Last month, Elon Musk’s private spaceflight company, SpaceX, suffered a heart-breaking end to a spotless record for their Falcon 9 rocket.
After 18 straight successful flights, a Falcon 9 carrying an unmanned Dragon spacecraft — loaded with over 4,000 pounds of supplies for astronauts on board the International Space Station &mdash exploded a few minutes after launch.
Over the last few weeks, SpaceX engineers have logged thousands of hours trying to pinpoint the problem. Today, Musk announced the company’s preliminary results, emphasising in a media teleconference:
“We’re not characterising this as a definitive result. We’re characterising this as the most-probable result.”
The likely culprit was a single, two-foot-long, one-inch-thick steel component called a strut. Falcon 9 rockets contain many of these struts and Musk said that over the course of Falcon 9’s flight history, several thousand of them have flown without a problem.
This particular piece, however, did not perform as expected. All rocket struts on a Falcon 9 are designed to handle forces that are 10 times Earth’s gravity, or 10 g. This strut broke at 2 g.
“In this case it failed five times below its normal strife, which is pretty crazy,” Musk said during the teleconference and later added. “It happened to be in the wrong place at the wrong time.“
And once the strut snapped, it was all downhill from there:
The particular piece in question was holding in place a bottle of helium in the upper, second-stage component of the rocket — as opposed to its longer, larger first-stage section. The helium bottles help maintain pressure inside the second-stage fuel tanks, which keeps them from imploding. As the rocket gradually depletes the fuel in its tanks, changing the volume inside, the pressure would normally change as well. To prevent this from happening, the bottles of helium slowly replace the vanishing fuel with helium gas, sustaining their inner pressure.
But when the single strut broke, the helium bottle it was holding went flying toward the fuel tank, which seems to be what caused the explosion, according to SpaceX’s latest preliminary results.
SpaceX has plans for a safer spacecraft
Although it looks like this is the most likely culprit for the Falcon 9 rocket’s failure on June 28, SpaceX is still continuing with their investigation:
“So far, the investigation is not showing any other issues,” Musk said. “But … we’re looking closely for any near misses and address anything that we can possible think of to improve the probability of success in the future.”
One of these improvements is already being put into place: The Dragon 1 spacecraft carrying the payload could have been saved, Musk said, if it had been programmed with software that the company has already programmed into their Dragon 2 spacecraft, which is planned to launch astronauts into space by 2017, and was flown in a test earlier this year.
This software acts like an eject button, so if something goes wrong, the spacecraft and its precious payload don’t go up in flames with the rest of the rocket.
“If the software had initiated the parachute deployment then the Dragon spacecraft would have survived,” Musk said. And for all future missions the Dragon 1 spacecraft will be programmed with this handy software so that it can try and save itself from disaster.
Including adopting some personal testing
What’s more, Musk announced that SpaceX will personally be testing each strut before it flies. Before this, the company had trusted that the manufacturer — which Musk won’t name — was providing sturdy struts.
But after testing thousands of yet-to-be-flown struts after the explosion on June 28, SpaceX discovered that several failed below their expected tolerances. None of these struts will ever fly.
“Obviously, what we’re going to do in the future is not use these particular struts, and we’re going to move to individually testing each strut independent of any material certifications,” Musk said in the teleconference according to Quartz. These additional testings will increase the cost of their Falcon 9 rockets but not to a significant amount, Musk estimated.
The first Falcon 9 failure has come with its share of setbacks. Musk said that SpaceX will not be flying anymore Falcon 9s until September at the earliest.
Despite the setback, Musk said that this will not jeopardize SpaceX’s plan to send astronauts into space in their next-generation Dragon 2 spacecraft in 2017.
Business Insider Emails & Alerts
Site highlights each day to your inbox.