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NASA's Beyond Einstein Program: An Architecture for Implementation (2007)
Space Studies Board (SSB)
 Board on Physics and Astronomy (BPA)

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146
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Nasa ’s Beyond Einstein Program: An Architecture for Implementation

E
Request for Information to Mission Teams

The instructions and questions contained in the Request for Information (RFI) reproduced in this appendix were sent to the Beyond Einstein Program candidate mission teams for additional input to the Committee on NASA’s Beyond Einstein Program. Questions requesting further clarification were sent at later dates to individual mission teams, based on their responses to this RFI.

Instructions for Responding


The committee requests that mission teams respond to the following questions as completely as possible. However, we fully recognize that the missions are at different stages of definition, and answers may not be available for many of the more detailed questions. For example, a specific spacecraft implementation may not have been selected, and so many details cannot be provided. In this case it is sufficient for the committee to understand the overall spacecraft complexity and requirements. We have attempted to indicate below where details are optional.

We also request that you please ensure that any written responses or diagrams that you include do not include ITAR-controlled information. The NRC will consider your response as public information and available to the public, if requested.

SCIENCE AND INSTRUMENTATION

Please answer the following as completely as possible:


Describe the scientific objectives and the measurements required to fulfill these objectives.


Describe the technical implementation you have selected, and how it performs the required measurements.


Of the required measurements, which are the most demanding? Why?


Present the performance requirements (e.g., spatial and spectral resolution, sensitivity, timing accuracy) and their relation to the science measurements.


Describe the proposed science instrumentation, and briefly state the rationale for its selection.


For each performance requirement, present as quantitatively as possible the sensitivity of your science goals to achieving the requirement. For example, if you fail to meet a key requirement, what will the impact be on achievement of your science objectives?


Indicate the technical maturity level of the major elements of the proposed instrumentation, along with the rationale for the assessment (i.e., examples of flight heritage, existence of breadboards, prototypes, etc.).

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146

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OCR for page 146
Nasa ’s Beyond Einstein Program: An Architecture for Implementation E Request for Information to Mission Teams The instructions and questions contained in the Request for Information (RFI) reproduced in this appendix were sent to the Beyond Einstein Program candidate mission teams for additional input to the Committee on NASA’s Beyond Einstein Program. Questions requesting further clarification were sent at later dates to individual mission teams, based on their responses to this RFI. Instructions for Responding The committee requests that mission teams respond to the following questions as completely as possible. However, we fully recognize that the missions are at different stages of definition, and answers may not be available for many of the more detailed questions. For example, a specific spacecraft implementation may not have been selected, and so many details cannot be provided. In this case it is sufficient for the committee to understand the overall spacecraft complexity and requirements. We have attempted to indicate below where details are optional. We also request that you please ensure that any written responses or diagrams that you include do not include ITAR-controlled information. The NRC will consider your response as public information and available to the public, if requested. SCIENCE AND INSTRUMENTATION Please answer the following as completely as possible: Describe the scientific objectives and the measurements required to fulfill these objectives. Describe the technical implementation you have selected, and how it performs the required measurements. Of the required measurements, which are the most demanding? Why? Present the performance requirements (e.g., spatial and spectral resolution, sensitivity, timing accuracy) and their relation to the science measurements. Describe the proposed science instrumentation, and briefly state the rationale for its selection. For each performance requirement, present as quantitatively as possible the sensitivity of your science goals to achieving the requirement. For example, if you fail to meet a key requirement, what will the impact be on achievement of your science objectives? Indicate the technical maturity level of the major elements of the proposed instrumentation, along with the rationale for the assessment (i.e., examples of flight heritage, existence of breadboards, prototypes, etc.).

