be ~ critical test of the technologies required for MS1~. Counbies over than the United rates are keenly interested in Mars exploration md have eommided signifi- emit resources to national md international programs. Mmy of these countries have expressed ~ willingness to participate in NASA's efforts md several joint effort are currently under way. The SSE Survey advocates that NASA actively pursue in~rn~iona1 eollabor~ions such as Missions of Opportunily on Europem orbiters md landers. The SiSE Survey recommend that NASA engage prospective international partners in the planing and implementation of Mars Simnple Return at an early stage in order for this complex minion to benefit fully from the ~pahiliti~ and resource offered by the international community.

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) HEW FR0~ IN =E 50~R HIM ADVANCED TECHNOLOGY Technology Development TheSSE Survey recommenils that NASA commit to significant new investments in advanced Ethnology so that future high-priority flight missions mn su~+ Unfortunately, erosion has occurred in ~e 1~1 of investment in Ethnology in ~e past several years. Flight-development cons have increased over projections, arid investments in and technologies have Den redirw~d to maintain flight-mission development schedules arid performer. For most of the history of plenary exploration' large-cost flight missions such as Voyager, Viking, Galileo' arid Cassini have carried ~ large portion of ~e ~chnology-development burden in their development cops. During the charge in the 1~ decade to ~ larger number of lower-cost flight missions, the consequent loss of Ethnology development by large missions was compensated by adding separate ~chnology-development cost lines to ~e perry exploration portfolio, such as X2000' under art understood policy of ``no mission cart before id ~chnologica1 time.~, This mechanism was intended to separate arid remove the uncertainties in ~chnologica1 development from early flight-development Gosh. However, flight-mission costs have In undere~ima~d, arid development plans have been too success-orim~d, resulting in erosion of technology-development lines by trar~sfer to flight-development posh. This trend needs to be reversed in order to realize He flight missions recommended in this report. This report identifies ~ clear set of missions for development in the next decade' providing ~ compelling focus for advanced technology development. NASA must maintain this focus' even as it increases competition in technology development' to ensure long-term Wilily md strong coordination win flight-mission needs. Generic Technologies Generic technologies exist ~~ will benefit almost every flightprogram. To focus technology development on the most impor~t needs for He next decade' He SSE Survey identified He most enabling technologies for key in~rplmetary spacecraft subsystems power' propulsion' eommunie~ion, architecture' avionics' md inshumen- tation md for plenary surface exploration envy in situ systems' surface mobility, communications' md Earth-return systems (Table 8.3~. The two most-eons~ained resources in the current generation of plme~ry spaceport are onboard power Id propulsion. Improvements in these two areas will enable the largest leaps forward in capability. Solar power is generally insufficient beyond the Steroid belt, provides limited power for spacecraft systems' Id severely limits the lifetime of landed spacecraft. Most solar-powered plenary spaceport have only ~ few hundred watt of TABLE S.3 Recommended Technology Development Ca~ gory Re commerce d+ Deve lopmerd Power Propulsion Commur~ic:~tior~ Archite Cure Aviorlics Ir~stru mere at i or prey to lar~+ir~g Ir1 situ operatiorls h] obility Contamirlatior Earth return Ad vaneed ra dioisot op ~ p ow er syst ems' in-sp ace fission-r eacto r p ow er sour ce Nuclear-electric propulsion' advanced ion engines' aerocapture Ka hand' optical communication' large arrterma :~rrays Autonomy' adaptability) lower mass) lower power Advanced packaging and miniaturization'st~+ard+ oper~irlg system Miniaturization' erlvirorlmer~1 tolerarloe (temperature) pressure) arid+ rad+i:~tio~ Autonomous entry' precision landing' arid+ hawrd+ avoiding Sample gathering) h~+lir~g) arid+ analysis; d+rillir~g; ir~skumer~ation Autonomy; surface) aeri:~l) arid+ subsurf:~e mobility; hard+-to-reach acoess Forward+-co~amirlation avoid+arloe Ascent vehicles' irl-spam rerld+~vous) arid+ E~rth-retum ~~ms NOTE: Bold+ Ape ir~+ic~s ~ priority I'm.

