Quote from: Joel on 10/08/2012 07:24 pmJust for my understanding. Does 30 seconds of extra burn roughly equate to 30 seconds of extra gravity losses, or around 300 m/s lost delta-v?Only if you're flying straight up. It's less of an issue if your velocity vector is more toward horizontal.
Just for my understanding. Does 30 seconds of extra burn roughly equate to 30 seconds of extra gravity losses, or around 300 m/s lost delta-v?
After an engine explodes, its non functional in every aspect of that word.
Lucky that they had performance margin on this flight
How can an engine "explode" and yet still send telemetry to SpaceX?
To me "explode" is very specific.
Quote from: titanmiller on 10/08/2012 06:06 pmQuote from: Kabloona on 10/08/2012 06:01 pm"the fairing ruptured...due to the engine pressure release..." so they already know it wasn't aero loads that broke the fairing loose, it was "engine pressure release," which I'm not sure how to interpret...a turbopump self-destructing, or "engine pressure release" sounds synonymous to "explosion" to me. Maybe it wasn't a catastrophic explosion, but it definitely went out with a bang.Think about it, if you were SpaceX, would you want to say that one of your engines "exploded"? We're going to have six pages of discussion about the definition of "explosion" now...In my opinion, mission-wise, a second stage restart failure, if that turns out to be the case, is more significant to potential SpaceX customers than the first stage engine shutdown, because a restart issue would be a flat out launch failure. - Ed Kyle
Quote from: Kabloona on 10/08/2012 06:01 pm"the fairing ruptured...due to the engine pressure release..." so they already know it wasn't aero loads that broke the fairing loose, it was "engine pressure release," which I'm not sure how to interpret...a turbopump self-destructing, or "engine pressure release" sounds synonymous to "explosion" to me. Maybe it wasn't a catastrophic explosion, but it definitely went out with a bang.Think about it, if you were SpaceX, would you want to say that one of your engines "exploded"?
"the fairing ruptured...due to the engine pressure release..." so they already know it wasn't aero loads that broke the fairing loose, it was "engine pressure release," which I'm not sure how to interpret...a turbopump self-destructing, or
Quote from: ugordan on 10/08/2012 07:26 pmQuote from: Joel on 10/08/2012 07:24 pmJust for my understanding. Does 30 seconds of extra burn roughly equate to 30 seconds of extra gravity losses, or around 300 m/s lost delta-v?Only if you're flying straight up. It's less of an issue if your velocity vector is more toward horizontal. Well... divided by the square root of two if horizontal... But we are still talking about between 200 and 300 m/s lost delta-v?
Do you have any *specific* examples where their indicated payload/orbit parameters are pushing the limits of the vehicles capabilities? If you don't then is there *any* reason to expect the results of such a mission to be any worse than the ones today?
Quote from: IRobot on 10/08/2012 05:13 pmYou have 9 engines. There are a few hundred of combinations of 1-2 engines out before shutdown72
You have 9 engines. There are a few hundred of combinations of 1-2 engines out before shutdown
Overall maybe this will calm down some of this Space X good ULA & everyone else bad I have noted about.
Am I late with this? - http://www.spacex.com/press.php?page=20121008"Approximately one minute and 19 seconds into last night's launch, the Falcon 9 rocket detected an anomaly on one first stage engine. Initial data suggests that one of the rocket's nine Merlin engines, Engine 1, lost pressure suddenly and an engine shutdown command was issued. We know the engine did not explode, because we continued to receive data from it. Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines. Our review of flight data indicates that neither the rocket stage nor any of the other eight engines were negatively affected by this event."
Quote from: Remes on 10/08/2012 07:25 pmQuote from: IRobot on 10/08/2012 05:13 pmYou have 9 engines. There are a few hundred of combinations of 1-2 engines out before shutdown72459 (9-take-1) combinations of one engine-out. 36 (9-take-2) combinations of two engines-out.
Quote from: Joel on 10/08/2012 07:42 pmQuote from: Remes on 10/08/2012 07:25 pmQuote from: IRobot on 10/08/2012 05:13 pmYou have 9 engines. There are a few hundred of combinations of 1-2 engines out before shutdown72459 (9-take-1) combinations of one engine-out. 36 (9-take-2) combinations of two engines-out.729 possibilities for the first engine times 8 possibilities (8 remaining) for the second. = 72
Quote from: Joel on 10/08/2012 07:42 pmQuote from: Remes on 10/08/2012 07:25 pmQuote from: IRobot on 10/08/2012 05:13 pmYou have 9 engines. There are a few hundred of combinations of 1-2 engines out before shutdown724572
Quote from: Remes on 10/08/2012 07:25 pmQuote from: IRobot on 10/08/2012 05:13 pmYou have 9 engines. There are a few hundred of combinations of 1-2 engines out before shutdown7245
Am I late with this? - http://www.spacex.com/press.php?page=20121008"Panels designed to relieve pressure within the engine bay were ejected to protect the stage and other engines. "
Quote from: Joel on 10/08/2012 07:30 pmQuote from: ugordan on 10/08/2012 07:26 pmQuote from: Joel on 10/08/2012 07:24 pmJust for my understanding. Does 30 seconds of extra burn roughly equate to 30 seconds of extra gravity losses, or around 300 m/s lost delta-v?Only if you're flying straight up. It's less of an issue if your velocity vector is more toward horizontal. Well... divided by the square root of two if horizontal... But we are still talking about between 200 and 300 m/s lost delta-v?What matters is how much extra time was spent flying up the vertical portion of the ascent vector. The majority of the extra seconds of flight in this case were likely spent flying horizontally in space, during the second stage portion of the ascent. Gravity losses in horizontal flight at orbital altitude are near-zero. Some pitch up gravity losses likely did occur, but I wouldn't as much as expect 200 m/s. - Ed Kyle
Quote from: Remes on 10/08/2012 07:25 pmQuote from: IRobot on 10/08/2012 05:13 pmYou have 9 engines. There are a few hundred of combinations of 1-2 engines out before shutdown72459 (9-choose-1) combinations of one engine-out. 36 (9-choose-2) combinations of two engines-out.