A Helicopter Will Try To Catch a Rocket Booster In Midair (ieee.org) 104
An anonymous reader quotes a report from IEEE Spectrum: The longest journey begins with a single step, and that step gets expensive when you're in the space business. Take, for example, the Electron booster made by Rocket Lab, a company with two launch pads on the New Zealand coast and another awaiting use in Virginia. [...] If all goes well, its next flight, currently targeted for 22 April, will carry 34 commercial satellites -- and instead of being dropped in the Pacific, the spent first stage will be snared in midair by a helicopter as it descends by parachute. The helicopter will then fly it back to base, seared by the heat of reentry but inwardly intact, for possible refurbishment and reuse.
"It's a very complex thing to do," says Morgan Bailey of Rocket Lab. "You have to position the helicopter in exactly the right spot, you have to know exactly where the stage is going to be coming down, you have to be able to slow it enough," she says. "We've practiced and practiced all of the individual puzzle pieces, and now it's putting them together. It's not a foregone conclusion that the first capture attempt will be a success." Still, people in the space business will be watching, since Rocket Lab has established a niche for itself as a viable space company. This will be its 26th Electron launch. The company says it has launched 112 satellites so far, many of them so-called smallsats that are relatively inexpensive to fly. "Right now, there are two companies taking payloads to orbit: SpaceX and Rocket Lab," says Chad Anderson, CEO of Space Capital, a firm that funds space startups.
"It's a very complex thing to do," says Morgan Bailey of Rocket Lab. "You have to position the helicopter in exactly the right spot, you have to know exactly where the stage is going to be coming down, you have to be able to slow it enough," she says. "We've practiced and practiced all of the individual puzzle pieces, and now it's putting them together. It's not a foregone conclusion that the first capture attempt will be a success." Still, people in the space business will be watching, since Rocket Lab has established a niche for itself as a viable space company. This will be its 26th Electron launch. The company says it has launched 112 satellites so far, many of them so-called smallsats that are relatively inexpensive to fly. "Right now, there are two companies taking payloads to orbit: SpaceX and Rocket Lab," says Chad Anderson, CEO of Space Capital, a firm that funds space startups.
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SJWs aren't fine, upstanding people. They are mouth-frothing lunatics, but it seems you find that kind of thing appealing. Carry on.
OK, but (Score:5, Insightful)
I actually think SpaceX's approach is more robust and practical.
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Re: OK, but (Score:4, Informative)
Re: OK, but (Score:4, Insightful)
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Unfortunately, rockets are not spherical cows in frictionless vacuums. There are many things about rocketry that don't follow a simple linear progression with respect to payload mass.
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Re: OK, but (Score:5, Insightful)
Think of it this way: can you build a chemical rocket that can even get to orbit without any payload at all at any arbitrarily small size?
(Answer: no)
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Landing requires leaving propellant behind. The propellant left directly cuts into payload, With small rockets, there's very little payload mass to begin with, so leaving propellant behind means you don't have any payload.
Parachutes by contrast have the opposite problem: they're light and scale down well, but it's very difficult to make parachutes for large rockets that still function properly. SpaceX actually started out attempting parachute recovery rather than powered landing and it just simply failed. P
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hmm. while
f(1)=1
f(2)=1
f(3)=1
. . .
is indeed monotonous, I suspect a monotone function in which f(x+dx) > f(x) would be more useful . . .
And unless you can get *everything* in the design into dimensionless numbers, *and* stay in laminar flow, as well as a couple of lesser conditions, nothing about this will simply scale directly.
The effects of compressing air as it passes alone will destroy non-dimensionality . . .
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a claim which sounds dubious and improbable.
just for openers, as booster sized drops, winds and gusts become relatively larger and stronger as compared to the booster
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I'm not talking about "extreme" weather; normal wind is enough for this to be different, with the descent being through multiple layers of different weather.
If we only launched with no wind all the way up (and down), we probably wouldn't have finished the Mercury launches yet.
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The parachute is also "dead mass" in relation to the launch mass fraction.
I can't say if the parachute "dead mass" is eating more into the fuel budget than a propulsive landing would (remember that SpaceX had to quadruple the reserve of hydraulic fluid for landing operations, so another extra mass there).
The big advantage is that you can actually use all the fuel for propulsion in case of a "marginal" launch (with one or two broken engines out of 9), or you can launch more mass if you don't need to recover
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but a first stage for such a launcher can't be caught by any aircraft.
