WASHINGTON — An independent safety panel recommended NASA not certify SpaceX’s commercial crew system until the agency better understands the behavior of pressure vessels linked to a Falcon 9 failure in 2016.
That recommendation was one of the stronger items in the annual report of the Aerospace Safety Advisory Panel (ASAP) released by NASA Jan. 11, which found that NASA was generally managing risk well on its various programs.
The report devoted a section to the composite overwrapped pressure vessels (COPVs) used to store helium in the second stage propellant tanks of the Falcon 9. The investigation into the September 2016 pad explosion that destroyed a Falcon 9 while being prepared for a static-fire test concluded that liquid oxygen in the tank got trapped between the COPV overwrap and liner and then ignited through friction or other mechanisms.
SpaceX has since changed its loading processes to avoid exposing the COPVs to similar conditions, but also agreed with NASA to redesign the COPV to reduce the risk for crewed launches. NASA has since started a “rigorous test program” to understand how the redesigned COPV behaves when exposed to liquid oxygen, the report stated.
ASAP argued that completing those tests is essential ...