Quote from: Craig_VG on 12/05/2015 09:50 pm"SpaceX launch date for return to flight now 19 Dec.- proximate cause a payload issue. AF approves booster return to land, Optimism FAA ditto"https://twitter.com/TheLurioReport/status/673270563742289920Lurio's tweet is deleted. Do we have any other confirmation of Dec 19?
"SpaceX launch date for return to flight now 19 Dec.- proximate cause a payload issue. AF approves booster return to land, Optimism FAA ditto"https://twitter.com/TheLurioReport/status/673270563742289920
Quote from: Jim on 12/06/2015 09:32 pmQuote from: vulture4 on 12/06/2015 04:26 pmRegarding the struts, the two mitigation steps I saw discussed were increasing the strength of the strut and possibly doing 100% testing. However the strut already had a more than adequate 5:1 load factor. The failure occurred because of poor control of the manufacturing process, not a design flaw. Wrong, it is a design flaw. Wrong, material and manufacturing technique for the applicationInteresting claim. What was the wrong material, and what was the wrong manufacturing technique? What should they have used instead?
Quote from: vulture4 on 12/06/2015 04:26 pmRegarding the struts, the two mitigation steps I saw discussed were increasing the strength of the strut and possibly doing 100% testing. However the strut already had a more than adequate 5:1 load factor. The failure occurred because of poor control of the manufacturing process, not a design flaw. Wrong, it is a design flaw. Wrong, material and manufacturing technique for the application
Regarding the struts, the two mitigation steps I saw discussed were increasing the strength of the strut and possibly doing 100% testing. However the strut already had a more than adequate 5:1 load factor. The failure occurred because of poor control of the manufacturing process, not a design flaw.
Quote from: LouScheffer on 12/07/2015 12:53 amQuote from: Jim on 12/06/2015 09:32 pmQuote from: vulture4 on 12/06/2015 04:26 pmRegarding the struts, the two mitigation steps I saw discussed were increasing the strength of the strut and possibly doing 100% testing. However the strut already had a more than adequate 5:1 load factor. The failure occurred because of poor control of the manufacturing process, not a design flaw. Wrong, it is a design flaw. Wrong, material and manufacturing technique for the applicationInteresting claim. What was the wrong material, and what was the wrong manufacturing technique? What should they have used instead?And why did it fly 18 times successfully if it was both wrong material and manufacturing technique?Don't design flaws reveal themselves early?
I don't know how reliable of a source this is, but:https://twitter.com/TheLurioReport/status/673270563742289920"SpaceX launch date for return to flight now 19 Dec.- proximate cause a payload issue. AF approves booster return to land, Optimism FAA ditto"
Quote from: AncientU on 12/07/2015 12:24 pmAnd why did it fly 18 times successfully if it was both wrong material and manufacturing technique?Don't design flaws reveal themselves early?Not always. Just think about various vehicle or equipment recalls. I recently had to replace my shower because of a bad design in a valve that sometimes locks up.
And why did it fly 18 times successfully if it was both wrong material and manufacturing technique?Don't design flaws reveal themselves early?
Quote from: ericspittle on 12/05/2015 11:30 pmI don't know how reliable of a source this is, but:https://twitter.com/TheLurioReport/status/673270563742289920"SpaceX launch date for return to flight now 19 Dec.- proximate cause a payload issue. AF approves booster return to land, Optimism FAA ditto"Fair play to him, because Orbcomm are saying the same (still a NET).Peter B. de Selding @pbdes 14m14 minutes agoOrbcomm: Best-guess estimate of Falcon 9 Upgrade launch of our 11 sats is Dec. 19. With the usual caveats.
Quote from: Chris Bergin on 12/07/2015 12:42 pmQuote from: ericspittle on 12/05/2015 11:30 pmI don't know how reliable of a source this is, but:https://twitter.com/TheLurioReport/status/673270563742289920"SpaceX launch date for return to flight now 19 Dec.- proximate cause a payload issue. AF approves booster return to land, Optimism FAA ditto"Fair play to him, because Orbcomm are saying the same (still a NET).Peter B. de Selding @pbdes 14m14 minutes agoOrbcomm: Best-guess estimate of Falcon 9 Upgrade launch of our 11 sats is Dec. 19. With the usual caveats.Chris, it looks to me that they are hedging their bets because the weather is unstable right now... forecast varies from day to day... we probably won't know for sure until a few days before the launch... btw, I'm just going on the basis of the public weather services... perhaps there is more detailed forecast from the "Real Weather Folks"...
Quote from: cro-magnon gramps on 12/07/2015 02:21 pmQuote from: Chris Bergin on 12/07/2015 12:42 pmQuote from: ericspittle on 12/05/2015 11:30 pmI don't know how reliable of a source this is, but:https://twitter.com/TheLurioReport/status/673270563742289920"SpaceX launch date for return to flight now 19 Dec.- proximate cause a payload issue. AF approves booster return to land, Optimism FAA ditto"Fair play to him, because Orbcomm are saying the same (still a NET).Peter B. de Selding @pbdes 14m14 minutes agoOrbcomm: Best-guess estimate of Falcon 9 Upgrade launch of our 11 sats is Dec. 19. With the usual caveats.Chris, it looks to me that they are hedging their bets because the weather is unstable right now... forecast varies from day to day... we probably won't know for sure until a few days before the launch... btw, I'm just going on the basis of the public weather services... perhaps there is more detailed forecast from the "Real Weather Folks"...From what I can understand, one advantage of a RTLS landing is simply that, if the weather is optimal for a LV to launch in Florida, the weather should be just as optimal for a stage to land close by in Florida.To The_Other_Doug's credit from another thread, this is actually a point against RTLS in that launch weather may be based on a fully-loaded launch vehicle. A lightly-fueled first stage, with a lot of its weight gone, heading in the opposite direction, might react differently to the same winds.
From what I can understand, one advantage of a RTLS landing is simply that, if the weather is optimal for a LV to launch in Florida, the weather should be just as optimal for a stage to land close by in Florida.
The thrusters aren't stabilizers. They're station keepers. They have no effect on vertical movement.
The subject of barge stability has been discussed extensively in several other threads. Summary: there is next to zero movement of the barge in ordinary sea states, horizontally or vertically. That's what all the powered stabilizers are for. A couple inches' uncertainty during a landing attempt isn't going to make or break the effort.
It would appear that wind is the main problem to overcome landing on the ASDS. Rocket comes down leaning into the wind and then has to go vertical in very short time. The wind is still pushing on the rocket and the rotational momentum of changing to vertical is working against you. I always though it would be better to drive the ASDS in the direction of the wind to match as close as possible and land on a moving target.
Quote from: Herb Schaltegger on 12/08/2015 01:14 pmThe subject of barge stability has been discussed extensively in several other threads. Summary: there is next to zero movement of the barge in ordinary sea states, horizontally or vertically. That's what all the powered stabilizers are for. A couple inches' uncertainty during a landing attempt isn't going to make or break the effort.It would appear that wind is the main problem to overcome landing on the ASDS. Rocket comes down leaning into the wind and then has to go vertical in very short time. The wind is still pushing on the rocket and the rotational momentum of changing to vertical is working against you. I always though it would be better to drive the ASDS in the direction of the wind to match as close as possible and land on a moving target.
It would appear that wind is the main problem to overcome landing on the ASDS.