Why not?
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Re:OK, but (Score:4, Funny)
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Ok now that was funny right there!
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Yeah, but they caught them only once. :P
The plan is to make that repeatable
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When someone announces plans for a vertical landing booster, people immediately say “they are copying SpaceX”.
When someone tries something different, people immediately say “SpaceX has a better approach”.
When someone launches a disposable booster, people immediately say they are out of date.
Cant win. Really cant win.
Re: OK, but (Score:3)
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They are all victims. Oppressed by SpaceX. It is impossible for them to succeed and become popular.
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I don't think anyone here would accuse me of not being a SpaceX fan. So does that mean that I'm not a Rocketlab fan? Hardly - I even invested in them when they went public.
Stereotyping people does no good. Let Alan have his viewpoint.
(And for what it matters: Rocketlab's approach is right for *its* context. Not most contexts, but for vehicles similar to theirs, it's a much better choice than propulsive).
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You're hand-waving. It doesn't change the fact that catching a rocket with a helicopter puts a human and an aircraft at risk unnecessarily because of an inferior solution to reuse.
SpaceX does have a better approach. A far, far better approach.
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It gives helicopter pilots an exciting new specialty to shoot for, plus I'm sure the line, "I snatch falling rocket boosters out of the sky for a living, what do you do?" would go over better than the normal "I'm an executive chauffeur."
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I'm sure they've found pilots excited about the opportunity, but that doesn't mean it's a good idea or that it makes sense.
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You should see some of the pilots that fly for magazine photo shoots with offshore performance boats.
They would fly 150+ MPH backwards and go under bridges right above the deck of the boat. If the bridge was too low, they'd go over it at the last second, and be right back down on the other side.
They would circle around you, always keeping the camera people pointed at the boat, spinning around rapidly.
It's nerve wracking trying to drive the boat when they're that close, but you can see the pilot, and he's h
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I didn't see anywhere in the article that said the helicopter would be flown by a human.
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You must not have watched the video someone posted earlier. The catching helicopter approaches the gliding chute from behind and above, and hooks it with a tether. Given that this happens at altitude, it's probably safer than any maneuver where a helicopter is used to pick something up off the ground with a tether, and people do that all the time. This is not some new dangerous stunt despite the headline writers' attempt to make it look like one.
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Given that this happens at altitude, it's probably safer than any maneuver where a helicopter is used to pick something up off the ground with a tether, and people do that all the time.
Helicopter crashes happen when just flying around, let alone carrying a load.
This is not some new dangerous stunt despite the headline writers' attempt to make it look like one.
No, it's a typically dangerous stunt. It's only necessary because of inherently inferior technology.
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As others have pointed out, in the context of these rockets, this is the cheaper and better approach.
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I find it absolutely fascinating that you don't see the propulsive descent of a rocket over land as less safe than catching a rocket over water.
It doesn't have to be over land, though apparently it's reliable enough for that now. If this approach is so safe, why not do it over land? If they're doing it only for testing, like SpaceX was, then it's deliberate hand waving on your part and that comparison makes no sense. If they plan to keep doing it over water, then even they clearly think it's not as safe.
As others have pointed out, in the context of these rockets, this is the cheaper and better approach.
That's assuming these rockets make sense in the first place.
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It doesn't have to be over land, though apparently it's reliable enough for that now.
SpaceX's landing reliability is around 91%. If the probability of a successful helicopter flight were 91%, we'd ground the things forever.
If this approach is so safe, why not do it over land?
Orbit insertion probably doesn't call for it. Alternatively, because if you fail to catch the damn thing, the rocket falls onto hard earth.
If they're doing it only for testing, like SpaceX was, then it's deliberate hand waving on your part and that comparison makes no sense.
This is nonsensical. They're doing it for testing because the alternative is retrieving it from the sea, which is expensive. This is cheaper.
It's not for testing for eventual self-landing, the rocket is too small. This is not a Falcon
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When someone announces plans for a vertical landing booster, people immediately say “they are copying SpaceX”.
When someone tries something different, people immediately say “SpaceX has a better approach”.
I think Relativity Space [relativityspace.com]has the most scalable approach going with 3D metal printed rockets. I am a fan of SpaceX however it's pretty clear to me that once R.S irons out their production process they have a big chance of outpacing SpaceX.
R.S's big technological advancement is their algorithms that calculate what the heat warping of a large 3D printed metal object is so they can compensate for it in the print to produce something that looks like a rocket.
