Because of the constraints cited above, the ETDP as created by NASA is a supporting technology program very closely coupled to the near-term needs of the Constellation Program. The ETDP is focused on only incremental gains in capability, and it has two programmatic gaps (integration of the human system, and nuclear thermal propulsion). NASA has in effect suspended research in a number of technology areas traditionally within the agency’s scope and has in many areas essentially ended support for longer-term technology research traditionally carried out within NASA and with strong university collaboration. These actions could have important consequences for aspects of the VSE beyond the initial, short-duration lunar missions—including an extended human presence on the Moon and human exploration of Mars and beyond.

With respect to the management of the ETDP, the program incorporates good processes for tracking Constellation Program requirements, for dealing with the mechanics of formal technology transfer, and for managing the programmatic risk of its own technology developments. However, there is a lack of clarity and completeness in the Constellation Program requirements as perceived by ETDP project personnel, as well as a need to improve the human side of the technology transfer process and to clarify how technology developments can contribute to a reduction in exploration (i.e., Constellation) programmatic risk.

Also, in general, the ETDP has not taken advantage of many external resources that could potentially reduce cost or schedule pressure, aid in the development of the NASA proposed technology, and/or provide alternative and backup technologies. Nor, in many cases, has the ETDP taken advantage of external peer reviews.

Finally, the present ETDP lacks an integrated, systematic test program. Of particular importance is that several ETDP projects, as currently formulated, do not include mission-critical tests—that is, system or subsystem model or prototype demonstrations in an operational environment—that are needed to advance the technology to technology readiness level (TRL) 6.


The 22 research projects of the ETDP are on subjects ranging from thermal protection systems to research on the International Space Station (ISS). The committee evaluated each of the 22 ETDP projects on the basis of the following:

  1. The quality of the research effort, taking into account the research team, contacts with appropriate non-NASA entities, and the plan for achieving the objectives;

  2. The effectiveness with which the research is carried out and transitioned to the exploration program, including progress to date, facilities, apparent gaps in the program, and the likelihood that the required TRL will be reached3 (the committee decided that simply noting gaps, as requested in the study statement of task, was too narrow an objective and that gauging “effectiveness” as defined here was more appropriate); and

  3. The degree to which the research is aligned with the Vision for Space Exploration (since the VSE includes the wording “in preparation for human exploration of Mars,” the committee chose to highlight any project that did not appear to have considered plans that included this aspect).4


See Appendix D for definitions of technology readiness levels.


The committee notes that after the completion of its assessments of the 22 individual projects in late 2007, the Congress passed the fiscal year 2008 Omnibus Appropriations Bill, which contained a provision prohibiting NASA from funding any activities devoted solely to preparing for the human exploration of Mars. The committee chose not to modify its findings on alignment with the VSE based on this language for several reasons. First, the committee interpreted as dominant its statement of task, which includes reference to the entire Vision for Space Exploration, explicitly including the human exploration of Mars. Second, by and large, on this alignment criterion the committee was critical of technology projects that did not consider extensibility of their technology to Mars. An example of potentially extensible technology is the Orion thermal protection system for Earth reentry. The committee did not criticize in the assessment of the 22 projects the absence of a Mars-unique technology, an example of which is a martian aerodynamic entry descent and landing system.

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