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RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED Al 903 with ~ s~dardimd software operating system. New md informed science measurement eapabilily in plmet~ science instruments md greater environmental tolerance will be required for less mass md power. Mini~uriz~ion is We key to Me reduction of mass md power requirement. For Me ironer solar system, elee~onies tolerant to extremes of temperature Cow hot md cold) are required. High-~mperature, eorrosion-resistmt md pressure-tolermt systems are required for in situ exploration on Venus. For Be outer planets, radiation-hard electronics, shielding, tolerance, md reliability are required. As planetary exploration moves into He new century with more in situ md sample-return missions, it will be necessary to develop planetary Ending systems' in situ exploration systems' md Ear~-return technologies. The key requirement for Ending systems are autonomous entry, descent heard avoidance, md precision lading systems. Once on He surface' sample gathering md analysis become key technologies' with attendant require- men~ for new surface science instrument' including biological measurements, md mems for moving about plmet on, above, md below He surface. Systems for accessing difficult-to-reach areas will be required.

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904 HEW FR0~ IN =E 50~R DIM Rover Ethnology should advent toward long-life arid long-rmge capability' with autonomous heard avoid- ar~e md the Vilify to operas on large slopes. Drilling techniques on both ~rrestria1 arid icy surfaces will be needed, Ding toward ~ep-ic~ penetration arid submarine exploration in subsurface occurs. Aerial platforms for hears arid Venus will ~ required; they will ~ ~e forerurmers of systems to be deployed on Titar~ arid ~e outer ply. Adverted autonomy will need to be built into all of Base mobile m~hmisms. The mourns to return perry samples needs to ~ developed, Regiving win small bodies arid the Moon' Ding toward Mars, Hen Venus, arid eventually to more disco Urged such as Mercury Ed the sa~lli~s of the outer plus. Some recommended missions will ~ sent to plmets arid sa~lli~s ~~ are targets for biological exploration arid will require meeting perry promotion requirements relend to forward Ed back contamination. Technologies will ~ required to meet Case requirements while reducing the costs to do so. l\Ii~ion-Spembe Technologies In addition to the generic technologies decried above arid summarized in Table 8.3, mission-sp~ific technologies are required for the flight missions selected for this decade. They are described below. Kipper Bek polo Explorer The Kuiper Belt-Pluto Explorer mission is ready now' has no requirements for new technology, md cm use one of the few remaining f~r~-gener~ion lapse This is ~ multiple-object flyby mission designed as the first recor~E~aissmee of ~ number of Kuiper Belt objects, including the largest md best studied example, Pluto-Charon. It is premature to consider ~ orbiter for my of these objects. For this reason, md because of Be low relative flyby velocities required md Be requirement to reach Pluto ~ the earliest possible date' ~ NEP option with Be necessary advanced ion engines is not appropriate. There is no confidence that both em be developed in time' nor are they necessary for this mission. Consideration should be given, however, to the use of ~ solar-eleetrie propulsion Page to avoid reliance on ~ singular Juniter ~ravi~-assist opportunity in 2006. Europa Copy Exposer ~ ~ ~ 1 ~ ~ lladi~ion-hard elee~onies is Be key requirement in addition to the generic technologies for outer-plmet missions given above. This mission is focused almost exclusively on Europa' where it is much easier to eor~f~rm the existence of ~ subsurface ocem md to determine id extent ~m it is ~ C~ymede or Callisto. This orbiter mission would not benefit significantly from NEP because of Be strong focus on ~ single object with ~ limited set of scientific measurement. Once confirmed on one Calilem satellite ~ follow-on mission might be considered using ~ NEP spacecraft to consecutively orbit all Free outer Calilem sa~lli~s to search for Be extent of subsurface ocems md to dispatch landed probes. Bock Pi ole-A`~= Bare Sample ~~m The SPA-81l mission to the farside of the Moon could be the first test of sample-return technologies to be used on Mars. The developments required for these missions are very nearly the same, except for Be system for braking from orbit. The common element are automated descent; heard avoidance md precision lading; advanced in situ sampling, perhaps even drilling; advanced in situ instrumentation' including radiometrie age-d~ing md chemical md mineralogical analysis; sample transfer; md ~ ascent vehicle md E~h-return system. A mems for communication with ~ lunar far side station will be required. A successful SPA-S1l mission will provide early demonstration of plmet~ sample-return technology without the need for plme~ry protection md will signifi- e~tly reduce Be risk for ~ Mars sample-return mission.

