from the long-long-time-'till-touchdown-brings-me-round-again dept.
Rocket Lab launches smallsats, catches but drops booster - SpaceNews:
Rocket Lab declared success in its effort to catch an Electron booster in midair after launch May 2, even though the helicopter had to release the booster moments later.
The Electron rocket lifted off from the company's Launch Complex 1 in New Zealand at 6:49 p.m. Eastern after a brief hold in the countdown. The rocket's ascent went as planned, with the kick stage, carrying a payload of 34 smallsats, reaching orbit about 10 minutes later.
[...] The company billed the midair capture as the final step in its efforts to reuse the stage. A successful midair recovery could allow the company to fly the stage again later this year, enabling the company to increase its flight rate without manufacturing more boosters.
About 15 minutes after launch, the descending booster came into view of Rocket Lab's Sikorsky S-92 helicopter. Video from the helicopter appeared to show the hook grappling the parachute to cheers from mission control. Moments later, though, there were groans and the webcast cut away, suggesting that perhaps the helicopter lost the booster.
More than a half-hour later, Rocket Lab confirmed that the helicopter had grappled, but then released, the booster. "After the catch, the helicopter pilot noticed different load characteristics than what we've experienced in testing," company spokesperson Murielle Baker said on the webcast. "At his discretion, the pilot offloaded the stage for a successful splashdown" for recovery by a boat, like on the three previous recovery attempts.
Despite the release, she called the catch "a monumental step forward in our program to make Electron a reusable launch vehicle." It was not clear when Rocket Lab would next attempt a midair booster recovery.
Rocket Lab launch webcast (booster capture about 50 minutes in)
(Score: 5, Interesting) by gznork26 on Wednesday May 04 2022, @11:35PM (1 child)
Back around '80, I had a software contract job at MacDonnell-Douglas, which was involved in a competition to design one of the cruise missile variants. At the end of a test, the cruise released a parachute, and it would be snagged by a 'copter so it could be examined as part of the testing process. Anyway, there was one instance in which a gust of wind snatched the 'chute away from the 'copter and it landed in the desert, where it got banged up.
I imagine they have much better info about the winds in the retrieval area now. The booster is also heavier than a cruise, and current copters are probably better at station-keeping, but I do wonder how much leeway there is for cross-winds during recovery.
(Score: 2) by JoeMerchant on Thursday May 05 2022, @01:27PM
As I have gathered from this and that source, the pilot had a hook in it, then felt a whole lot of "nope" from the dynamic loads which were apparently NOT like what he had experienced in simulation testing.
The Sikorsky S-92 maybe isn't the most capable helicopter for the job (the H92 and a tank like a CH-47 come immediately to mind as options), but the S-92 almost certainly good enough. The whole thing is a game of differential costs - a more costly helicopter might have a marginally better success rate, but is that margin enough to justify the reduced cost of rework on the boosters for air-capture vs splashdown and ship recovery? Also, it may be more a question of technique than raw vehicle capability, and technique can improve dramatically with practice. Not that the pilot is "green" here, they did simulations, I'd guess it was more the simulations that weren't quite up to real-world levels than anything.
If they can get to near 100% confidence in the helicopter system, dropping the surface ship recovery operations should be a big cost savings.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 0) by Anonymous Coward on Thursday May 05 2022, @03:59AM (4 children)
They failed, just like everyone thought they would.
(Score: 5, Insightful) by janrinok on Thursday May 05 2022, @06:33AM (3 children)
I disagree. They achieved what they set out to do. They successfully captured the booster.
However, when they did so they discovered that the booster did not behave as aspected. So was it still carrying some dangerous fuel? Were there other factors that had not been accounted for? As a pilot you are responsible for the safety of the aircraft and any other persons on board. He could have chosen to try to be the hero and risk his own life and the lives of his crew, the aircraft and perhaps also endanger the lives of others on the ship waiting to receive the booster. He could have have done that - but it seems he was smart enough to realise that it wasn't worth it. He took the sensible option and released the successfully captured booster. If it hadn't been successfully captured he could not have done that and we would have been none the wiser about other useful data that we have learned.
The aim was to successfully capture the booster using a helicopter. They did that.
All emphasis mine.
Are you the kind of guy that, when your vehicle brakes fail, you would simply carry on regardless because you don't actually need the brakes until sometime later, and you will worry about that problem then? Intelligent people would address the problem immediately.
(Score: 2) by Runaway1956 on Thursday May 05 2022, @10:41AM
I was one who sat on the edge of his seat, watching Musk crash one rocket after another. Ooops, he failed. Failed again. Failed again. Ooooh! Nailed it! Then it blew up, which made it another failure.
And, with every failure, more telemetry was collected, people did their figuring, the computers did their number crunching, until finally, the rockets landed, cooled off, were overhauled, and reused.
I'm less enthused about catching rockets with helicopters, so it would be much easier to write the thing off as a failure. But, again, they collected telemetry, and they are learning from the failure.
It's all good, I guess.
Abortion is the number one killed of children in the United States.
(Score: 2) by JoeMerchant on Thursday May 05 2022, @01:59PM
Well, I'm that guy who drove 15 miles across town, had a hydraulic line blowout and drove the 15 miles back across town using the cable actuated backup brakes - very carefully - to deliver the vehicle immediately and directly to my preferred repair shop instead of calling for a tow and spending an additional 4 to 6 hours dealing with the same problem in a more "better safe than sorry" (aka better somebody else's responsibility than my own) manner. Yes, safely driving a 5000 lb truck 15 miles through the city on e-brakes only is challenging, but far from impossible.
And, as pilot in charge of a vehicle with unusually challenging dynamics, I would absolutely make the safer call whenever a questionable situation presented. In the truck with feeble brakes, driving more slowly (within the brakes' capabilities) is the safer call, in that helicopter dropping the load was the option. Anybody who wasn't in that cockpit with hands on the controls isn't in a position to second-guess the call.
The mission parameters included "drop if unsafe" and that was successfully executed.
However, it certainly would have been a bigger success if the booster was softly touched down on land instead.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by requerdanos on Thursday May 05 2022, @08:20PM
I respectfully disagree, in that I would assert that a successful booster capture involves keeping the booster, not throwing it immediately into the water.
Calling a fumbled catch "successful" may be popular for fishermen (you should have seen the one that got away!) but I think isn't a great description here.
Sure, they didn't miss it, but they didn't capture it, either.