Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

SpaceX successfully catches both fairing for the first time

engadget.com

Post reply on HN
Print view View original

41–50 of 57 posts

Re: SpaceX successfully catches both fairing for the first time

#41

Post by wittyusername »

exabrial wrote: post #40

Dumb question I'm sure has been asked... we've been throwing stuff into the sea for awhile then going and picking it up later as it's bobbing gently in the waves. Why not just have some inflatable buoys that deploy in the water and have it float? Catching it seems pretty difficult, albeit pretty sweet.

I think the salt water even for brief periods even surrounded and raised up a few feet by bouys is a corrosive disaster. Maybe reusable a few times but not the long term solution if they want to reuse them 10's / 100's of times.

Re: SpaceX successfully catches both fairing for the first time

#42

Post by 2trill2spill »

exabrial wrote: post #40

Dumb question I'm sure has been asked... we've been throwing stuff into the sea for awhile then going and picking it up later as it's bobbing gently in the waves. Why not just have some inflatable buoys that deploy in the water and have it float? Catching it seems pretty difficult, albeit pretty sweet.

My guess would be to avoid the salt water. NASA had to make significant changes to the Solid Rocket Boosters because they landed in the water[1].

[1]: https://llis.nasa.gov/lesson/836

Re: SpaceX successfully catches both fairing for the first time

#43

Post by Robotbeat »

exabrial wrote: post #40

Dumb question I'm sure has been asked... we've been throwing stuff into the sea for awhile then going and picking it up later as it's bobbing gently in the waves. Why not just have some inflatable buoys that deploy in the water and have it float? Catching it seems pretty difficult, albeit pretty sweet.

First: saltwater damage. Ever tried to run a car or a laptop or an airplane after it was dunked in saltwater? Hardening for saltwater immersion isn’t always practical and will always add some weight.

Second: They already do float. They recover them quickly (& sometimes reuse them) if they miss the catch. But the fairing halves are 800km down range. You need to have a boat nearby anyway, so might as well try to catch it before it lands in saltwater and screws it up.

Re: SpaceX successfully catches both fairing for the first time

#44

Post by SEJeff »

gt565k wrote: post #37

"Elon Musk, SpaceX’s founder and CEO, told reporters last year that the fairing costs around $6 million." Pretty good if they can recover them and refurbish them. Could save a few million dollars per launch, even more if they can be re-used more than once.

FWIW, this isn't the first time they've caught the fairings, it is the first time they've caught both of them.

They've actually reflown 4 fairings now however a few of them they fished out of the ocean and had to do further inspections and refurbishing due to salt water corrosion.

Go to https://www.spacexstats.xyz/#reuse-fairings for some more info.

Re: SpaceX successfully catches both fairing for the first time

#45

Post by SEJeff »

JshWright wrote: post #38
gt565k wrote: post #37

"Elon Musk, SpaceX’s founder and CEO, told reporters last year that the fairing costs around $6 million." Pretty good if they can recover them and refurbish them. Could save a few million dollars per launch, even more if they can be re-used more than once.

Perhaps even more importantly, they are a big bottleneck on their flight rate. They require a massive autoclave (for curing the composites), and it wouldn't be practical to scale up their production significantly. Even if it didn't save them a penny, my guess is it would still be a priority.

^ This.

The second stage (which is not reused on a Falcon 9), the fairings, and the grid fins are three of the longer lead time items for the Falcon series rockets. Reusing as much as possible helps keep their crazy launch cadence up.

Re: SpaceX successfully catches both fairing for the first time

#46

Post by mabbo »

exabrial wrote: post #40

Dumb question I'm sure has been asked... we've been throwing stuff into the sea for awhile then going and picking it up later as it's bobbing gently in the waves. Why not just have some inflatable buoys that deploy in the water and have it float? Catching it seems pretty difficult, albeit pretty sweet.

(Copy-pasting my own reply to a similar question below)

Salt water is the worst. It takes a lot of effort to clean it all off and it causes corrosion all the while. Even the ones that do hit water, they get them out as fast as they safely can.

As far as I know (correct me if I'm wrong), SpaceX have only reused previously-wet fairings on their own Starlink launches. They don't risk potentially damaged parts on external customers.

Re: SpaceX successfully catches both fairing for the first time

#47

Post by ogre_codes »

exabrial wrote: post #40

Dumb question I'm sure has been asked... we've been throwing stuff into the sea for awhile then going and picking it up later as it's bobbing gently in the waves. Why not just have some inflatable buoys that deploy in the water and have it float? Catching it seems pretty difficult, albeit pretty sweet.

By catching the farings, SpaceX pockets $6m per launch. If they catch them, they can reuse them 5+ times. If they get dumped in the ocean, they might be able to use them a second time, but the salt water degrades them so more than a couple launches is unlikely. So each time a faring hits the water, it costs SpaceX $500,000 – $1 million dollars or more. At 22 launches per year, that adds up in a hurry.

Re: SpaceX successfully catches both fairing for the first time

#48

Post by blackrock »

wittyusername wrote: post #41
exabrial wrote: post #40

Dumb question I'm sure has been asked... we've been throwing stuff into the sea for awhile then going and picking it up later as it's bobbing gently in the waves. Why not just have some inflatable buoys that deploy in the water and have it float? Catching it seems pretty difficult, albeit pretty sweet.

I think the salt water even for brief periods even surrounded and raised up a few feet by bouys is a corrosive disaster. Maybe reusable a few times but not the long term solution if they want to reuse them 10's / 100's of times.

Perhaps their next move is to build another machine to spray some kind of rubber sealant foam on it, immediately after they capture it, in order to minimize and prevent the spray of ocean water and air, on the surface of the fairings.

Then, when it returns to land, someone can peel off the rubber sealant, do some quick quality control inspections, and authorize the fairing to be reused on its next launch.

Re: SpaceX successfully catches both fairing for the first time

#50

Post by NortySpock »

praveen9920 wrote: post #49

Did they ever try catching it mid air? Something like a hook to helicopter perhaps? $6 mil is big number not to try.

Depending on the launch trajectory, these fairings come down between 40 km and 1400km offshore. So you either need a helicopter with incredible range and dwell time, or a boat with a helicopter pad AND a place to put the fairing if you catch it.

Say you catch the fairing. Great, now you have a giant composite/plastic sail, the size of school bus, bouncing around in your rotor downdraft. Not exactly the safest thing, and you're over water so you can't just put down anywhere.

So, it's complicated, and SpaceX decided to go with a boat rather than a helicopter-and-a-boat.

https://www.teslarati.com/spacex-mr-steven-renamed-falcon-he...

https://www.theverge.com/2020/4/8/21213917/rocket-lab-rocket...

Rocketlab first stage catch demo; they've got a heavy stage to catch (with heavy engines at the bottom to act as a counterweight) and it's not nearly as big as the Falcon 9 booster. https://www.youtube.com/watch?v=N3CWGDhkmbs&feature=emb_titl...

Post reply on HN