Reply To: What is the current state of the project?

[emmetb]

The Japanese research story that Brian linked to above doesn’t seem to think that impact is going to be a show-stopper.

Do they also say why not? 😉

Tethers.com uses a hybrid approach similar to launching and recovering small planes from a blimp. And unless they use a rigid tether, I don’t understand how their tether could restore the momentum transferred to the payload.

Now that you mention it, i must admit that when i posted the link i hadn’t the foggiest idea how their system really works. 8-/

So i took a second look at it: they certainly don’t seem to be using a rigid tether, instead it is two masses connected by the tether that form a rotating two-body system. Then when they grab something at the base of the rotation and let it go at the apex momentum gets transfered from this two-body system to the payload. They say they can boost the orbit of the facility by simply riding the earth’s magnetic field by running a large current through the tether itself.

Now i wonder if another way to boost the facility orbit would be for the facility to climb the tether when it is at the base of the rotation. Maybe this way momentum can be transfered back into orbital velocity while shortening the cable (and the time it is exposed to debris).