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RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED At Jumper Bomb Or6~r why Probe 905 The JPOP mission will require advar~d RPSs' radi~ion-hard avionics' arid the revival of the Jupiter en~- sys~m technologies first developed in the 1970s. The probes should survive arid be in communication to 100 bars' whereas the signal from the Galileo prom was lost ~ 22 bars. Lightweight mass spectrometers for sampling high pressures win inferno gas processing for complex analysis are ~e key science instrument Ethnology. The deep proms developed for this mission will then be available for similar missions to the over girt ply Saturn' Urmus, md Neptune. NEP is not required for this mission. V=~ ~ She Explorer The key technologies for the VISE mission are those for system survivability' shallow drilling' sample acquisition, arid sample trar~sfer ~ extreme high temperature arid pressure in ~ corrosive environment; high- temperature balloon materials; arid long-lived compact power sources. The mission will require in situ instruments thy earl survive Me Venus surface environment md ~~ earl accomplish radiomebie age-dating arid chemical arid mineralogical ar~alysis of surface samples while ~ altitude. The use of advanced solar-eleeLie propulsion coupled with aeroeapture would markedly increase the performar~ee of this mission. Comet Surface Sample Chum The key technology required for We CSS1l mission is ~ sample-acquisition system without signif~e~t on- surface time' drilling, or sample manipulation md Forage ~ cryogenic temperatures. Advances in automation' ion propulsion' md solar- mdior nuclear-power sources will improve Me performance of this mission. Mars Meows In addition to Me generic orbital, in situ, md sample-return mission technologies listed above' for which Mars is ~ prototypical benefactor' planetary protection technologies (both forward md back) md attendant sample containment Earth return' md handling md examination facilities are the key technical issues to be addressed. A Mars-Earth return system' including ~ ascent vehicle md in-space rendezvous md sample capture, are key technologies that em evolve from the vehicles developed for Me South Pole-Ai~en Basin Sample lecture mission. Technologies for We Following De~de Technology development necessarily precedes flight-mission development' md Me technologies developed for this de eade must evolve into the technologies required for missions early in the next decade. The most important of the technologies developed in this decade for use in the next are advanced in-space NEP md spacecraft nuclear power systems. These power md propulsion technologies will enable missions that cannot otherwise be accomplished. NEP will reduce or eliminate Me need for gravity assist enable launch in my year' yield shorter trip times for mmy types of missions' reduce launch vehicle requirements enable tours of mmy different definitions on the same mission, md enable ou~r-plmet orbiters with long life' propulsion for extensive system touring, high power output' md significantly larger payloads. Active remote-sensing instruments' including s~thetie-aperture radar md laser-activated techniques, will be enabled by fission power sources. Examples of missions following naturally in Me next decade from those recommended in this decade' md which are enabled or enhanced by NEP' include ~ Neptune Orbiter carrying Neptune atmospheric probes md Triton surface probes, ~ Tim Explorer mission carrying ~ aerial vehicle md landers for Titm, md ~ Saturn fling Observer for maneuvering above Saturnts ring plane. The addition of aeroeapture technology to these missions will yield ~ combination of enhanced capabilities, reduced launch vehicle requirements mdior reduced in-space propulsion system requirement.

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cod HEW FR0~ IN =E 50~R HIM Optical communications' including advanced science instrumentation to utilize the increased bar~dwid~' should be available for missions in ~e next decade. The perf=tion of Mars sample-return Ethnology should be followed by id adaptation for return of samples from the surface of Venus. Drilling arid cryogenic sampling will be required for the return of ~ complexly preserved core sample of ~ comet nucleus. Aerial vehicles will be required for the exploration of Titers Mars, arid Venus; subsurface vehicles for Mars arid perhaps Europa; arid complex orgar~ic chemist md microbiology laboratory packages for exploring orgar~ic-rich environments' including Europa arid Tim arid perhaps even subsurface aquifers of Mars. Long-lived' high-~mperature' arid high-pressure systems will be required for Venus sample return arid surface Anions such as seismic networks. The Deep Space Network The Amp Space Network (~SN) is suffering from insufficient communications capability arid occasional failures as it ages. Limitations on downlink bedside restrict the return of dam from spacecraft ranging from some Discovery flights ~.