Four months from fiery explosion to return to flight. SpaceX announced the quick turnaround in an update on their website this morning. For four months, officials from across the aerospace industry have worked together to investigate what caused the “anomaly.” Investigators looked at thousands of pieces of data to piece together what caused a Falcon 9 rocket to explode (technically a fast fire).
@scrappydog yes. This seems instant from a human perspective, but it really a fast fire, not an explosion. Dragon would have been fine.
— Elon Musk (@elonmusk) September 1, 2016
SpaceX has concluded its investigation into the explosion of its Falcon 9 rocket during pre-launch testing on September 1 and will resume launches on Sunday, January 8, according to a statement on the company’s website.
The company determined the explosion was caused by the failure of one of three high-pressure helium tanks used to pressurize the liquid oxygen tank used for the rocket’s second stage.
Cooling propellant to very low temperatures gives it a higher density, resulting in increased power to the engines and the ability to store a higher amount of fuel.
However, if temperatures fall too low, oxygen trapped in special bottles known as composite overwrap pressure vessels (COPVs) can solidify, generating friction that can cause an explosion.
This is what happened on the ill-fated Falcon 9 last September.
“Specifically, the investigation team concluded the failure was likely due to the accumulation of oxygen between the COPV liner and overwrap in a void or a buckle in the liner,” the company statement said.
The investigation report discusses precautions that will be taken to prevent such failures, such as changing the design of the COPVs so they can be loaded with warmer helium, going back to an older helium-loading procedure that worked successfully every time it was followed, and changing the helium bottle design to prevent buckling.
In the statement, SpaceX said they will resume launches on Sunday, January 8, with a commercial mission that will launch from Vandenburg Air Force Base near Los Angeles, California.
The Falcon 9 will carry 10 Iridium NEXT satellite telephone relay stations into Earth orbit.
Iridium is partnering with SpaceX for seven launches. Each one deploying ten Iridium NEXT satellites at a time. A total of 81 satellites are being built. 66 will be operational at any given point.
Like with most satellite constellations, Iridium is preparing for the occasional satellite hiccup. 15 spares will be available. 6 in-orbit and 9 more on the ground. The satellites in orbit will be able to be activated and repositioned whenever they are needed.
In a statement last month, Iridium remains confident in SpaceX’s abilities. “We’re excited to launch the first batch of our new satellite constellation. We have remained confident in SpaceX’s ability as a launch partner throughout the Falcon 9 investigation,” said Matt Desch, chief executive officer at Iridium. “We are grateful for their transparency and hard work to plan for their return to flight. We are looking forward to the inaugural launch of Iridium NEXT, and what will begin a new chapter in our history.”
A cargo delivery mission to the International Space Station (ISS), as required under SpaceX’s contract with NASA, will launch on an as yet unspecified date following a second commercial mission.
That mission will launch from the Kennedy Space Center in Florida using a redesigned space shuttle launchpad.
SpaceX’s launch pad on Cape Canaveral took serious damage from the September explosion, and no date has yet been set for resumption of flights from the site.