tomf

I expect that the fact it flies up in one direction and down in the other would make designing air intakes pretty tough to start with.

Looks like it pretty much keeps the same orientation but with a 15 degree wobble in what they call the torque equilibrium attitude or TEA. https://www.forbes.com/sites/quora/2017/04/26/how-does-the-international-space-station-keep-its-orientation/?sh=17f52e433a18

I think a counterweight could be fired into a long coil, bringing it gently to a halt and recapturing it's energy as electricity. You might need to get that pesky air out of the way.

I may have been taking a loose definition of life and I can't find the source I thought I had read that says that DNA organisms are outnumbered significantly by RNA viruses

Human Viruses are beautifully engineered things for entering human cells. Most viruses only infect a very small range of creatures and jumping species is pretty rare despite the fact all vertebrates are pretty much indistinguishable biochemically speaking. So the idea that an alien virus equivalent would be able to in any way thrive inside us is laughable. Alien bacteria might be able to do a little better but still would be massively outcompeted by the bacteria that have evolved to use us as hosts. Also the idea that alien life would use DNA seems very myopic, most life on earth doesn't use DNA.

This tickled me. https://www.theonion.com/spacex-under-fire-after-autonomous-rocket-hits-pedestri-1847946787

I just set myself a challenge, to list all the active probes humanity has launched that are still actively returning data. Without looking anything up and excluding earth sensing satellites. What did I miss/get wrong?

Arranging your towers onto the earth looks like it is going to be equivalent to the Thomson problem of packing charges onto a sphere. It looks like the optimum solution isn't known for more than a few towers.

I saw this a while ago but I don't think it got posted here. This company claims to have invented a way of using the exhaust of a hovering rocket to bind lunar dust on the surface to make a pad that can be landed on seconds later. By injecting molten rock into it. https://masten.aero/blog/mitigating-lunar-dust-masten-completes-fast-landing-pad-study/

And just to repeat something from up thread, of the cable breaks the separation speed is only in double digit m/s, well within the rounding errors of your maneuvering engines. If the cable breaks you just re-dock, bolt the ends of the cable back together and wind out again

If you are going to start nuclear war you are probably willing to expend some upper stages. You would want to launch on an entirely typical trajectory that just happens to overfly the enemy territory and not reveal your true nature until practically overhead for minimal warning.

I don't think even the most paranoid general would think that spaceX would start a nuclear was on their own, where would they get the warheads for a start? But if spaceX independence is a sham and really it is cover for a secret DOD black project...

Imagine you are a paranoid general in a rival power to the US. What scenarios enabled by the planned starship system are you going to be presenting to leadership in order to justify increased spending on your project? It has to be plausible enough that you can convince the leadership that something needs to be done to counter the threat. In another thread the general consensus was that p2p was going to be niche at best so probably not worth worrying about. 1. ASAT missiles. With rapid launch cadence they can replace satellites that are shot down and with a huge mass budget the next one will be armoured! 2. First strike weapon. With in orbit refueling it might be common to have two large spacecraft rendezvousing over your territory. Except these aren't regular starships, these are disguised warhead busses about to rain 500 tonnes of warheads down on us with almost no warning! P.s. I'm not interested in whether you think starship will work as advertised, this is about reasonably slightly plausible military uses assuming it does.

Any that have gone to trial with a public verdict though? Ok I can just Google that, I can't find any cases that have publicly concluded, although Germany did fine Tesla for overstating the autopilot capability

Has the autopilot liability been tested in a US court yet? It's hard to imagine that no enterprising lawyer yet hasn't tried an argument that a product that is so easy to use irresponsibly, even with good intentions must give some liability to the manufacturer. If I were Tesla's lawyers I would be up at night worrying.

This mod was taken over by linuxgurugamer a while ago. He created a new thread for it and you should post this there

If you try to build it out of steel I think the top of the cable has to have a thickness of something like the moon. Steel ain't gonna cut it. Wikipedia mentions a proposal for a 20 tonne, hair thickness cable which successively larger climbers would climb adding more strands as they go.

I can't believe no-one yet has mentioned sunrise from also sprack Zarathustra or the blue Danube waltz (2001's music)

You would start with your cable in geostationary orbit and then simultaneously lower one end and raise the other. The centre of mass stays at geostationary so doesn't move relative to the earth. I think tidal forces should keep the down bit pointing down and up up but you might need to deliberately remove angular momentum to stop the whole thing spinning. Eventually nice and gently the end of your cable touches down If you change the shape the centre of mass cannot change, otherwise you could boost your orbit by rotating and pumping fuel the way you can in ksp. So if you extend two cables with weights in different directions the com has to remain at geo. What will happen is the elevator will start to spin to maintain angular momentum. Not sure if tidal forces are strong enough to keep that under control or if you are going to need thrusters to control it. Probably depends on the cable winching speed But in principle orbital mechanics aren't the issue

The shuttle had the requirement for the enormous cross range capability, and lacked the processing to do the flip and propulsive landing which would have been significant drivers in choosing a winged design

I think the point Kerbiloid is making is that a cylinder is a worse shape for reentry heating then the flat bottomed shapes of all(?) Successful manned spacecraft. My guess as to the reason that the simulations that spaceX must have run are making them believe it might work might be simply sure to scale. SS is significantly larger than any capsule, and by the time it is re-entering is going to be pretty empty. I suspect it is going to be "fluffy" enough that the reentry heating is manageable with a suboptimal shape.

That's a pretty standard, deliberate, humorous mixing of metaphors.

Ball games on the inside of a cylinder spinning to give artificial gravity would be fun, small enough that you could pass straight upwards to someone in the opposite side. The coriolis effect would do the head in of a poor earthbound human like me.

If it is a small boat electric outboards exist https://www.google.com/search?q=electric+outboard+motor&oq=electric+oub&aqs=chrome.1.69i57j0i10i433j0i10j0i10i457j0i10.8277j0j7&client=ms-android-oneplus&sourceid=chrome-mobile&ie=UTF-8#scso=_zowHYaD6N5XD8gKcmrTwBg7:0

Or use the kerbal method of releasing the cargo stationary , then translating the launching vessel out of the way. Ok that isn't the real kerbal method, the real kerbal method is releasing the cargo then time warping until it drifts out through the walls.