Anyway, is this booster going to be used again? Maybe for a LEO flight to ISS?
...Unless you have evidence beyond the TLEs, I'd say there's not reason to imagine that the launch undershot...
Quote from: jcm on 04/05/2017 08:01 pm...Unless you have evidence beyond the TLEs, I'd say there's not reason to imagine that the launch undershot...Some of us (myself included) are imagining a shortfall based on the announcer's reaction at SC separation, his reaction seemed hesitant as he looked at the screen and finally said the orbit is 'good enough'. (and we all know that 'good enough' is NOT good enough).Of course that is not evidence, his data might not have been 100% clear and just because he wasn't sure doesn't mean it wasn't as expected.And finally even after confirming that 'it didn't fall short', doesn't preclude the possibility that they were expecting a bit more.Anyway just explaining why at least I (and perhaps others) am left wondering.Edit: removed irrelevant parts of quote.
Quote from: mn on 04/05/2017 09:05 pmQuote from: jcm on 04/05/2017 08:01 pm...Unless you have evidence beyond the TLEs, I'd say there's not reason to imagine that the launch undershot...Some of us (myself included) are imagining a shortfall based on the announcer's reaction at SC separation, his reaction seemed hesitant as he looked at the screen and finally said the orbit is 'good enough'. (and we all know that 'good enough' is NOT good enough).Of course that is not evidence, his data might not have been 100% clear and just because he wasn't sure doesn't mean it wasn't as expected.And finally even after confirming that 'it didn't fall short', doesn't preclude the possibility that they were expecting a bit more.Anyway just explaining why at least I (and perhaps others) am left wondering.Edit: removed irrelevant parts of quote."good enough" means under the nominal expected value but within the allowed range.If you always exceeded the expected value, then it wouldn't be "expected", it would be "minimal"...
Quote from: meekGee on 04/05/2017 10:06 pmQuote from: mn on 04/05/2017 09:05 pmQuote from: jcm on 04/05/2017 08:01 pm...Unless you have evidence beyond the TLEs, I'd say there's not reason to imagine that the launch undershot...Some of us (myself included) are imagining a shortfall based on the announcer's reaction at SC separation, his reaction seemed hesitant as he looked at the screen and finally said the orbit is 'good enough'. (and we all know that 'good enough' is NOT good enough).Of course that is not evidence, his data might not have been 100% clear and just because he wasn't sure doesn't mean it wasn't as expected.And finally even after confirming that 'it didn't fall short', doesn't preclude the possibility that they were expecting a bit more.Anyway just explaining why at least I (and perhaps others) am left wondering.Edit: removed irrelevant parts of quote."good enough" means under the nominal expected value but within the allowed range.If you always exceeded the expected value, then it wouldn't be "expected", it would be "minimal"...And to my simple mind "under the nominal expected value but within the allowed range" = "undershot" aka "less than expected" aka "something didn't quite work as expected but we still made it". (The range of acceptable values for the launch contract is hopefully wider than the range of 'expected' values).
Quote from: mn on 04/05/2017 10:28 pmQuote from: meekGee on 04/05/2017 10:06 pmQuote from: mn on 04/05/2017 09:05 pmQuote from: jcm on 04/05/2017 08:01 pm...Unless you have evidence beyond the TLEs, I'd say there's not reason to imagine that the launch undershot...Some of us (myself included) are imagining a shortfall based on the announcer's reaction at SC separation, his reaction seemed hesitant as he looked at the screen and finally said the orbit is 'good enough'. (and we all know that 'good enough' is NOT good enough).Of course that is not evidence, his data might not have been 100% clear and just because he wasn't sure doesn't mean it wasn't as expected.And finally even after confirming that 'it didn't fall short', doesn't preclude the possibility that they were expecting a bit more.Anyway just explaining why at least I (and perhaps others) am left wondering.Edit: removed irrelevant parts of quote."good enough" means under the nominal expected value but within the allowed range.If you always exceeded the expected value, then it wouldn't be "expected", it would be "minimal"...And to my simple mind "under the nominal expected value but within the allowed range" = "undershot" aka "less than expected" aka "something didn't quite work as expected but we still made it". (The range of acceptable values for the launch contract is hopefully wider than the range of 'expected' values).If you're going to forecast a range, and you say 10 +/- 1, and it comes out as 9.5, did it "underperform"?That's the nature of expected values - you get a cluster around them, not above them.
