Wow thank you! I’ve just sat down at home and hadn’t checked yet, now I’m excited again.

The problem with space being cold is that it’s also empty. You know how a windy day at 40 degrees out feels much colder than when it’s 20 degrees out but with no wind? Take that to its logical extreme. Things do cool down in space, but not by convection or conduction so it’s very slow.

That's a hell of a starting point. I bet within a decade they get it from 45 days to 5 if they aren't already capable now. We usually find out about new technology 2 decades after the government gets a hold of it.

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I would like to see some testing of subsonic drivers for deep space propulsion. As they have discovered that low frequency vibrations can produce thrust in the vacuum of space a ship outfitted with a wall of specially designed and built "subwoofer type" drivers could very well get us to much higher speeds than ever before. My concept is similar to the guy with the piezo electric drivers but going the opposite direction and using low frequency energy rather than high frequency energy. The system could even be solar powered and would require less energy than any previously or currently designed system.

> nuclear-powered spacecraft, which would allow spacecraft to travel further distances without needing liquid fuel

Nuclear thermal rockets still use a liquid fuel. There still has to be some mechanism for momentum transfer, and that means shooting something out the back of the rocket really fast.

Specifically, NTR thrusters use hydrogen superheated from passing over a nuclear reactor. Exhaust velocity of tested variants from the 60s and 70s were up to roughly twice the exhaust velocity of typical chemical propulsion systems.

The disadvantages are the ones you’d expect: putting a nuclear reactor on top of a giant controlled explosion is risky, and mounting a nuclear reactor makes the engine weight significantly higher so thrust to weight ratios are much lower. Still, it’s expected they would provide a significant performance advantage if engineered to fruition.

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If you can eliminate space junk, you can just as easily get rid of an enemy’s satellites.

Kerbal Space Program for not teach you the underlying math.

But it's a good time!

A small telescope

I believe so. However some of them are so small they would be difficult to spot even with a very strong telescope

Yep - RocketLab for one

AstroScale

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For TOI-700, we know the properties of the star, the radii of the planets and the characteristics of their orbits. My quick assessment is based on the same info for Venus and Mars in our solar system.

I was wondering the same thing.

> I guess an issue could be heat exchange from a vacuum to whatever the cooling system is, but that's above my brain grade.

That's sort of the whole problem though. Whatever particles are around in a near-vacuum might be very cold, but there are also very very few of them. There just isn't anything to exchange the heat to. A vacuum is an insulator, that's how Thermos bottles work for example.

Are those conclusions we could draw from what we could observe at 100 ly?

Oh, the shcramjet (not a typo). Yeah, I'd forgotten about those.

Standing oblique detonation ram jets are also a thing. Instead of the detonation wave revolving around an annulus it occurs in a static position downstream of a really interesting series of C-D nozzles and fuel injectors. It uses the ram effect for oxygen intake and compression but undergoes a pre-burn through an upstream CD nozzle to accelerate the gas further to higher mach numbers. The gas then flows into another CD nozzle where more fuel is injected at the throat. This mixture then accelerates again and just downstream of the throat there's a ramp that causes a standing oblique shock wave. The rapid increase in heat and pressure crossing the boundary of the oblique shock causes the fuel rich hypersonic gas to detonate constantly.

Aren’t there around 40 or so?

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I remember looking up at Jupiter about 4 years ago and seeing i think 5 of the moons. So surreal that you can see that stuff from so far away

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