~., the D=p Impact encounter source requiring real-time links) Trough the Flagship Cassini mission (constrained by ~e feeble signal from distar~t Saturn). While efforts to increase the Premier power on spacecraft are valuable' likely it will ~ less expensive to augment bow Fumier power arid commu- Dictions capacity on Earth Bars to correspondingly increase Case factors on all spa~cr~. Furthermore' additional ground stations would be valuable to provide geographic redundancy for the system as ~ whole' arid Hey would grant more freedom in ~e timing of critical spacecraft events. Studies should consider whether it is better to move toward shorter wavelengths such as Ka b~d' toward very large collecting areas' or toward optical communication links. Studies should also examine the efficiency gains thy might be realized by using ~ packet-swi~hed network protocol for communicating with ~ large number of plenary spacecraft. The SSiE Survey recommence upgrades and incised communications ~pahility for the AN in order to meet the specific needs for this program of minions throughout the deemed and that this he paid from the technology portion of the Supporting loch and Technology (S11&T) line rather than from the mission budgets' While it is perfectly reasonable' under full cost accounting' to use ~ straightforward algorithm that assesses costs for operating the DON to spec ific missions' my upgrade coot realistically be charged to ~e first mission that uses it, md ~ amortization schedule would be entirely ad hoe given He underpin number of prospective client missions that might employ the DSN. Such ~ voluntary system of payment would make He finmeia1 status of the entire upgrade program unstable' since He program would be subject to the finmeia1 . . ~ . . . . . c mesons o: : mc `~'c ua mission mmagers. EAlITH-BA5iED TELESCOPES NASA currently provides support' in widely Awing pereent~es, for planets science operations ~ Areeibo' Coldstone, Keek' md the Infrared Telescope Facility in collaboration with the Nations Science Foundation (NSF)' DON, ~ private consortium, md NSF, respectively. As described in Shaper ~ of this report' these facilities have made major eon~ibutions both to planetary mienee in general md to speeif~e flight missions. The I1lTF' He only facility dedicated to NASA planetary astronomy' has provided vim dam in support of flight missions. The SSE Survey recommend that the planetary rear facilities' the Infrared Telescope facility and NASA support for planetary oh~ervations at large facilities such ~ Kent he continued and upgraded Us appm- priate' for ~ long ~ they provide significant scientific return andlor provide mission-eriti~l service+ The recent so-called Augustine report urged that NASA md NSF collaborate in astronomy in order to coordinate Heir efforts md produce He best science for the nations investment.3 In particular' ~~ reportts second recommendation urged the federal government < OCR for page 189
RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED Al 907 provide very limited support for perry science in recant years' ~ situation the is particularly unfortunate' given NSF,s Sharer to support the ~~t science arid its leadership role in other aspects of ground-based astronomy. While the SSE Survey presumes ~~ the Solar System Exploration programs currentcollabor~ions win NSF arid priced consortia will continue as long as Hey are scientifically productive arid relevar~t to NASA's missions' it nods the the coming decade present ~ nearly unique opportunity to develop beer coordination arid collabora- tion' particularly in light of significar~t overlap between recommendations of his survey arid those of ~e 2W! astronomy arid astrophysics decada1 surveys In the spirit of the Augustine reports second recommendation' the SSE Survey recommends that NASA partner equally with the National Science Foundation to design' huild' and operate ~ survey facility, such the Large Synoptic Survey Telescope (LSST) described in Astronomy ~d Ast~phys'cs 'n He New M',I,Ien- n'F'm, too ensure that LSST,~ prime solar system objective are accomplished+ The particular perry objectives of LSST are as follows: ~ ~~rmine the conches arid nature of the Kuiper Belt to provide scientific context for the targeting of spacecraft missions to explore this new region of the solar sys~m; ~ Assess the population of near-E~h object (NEOs) down to 3W-m in diameter arid provide ~ measure of the impact heard; arid ~ Ascertain ~e relative imported of long-period comets as impel hoards to Earn. The LSST (Figure 8.