Initially their rockets are heavier and less smoot
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Also - forgot to mention, R.S is fueling their rockets with LNG, liquid natural gas, so I think that reduces complexities in terms of temperature variations, the need for additional insulation in keeping the fuel in the correct temperature range whilst having a more available, cheaper fuel source.
IIRC with hydrogen fuels the air freezes on the rocket and as it melts and combines with insulation it becomes explosive as it returns to gas - so that is something RS are avoiding with their fuel choice as a p
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Cool - pun intended :)
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R.S. is absurd. "Hey, let's use the slowest and most expensive production technology on Earth, and still somehow end up with rockets that are heavier and draggier than normal!"
If there's anything that should be made out of sheet metal (or arguably composite overwraps in some cases), it's rocket bodies. Go on and 3d print engine parts, by all means, but 3d printing *rockets* is an absurd idea - an exemplar case of "when you have a hammer, everything looks like a nail".
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R.S. is absurd. "Hey, let's use the slowest and most expensive production technology on Earth, and still somehow end up with rockets that are heavier and draggier than normal!"
I think that is the next step in their process and it is a consequence of their prototype, it is something they are refining.
If there's anything that should be made out of sheet metal (or arguably composite overwraps in some cases), it's rocket bodies. Go on and 3d print engine parts, by all means, but 3d printing *rockets* is an absurd idea - an exemplar case of "when you have a hammer, everything looks like a nail".
Maybe, who knows what innovations will come out of it.
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I'll believe that when they start spitting out rockets as quickly as SpaceX is spitting out Starship prototypes.
Re: OK, but (Score:2)
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Actually, I disagree. I'm gobsmacked that this idea wasn't implemented sooner.
There's no critical research needed in rocket control, automated maneuver controls, wind calculations for a precise landing location, etc.
All a booster would need is a drogue package which is released at a set time after apogee. All the trajectories are ballistic; you just need a cargo helicopter that can do the equivalent of a Fulton Skyhook (STARS). Even if you used an airplane to do it, you could easily arrange a dump spot,
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Not many fresh water lakes around New Zealand.
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Yeh right.
https://nzpocketguide.com/new-... [nzpocketguide.com]
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The launch is on an eastward trajectory from Mahia Launch Complex.
Not many fresh water lakes eastward of New Zealand...
If they do polar launches then the launch trajectory is either southward or northward, with a small component westward. In any way, the launch trajectory avoids inhabited places.
SpaceX is not launching from Florida (the classical launch place for the USA missions, Apollo, Space Shuttle, ...). Even so, they have the Gulf of Mexico eastward of their launch platforms.
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SpaceX is not launching from Florida
Fascinating. I've watched 2 SpaceX launches at Cape Canaveral, now.
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I actually think SpaceX's approach is more robust and practical.
It depends on the scale. SpaceX originally tried parachutes, but it turns out that Falcon 9 was too big, and propulsive landing (as used in the 1960s) was better for it.
Rocket Labs' planned Neutron rocket, which is an evolution of Falcon 9, also uses propulsive landing. But Electron is much smaller, so different economics.
Re:OK, but (Score:4, Insightful)
I actually think SpaceX's approach is more robust and practical.
No. SpaceX's approach is simply proven. There's nothing robust or practical about it. Relanding the boosters requires quite a lot of additional equipment, guidance systems, the same level of prediction as catching them, and extra fuel too (yeah the helicopter requires fuel, but so does the drone boat).
The only thing good about it is that this complex, expensive and impractical approach is not as expensive as actually making a new booster each time. That doesn't mean there aren't other ways to do this.
Re: Not gonna work (Score:3)
Re: Not gonna work (Score:4, Interesting)
My first guess at how things could go wrong would be that the helicopter pilot will 'miss' the parachute and not have time for a second attempt, allowing the rocket to drop into the ocean.
My second guess is that the helicopter could get tangled up in the parachute or somehow otherwise compromised by its attachment to the rocket, resulting in loss of control of the helicopter and a crash of both the helicopter and the rocket.
But then again, I never expected any of those powered Mars landings to work either, so I'm probably overly pessimistic.
Re: Not gonna work (Score:4, Informative)
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Agreed. Most people don't think about a square, ram-air parachute. The chute causes the booster to glide in a forward descent trailing a long tether with a small drogue chute. The helicopter is capturing this long tether which it then uses to carry the booster back to the recovery location.