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Nasa ’s Beyond Einstein Program: An Architecture for Implementation Briefly describe the overall complexity level of instrument operations, and the data type (e.g., bits, images) and estimate of the total volume returned. If you have identified any descope options that could provide significant cost savings, describe them, and at what level they put performance requirements and associated science objectives at risk. In the area of science and instrumentation, what are the three primary technical issues or risks? Fill in entries in the Instrument Table to the extent possible. If you have allocated contingency, please include as indicated; if not, provide just the current best estimate (CBE). Optional details—If you have answers to the following detailed questions, please provide: For the science instrumentation, describe any concept, feasibility, or definition studies already performed (to respond you may provide copies of concept study reports, technology implementation plans, etc.). For instrument operations, provide a functional description of operational modes, and ground and on-orbit calibration schemes. Describe the level of complexity associated with analyzing the data to achieve the scientific objectives of the investigation. Provide an instrument development schedule if available. Provide a schedule and plans for addressing any required technology developments, and the associated risks. Describe the complexity of the instrument flight software, including an estimate of the number of lines of code. Compare the scientific reach of your mission with that of other planned space- and ground-based missions. Instrument Table Item Value/Description Units Number and type of instruments     Number of channels     Size/dimensions (for each instrument)   m × m × m Payload mass with contingency   kg, % Average payload power with contingency   W, % Average science data rate with contingency   kbps, % Instrument fields of view (if appropriate)     Pointing requirements (knowledge, control, stability)   Deg, deg/s MISSION DESIGN Please answer the following as completely as possible: Provide a brief descriptive overview of the mission design (launch, orbit, pointing strategy) and how it achieves the science requirements (e.g., if you need to cover the entire sky, how is it achieved?). Provide entries in the mission design table to the extent possible. Those entries in italics are optional. For mass and power, provide contingency if it has been allocated; if not, provide just your current best estimate (CBE). To calculate margin, take the difference between the maximum possible value (e.g., launch vehicle capability) and the maximum expected value (CBE plus contingency). Provide diagrams or drawings (if you have them) showing the observatory (payload and S/C) with the components labeled and a descriptive caption. If you have a diagram of the observatory in the launch vehicle fairing indicating clearance, please provide it. Overall (including science, mission, instrument and S/C), what are the three primary risks?

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Nasa ’s Beyond Einstein Program: An Architecture for Implementation Optional detail (provide if available): If you have investigated a range of possible launch options, describe them, as well as the range of acceptable orbit parameters. If you have identified key mission trade-offs and options to be investigated, describe them. Mission Design Table Parameter Value Units Orbit parameters (apogee, perigee, inclination, etc.)     Mission lifetime   mos Maximum eclipse period   min Spacecraft dry bus mass and contingency   kg, % Spacecraft propellant mass and contingency   kg, % Launch vehicle     Launch vehicle mass margin   kg, % Spacecraft bus power and contingency by subsystem   W, % Mass weighted reuse percentage of payload an spacecraft subsystem components   % Mass weighted redundancy of payload and spacecraft subsystem components     SPACECRAFT IMPLEMENTATION Please answer the following as completely as possible: Describe the spacecraft characteristics and requirements. Include, if available, a preliminary description of the spacecraft design and a summary of the estimated performance of the spacecraft. Provide an overall assessment of the technical maturity of the subsystems and critical components. In particular, identify any required new technologies or developments or open implementation issues. What are the three greatest risks with the S/C? Optional detail (provide if you have selected a specific S/C implementation): If you have required new S/C technologies, developments, or open issues and you have identified plans to address them, please describe (to answer you may provide technology implementation plan reports or concept study reports). Describe subsystem characteristics and requirements to the extent possible. Such characteristics include: mass, volume, and power; pointing knowledge and accuracy; data rates; and a summary of margins. Describe the flight heritage of the spacecraft and its subsystems. Indicate items that are to be developed, as well as any existing instrumentation or design/flight heritage. Discuss the steps needed for space qualification. Address to the extent possible the accommodation of the science instruments by the spacecraft. In particular, identify any challenging or non-standard requirements (i.e., jitter/momentum considerations, thermal environment/temperature limits, etc.). Define the Technology Readiness Level of critical S/C items along with a rationale for the assigned rating. Provide a preliminary schedule for the spacecraft development.

