Virgin Galactic Crash Update: Don't Blame the Fuel
This past Halloween, Oct. 31, space-faring private company Virgin Galactic suffered a major tragedy, with the fourth powered test flight of SpaceShipTwo resulting in destruction and death. Now, investigators say they will soon be wrapping up the on-site investigation, having found some startling evidence about what may have occurred.
According to eyewitness accounts of the tragic event that took one test pilot's life and injured one other, it appeared that everything was going fine until SpaceShipTwo suddenly and violently ripped apart in the air, crashing down in the Mojave Desert's Antelope Valley in pieces.
This was the first thing confirmed by National Transportation Safety Board (NTSB) when they came to the scene to aid Virgin Galactic with the investigation.
"The wreckage is dispersed about five miles end-to-end, and when the wreckage is dispersed like that, it indicates an in-flight-breakup," acting chairman Christopher Hart revealed on Saturday.
It has been speculated that a likely cause of this event was an anomaly with one of the fuel grain chambers for SpaceShipTwo's unique rocket engines. The fuel in question, a solid plastic-type propellant that is ignited by nitrous oxide, was being used for the first time in a powered flight test, and seemed a likely candidate for something to go wrong.
Fuel Faux Pas
And in wake of this speculation, Virgin Galactic found itself facing heavy criticism.
"I warned them that the rocket motor was potentially dangerous," Carolynne Campbell, a rocket propulsion expert at the Netherlands-based International Association for the Advancement of Space Safety (IAASS), told ABC on Sunday. "We were concerned about what was going on at Virgin Galactic and that what they were doing wasn't up to speed."
However, Virgin Galactic has assured the media that the new fuel had gone through extensive on-ground testing, and appeared perfectly safe for flight.
"Now is not the time for speculation. Now is the time to focus on all those affected by this tragic accident and to work with the experts at the NTSB, to get to the bottom of what happened," the company said in a statement over the weekend.
"I strongly reject any assertion that something pushed us to fly when we weren't ready," former NASA official and Virgin Galactic CEO George Whitesides added in an interview with the Wall Street Journal. "At the end of the day, safety of our system is paramount."
Now it looks like Campbell may have jumped the gun with her accusations. As of Tuesday, the NTSB has revealed that SpaceShipTwo's engine and rocket propulsion fuel tanks have no signs of burn through or mid-air explosion.
"While we cannot speculate on the causes of the incident... this definitively dismisses the premature and inaccurate speculation that the problem was related to the engine or the fuel," Virgin Galactic announced.
So What Do We Know?
Hart announced Monday that the on-site investigation will be wrapping up "in a few days," indicating that all that can be learned from the site has been learned.
"Now is not the time for speculation," the chairman reiterated during the fourth and last press conference. However, that doesn't mean we can't hear the facts. (Scroll to read on...)
"Thirty one seconds [into flight], we're showing 1.02 mach, and in that period of time the telemetry data shows that the feather went from locked to unlocked. Two seconds after that, the feathers moved to the deployed position," Hart said. "At seven minutes [and] 34 seconds - the telemetry and video data were lost."
The chairman is talking about structures on the spacecraft that provide stability during mach speeds. These long "feathers" - looking like a pair of tails on the back of the spacecraft - are designed to rotate to a more vertical angle, tilting the entire craft to create more drag as it reenters the atmosphere. If these are deployed before their appropriate time, it could prove catastrophic.
However, it appears these mechanisms may have unlocked much earlier than intended, as the investigators quickly found that these should not have been unlocked until the craft hit a speed of mach 1.4. The result, as it appears, was that the feathers moved - either by pilot error or on their own accord - sooner than they should have.
Hart added that, as of Tuesday, investigators have not had a chance to speak with the surviving test pilot, who is still recovering from his injuries.