Totally gonna work! (Score:2)
That Hans Zimmer-esqe movie music sells it for me!
That must be a relatively light rocket booster though.
Re: Totally gonna work! (Score:2)
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Interesting that the pilot is just sticking his heat out the side to look down. I'd have thought they would have used a camera. Maybe in the production version.
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Yeah post that anonymously so there's no cost for being wrong and spreading negativity.
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The Soviets were catching reentering capsules since the 1960s, it's not rocket science. Oh, wait . . .
But this one weird trick... just use a boat? (Score:1, Interesting)
Helicopter capture is an unnecessary marketing stunt bullshit. Here's why.
If you think that you can place a helicopter within a reasonable position to catch parachuting space debris mid-return, would that not also suggest that you could place a boat within a reasonable proximity? Why not let the booster splash down and capture it with a boat instead? Boats can idle practically for free, compared to the hourly fuel burn of a helicopter. You're already putting a parachute on the vehicle to make it slow enough
Re: But this one weird trick... just use a boat? (Score:4, Insightful)
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Eventually, they will use an autonomous helicopter or drone, not human-piloted.
Re: But this one weird trick... just use a boat? (Score:3)
The ram-air parachute has a very low descent rate, and the helicopter flies far away from its turbulence, which is behind rather than above the fabric.
And helicopters only cost a lot when buying and flying them, rather than all the time.
Re: But this one weird trick... just use a boat? (Score:2)
Interesting video. (Score:1)
Thanks for the video, interesting to see how that is done - does seem quite safe, the capture lines are all well away from the helicopter and the whole system seems to work pretty well. Will be interesting to see how that fares with a real-life capture.
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Well, it works, at least during drop practice: https://youtu.be/HOnNYWu6onU [youtu.be] [youtu.be]
Wow, that's pretty cool
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Oh wow. Sorry, I wasn't aware that the super chief marketing officer already crunched the numbers on this.
So since they're forgoing the boat(s), how do they plan to get their helicopters far enough out to sea to capture debris from a reentry plan with a sufficiently large error window? It's not like they're gonna be catching boosters just outside the swimming area off the coasts.
If only they could launch a helicopter off a boat -- then they could idle about practically for free until they were ready to exec
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Re: But this one weird trick... just use a boat? (Score:2)
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Yeah, I am sure the salt-water will have a cleansing effect on all the rocket engine parts.
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how is that chute not sufficient to prevent significant damage if it comes in contact with the water?
How is *any* chute sufficient to prevent the contact of hot metal with salt water?
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Re:But this one weird trick... just use a boat? (Score:4, Interesting)
I'm not saying that a drone ship (barge, whatever) doesn't have large advantages. ... The barge and towboat need to be away for at least two days, more probably 3. Also, towboats don't have much space for anything other than its crew so you might need a second ship for the "away" team.
However, the landing of the first stage is some 600km eastward.
With a helicopter, you fly three hours to there, you recover the stage and fly three hours back. Total cost: preparation, money for eventual delayed launches and 7 hours of flight time.
Meanwhile, you basically need to own the barge and ensure towing (with a towboat, a remote team to secure the booster after landing),
So, a drone ship also costs you a lot. Whether it is cheaper is unclear, but - at least as a showpiece - catching the first stage from air by helicopter beats even unsuccessful recoveries on droneships (barges).
What about carrying a giant inflatable raft? (Score:1)
Helicopter flies very close to the expected impact point on sea or land, and carries under it a giant capsule with an inflatable platform.
Can be fired a short distance and steered somewhat to land precisely in the right spot. Hyper-Kevlar reinforced yadayada.
Fake news! Fake news! (Score:2)
The proper way to catch a returning sub-orbital booster is with rms' testicles.
Possible extension to this idea (Score:2)
If this works, why don't we try catching incoming menacing asteroids with a large, large helicopter?
Maybe if we ask Bruce Willis to pilot? Could work?
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We'd have to attach a big-ass parachute to it first.
they used to do that with spy satellites... (Score:1)
we didn't always have jpeg or whatever nasa uses. they used to have to dump the film from orbit and catch that midair too....
Done in the 50's with aircraft (Score:5, Informative)
This will never be as cool (Score:2)
as the dual SpaceX landing. That was sci-fi come to life.
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That, and someone driving by me on a self-balancing one wheel, while another person ran a big remote-controlled lawnmower nearby.
Nothing new (Score:2)
The Russians are doing this almost every day in the Ukraine.