Scott Manley
2 HN recommenders · recommended in 4 months, 2021–2022
11:08 · 3.2M views · Nov 10, 2021
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.
HN treats it as the more informed, balanced take on SpinLaunch's tradeoffs.
6 comments from Hacker News
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
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
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 launch facility and whatever is in the way. this video I once had a CDROM open while the CD was spinning at like 40x or so, it ejected and went into the plaster wall. And that was just a CD..
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
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.