SpaceX CRS-3 Launch "Good to Go" for April 14; Spacewalk April 22 to Fix MDM

NASA International Space Station (ISS) Program Manager Mike Suffredini said the agency will go ahead with the launch of SpaceX’s CRS-3 cargo mission tomorrow, April 14, despite a malfunctioning computer aboard ISS.  A spacewalk is now planned for April 22 to repair that unit.

The launch of a Dragon spacecraft aboard a Falcon 9 rocket  is scheduled for 4:58 pm ET Monday and the weather is 80 percent favorable for the launch.  If anything should delay it, the next opportunity will be on Friday, April 18, when the weather outlook is worse.

Suffredini declared at a noon press conference that the launch is “good to go” after mission managers concluded that appropriate positioning of the ISS solar arrays would protect ISS operations in case of another MDM failure.  MDM is a Multiplexer/Demuliplexer – a computer that controls some of the robotic functions aboard the ISS.   The primary MDM is working fine; it is the backup that is not responding to commands.  Suffredini said they did not know why and will replace it with a new unit during a spacewalk now planned for April 22. 

Among the cargo being taken to the ISS is a new spacesuit and replacement parts for the spacesuits already on board.  A clogged filter in one of the onboard spacesuits imperiled European astronaut Luca Parmitano during a spacewalk last summer when his helmet filled with water from the spacesuit’s cooling system.   NASA ultimately traced the problem to silica contamination from filters in the spacesuit that are designed to clean and scrub the water loops.  New filters are included in the spacesuit components being taken to ISS aboard Dragon.

SpaceX Vice President of Mission Assurance Hans Koenigsmann said at the same press conference that SpaceX is only 30-40 percent confident that its test of landing legs for the Falcon 9 rocket’s first stage will work.  SpaceX is working on making the Falcon 9 reusable and is experimenting with landing legs that someday could allow the first stage to return to a landing pad.  The test on this flight is not that ambitious and will take place over the ocean.  Stressing that it is experimental, Koenigsmann said that the first stage will descend vertically and deploy the four 25-foot high legs over the water before eventually falling over into the water.  The first stage is heavily instrumented and cameras aboard a recovery ship will try to take video.  He said the test happens quickly and will be over by the time the rocket’s second stage reaches orbit.

When asked for NASA’s reaction to SpaceX’s reusability test, Suffredini said NASA supports commercial space and is happy to help as long as the primary mission is not affected.   NASA determined this test would not impact Dragon’s mission to ISS.