~) will also assess ~e distribution of Centaurs md search for urmim md neptunim Trojans. Such ~ facility has been separately recommended by He most recent astronomy md astrophysics decada1 survey.6 The latter report lists NEO detection md Kuiper Belt object surveys as LSST's two top science drivers' followed by ~ host of ashophysiea1 applications. Indeed, the parameters of the LSST are largely determined by the need to detect NEOs, since this is the most difficult measurement to make with the telescope. The cosign of missions to the mull bodies of the solar Totem requires extensive ohmic ch~r:~cteri~:~tion of ~ set sunset of these obeys In order to properly choose the best Urged to answer particular seethe questions. This physical eharaeterizanon is best done with telescopes having ~ suite of instrument for imaging md speetromopy ~ various wavelengths. While the brighter of the small bodies of She solar system em be readily studied with what are now thought of as small to medium telescopes' She fainter members of the Kuiper BelL which are orders of magnitude more numerous than the bright members' ergot be eharae~rized with existing facilities. Similarly, assessment of the heard from NEOs requires physical eharaeterizanon of the ensemble by remote sensing in order to carry out the missions to inveshga~ more detailed physical eharae~risties in situ. As with the Kuiper Belt objects' the fainter NEOs md long-period comets require ~ very large telescope for physical eharae- terizahon. The high-~gular-resolution eapabilily of large ground-based telescopes equipped with adaptive opines (AO) now surpasses that oftelemopes in space. For example' the Keek md Gemini telescopes routinely achieve angular resolutions better ohm 50 milliareseconds (mas) ~ near-irnfrared wavelengths. Planed ground-based Lopes will have resolutions better ohm 10 mast At this resolution' the disks of Jupiter md Neptune em be resolved into 107 md 4 x 104 resolution elements, respectively' opening the intriguing possibility for longhorn studies of atmospheric dummies md speetromopy from the ground. Speetromopy of the Mint planets is crucial for under- s~ding She altitude Derisions of their atmospheric properties. The requirement of ~ telescope capable of performing the physical eharae~ri=tion of smut solar system bodies described above ~ 30-m-class, fully steerable facility equipped with adaptive optics are similar to those of the Gist Segmented Mirror Telescope (GSMT) as proposed by the 2001 astronomy md astrophysics deeada1 survey (Figure 8.2~.7 This telescope will allow eharaeteriz~ion of 10-km bodies in She Kuiper Belt md allow targeted searches for 1-km objects that are inaccessible by other mems. It will permit eonunuous study of the atmospheres of the plme~ as ~ precursor md complement to the missions prioritized in this report. The planets community should be fully involved in defining the capabilities of the C8MT' including its all-impor~t AO system md the specific instrument that will be developed for this telescope.

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Amos HEW FR0~ IN =E SOLAR MOM FIGURE 8. ~ An artistes impression of one particular concept for ~e Large Synoptic Survey Telescope. Soured of ~e Nation Optical Astronomy Ob~rvatorics. The SSE Survey endorses the 2001 Astronomy and Trophy I decal survey ~Dn~ion for ~ Giant SiegEnenbed Mirror Telewnpe and further reco~nen~ that it he utilized for the physical ~ra~er- i~tion of solar system object. The Back record of contributions to solar system exploration by Earth-orbi~l missions sponsored by ~e other themes ~ NASA has been exceptional Id was made possible only by ensuring ~~ Nose facilities have ~ appropriate capability to track moving targets. The James Webb Space Telescope (lWST) clearly has the eapabil- i~ to make major contributions as long as it is provided win We capability to back moving targets. The SSE Survey recommends that ~pahilities particular to planetary science (erg+' the need to tram non-sidere~l object he incorporated into the Awns WeLh Sipace Telescope ~ fully ~ pmsible in order to maximize the science retime

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RECOMMENDED FLIGHT I~OANO~ AND SUPPOTH~G GTOUND-BASED ACES 909 FIGURE 8.2 An artistes concept of one particular configuration for ~ proposed Giant Segmented Mirror Telescope. Soured of ~e Nation Optical Astronomy Ob~rvatorics. llEF Elk EN C ES 1. Executive Office of the Presiders of the Ur~i~d Stamp> Budget of ~e US Oover~tF`~l Year 20~> U.S. Goverr~merd Prirdir~g Offing Washin~or~' D.~.' 2002. Available online at chap ilwww.whitehou~.goviomb~ud~tify2003~ud~t.html>. 2. Spam Audits Poard' N~ior~1 Research Council, An of Mare $~e a~ M=`o~ Prior N~ior~1 Academies Press' Washir~or~> D.~.> 2003. 3. Spam Studies Board Id Board or Physics Id Astronomy' N~ior~1 Monarch Councils U.$. Astro~o~ a~Astrop~Ma~gt a~ ~~gr~1Progr~' N~ior~1 Academy Press' Washir~on' D.~.' 2001. 4. Spam Studies Board Id ~ card ore Physics Id Astronomy' N~ior~1 ~ march Councils U.~. A~tro~o~ a~A~trop~Ma~g~ a~ ~~gr~1Program' N~ior~1 Academy Press' Washir~on' D.~.' 2001' p. 4. S. Board ore Physics Id Astronomy Id Span Studies Board' N~ior~1 Research Councils Astronomy a~A~troph~ ~~ ~e N Mod N~ior~1 Academy Press' Washir~or~> Deco.> 2001. 6. Board ore Physics Id Askor~omy Id Span Studies Board' N~ior~1 Research Councils Astronomy a~Astroph~ t~ ~e N Mod N~ior~1 Academy Press' Washir~or~' Dead.> 2001. 7. Board or1 Physics Id Askorlomy Id Span Studies Foard' N~iorla1 Research Courloil' Astronomy a~A~troph~ ~~ ~e H Mud N~ior~1 Academy Press' Washir~or~' Darn.' 2001.

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