Of course this method, elegant as it appears to be, has failed to fully lock a leg at least once, with resultant loss of the vehicle.
From the "last second" deployment before touchdown,I assume that the landing legs deploy and lock mostly passively, under the Gs generated by the landing deceleration, perhaps aided by an internal spring or compressed gas cylinder. There also seems to be some form of actuator on the hull near to top of the folded leg, which I would guess kicks off the process, but pics of them post-landing appear to show a stroke length only a fraction of what would be required for those actuators to fully extend the leg, and show that they are no longer attached to the leg, only to the hull. This may be a very simple and lightweight design for deploying the legs, but would seem to preclude the legs being deployed against the slipstream at altitude. Of course this method, elegant as it appears to be, has failed to fully lock a leg at least once, with resultant loss of the vehicle.
Anyone have any idea if there has been discussions here about the stress testing of the fuselage of the reused F9?
Quote from: Brian45 on 03/25/2017 01:42 pmdoesn't mean they were successful ... None of what they've done has proved the concept ... we'll find out if refurb can be done ... I hope they don't have to have 3 failures to figure out if it works!Quote from: Brian45 on 03/25/2017 03:34 pmnitpickingI believe the colloquial term is "concern trolling."
doesn't mean they were successful ... None of what they've done has proved the concept ... we'll find out if refurb can be done ... I hope they don't have to have 3 failures to figure out if it works!
nitpicking
Quote from: Req on 03/25/2017 03:37 pmQuote from: Brian45 on 03/25/2017 01:42 pmdoesn't mean they were successful ... None of what they've done has proved the concept ... we'll find out if refurb can be done ... I hope they don't have to have 3 failures to figure out if it works!Quote from: Brian45 on 03/25/2017 03:34 pmnitpickingI believe the colloquial term is "concern trolling."it is. And it's not really a good thing to do. Please dial back the concern a bit Brian45...
In reading about re-use of a first stage, all I've seen are concerns about the engines, pumps, tanks, etc. ie the "guts" of the rocket. Was there any discussion about the actual structure of the metal tube that holds everything together?
Quote from: Lar on 03/27/2017 07:01 pmQuote from: Req on 03/25/2017 03:37 pmQuote from: Brian45 on 03/25/2017 01:42 pmdoesn't mean they were successful ... None of what they've done has proved the concept ... we'll find out if refurb can be done ... I hope they don't have to have 3 failures to figure out if it works!Quote from: Brian45 on 03/25/2017 03:34 pmnitpickingI believe the colloquial term is "concern trolling."it is. And it's not really a good thing to do. Please dial back the concern a bit Brian45...So now anyone who points out that "unknown unknowns" are a real danger in aerospace is now "concern trolling" and essentially told to pipe down? I'm disappointed, frankly. Fueling a rocket on a pad was pretty well-known until someone tried something outside the experience base and things went pear-shaped. For every commercially-manufactured aircraft that flies, there are thousands of flight-hours logged in rigorous test-flights to prove out the structures, the systems and the operating procedures, and these things STILL fall out of the air or fly into the dirt with depressing regularity. SpaceX has launched a few dozen rockets and recovered a small-ish percentage of those. There are plenty of unknown unknowns out there, especially if reuse become a real thing. If NSF isn't the place to discuss what SpaceX may have done to narrow those down, and what they might or might not have done for whatever reason, in a sober, rational and thoughtful way without being labeled or attacked for raising the discussion, where is?
Quote from: FutureSpaceTourist on 03/28/2017 03:23 pmQuoteOur CTO Martin Halliwell talks about #SES10 and the launch on #flightproven rocket!https://twitter.com/ses_satellites/status/846742078310690818https://www.periscope.tv/w/a6kjoTFETEtCeURWT2FEUUp8MWpNSmdZd3JPYXlLTOkPzfjLKb6zX572-CwWcPxK89_4GMQLEeCpVDy3-Oo7Here are some notes:* Mass is 5281.7 kg, insertion orbit will be 35410 km x 218 km at 26.2º, so barely subsynchronous GTO. Orbit raising will be done with chemical engines.* SES block bought SES-10, SES-11, SES-14, SES-16. Then last August they were approached with the opportunity to use a pre-flown booster.* Essentially no change in the insurance premium, 100th of a percent.* First stage booster is contractually obligated to make certain altitude, velocity, downrange, etc. SpaceX works with the leftovers for landing. This will be a very hot landing, but if it comes back, SES gets "bits" for their boardroom.* Satellite requires 13 hours of checkouts once the full stack is vertical on the pad.
QuoteOur CTO Martin Halliwell talks about #SES10 and the launch on #flightproven rocket!https://twitter.com/ses_satellites/status/846742078310690818https://www.periscope.tv/w/a6kjoTFETEtCeURWT2FEUUp8MWpNSmdZd3JPYXlLTOkPzfjLKb6zX572-CwWcPxK89_4GMQLEeCpVDy3-Oo7
Our CTO Martin Halliwell talks about #SES10 and the launch on #flightproven rocket!
The odds on bet must be that SX will get some things wrong. The worst case being they are unable to recover the stage.
Quote from: john smith 19 on 03/28/2017 07:22 pmThe odds on bet must be that SX will get some things wrong. The worst case being they are unable to recover the stage.Wrong. Worst case is that there will be launch faliure.
Essentially the whole history of first stage reuse started with the first Grasshopper landing. Everything prior to this for the reuse or reflight of high aspect ratio TSTO VTO LV's was theoretical.
Quote from: john smith 19 on 03/28/2017 07:22 pmEssentially the whole history of first stage reuse started with the first Grasshopper landing. Everything prior to this for the reuse or reflight of high aspect ratio TSTO VTO LV's was theoretical. I think Armadillo Aerospace and Masten might disagree with this statement. They both demonstrated Grasshopper levels of control, albeit on a smaller scale.
Quote from: JamesH65 on 03/29/2017 12:39 pmQuote from: john smith 19 on 03/28/2017 07:22 pmEssentially the whole history of first stage reuse started with the first Grasshopper landing. Everything prior to this for the reuse or reflight of high aspect ratio TSTO VTO LV's was theoretical. I think Armadillo Aerospace and Masten might disagree with this statement. They both demonstrated Grasshopper levels of control, albeit on a smaller scale.Neither have put a payload into orbit and brought a booster back from hypersonic velocities nor did they use boosters capable of that. Hence the explicit mention of doing it with a "high aspect ratio TSTO VTO LV."We (the forum) always get into a Simpsons did it first arguments. I know people sometimes make outrageous claims about SpaceX firstyness/bestyness, but this one seemed fairly explicitly constrained.