Could a SpaceX like boost back burn followed by a grid fin controlled reentry make parachute or mid-air recovery viable for something like the Electron? (Of course maybe SpaceX has patented it so they’d need to pay a license fee?, or find some other method like an enormous streamer or foldout helicopter blades?)
Quote from: HVM on 01/21/2018 07:50 pmQuote from: edkyle99 on 01/21/2018 07:17 pm...Speaking as an electrical engineer, I can tell you that the "hot swap" was a very big deal. There's a reason they were applauding in the control room...72 KW ~ 9 electric sauna stoves, doesn't sound so bad. (Ok if you need put a considerable amount of kerosene and LOX thought those stoves in mach 13, then it can bit tricky)I picture the electric pumps as being roughly equivalent to an electric drivetrain in a car. Power should be roughly similar.I'm not an electrical engineer, but what strikes me as difficult is that battery voltage will fall as it discharges, meaning cutting in the other battery is tricky since it will be at its fully charged open circuit voltage. Connecting batteries with different voltages in parallel is usually to be avoided. DC-DC voltage conversion to allow different batteries at different voltages is possible but doing it at probably 100+ KW would have significant dry mass penalty.So it seems like they figured out a way to manage the transition with the engine running at high power, without disrupting propellant flow. Gotta agree with Ed, that caught my attention as well. Not obvious to me what they even did. Just had them connected simultaneously for a couple milliseconds?
Quote from: edkyle99 on 01/21/2018 07:17 pm...Speaking as an electrical engineer, I can tell you that the "hot swap" was a very big deal. There's a reason they were applauding in the control room...72 KW ~ 9 electric sauna stoves, doesn't sound so bad. (Ok if you need put a considerable amount of kerosene and LOX thought those stoves in mach 13, then it can bit tricky)
...Speaking as an electrical engineer, I can tell you that the "hot swap" was a very big deal. There's a reason they were applauding in the control room...
Quote from: Bubbinski on 01/22/2018 06:50 pmCould a SpaceX like boost back burn followed by a grid fin controlled reentry make parachute or mid-air recovery viable for something like the Electron? (Of course maybe SpaceX has patented it so they’d need to pay a license fee?, or find some other method like an enormous streamer or foldout helicopter blades?)If you are already using grid fins and in-air relight capability, it would save on complexity and possibly weight to just soft land using the engines - assuming that the engines can be throttled within a decent range.
WRT reuse: Isn't Vector planning to do mid air recovery of the first stage as it descends by parachute? That doesn't sound like it would add a lot of mass to the launcher.
Rocket Lab has stated that they have no plans to make Electron recoverable.
Quote from: IntoTheVoid on 01/22/2018 12:42 amQuoteLimited edition "I never want to hold again" tees available for pre-order now. 48 hours only. https://twitter.com/RocketLabWay to capitalize on a (probably) iconic moment.Quote from: RocketLabTranscript from Rocket Lab 'Still Testing' attempt"Flight VMS, mission coord...""Go ahead, VMS""Do you want any hold points?""Say again""Do you want any hold points?""I... didn't get'cha. One more time.""Do you want any hold points? As in, do you want to hold again at T-... 18, or 20?""I never want to hold again."I'd buy that shirt immediately if Rocketlab was shipping to Europe .
QuoteLimited edition "I never want to hold again" tees available for pre-order now. 48 hours only. https://twitter.com/RocketLabWay to capitalize on a (probably) iconic moment.Quote from: RocketLabTranscript from Rocket Lab 'Still Testing' attempt"Flight VMS, mission coord...""Go ahead, VMS""Do you want any hold points?""Say again""Do you want any hold points?""I... didn't get'cha. One more time.""Do you want any hold points? As in, do you want to hold again at T-... 18, or 20?""I never want to hold again."
Limited edition "I never want to hold again" tees available for pre-order now. 48 hours only.
Transcript from Rocket Lab 'Still Testing' attempt"Flight VMS, mission coord...""Go ahead, VMS""Do you want any hold points?""Say again""Do you want any hold points?""I... didn't get'cha. One more time.""Do you want any hold points? As in, do you want to hold again at T-... 18, or 20?""I never want to hold again."
RocketLab: We successfully tested a previously unannounced kick stage on the "Still Testing" Electron launch, using it to circularize the orbits of the two Spire Lemur-2 CubeSats on board.
Rocket Lab Reveals Secret Engine and "Kick Stage" for the Electron Rockethttp://www.popularmechanics.com/space/rockets/a15854376/rocket-lab-engine-kick-stage-electron-rocket/
Capacitors could do it, though they'd probably need to be big though and designed for high voltage.
The kick stage has avionics and RCS on board. I wonder if that is the guidance for the entire Electron vehicle, and if that is also the RCS used during second stage flight.
The kick stage has avionics and RCS on board. I wonder if that is the guidance for the entire Electron vehicle, and if that is also the RCS used during second stage flight. A mean trick Rocket Lab pulled there, I think, making us all think it was a successful launch while the actual flight with 2/3rds of the payloads continued for another 40 minutes. I wonder if they would have told us if a failure had occurred during that black-out phase.I wonder, too, how this kick stage affects the claimed performance (150 kg to a 500 km sun synchronous orbit). This flight only carried 13 kg of payload. Perhaps much of the payload capability was used up by having the kick stage on board. - Ed Kyle