This is a very light payload for this rocket. If they are already worried about first stage return-to-launch-site margins, how is this design supposed to work with "real" payloads? - Ed Kyle
Quote from: edkyle99 on 12/20/2015 08:43 pmThis is a very light payload for this rocket. If they are already worried about first stage return-to-launch-site margins, how is this design supposed to work with "real" payloads? - Ed KyleI could imagine the rule for the first stage, for each mission, says "stop when you have X percent of fuel left", where X should be (barely) enough for landing.
Quote from: LouScheffer on 12/20/2015 09:20 pmQuote from: edkyle99 on 12/20/2015 08:43 pmThis is a very light payload for this rocket. If they are already worried about first stage return-to-launch-site margins, how is this design supposed to work with "real" payloads? - Ed KyleI could imagine the rule for the first stage, for each mission, says "stop when you have X percent of fuel left", where X should be (barely) enough for landing. I consider that unlikely. It would place more priority on getting the S1 back than getting the payload to the proper orbit. Typically - on liquid fuel boosters - the first stage burns until certain trajectory requirements are met, like speed and altitude along a given azimuth. That's why you'll see BECO occurring at different times from mission to mission. If the S1 underperforms, it then will have to use some of its landing fuel margin in order to get to a staging point where the S2 can get its payload where it needs to be.
If the S1 underperforms, it then will have to use some of its landing fuel margin in order to get to a staging point where the S2 can get its payload where it needs to be.
I agree with you 100% that the first priority should be getting to the payload to orbit, and if that leaves not enough fuel for landing, so be it.
This may be one more of an endless series of repeated answers but the ASDS was supposedly able to hold its position to 3 meters. This is less than the diameter of the rocket and not significant on the scale of the ~53 meter wide ASDS. Another ten feet of deck wouldn't have enabled either of the previous landing attempt to succeed.
Quote from: leaflion on 12/20/2015 08:08 pmWonder how Orbcomm feels about this...I've got a sneaky feeling they got a very, very cheap ride (relatively speaking) to go as RTF and ride along with what is a validation flight of the upgraded F9 and a landing attempt.
Wonder how Orbcomm feels about this...
Quote from: Kim Keller on 12/20/2015 09:25 pmIf the S1 underperforms, it then will have to use some of its landing fuel margin in order to get to a staging point where the S2 can get its payload where it needs to be.Newb question . . .In the case of (insert vehicle here) S1 underperformance, would flight software use the landing-margin to put S2 within the middle of it's envelope? Bottom 10%, 25% . . . . Thanks in advance!
... they passed the data and the LRR, then not happy again. Bit confusing
Quote from: Chris Bergin on 12/20/2015 08:10 pmQuote from: leaflion on 12/20/2015 08:08 pmWonder how Orbcomm feels about this...I've got a sneaky feeling they got a very, very cheap ride (relatively speaking) to go as RTF and ride along with what is a validation flight of the upgraded F9 and a landing attempt.Yup. They probably paid around $10 million. Originally supposed to be a Falcon 1e or something.
Surely they don't mean that there is a 10% greater chance the payload will tomorrow be destroyed, surely its there's a 10% greater chance that weather will delay the launch tomorrow.
Having a little trouble reconciling Musk's tweet with Orbcomm's. Increased odds of landing vs. looking more closely at static fire data aren't really the same thing. A bit of obfuscation, IMO.
Quote from: WHAP on 12/20/2015 11:38 pmHaving a little trouble reconciling Musk's tweet with Orbcomm's. Increased odds of landing vs. looking more closely at static fire data aren't really the same thing. A bit of obfuscation, IMO.Orbcomm said: - "an additional day prior to launch will allow for more analysis" this is certainly true, whether or not it's a reason. - "and time to further chill the liquid oxygen in preparation for launch." (so more delta-v in case of problems)Musk said: - "Monte Carlo runs show tmrw night has a 10% higher chance of a good landing." Probably lower winds, but maybe more delta-V available with lower temp fuel.And no-one said: - Gives launch team a little time to rest after a few hard days, and reflect if launch fever might be operating.I see no contradiction here - the combination of all these reasons made Monday look better than Sunday. Then each tweeted what they thought was the most compelling reason.
- Gives launch team a little time to rest after a few hard days, and reflect if launch fever might be operating.
The reason with the customer's buyin would be the most compelling one.