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Another ‘Successful Failure’ for SpaceX

The vessel's excellent team overcame a mid-flight glitch and completed the mission.

by
Rand Simberg

Bio

March 5, 2013 - 7:31 am
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On its last trip to the International Space Station (ISS), the SpaceX Falcon 9 rocket lost an engine in ascent, losing a little performance but achieving orbit anyway. On Friday’s flight, the Falcon seems to have performed flawlessly in delivering the Dragon capsule to orbit.

This time, it was the Dragon itself that failed, at least initially. Normally, after initial orbit insertion the solar panels would be deployed, but SpaceX personnel delayed deployment because they were having problems with the orbital maneuvering thrusters needed to circularize the orbit and to match it with that of the ISS. Only one of the four was working, and NASA rules required at least three of them to be functional before attempting an approach to the station.

They had limited time to solve either the thruster or solar panel problem — they were in an orbit with a low perigee and relatively high drag that wouldn’t have lasted more than a day or two, and their batteries were likely to die in about the same time frame. It seemed to be a problem with a propellant valve (the four propulsion systems are cross connected to share propellant tanks). So for a time, it was nerve wracking for the team. If they were unable to fix the problem it would have meant an early end to the mission, without delivering or retrieving cargo from the ISS, and
a forfeiture of at least part if not all of the payment for the flight. It may also have resulted in the loss of the vehicle if the propulsion system was unable to perform a proper entry or orientation, with the vehicle potentially burning up in the upper atmosphere.

But shortly after, they made the decision to deploy the arrays while they worked the propulsion issue. Eventually, after cycling the valves and blasting them with pressurant to clean them out, first one more propulsion pod came up, and then the other two.

The working theory as of this writing was that it was frozen oxidizer in one of the lines. By late afternoon they were go for rendezvous with ISS, though the delay cost them their window for their planned berthing early Saturday morning, pushing it off until Sunday instead. The company celebrated a slightly belated but happy “berth day,” with a delivery of a ton of equipment and supplies — with a bonus of fresh fruit — to the ISS crew.

Like that of the previous flight, it was a valuable failure in that it identified a potential problem with either the design or operations but didn’t cost them the mission. On the first successful Dragon flight, Elon Musk, the company’s founder and chief executive, noted that it made him a little nervous because it was almost too perfect, and provided nothing to learn from or room for improvement.

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All Comments   (7)
All Comments   (7)
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From the pages of the old science fiction pulps to an actual headline. Well done America.
1 year ago
1 year ago Link To Comment
I just love all these private space companies. It's about time. Per aspera ad astra!
1 year ago
1 year ago Link To Comment
And that's how things should be designed and run, in such a way that problems can be overcome or even can be shrugged off because of redundant systems.

No blowing up spacecraft because a single rubber sealing ring was a few degrees too cold...
1 year ago
1 year ago Link To Comment
Elon Musk is the Henry Ford of outer space. SpaceX's vehicles were meant to be robust, so that glitches don't scratch a mission. That and the likelyhood that SpaceX will dramatically lower the cost of doing business in space are the bright spots in a desultory era for space exploration.
1 year ago
1 year ago Link To Comment
And as you well know, Rand, we learn oh so much more from our failures than our successes.

Go SpaceX!
1 year ago
1 year ago Link To Comment
Look at SpaceX's "Reusability Designs" video, then go read G. Harry Stine's "Halfway to Anywhere." All Falcon 9s going forward will be larger, with more powerful and simple (and presumably reliable) Merlin 1D engines with more performance.... The new Merlins are a step forward towards the requirements for a fully reusable launch system, giving the thrust necessary to carry the small additional fuel required for landing the stage after launch.

A fully reusable launch vehicle will drop cost-to-orbit significantly, and make possible the dreams of other entrepreneurs like Dennis Tito (private Mars missio) and Robert Bigelow (private space stations).
1 year ago
1 year ago Link To Comment
Per aspera ad astra
1 year ago
1 year ago Link To Comment
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