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Nasa ’s Beyond Einstein Program: An Architecture for Implementation Spacecraft Characteristics Table (Optional—fill out any known entries if you have selected an implementation.) Spacecraft Bus Value/Summary, Units Structure   Structures material (aluminum, exotic, composite, etc.)   Number of articulated structures   Number of deployed structures   Thermal Control   Type of thermal control used   Propulsion   Estimated Delta-V budget, m/s   Propulsion type(s) and associated propellant(s)/oxidizer(s)   Number of thrusters and tanks   Specific impulse of each propulsion mode, seconds   Attitude Control   Control method (3-axis, spinner, grav-gradient, etc.).   Control reference (solar, inertial, Earth-nadir, Earth-limb, etc.)   Attitude control capability, degrees   Attitude knowledge limit, degrees   Agility requirements (maneuvers, scanning, etc.)   Articulation/#−axes (solar arrays, antennas, gimbals, etc.)   Sensor and actuator information (precision/errors, torque, momentum storage capabilities, etc.)   Command and Data Handling   Spacecraft housekeeping data rate, kbps   Data storage capacity, Mbits   Maximum storage record rate, kbps   Maximum storage playback rate, kbps   Power   Type of array structure (rigid, flexible, body mounted, deployed, articulated)   Array size, meters × meters   Solar cell type (Si, GaAs, multi-junction GaAs, concentrators)   Expected power generation at beginning of life (BOL) and end of life (EOL), watts   On-orbit average power consumption, watts   Battery type (NiCd, NiH, Li-ion)   Battery storage capacity, amp-hours  

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Nasa ’s Beyond Einstein Program: An Architecture for Implementation MISSION OPERATIONS Provide a brief description of mission operations, aimed at communicating the overall complexity of the ground operations (frequency of contacts, reorientations, complexity of mission planning, etc.). Analogies with currently operating or recent missions are helpful. Identify any unusual constraints or special communications, tracking, or near-real-time ground support requirements. Identify any unusual or especially challenging operational constraints (i.e., viewing or pointing requirements). Mission Operations and Ground Data Systems Table (Optional—provide only if you have selected an S/C and operations implementation.) Downlink Information Value, Units Number of data dumps per day   Downlink frequency band, GHz   Telemetry data rate(s), bps   S/C transmitting antenna type(s) and gain(s), DBi   Spacecraft transmitter peak power, watts   Downlink receiving antenna gain, DBi   Transmitting power amplifier output, watts   Uplink Information Value, Units Number of uplinks per day   Uplink frequency band, GHz   Telecommand data rate, bps   S/C receiving antenna type(s) and gain(s), DBi  

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Nasa ’s Beyond Einstein Program: An Architecture for Implementation TOTAL MISSION COST FUNDING PROFILE TEMPLATE (FY costsa in Real-Year Dollars, Totals in Real-Year and 2007 Dollars) Item FY1 FY2 FY3 FY4 FY5 … FYn Total (Real Yr.) Total (FY 2007) Cost                   Concept study                   Science                   Instrument A                   Instrument B                   Spacecraft                   Ground data system development                   MSI&Tb                   Launch services                   MO&DAc                   Education/outreach                   Reserves                   Other (specify)                   Total cost $ $ $ $ $ $ $ $ $ Contributions                   Concept study                   Science                   Instrument A                   Instrument B                   Spacecraft                   Ground data system development                   MSI&Tb                   Launch services                   MO&DAc                   Education/outreach                   Reserves                   Other (specify)                   Total contributions $ $ $ $ $ $ $ $ $             Total mission cost $ aCosts should include all costs including any fee. bMSI&T, Mission System Integration and Test and preparation for operations. cMO&DA, Mission Operations and Data Analysis.