It didn't "fall short." We have direct word on that in L2.
Quote from: meekGee on 04/05/2017 10:34 pmQuote from: mn on 04/05/2017 10:28 pmQuote from: meekGee on 04/05/2017 10:06 pmQuote from: mn on 04/05/2017 09:05 pmQuote from: jcm on 04/05/2017 08:01 pm...Unless you have evidence beyond the TLEs, I'd say there's not reason to imagine that the launch undershot...Some of us (myself included) are imagining a shortfall based on the announcer's reaction at SC separation, his reaction seemed hesitant as he looked at the screen and finally said the orbit is 'good enough'. (and we all know that 'good enough' is NOT good enough).Of course that is not evidence, his data might not have been 100% clear and just because he wasn't sure doesn't mean it wasn't as expected.And finally even after confirming that 'it didn't fall short', doesn't preclude the possibility that they were expecting a bit more.Anyway just explaining why at least I (and perhaps others) am left wondering.Edit: removed irrelevant parts of quote."good enough" means under the nominal expected value but within the allowed range.If you always exceeded the expected value, then it wouldn't be "expected", it would be "minimal"...And to my simple mind "under the nominal expected value but within the allowed range" = "undershot" aka "less than expected" aka "something didn't quite work as expected but we still made it". (The range of acceptable values for the launch contract is hopefully wider than the range of 'expected' values).If you're going to forecast a range, and you say 10 +/- 1, and it comes out as 9.5, did it "underperform"?That's the nature of expected values - you get a cluster around them, not above them.No I would not consider that to be an underperform.BUT if the contractual 'acceptable' range is 100 +-6 and the 'expected/forecasted' range is 100+-2 and the result is 95, I would consider that both 'good enough' and 'underperform'.What actually happened here I don't know.Quote from: cscott on 04/05/2017 04:40 pmIt didn't "fall short." We have direct word on that in L2.Just trying to get clarity on that statement: does it mean the original statement of 'good enough' was incorrect? or was it both 'within the acceptable range' and 'less than expected'? (the point I'm trying to make is that these two statements are NOT mutually exclusive, and therefore the result is still unclear to me.)
They were clear it was the first case. "Good enough", in the tone used, meant under the nominal value, but within the range.
Quote from: meekGee on 04/05/2017 11:00 pmThey were clear it was the first case. "Good enough", in the tone used, meant under the nominal value, but within the range.Please clarify 'within the expected range' or 'within the acceptable range'
Here's Jeff Foust's write-up of Gwynne's remarks today:http://spacenews.com/spacex-gaining-substantial-cost-savings-from-reused-falcon-9/
Shotwell said she believed an industry skeptical of SpaceX’s efforts to reuse Falcon 9 boosters had become convinced it would be useful. She recalled a quote from science fiction author Arthur C. Clarke describing the three stages of reactions to revolutionary ideas. “‘It’s completely impossible.’ We’ve heard that for 15 years. ‘It’s possible, but not worth doing.’ We’re still hearing that a little bit,” she said.”“But,” she added, “we’re also starting to hear, ‘I said it was a good idea all along.’”
Quote from: mn on 04/05/2017 11:16 pmQuote from: meekGee on 04/05/2017 11:00 pmThey were clear it was the first case. "Good enough", in the tone used, meant under the nominal value, but within the range.Please clarify 'within the expected range' or 'within the acceptable range'Frankly, what difference does it make? The customer was satisfied, SpaceX was satisfied and unless you work for either of them or their insurance underwriters, you're not likely to ever have the technical insight into specifics to know one way or the other.
