A prototype communications satellite flying as a secondary payload aboard a Space Exploration Technologies Falcon 9 rocket was sent into the wrong orbit because of a problem during launch Sunday evening, officials said Tuesday.
One of the nine Merlin engines powering the Falcon 9 rocket shut down early, though the other engines burned longer to make up for the loss of thrust, saving the primary mission of delivering a Dragon cargo capsule to the International Space Station for NASA.
http://www.ecnmag.com/news/2012/10/spac ... rong-orbit
SpaceX has a glitch
SpaceX has a glitch
Engineering is the art of making what you want from what you can get at a profit.
You are late, Msimon.
The problem was not so much that the fist stage engine failed, but that the second stage was not allowed to push the secondary payload into the desired orbit due to the range savety concerns by NASA about Dragon and the ISS. Had NASA allowed it, the satellite would have made it into its desired orbit just fine.
I find it quite remarkable that a first stage engine could fail like that and F9 was still able to complete the mission without problems (even the secondary payload would have worked fine, had NASA allowed the second stage to do the necessary burn).
The problem was not so much that the fist stage engine failed, but that the second stage was not allowed to push the secondary payload into the desired orbit due to the range savety concerns by NASA about Dragon and the ISS. Had NASA allowed it, the satellite would have made it into its desired orbit just fine.
I find it quite remarkable that a first stage engine could fail like that and F9 was still able to complete the mission without problems (even the secondary payload would have worked fine, had NASA allowed the second stage to do the necessary burn).
I'm not paying as close attention as I used to. I have some projects I'm working on.Skipjack wrote:You are late, Msimon.
The problem was not so much that the fist stage engine failed, but that the second stage was not allowed to push the secondary payload into the desired orbit due to the range savety concerns by NASA about Dragon and the ISS. Had NASA allowed it, the satellite would have made it into its desired orbit just fine.
I find it quite remarkable that a first stage engine could fail like that and F9 was still able to complete the mission without problems (even the secondary payload would have worked fine, had NASA allowed the second stage to do the necessary burn).
Engineering is the art of making what you want from what you can get at a profit.
I believe the problem with the second stage was that the ISS was in the same orbit plane and anything less than a perfect boost would risk the station. Probability of such perfect boost was estimated to be 95% with the fuel remaining in the second stage, but NASA required something like 99% probability for acceptable risk to the ISS, so the boost to final orbit was not allowed. This was because the second stage burned more fuel than planned to achieve orbit insertion due to the engine shutdown on the first stage.
Aero
Yeah, I think that it would be really hard to hit the station without course corrections even if they tried. But oh well. The Dragon was the primary mission and that worked out.I believe the problem with the second stage was that the ISS was in the same orbit plane and anything less than a perfect boost would risk the station.
Remember that the stage was starting below the ISS altitude and planned to orbit above the ISS altitude. To raise the orbit requires two engine burns, first to raise the apogee to an altitude above the ISS, then a second burn to raise the perigee to above the altitude of the ISS. If the second burn had been less than completely successful, the risk was that the stage would cross the ISS orbit altitude twice during each of the stage's orbits about Earth. It would have been a relatively long lived orbit resulting in many opportunities (about 36 per day) to accidently hit the ISS or one of the future spacecraft servicing the ISS. That's why they didn't do the burn.Skipjack wrote:Yeah, I think that it would be really hard to hit the station without course corrections even if they tried. But oh well. The Dragon was the primary mission and that worked out.I believe the problem with the second stage was that the ISS was in the same orbit plane and anything less than a perfect boost would risk the station.
Aero