Failure is Still Not an Option: SpaceX Restores Dragon Systems

CRS-2 Pre Launch 065


Update: 4:05 PM EST

SpaceX has now reported that all four thruster pods are operational, and orbital adjustments will begin shortly

Original post

SpaceX’s CRS-2 mission to the International Space Station is beginning to get back on track following a successful effort to pressurize three of four oxidizer tanks aboard the Dragon spacecraft. Although the exact cause of the issue which led to low pressurization in the line running from a high pressure helium tank to the oxidizer tanks has not been identified; it could have been a stuck valve, or a blockage such as ice in the line, repeated efforts at cycling the system have established nominal pressure in all four tanks.
Currently two of the craft’s four Draco thruster quads are on line, specifically numbers one and four, with two and three expected to be brought on line within the hour. After successfully enabling the remaining two thruster elements, flight controllers will raise the Dragon’s perigee from its current altitude of 200 km, to a more comfortable 250 km, which will prevent orbital decay from atmospheric drag.
After that point, SpaceX will work closely with NASA to verify that the Dragon is functioning normally. NASA requires that at least three of the four units be operating to approach ISS.
Earlier today, after first achieving orbit, SpaceX originally elected to refrain from deploying the solar arrays until two Draco quads were operating, but upon noticing that actuator temperatures in the array assembly were dropping, mission managers gave the command to deploy the solar panels to avoid a frozen mechanism.
Rendezvous and berthing with ISS, originally expected to occur tomorrow, will now be delayed for at least a day and possibly more. Musk pointed out that the craft could actually loiter for much longer, but at the moment that appears extremely unlikely.
While both SpaceX and NASA would have preferred the mission to go off without a hitch, the professionalism and teamwork displayed on both sides in correcting today’s issue is likely to become yet another piece of evidence that the novel working arrangement between NASA and private industry in both the COTS/CRS and Commercial Crew programs is capable of handling even the most challenging of tasks.

Posted in: SpaceX

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