Quote from: Herb Schaltegger on 04/05/2017 11:22 pmQuote from: mn on 04/05/2017 11:16 pmQuote from: meekGee on 04/05/2017 11:00 pmThey were clear it was the first case. "Good enough", in the tone used, meant under the nominal value, but within the range.Please clarify 'within the expected range' or 'within the acceptable range'Frankly, what difference does it make? The customer was satisfied, SpaceX was satisfied and unless you work for either of them or their insurance underwriters, you're not likely to ever have the technical insight into specifics to know one way or the other.Seems to me there's a big difference between the two, but I guess I'm the only one. So forget I asked, let's move on.
It seems to me that there is probably enough knowledge on this site and/or ability to do some math, to determine some plausible ranges for both:(a) contract requirements in terms of acceptable deviation from desired orbit(b) distribution of deviations from target orbit for nominal flights.Depending on how similar or not those ranges are could have a bearing on how interesting it would be to hear things like "good enough."But this sounds very general and therefore if I were going to discuss it further I would start a new thread.
Quote from: sewebster on 04/06/2017 03:25 amIt seems to me that there is probably enough knowledge on this site and/or ability to do some math, to determine some plausible ranges for both:(a) contract requirements in terms of acceptable deviation from desired orbit(b) distribution of deviations from target orbit for nominal flights.Depending on how similar or not those ranges are could have a bearing on how interesting it would be to hear things like "good enough."But this sounds very general and therefore if I were going to discuss it further I would start a new thread.Is it just me, or is this whole argument utterly pointless? The satellite is in an orbit which is correct, and the satellite owners are happy. What on earth is there to argue about?Correct means within the range of acceptable orbits. There is no argument - if it is in the range, it is in the correct orbit, because anything in that range is the correct orbit. There is no 'slightly more correct' or 'slightly less correct'.
Quote from: envy887 on 04/05/2017 07:06 pmQuote from: edkyle99 on 04/05/2017 06:57 pmQuote from: BabaORileyUSA on 04/05/2017 06:03 pmThe values you are showing for the SES-10 are after a velocity augmentation maneuver. The apogee height of Elset One was 33,460 km, about 1,200 km lower than what you are showing.I'm using the oldest TLE listed at Space-Track, Epoch Fri Mar 31 2017 13:57:30 GMT, 14 or 15 hours after launch so time enough for one complete orbit. - Ed KyleIsn't it odd that the stage is now at a 240 km perigee, over 20 km higher than the first TLE?The Stage 2 has the lower apogee height, but the earliest elset for the payload has the higher one.Yes, it's possible there was a PVA burn, but much more likely there was a Stage 2 CCAM/depletion burn which lowered its apogee from an initial one that was the same as the payload. Unless you have evidence beyond the TLEs, I'd say there's not reason to imagine that the launch undershot.
Quote from: edkyle99 on 04/05/2017 06:57 pmQuote from: BabaORileyUSA on 04/05/2017 06:03 pmThe values you are showing for the SES-10 are after a velocity augmentation maneuver. The apogee height of Elset One was 33,460 km, about 1,200 km lower than what you are showing.I'm using the oldest TLE listed at Space-Track, Epoch Fri Mar 31 2017 13:57:30 GMT, 14 or 15 hours after launch so time enough for one complete orbit. - Ed KyleIsn't it odd that the stage is now at a 240 km perigee, over 20 km higher than the first TLE?
Quote from: BabaORileyUSA on 04/05/2017 06:03 pmThe values you are showing for the SES-10 are after a velocity augmentation maneuver. The apogee height of Elset One was 33,460 km, about 1,200 km lower than what you are showing.I'm using the oldest TLE listed at Space-Track, Epoch Fri Mar 31 2017 13:57:30 GMT, 14 or 15 hours after launch so time enough for one complete orbit. - Ed Kyle
The values you are showing for the SES-10 are after a velocity augmentation maneuver. The apogee height of Elset One was 33,460 km, about 1,200 km lower than what you are showing.