Space Exploration Technologies (SpaceX) will make its next attempt to launch the Falcon 1 rocket on its maiden mission Feb. 9. The launch will take place from the company’s launch site on the Kwajalein Atoll in the Pacific Ocean’s Marshall Islands chain.
SpaceX has made two attempts to launch the Falcon 1 from the remote island launch site since November. Both attempts were aborted during fueling operations fairly early in the countdown after technical problems arose.
SpaceX President Elon Musk, who has funded the roughly $100 million Falcon 1 development effort out of his own pocket, appears to be taking the setbacks in stride. “Overall, we basically have had one vehicle and one pad countdown abort,” he told Space News. “This was frankly the most likely outcome for a brand new rocket and brand new launch site.”
A Nov. 26 attempt was scrubbed due to a fueling problem that was traced back to a manual vent valve mistakenly left open on a liquid oxygen supply tank. By the time the error was discovered, the SpaceX team found itself with insufficient liquid oxygen on hand to keep the rocket’s uninsulated fuel tank topped off and unable to chill and pressurize the rocket’s onboard helium to prevent it from venting back to its supply tank. The Falcon 1 also experienced a computer engine reboot during the countdown that SpaceX attributed to a ground power problem it has since remedied.
Nearly a month later, with a fresh supply of liquid oxygen shipped in from Hawaii and the company’s on-site liquid oxygen plant back in service (it had stopped working prior to the first launch attempt), SpaceX was ready to try again.
But once again, another valve problem — this time one on the rocket itself — would keep the Falcon 1 from launching.
With high winds buffeting the launch pad on Dec. 19, launch countdown was halted to await a favorable turn in the weather. The launch team proceeded to drain off some of the fuel from the rocket, a standard procedure to reduce boil off. During the operation a section of the rocket’s first-stage fuel tank deformed and bent inward. SpaceX says a pressurization valve failure allowed a vacuum condition to form in the tank, causing it to buckle.
“This was extremely unlucky,” Musk said. “We have never seen this component fail in 3.5 years of exhaustive testing.”
Musk said it was an electronic component in the pressurization valve, not the valve itself, that failed.
“I would actually classify this as an electronics failure and obviously vehicle related,” he said. “That said, our ground support software should have more clearly alerted the launch engineers before damage occurred. It did register a red flag, but the flag was not prominent enough to be noticed immediately and so the fuel tank was damaged in the several seconds it took to react.”
Musk said the fuel tank can be easily repaired at the company’s El Segundo, Calif., factory. But because the round trip would take so long, he said, a new first stage has been dispatched to Kwajalein to replace the damaged unit.
The Falcon 1’s next countdown is scheduled to begin Feb. 9.
“We could launch sooner, but I want to do another all up vehicle [and] pad review before launch,” Musk said.
The payload for the Falcon 1’s maiden launch is an experimental spacecraft dubbed FalconSat 2 that was built by students at the U.S. Air Force Academy. The Defense Advanced Research Projects Agency is paying for the approximately $6 million launch.
The Falcon 1’s second launch, carrying the Pentagon’s experimental TacSat-1, is tentatively slated to lift off sometime this winter from Vandenberg Air Force Base in California. Musk said he still is awaiting an “official green light” from the Air Force, which has said it may evict SpaceX from its Complex 3 West launch site because of safety concerns expressed by Lockheed Martin, which occupies the neighboring launch site.
Fran Slimmer, a spokeswoman for International Launch Services, the McLean, Va.-based company that markets Lockheed Martin rockets, said she personally was not familiar with the launch pad dispute but noted that the company has several contracts for Atlas 5 launches from the Vandenberg pad.
