Silent_Sky

I'm so proud to be punching the same planets Elon Musk is landing on.

Yes, the engines used are quite old. However, they use something called a closed-cycle fuel pump. This gives the engine a crazy high specific impulse (thrust per unit of fuel consumed) and makes them extremely efficient first stage engines. This is technology that other countries have not bothered to use in their engines. Not to mention the cost of developing a new rocket engine when Russia has dozens just lying in a warehouse. They have a very high success rate in modern launches, so while they're old hardware, they're still excellent engines.

Hey Andromeda!

Back in college when I first learned how radio telescopes work, I've had a thought in the back of my head you might be able to address.

Let's assume we have plenty of funding and the tech to establish a long term lunar base. Would it be useful for us to clear out (remove boulders and debris) a properly shaped crater on the lunar far side and adapt it for use as a radio telescope, a lá Arecibo? I realize it wouldn't be able to change direction (unless moving the subreflector gives you some wiggle room) but even so, would such a thing be useful for radio astronomy?

It'd be difficult, but we'd end up with a colossal telescope bigger than anything we can build that would be insulated from earth's radio chatter by thousands of miles of rock. Is such a project even worth the effort? This is something I've always wondered. Thanks for doing the AMA!

It's something like 92-95%. Gimme a minute or two to look that up and I'll edit this comment with the actual figure.

Edit: That number was from the success rate of Russian launches. Turns out it's hard to find such a number for just engines, and wouldn't be useful anyway, as the vehicles they're used on vary greatly. Nevertheless, these engines wouldn't have been approved for flight if they didn't meet all qualifications. However, spaceflight is a very tricky business. No matter how good your hardware is, there are always going to be unexpected failures.

For those who don't know, when a piece of space hardware is man rated, that means that engineers are confident enough in the functioning of the machine in question to entrust the lives of one or more astronauts to it.