I haven't tried to calculate the physical forces of any of it, that'd take too long and hurt my brain, but just thinking intuitively, it would seem that one answer would be to make the station orbit at a velocity higher than necessary to remain at that altitude. The tether would provide the angular momentum necessary to maintain orbit and the tangential moment of inertia of the station would maintain tension on the tether. That would require a sufficiently (impossibly?) strong tether, and enough energy to maintain the station at its excessive speed.

Little issues like weather can be addressed by the impossible materials of the tether. Interfering spacecraft would be an interesting challenge to map out since the tether would go through all of the Low Earth Orbital altitudes.

Transit time sounds like a relatively minor consideration after you solve the other issues.

We'll just have the FCC auction off the allowed orbits. Then install a defensive system to destroy any offending satellites.

This will help:

https://en.wikipedia.org/wiki/Space_elevator

Need massive counter weight beyond geo sync to keep cable taught.

Failure modes will be spectacular! All you need is one satellite or meteor to hit the cable, and the whole thing flings off into space.

For an alternative, the skyhook:

https://en.wikipedia.org/wiki/Space_elevator

Massive LEO "tug" satellite drags a hook that picks up high altitude payloads and flings them into space. The tug then adds energy back with some form of propulsion. Wins over a rocket because the mass of the rocket isn't lifted, just the payload, and the tug has no air resistance.

Still hard to build, but WAY easier than an elevator.

Mike C.

Orbital mechanics are anything but intuitive. A higher orbit requires less speed since the gravitational attraction is less.

Yes, what I'm saying is that if you fly at a speed that is greater than needed to orbit at a given altitude, you will rise to whatever altitude that speed will support. If instead you tether the object and maintain the speed and altitude, it will try to climb, but can't. The result would be tension on the tether. Sadly, I realize that the result would be an arc and the object likely crashing back to the ground (or burning up trying to do so). Mike's solution of a mass outside the geostationary orbit would have the same tensioning effect without the resultant crash.

Yes, the orbital station needes to be above normal geosync orbit so you are pulling it constantly toward the earth.

The weight of the cable (if smaller than the orbital mass) makes it more comlicated to work, but possible. If the cable weights more than the station (by some factor?) I think it just fails.

Material strength is insane.

Yes, the lateral force is a big problem (forgot to mention) because you need to add angular momentum to the station. I *think*, (not sure) if the car mass is light. the station can gain angular momentum by lagging behind so the cable is not verticle, I'm not sure if that works for unlimited mass transported, or if you need a (low thrust) engine on the station.

If you imagine an extreme case where the cable leaves the earth almost horizontally, it is decreasing the earth's angular momentum from tension, so increasing the stations. But I'm not sure it all works out.

So you get the cable and satellite all precisely balanced. Finally after painstaking calculations and precision rotation, having overcome issues of cable weight, strength, atmospheric friction, bla, bla, bla, then some poor fool pushes the elevator button and all H3LL breaks loose!!!

Yes, exactly, because now you've introduced a mass that moves along the cable and theoretically adds to the mass of the station, then descends with or without some additional mass from the station.

This is why we don't have space elevators.

The skyhook must need some sort of power source since / rocket, but that can be low thrust, still needs a lot of energy - need to look at the energy balance vs conventional rocket

Since its imparting a large fraction of orbital velocity, it still needs material strength to weigh that is not a lot less than a space elevator, but it i a lot shorter (still pretty big if the accelerations are modest)


The fundamental problem with all of these is trying to understand why they are better than rockets. A H2/O2 rocket doesn't pollute, fuel cost is not a significant part of launch costs - what is the problem people think they are solving with thousand -kilometer scale structures made out of ultra-high strength materials?



This will help:

https://en.wikipedia.org/wiki/Space_elevator

Need massive counter weight beyond geo sync to keep cable taught.

Failure modes will be spectacular! All you need is one satellite or meteor to hit the cable, and the whole thing flings off into space.

For an alternative, the skyhook:

https://en.wikipedia.org/wiki/Space_elevator

Massive LEO "tug" satellite drags a hook that picks up high altitude payloads and flings them into space. The tug then adds energy back with some form of propulsion. Wins over a rocket because the mass of the rocket isn't lifted, just the payload, and the tug has no air resistance.

Still hard to build, but WAY easier than an elevator.

Mike C.

Interesting article about the cooling process and temperature data. I didn't realize that NASA has a mini-fridge, closed-cycle gaseous-helium cryocooler, for cooling one instrument - MIRI. It was turned on earlier this week. Way over my head but amazing never the less.

https://scitechdaily.com/james-webb-spa ... lling-out/

That's just too cool. Thanks for sharing. I'm not even sorry for the pun. (left click and highlight this apparent gap.... )

Yep. When you have a sensitive IR (i.e. heat) detector it needs to be as cold as possible to work well. Even in deep space it helps to add cooling.

Yep. When you have a sensitive IR (i.e. heat) detector it needs to be as cold as possible to work well. Even in deep space it helps to add cooling.

Yep. When you have a sensitive IR (i.e. heat) detector it needs to be as cold as possible to work well. Even in deep space it helps to add cooling.

The telescope has received its first photons. Details at the mission blog.

You can also see a selfie of the primary mirror. It's the first closeup of the telescope since it separated from the launch vehicle.