The latest failure of a U.S. hypersonic flight experiment should give U.S. developers in government and industry pause and make them debate whether they are putting enough engineering rigor into those trials.
The latest incident is the July 29 failure of a Boeing HyFly missile demonstrator for the Defense Advanced Research Projects Agency (read our subscription-only AWIN story here). It is the third HyFly failure; the test itself was only planned because two prior attempts failed, and Darpa okayed Boeing to build a third vehicle largely out of parts already in existence.
This failure was linked to the booster motor on HyFly not igniting. Darpa stresses the dual-combustion ramjet technology, which HyFly was really trying to validate, was not at fault.
The failure comes just a few months after the test of an X-51A hypersonic vehicle had to be cut short owing to range safety concerns. The Air Force Research Lab believes some seals may have failed (read Guy Norris’s Aviation Week & Space Technology story on the subject here).
That component parts rather than the underlying technology are at fault in test failures is not something unique to the realm of hypersonic flight testing. Regular missile developments and the U.S. ballistic missile defense program have seen similar missteps. But the concern in the hypersonic realm is that budgets are limited, and as a result there are few tests (some may say too few), so losing precious test opportunities to such miscues is particularly frustrating.
That raises the question of whether anything can be done. Would there be value in a “red team” going through a missile design prior to flight testing to specifically look for the ten-cent component that could fail and doom an entire experiment, or would such an exercise do little more than drive up cost and slow development in the entire field? It is a question the Pentagon’s engineering community should discuss with some urgency, especially as AFRL looks to resume X-51 flight trials late this year or early next.