Rocket Lab wants to dry off and reuse Electron booster recovered from the ocean

Rocket Lab has successfully launched seven satellites into space and recovered the booster for its Electron rocket from the Pacific Ocean. After a few days of bad weather, the 18m launch vehicle finally lifted off from Launch Complex 1 in Māhia, New Zealand, at 13:27 NZST on July 17 (01:27 UTC, July 18). The mission, named …

[heyrick]

Probably just as well

I mean, catching a bit of a rocket with a helicopter sounds like something out of Mission Impossible (heh, and bloody Tom Cruise would probably pull it off too), but in reality it just seemed like a massive risk that, well, was it even necessary? Or was this just Rule of Cool because they wanted to stand out from under SpaceX's shadow?

[Flocke Kroes]

Re: Probably just as well

Spy satellites used to return film to Earth that was slowed by a parachute and caught by a helicopter. Electron rockets are heavier than a film capsule (but far lighter than a Saturn V booster). One was caught but dropped because it was swinging beyond the safe range. Perhaps with practice Electrons could be recovered by helicopter but early failures gave Rocket Lab experience of what gets damaged by a dunk in the ocean. They have reused components already and modified the first stage to better withstand sea water. Apparently those modifications and a boat are cheaper than a helicopter - especially if you have a boat in place anyway for if the catch fails.

Catching (part of) a larger rocket with a helicopter might still happen. ULA published their smart reuse plan years ago. At the time everyone thought it was about as likely as catching a Saturn V. Later, ULA got a contract for 38 Kuiper launches with Vulcan. Back then Blue Origin had not delivered any BE-4 engines to ULA and each Vulcan requires 2. Last I heard, BO might be able to deliver 2 engines per quarter. That would be over 9 years just for Kuiper and ULA has other customers. Blue Origin want to put 7 BE-4 engines on their reusable New Glenn rocket. I am sure there is a promise to increase the rate of production but the obvious shortage of engines caused ULA to dust off there smart reuse power point and see if the numbers add up. If this happens at all, it will be years away. Very unlikely, probably not worth the R&D money but not technically insane.

[Lee D]

Re: Probably just as well

Or they could just, you know, make something that's explicitly designed to land and launch again.

(And, no, I'm not referring to SpaceX because landing "upright" is a dumb idea that cost them lots of money during testing and offers zero advantage and burns even more fuel in Earth's atmosphere. Make the damn thing able to GLIDE BACK DOWN in a controlled manner rather than just sever it and make it plummet into the ocean at random places. Yes, it'll cost more. But then it'll be properly reusable without stupendous risk in the landing zones, and it won't have to be checked over constantly because it's made of metal and has been swimming in a saltwater ocean... All this fancy rocket, computer and drone tech and we can't make a fuel-empty rocket turn into a small glider for the journey back down).

[Anonymous Coward]

Re: Probably just as well

I'm not referring to SpaceX because landing "upright" is a dumb idea that cost them lots of money during testing and offers zero advantage and burns even more fuel in Earth's atmosphere

Great minds think alike - I agree, the upright landing trick requires quite a lot of extra payload to pull off. That said, there is an open question of how much damage is sustained by plunking a hot rocket into a cold bath of corrosive fluid (seawater is not a friendly liquid) as opposed to landing and being allowed to cool down at a more leasurely pace. Anyone?

[John Robson]

Re: Probably just as well

The landing upright "trick" also means that you don't need a secondary set of engines, or a structure designed to take static and shock loadings across the vehicle.

It's not nearly as dumb idea as you might imagine.

[fpx]

Re: Probably just as well

How hard would it be to stick some small wings and wheels on the rocket, and have it come gliding down, Space Shuttle style? No fuel needed.

It would not have to be a very soft landing, since there's no people onboard, and the structure can withstand quite a few G's.

[that one in the corner]

Re: Probably just as well

> and the structure can withstand quite a few G's

Along the long axis and whilst its tank(s) are pressurised (IIRC some of the non-reusables are/were described as tin foil, unable to hold their own weight upright with empty tanks - reusables won't be any stronger/heavier than they need to be).

Unless you are imagining some really weird gliding, the stresses are going to be in all the other directions, requiring more strengthening. Especially if you are going to experience those Gs landing (and the landing gear will be rolling, presumably, so - big tyres, wheels? getting heavier).

[FeepingCreature]

Re: Probably just as well

Gliding hardware has weight as well, and it still lands you in the corrosive saltwater unless you go full Space Shuttle - which is even heavier. I could easily see SpaceX's approach being better in terms of payload mass.

Keep in mind that when landing, the booster basically only has to hold the weight of its engines. Without the second stage and almost all of its fuel, it has a small fraction of its launch mass. That's why they go down to one out of nine engines firing for landing - and that one can't even throttle down low enough to hover.

[John Robson]

Re: Probably just as well

They do glide, but the glide angle is rather steep.

You want to add wings, and enough structure to maintain the integrity of the vehicle in a transverse direction to the loadings actually required for flight, and landing gear, brakes and who knows what else that I haven't thought of in ten seconds...

Have you calculated the likely mass required there and compared that with the relatively small propellant mass needed?

[Pascal Monett]

Re: Probably just as well

I remember being skeptical back when El Reg first described these aerobatics, and getting the downvotes as well.

It would seem that the downvoters refuse to admit that it's a hair-brained idea best left to the drawing board.

Yes, I know they used to recover film from spy satellites like that, but a roll of film dangling from a parachute is a far cry from a first stage rocket booster.

And now, Rocket Lab has officially ended the practice. They tried and they stopped trying after seven failures. That should be enough to take a step back and reevaluate the situation, no ?

[Anonymous Coward]

Re: Probably just as well

.. which is exactly what they did?

PBC?*

* _{Posted before coffee?}

[John Robson]

Re: Probably just as well

Marine systems (barges, tugs etc) are famously expensive, and catching things with a chopper has quite a long history in spaceflight.

It's not unreasonably to try and avoid having clean out the saltwater, which is generally not good for things.

[TM™]

I wonder what the maths of a single orbit ballistic trajectory looks like. One where you almost make it into orbit but (mostly) glide back down to the takeoff point.

P.S. See Dawn Aerospace for a space glider project (also New Zealand).

[John Brown (no body)]

BRING BACK HOTOL :-)

I wonder what Reaction Engines are up to these days? Where would they be now if they had the resources of a SpaceX or Blue Origin?

[John Robson]

It looks almost identical to a single stage to orbit vehicle - that is it looks generally rubbish.

Dropping ~100 tons (Falcon 9) of engines/tanks makes a *huge* difference to the performance of the upper stage.

[Jan 0]

Baby Come Back!

Is that a not very obscure way to say "Equals (Elon)"?

Top of the Pops, 1968: https://www.youtube.com/watch?v=5AcigKiu_Gk