We need not worry if the truth isn’t immediately obvious.
SpaceX has been working on using more of the atmosphere to slow down Falcon 9 as that saves propellant and will be important for BFR.
INTERESTING!SpaceX recovery support ships Go Quest and Go Searcher have left Port Canaveral.Possible fairing recovery test!
Quote from: ATPTourFan on 01/31/2018 11:25 am We need not worry if the truth isn’t immediately obvious.I would say that is pretty much the mantra of science (and good technology). Religion and politics require immediate truth. Science can afford to be patient.
Quote from: Michael Baylor on 01/27/2018 07:53 pmINTERESTING!SpaceX recovery support ships Go Quest and Go Searcher have left Port Canaveral.Possible fairing recovery test!No, more likely telemetry relay
A ways back Elon mentioned wanting to reduce some return velocity by deploying the legs sooner. Perhaps they'll test that here. Or not. There could be a few components on one or all legs that are being tested for a Block 5 implementation.
Quote from: rcoppola on 01/31/2018 03:23 pmA ways back Elon mentioned wanting to reduce some return velocity by deploying the legs sooner. Perhaps they'll test that here. Or not. There could be a few components on one or all legs that are being tested for a Block 5 implementation.Errr... what legs? Look at the pictures. This Falcon's had a leg-otomy
It is evident that SpaceX believes in minimum refurbishment. “Why detach the legs? Why not expend the entire hardware first launched with NROL 76?” Reduce labor by finding areas that don’t require intervention. However, the legs were detached at LZ1. Furthermore, they appear to be cleaned (not sooty). Why go through the trouble of cleaning the legs and adding weight to a minimum fuel payload for some science that has already been collected two dozen times? There is clearly a great reason, but I cannot fathom what that is.Mark Eagon
Errr... what legs? Look at the pictures. This Falcon's had a leg-otomy
Quote from: ATPTourFan on 01/31/2018 11:25 amSpaceX has been working on using more of the atmosphere to slow down Falcon 9 as that saves propellant and will be important for BFR. F9 1st stage is having quite big angle of attack when it's flying back towards landing location. Quite much of body lift can be gotten even from a cylinder shape, when it's light enough.And the higher angle of attack saves fuel used to both flying back AND slowing down to landing velocity
Quote from: hkultala on 01/31/2018 01:04 pmQuote from: ATPTourFan on 01/31/2018 11:25 amSpaceX has been working on using more of the atmosphere to slow down Falcon 9 as that saves propellant and will be important for BFR. F9 1st stage is having quite big angle of attack when it's flying back towards landing location. Quite much of body lift can be gotten even from a cylinder shape, when it's light enough.And the higher angle of attack saves fuel used to both flying back AND slowing down to landing velocityI do wonder why they aren't using the titanium fins then, won't those do better at holding higher angles of attack for both heating and control authority reasons (I'm assuming that using the fins that way heats them up a lot more than gentler angles)?
Quote from: pb2000 on 01/30/2018 07:15 pmQuote from: lrk on 01/30/2018 07:08 pmQuote from: pb2000 on 01/30/2018 07:05 pmQuote from: Jim on 01/30/2018 06:12 pmQuote from: pb2000 on 01/30/2018 04:28 pmIf they filled the RP-1 tank to the max and had just enough LOX to get down...Rockets always basically filled to 100% no matter what the payload mass isMakes sense on a normal rocket to have as much margin as possible, but do you know for sure if this applies to the F9? The second stage can obviously dump it's excess fuel after the deorbit burn, but the first stage brings it home - seems like a bad idea if things go pear shaped.F9 S1 can always use any extra fuel for a less-efficient but more gentle entry and landing. The mission I'm specifically thinking of was formosat - the payload was tiny and it landed on the drone ship downrange. I'll go back and re-watch that mission, but I don't recall any sort of excessively long post sep burns.They also need to keep extra margin on board in case of an engine out. There are a number of engine failure scenarios that could still make orbit but would require the entire fuel margins leaving nothing left for return.
Quote from: lrk on 01/30/2018 07:08 pmQuote from: pb2000 on 01/30/2018 07:05 pmQuote from: Jim on 01/30/2018 06:12 pmQuote from: pb2000 on 01/30/2018 04:28 pmIf they filled the RP-1 tank to the max and had just enough LOX to get down...Rockets always basically filled to 100% no matter what the payload mass isMakes sense on a normal rocket to have as much margin as possible, but do you know for sure if this applies to the F9? The second stage can obviously dump it's excess fuel after the deorbit burn, but the first stage brings it home - seems like a bad idea if things go pear shaped.F9 S1 can always use any extra fuel for a less-efficient but more gentle entry and landing. The mission I'm specifically thinking of was formosat - the payload was tiny and it landed on the drone ship downrange. I'll go back and re-watch that mission, but I don't recall any sort of excessively long post sep burns.
Quote from: pb2000 on 01/30/2018 07:05 pmQuote from: Jim on 01/30/2018 06:12 pmQuote from: pb2000 on 01/30/2018 04:28 pmIf they filled the RP-1 tank to the max and had just enough LOX to get down...Rockets always basically filled to 100% no matter what the payload mass isMakes sense on a normal rocket to have as much margin as possible, but do you know for sure if this applies to the F9? The second stage can obviously dump it's excess fuel after the deorbit burn, but the first stage brings it home - seems like a bad idea if things go pear shaped.F9 S1 can always use any extra fuel for a less-efficient but more gentle entry and landing.
Quote from: Jim on 01/30/2018 06:12 pmQuote from: pb2000 on 01/30/2018 04:28 pmIf they filled the RP-1 tank to the max and had just enough LOX to get down...Rockets always basically filled to 100% no matter what the payload mass isMakes sense on a normal rocket to have as much margin as possible, but do you know for sure if this applies to the F9? The second stage can obviously dump it's excess fuel after the deorbit burn, but the first stage brings it home - seems like a bad idea if things go pear shaped.
Quote from: pb2000 on 01/30/2018 04:28 pmIf they filled the RP-1 tank to the max and had just enough LOX to get down...Rockets always basically filled to 100% no matter what the payload mass is
If they filled the RP-1 tank to the max and had just enough LOX to get down...
It is possible to surmise that this mission falls right on the cusp of recoverability and so SpaceX was left with a conundrum: It is too heavy to recover intact, but light enough to add the cleaned legs to test more aggressive profiles.