Quote from: Danderman on 01/17/2017 07:29 pmand the 2nd stage is only good for one re-start,That's a big assumption, and doesn't fit with what Gwynne said pre-launch (three S2 burns).
and the 2nd stage is only good for one re-start,
I suppose there was never an announcement by SpaceX of the de-orbit of the 2nd stage.
Quote from: old_sellsword on 01/17/2017 07:36 pmQuote from: Danderman on 01/17/2017 07:29 pmand the 2nd stage is only good for one re-start,That's a big assumption, and doesn't fit with what Gwynne said pre-launch (three S2 burns).A single re-start is what has been demonstrated, AFAIK. ...
There have been numerous launches where they performed a de-orbit burn. Even after a 2 burn gto launch. Which would make it 3 burns.
Quote from: rsdavis9 on 01/17/2017 07:40 pmThere have been numerous launches where they performed a de-orbit burn. Even after a 2 burn gto launch. Which would make it 3 burns.Source on this? I don't doubt you but I don't remember another launch doing 3 second stage burns.
Quote from: stcks on 01/17/2017 07:51 pmQuote from: rsdavis9 on 01/17/2017 07:40 pmThere have been numerous launches where they performed a de-orbit burn. Even after a 2 burn gto launch. Which would make it 3 burns.Source on this? I don't doubt you but I don't remember another launch doing 3 second stage burns.I found this out not because of any annoucement but by tracking the orbits of various launches from the orbit TLE sites. Some are not de-orbitted and some are. I am pretty sure SES was left in orbit. Thiacom maybe?
Quote from: rsdavis9 on 01/17/2017 08:04 pmQuote from: stcks on 01/17/2017 07:51 pmQuote from: rsdavis9 on 01/17/2017 07:40 pmThere have been numerous launches where they performed a de-orbit burn. Even after a 2 burn gto launch. Which would make it 3 burns.Source on this? I don't doubt you but I don't remember another launch doing 3 second stage burns.I found this out not because of any annoucement but by tracking the orbits of various launches from the orbit TLE sites. Some are not de-orbitted and some are. I am pretty sure SES was left in orbit. Thiacom maybe?The Jason-3 mission is an example where stage 2 was deorbited on a 3rd burn. Also F9-021/Orbcomm
The Jason-3 mission is an example where stage 2 was deorbited on a 3rd burn. Also F9-021/Orbcomm
I wonder if the loss of tracking during the satellite deployment meant they lost their window for for the deorbit burn. Ie, the d/o burn was to happen x minutes after the last separation, but they didn't regain tracking until x+n minutes when they could confirm deployment, and a d/o burn would have them coming down outside the planned hazard area. So, at that point all they can do is passivate the stage and wait 20 years.
Quote from: yokem55 on 01/17/2017 08:53 pmI wonder if the loss of tracking during the satellite deployment meant they lost their window for for the deorbit burn. Ie, the d/o burn was to happen x minutes after the last separation, but they didn't regain tracking until x+n minutes when they could confirm deployment, and a d/o burn would have them coming down outside the planned hazard area. So, at that point all they can do is passivate the stage and wait 20 years.I'm pretty sure the stage computer control the burns. There isn't a need to wait for commands from the ground, so loss of signal wouldn't matter.
Some awesome pics in that, Jarnis. Local media also getting involved, with some good pics (and a good write up):http://www.dailynews.com/science/20170117/spacex-rocket-docks-at-san-pedro-home-port-after-successful-mission
Quote from: Chris Bergin on 01/17/2017 04:49 pmSome awesome pics in that, Jarnis. Local media also getting involved, with some good pics (and a good write up):http://www.dailynews.com/science/20170117/spacex-rocket-docks-at-san-pedro-home-port-after-successful-missionChris Bergin, that article mentions a boost-back burn and two more burns to land. I was under the impression this flight did not perform any boost-back.
The boostback burn on this mission just decelerates the stage before reentry. They still call it "boostback." It's on the timeline at the bottom of the technical webcast and you can see it at about T+4:23 (24:02 into the webcast).
Quote from: manoweb on 01/17/2017 09:55 pmQuote from: Chris Bergin on 01/17/2017 04:49 pmSome awesome pics in that, Jarnis. Local media also getting involved, with some good pics (and a good write up):http://www.dailynews.com/science/20170117/spacex-rocket-docks-at-san-pedro-home-port-after-successful-missionChris Bergin, that article mentions a boost-back burn and two more burns to land. I was under the impression this flight did not perform any boost-back.The boostback burn on this mission just decelerates the stage before reentry. They still call it "boostback." It's on the timeline at the bottom of the technical webcast and you can see it at about T+4:23 (24:02 into the webcast).