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2h
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answered | Why can't we smash asteroids into Mars so it will move closer to the sun for colonization of the planet |
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4h
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comment |
Reducing required length of a mass driver using loop? That sounds vaguely like a skyhook kind of design. Plenty of stuff on the internet (wikipedia, or this website is a good starting point). They're not an obviously impossible design, although still short of what would be economically plausible today. |
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1d
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awarded | Nice Answer |
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2d
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comment |
Reducing required length of a mass driver using loop? Basically yes. Unless you believe SpinLaunch, but they're probably a scam trying to make money from investors who don't know better. |
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2d
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comment |
Reducing required length of a mass driver using loop? Mountains are too low. Even at the very peak of mountain Everest (where, needless to say, constructing a massive facility would be very hard) the air is only 3 times thinner than at sea level and 3000x denser than at the Karman line (which is roughly where reentry physics starts being important). There's always a trade off between multiple factors (velocity given by accelerator, g forces felt, size of upper stage being accelerated, altitude, cost of construction) and no compromise between these factors looks plausible or worth it. |
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2d
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revised |
Reducing required length of a mass driver using loop? added 599 characters in body |
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Jul
17 |
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comment |
Reducing required length of a mass driver using loop? @Cadence I guess it might be desirable to keep all the "accelerator parts" close together on the ground, rather than having them spread out in a kilometres long vacuum tube? Keeping the latter simple and free of machinery could be better? But as it's all fantasy from current technology, fine tuning the details like this seems rather pointless. |
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Jul
17 |
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revised |
Reducing required length of a mass driver using loop? added 2 characters in body |
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Jul
17 |
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revised |
Reducing required length of a mass driver using loop? Typos |
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Jul
17 |
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answered | Reducing required length of a mass driver using loop? |
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Jul
13 |
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awarded | Custodian |
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Jul
13 |
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reviewed | Looks OK Has the cause of a rocket failure ever been mis-identified, such that another launch failed due to the same problem? |
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Jul
13 |
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reviewed | Looks OK How do satellite trackers work when showing a "satellite"? |
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Jul
12 |
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comment |
What are the tradeoffs in propellant choices for ion/electric based engines? Great and knowledgeable answer, but paragraphs 2-4 were very confusing. You're jumping around between velocity and acceleration all the time as if they were the same thing ("v in the second equation = a in the first"). If you're going to use equations, better to lay them bare and explain them, than muddle them with wrong hand waving IMO. |
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Jul
11 |
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revised |
Would it be possible to create a relatively permanent Kessler syndrome event in interplanetary space between Earth and Venus? Alternative calculation added |
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Jul
11 |
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awarded | Citizen Patrol |
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Jul
10 |
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awarded | Commentator |
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Jul
9 |
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comment |
What are the tradeoffs in propellant choices for ion/electric based engines? This is one of the few cases where propellant costs actually matter too (see Starlink using cheap argon rather than xenon) ! So I guess the factors are: ISP, Thrust, Fuel Density, and Cost. |
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Jul
8 |
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comment |
Would it be possible to create a relatively permanent Kessler syndrome event in interplanetary space between Earth and Venus? I should think that the timescale at which light pressure matters is orders of magnitude greater than the stability of pseudo-orbits around L1 or L2 in practice |
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Jul
7 |
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revised |
Would it be possible to create a relatively permanent Kessler syndrome event in interplanetary space between Earth and Venus? Improved estimates |