• Individual observations on technology development. One workshop attendee provided a relatively detailed set of observations based on his being involved in the technology development efforts at a U.S. government agency. He noted that materials are very different for space systems, as issues with radiation resistance and aggressive environments need to be accounted for. He also commented that space systems are typically low-rate production programs. This attendee then suggested that in computational modeling, most methods do not account for manufacturing variability, and that there have been some spectacular failures when this was used as the basis for validating the system. He emphasized that there is no substitute for testing; while there are many physics-based models out there, there is an issue with not knowing everything that might impact a system. An example he provided of this is for impurities in lithium ion batteries, and the fact that these components still need to be tested for 10 years to understand their 10 year lifetime. Finally this attendee noted the need to think politically to be successful in receiving technology funding; he suggested that looking for dual-use technologies at low manufacturing readiness, and looking at productizing these, might be a way to do this.
• Collaboration with other agencies. During the discussions in the day, several presenters and attendees highlighted the need for NASA to look at how to take advantage of other agencies’ investments in technology development. One workshop attendee indicated that there is a lack of a formal interchange process for technology development among these different groups, and suggested that the NASA Office of the Chief Technologist look to stand up a process like this. This attendee also commented that NASA should look at the National Research Laboratories, AFRL, and other groups, and perform a gap analysis to find out which areas might be most applicable to and worthy of NASA investment.
• Radiation protection. One of the panel members noted that NASA had identified radiation protection as one of its top technical challenges in the roadmap. This spurred many comments, including some from the NASA team suggesting that they are looking at materials like metal organic foam in tanks to help as shielding for habitat modules. Another workshop attendee noted that for protecting electronics, there are two approaches: radiation-hardened electronics, or radiation protection for non-radiation-hardened electronics. He commented that if NASA develops better ways to shield spacecraft from radiation, it could have a large benefit for uncrewed spacecraft systems as well. Building on this comment, another attendee noted that taking more of an active materials approach might be beneficial.
• Certification of materials. Participants commented that it appears as if there are substantial costs associated with certification, and that this frequently is a barrier to using new materials in actual systems. One participant additionally commented that in the past there were mission requirements to use technologies that were TRL 6 or higher, whereas the organizations developing push technologies frequently stop at about TRL 4— this leads to a “valley of death” that is hard to overcome. Finally, there was a comment from another attendee that improving physics-based modeling is one way to try and streamline certification, but there is a need to find a good balance between modeling and testing for certification.
• Reliability. Toward the end of the public discussion session, one workshop participant asked what others thought about having reliability as a grand challenge for the roadmap. In response, one of the NASA team members noted that having precise knowledge of the structural reliability is important relative to integration and saving mass/volume. A workshop attendee also suggested that it is important to consider whether these technologies are being used because they can, or because they should (e.g., embedded sensors). He commented that the benefit from embedding sensors in laminates versus metals needs to be addressed, for example, and that it is important to take a pragmatic approach in applying these technologies. Another example he provided was self-healing: if a structure has many tubes and holes, there will be a reduction in strength. He noted that there needs to be a filter applied so that these technologies make their way onto a vehicle to make it more robust.
Braun, R., National Aeronautics and Space Administration. 2011. “Investments in Our Future: Exploring Space Through Innovation and Technology,” presentation at the Johns Hopkins University Applied Physics Laboratory, Laurel, Md., May 25, 2011. Available at http://www.nasa.gov/pdf/553607main_APL_Bobby_5_27_11_DW2.pdf.