Can Spinlaunch Throw Rockets Into Space?
Why Hacker News recommends it
HN treats it as the more informed, balanced take on SpinLaunch's tradeoffs.
What it is
Scott Manley looks at SpinLaunch, which aims to throw launch vehicles out of a spinning launcher at hypersonic speed. He covers its recent Mach 1 test of a one-third scale launcher and the engineering problems that remain.
Recommended by 2 HN commenters across 2 different months, 2021 to 2022.
What Hacker News said
Strong rec Robotbeat · 2021-12 · on “Scientists find a way to ‘catapult’ rockets into space like ‘slingshots’”
Man, I have my opinions on Spinlaunch, too, but I find thunderf*t’s videos (especially the BUSTED ones) unenlightening & unhelpful to rationally discussing the pros and cons of some technology. Scott Manley’s video (if video is the format you prefer) on Spinlaunch was much better. Scott Manley also has a much better understanding of rockets and space technology than thunderf*t. [this video]
Recommends dotnet00 · 2022-04 · on “NASA will test SpinLaunch's ability to fling satellites into orbit”
I think their basic idea is sound, it'll probably eventually function. My concerns are if it'll be worth it, since there's a trade-off being made between fuel mass and heat shield mass, and at least based on Scott Manley's summary video this week, the rocket with the heat shield is close to the same mass as the Electron rocket. In which case I'm not sure the complexity of SpinLaunch is worth it. Edit: the video in question: [LINK] and a more honest and detailed look at the company, again from Scott: [this video]
Cites andreareina · 2021-11 · on “Spinlaunch completes suborbital launch without engine”
Per Scott Manley[1] release velocity was Mach 1, they're targeting Mach ~7 for the final version. [1] [this video]
Cites yholio · 2021-11 · on “SpinLaunch completes first test flight with rocket-flinging launch system”
I believe the parent is right, you couldn't hide it. Even if you succeed in building them completely stealthy, it's just a matter of time until the enemy finds out the locations using espionage or signals intelligence, and after that they will place the site unde non-stop satellite surveillance. They are massive and can't be moved, so they are sitting ducks. As for launching, you are guaranteed to produce a thermal signature in the first few seconds of flight, since you hit the high density atmosphere at a 3-5 Km/s speed. You will leave a distinct, large and highly detectable infrared signature and the enemy will be alerted: [this video]
Cites l33tman · 2022-02 · on “New material that can absorb and release enormous amounts of energy”
A full tank is safer than an almost empty tank.. Also the tank is designed to keep the vapor part of the gasoline too saturated to explode, this is why there is a latch on the fill tube. I found this Quora post: [LINK] And even if it can explode in the situation where there's almost no fuel left, in that case it's not as bad as liberating the full energy of a full tank, which is what you'd do if you have a flywheel spinning with the same total energy as a full tank of gasoline. That would be madness. Heh I came to think of the recent demo of the company that wants to spin up satellites on earth and THROW them into orbit. If something goes wrong in that spin-up, they would destroy the entire
Cites LeifCarrotson · 2022-04 · on “NASA will test SpinLaunch's ability to fling satellites into orbit”
Scott Manley also put out a video on Spinlaunch: [this video] He...encourages caution. It's one thing to call a technology "debunked", another to say it's very difficult or that it has a low probability of success.