NASA Safety Panel Urges Vigilance as U.S. Resumes Human Space Launches

NASA’s Aerospace Safety Advisory Panel (ASAP) is urging NASA to “maintain vigilance” as it prepares to resume launching astronauts into space.  NASA has not been able to launch people into space since the final space shuttle mission in 2011.  The first flights of two new “commercial crew” space transportation systems, owned and operated by SpaceX and Boeing, are scheduled for this year with NASA as their customer. NASA is also building its own system, SLS/Orion, to go beyond low Earth orbit (LEO) in the next several years.

The schedules for the commercial crew and SLS/Orion systems have slipped repeatedly.  ASAP is keeping a close eye to make sure that any desire to get those systems off the ground does not negatively impact safety.

In its new report, the panel asserts that it has not detected any “direct evidence that schedule pressure” is driving decisions.  Still, it cautions NASA “to remain cognizant of the perils inherent to space flight” and “maintain vigilance and attention to test results, engineering understanding, disciplined processes, and consideration of mitigation alternatives.”

For the commercial crew systems, ASAP identifies the two “primary risk drivers” as micrometeoroid and orbital debris (MMOD) damage while the spacecraft are docked to the ISS and parachute performance.  It characterizes the MMOD safety issue as evolving, while “[p]arachutes remain a challenging area for both providers.”

SpaceX’s Crew Dragon/Falcon 9 system continues to cause the panel uneasiness because of two features:  the “load and go” fueling procedure where the crew will be aboard the vehicle while it is being fueled instead of waiting until after fueling is completed (as has been done historically), and SpaceX’s Composite Overwrap Pressure Vessels (COPVs), which have been redesigned to address earlier concerns.

As for NASA’s SLS/Orion system, ASAP raises a red flag about recent decisions related to testing the new Orion heat shield, which replaces the type of heat shield that was tested by the 2014 Exploration Flight Test-1 (EFT-1).  The new version has a “potential failure mode that involves the differential ablation rate between the block material and the gap filler which could lead to heat shield failure.”  A complete understanding of heat shield performance can only be obtained through flight test, but “ASAP has now learned that recent decisions about launch commit criteria could result in a situation when the EM-1 flight test could occur without the ability to obtain to this data.”  It cautions NASA to find alternative means to collect the critically needed data.

ASAP also oversees safety issues for the International Space Station (ISS).  It recommends that NASA have a mitigation plan in place to assure U.S. astronauts can remain aboard ISS if the commercial crew systems are delayed.  NASA pays Russia to take astronauts to and from the ISS on Soyuz spacecraft, but the contract expires soon.  The Government Accountability Office (GAO) already has expressed concern about this issue.  NASA responded that it is looking at options including “operationalizing” the commercial crew test flights.  Both companies are required to conduct first an uncrewed test flight and then a crewed test flight as steps toward certifying the systems for operational use.  NASA’s option would mean the crewed test flights might be used as operational missions before the systems are formally certified.  ASAP emphasizes the need for NASA to clearly identify and communicate the “elements of the systems and their configurations that must be tested and proven on the uncrewed demo flights before launching with crew on board” and urges NASA and Congress to agree on a mitigation plan to keep Americans aboard ISS if the schedule slips.

The Trump Administration wants to end direct U.S. government support of ISS in 2025 with the expectation that commercial space stations will be available by then and it can lease whatever services it needs rather than owning and operating a government facility — the so-called commercialization of LEO.  ASAP found the concept of LEO commercialization to be “reasonable,” but stressed the importance of NASA maintaining “a persistent presence in low-Earth orbit for the long term to mitigate the considerable risk of human exploration in the far reaches of space.”

The report covers many other issues.  The following table from the report summarizes what ASAP identifies as the 11 key topics and its assessment of them.

ASAP was created by Congress in the NASA Authorization Act of 1968 (P.L. 90-67)  following the January 27, 1967 Apollo fire that killed Virgil “Gus” Grissom, Ed White and Roger Chaffee during a pre-launch ground test of what was intended to be the first Apollo mission.  The 2005 NASA Authorization Act (P.L. 109-155) codified additional responsibilities.  ASAP reports annually to Congress and the NASA Administrator.