Update 10:40 a.m. EST: The Dragon spacecraft is in the proper orbit, but there is a problem with the spacecraft itself. Elon Musk messaged that there is an “issue with Dragon thruster pods. System inhibiting three of four from initializing. About to command inhibit override.” More details will be provided as they become available.
Update 11:10 a.m. EST: It appears the problem with the thrusters on the Dragon is keeping SpaceX from deploying the solar arrays. There is 18 hours of battery life on board the Dragon which can be used during the flight, but for more duration, the solar arrays are needed to generate power. Elon Musk’s latest tweet reads, “Holding on solar array deployment until at least two thruster pods are active.”
Update 11:50 a.m. EST: SpaceX waited until the Dragon was over a ground station in Australia to communicate with the spacecraft, overriding an inhibit instruction that was preventing two of the three thruster pods from working properly. The pressure in one of the two inoperative thruster pods was “trending positive” according to Musk and the team was able to successfully deploy the Dragon’s 54 foot wide solar arrays which will allow the spacecraft to generate electrical power. SpaceX says the delay in the deployment means there “may be a rearrangement of the planned burn sequences for the Dragon spacecraft” as it approaches the ISS.
SpaceX successfully launched its third flight to the International Space Station this morning carrying more than 1,200 pounds of cargo as part of the company’s ongoing orbital trucking contract with NASA. This morning’s launch was the first daytime launch of the Falcon 9 from Cape Canaveral, with the liftoff taking place at 10:10 a.m. EST.
After a hotfire test on Monday, the Falcon 9 was returned to its hangar at launch complex 40 earlier this week where final preparations were made for today’s launch. This is the third flight of the Dragon spacecraft to the ISS, but just the second contracted cargo mission for NASA. The first flight last May was a demonstration mission, though a small amount of cargo was delivered.
At the pre-launch press conference on Thursday, SpaceX’s Shotwell explained for the first time the root cause of the engine shutdown during the last Falcon 9 launch to the ISS in October. She said the SpaceX team traced the problem to a “material flaw in the jacket of the engine.”
Shotwell did not elaborate on the nature of the flaw saying a final report was still being wrapped up and that the rocket engines are one of the main things covered by the International Trade in Arms Regulations (ITAR) the company must follow.
“I don’t look good in horizontal stripes,” she said half jokingly since breaking ITAR regulations could result in jail time, “and I want to see my kids graduate from college.”
The flaw in the jacket of the engine led to a breech causing a “depressurization in the combustion chamber. Though the engine did not explode as initially thought, Shotwell was quick to point out the upside to the failure. She told reporters the engine shutdown did show the redundancy in the Falcon 9 design works.
“Though you never necessarily want to see it happen,” she said of the eight (out of nine) engine boost to orbit, “it’s nice that we’ve demonstrated the vehicle as it was designed.”
Today’s flight includes numerous scientific experiments, including one that will be both carried up by the Dragon spacecraft, and carried back to earth when Dragon departs the ISS. The return schedule is partly dependent on the successful completion of the research according to NASA.
In addition to the scientific cargo on board today’s flight, there are some crew care items including fresh apples from an orchard belonging to a SpaceX employee’s family according to SpaceX president Gwynne Shotwell.
“It’s a little bit healthier, I think, than the one that NASA sent last time,” she said referring to the ice cream sent on the last Dragon spacecraft.
The flight also marks the first time cargo will be carried in the unpressurized trunk of the spacecraft. All of the cargo on the first two flights was carried inside the Dragon capsule which is designed for human passengers. But the spacecraft also has room for cargo in the cylindrical section beneath the Dragon. On this flight a pair of grapple bars that will be used on the ISS are being carried in the unpressurized section.
In addition to a few firsts, today’s launch marks the last time SpaceX plans on using the first version of its Falcon 9 rocket. Beginning this fall, the launch company plans on using v1.1 of the Falcon 9 with upgraded Merlin engines which will be arranged in a circular pattern rather than the 3×3 grid used on v1.0.
Today’s rocket is familiar to Wired readers as it was being built in the SpaceX factory when we visited last spring, and was undergoing testing at the company’s testing facility in Texas when we watched the new Merlin engines being tested last summer. Right now the Falcon 9 and Dragon capsule are not used again, but SpaceX plans to use the hardware for multiple flights in the future.
Unlike the previous two flights to station which took more than a day, because of the phasing between launch and the orbit of the ISS, NASA expects Dragon to dock with the station about 20 hours after liftoff.
There are six astronauts on board the ISS right now, but three of them will return to earth aboard a Russian Soyuz capsule while the Dragon is on station. The SpaceX capsule is scheduled to return itself with more than a ton of cargo on March 25th.