SpaceX returned to the cosmos Saturday, launching its first mission since one of the company’s Falcon 9 rockets exploded on Sept. 1.
After the explosion, SpaceX halted its launch schedule until the company could determine its root cause. A final assessment released on Jan. 2 stated that the protective lining likely failed in a pressurized vessel for one of the rocket’s liquid oxygen fuel tanks. Helium containers within the tank, used to maintain pressure balance, buckled. The friction between the liquid oxygen and the broken container caused a spark, which blew up the Falcon 9 booster.
“There were just 93 milliseconds from the first sign of anomalous data to the loss of the second stage, followed by loss of the vehicle,” according to the mission assessment. Investigators used 3,000 sources of data to ascertain the nature of the accident, and they determined the Falcon 9 is once again go for launch.
Saturday’s launch marks SpaceX’s third attempt to deliver 10 Iridium NEXT communications satellites. Both prior attempts were scrubbed due to poor weather. Iridium runs the largest constellation of communications satellites, consisting of 66 individual spacecraft over six different orbits. Iridium’s new series of satellites, currently undergoing testing, are planned to increase data capability for satellite phones, allowing them to have faster internet access. A secondary payload on the NEXT satellites will be used to improve Air Traffic Control communications.
SpaceX is planning six more launches for this year, which will replace all satellites in the current Iridium constellation network by early 2018.
Vandenberg Air Force Base is one of three launch facilities that SpaceX uses and the only one on the West Coast. Its location is prime for the polar orbits used by communications and spy satellites.