Satellite Technology Feature Article
SpaceX COTS Launch Attempt Hiccups, Resets to May 22
By Doug Mohney, Contributing Editor
SpaceX’s (News - Alert) first full-up attempt to launch its International Space Station supply demo flight stopped at the last second on Saturday, May 19, due to a hardware problem. The company plans its second attempt early on Tuesday, May 22.
The SpaceX Falcon 9 rocket had started all of its nine Merlin engines before its flight computer detected slightly high combustion chamber pressure on engine, triggering an abort shutdown and safing of the rocket and the Dragon spacecraft on top. During “rigorous inspections” of the engine, SpaceX engineers found the root cause of the program -- a faulty check valve on the Merlin.
An update from SpaceX on Saturday said the company was in the process of replacing the failed valve with the expectation repairs would be completed in the evening, with further data reviews on Sunday. Assuming everything is good, the company will try to launch again at 3:44 AM Eastern time on May 22.
SpaceX is definitely in a glass half-empty/half-full situation here. Its many detractors in the existing “Old Boys” aerospace club will no doubt seize upon the incident as the latest gaff by the commercial entrant on the COTS 2/3 flight originally planned to fly late last year. The engines had been tested at least twice before, once at SpaceX’s Texas facility and earlier this month in a full-blown launch simulation with a two second firing on the pad.
On the plus side of the ledger, SpaceX’s “Yoda” launch management software did exactly what it was supposed to do: Abort when it sees a problem. Further, it aborted because there was an actual hardware problem, not a “false positive.” Launch pad aborts are not rare; last year an ArianeSpace Ariane 5 had fired up its engines for a commercial satellite launch when it abruptly shut down due to a last second problem.
SpaceX also gets to again demonstrate its rapid response flexibility in fixing problems. Normally, it would take several days -- if not weeks -- for existing launch providers to identify, fix, and recycle for another attempt.
In the COTS 1 launch back in December 2011, one of the company’s Merlin engines had a slight crack in the bell which was discovered at the last minute. A SpaceX technician flew out from the company factory and simply lopped off the bottom part containing the crack, with the Falcon 9 successfully delivering the first Dragon spacecraft into orbit for a four hour flight culminating in a Pacific Ocean splashdown.
In the bigger picture, the abort and a little delay is a good thing. SpaceX plans to use Falcon 9 to carry people into space, so it is better to have safety system and protocols that work to prevent a “Big Bang (News - Alert)” launch failure.
Edited by Rich Steeves