Japan is taking us one step closer to a space elevator.
Elon Musk may not believe in space elevators yet, but Japan is taking a step forward to realise the dream of travelling to space by elevators instead of the traditional rocket.
A team of researchers from Japan's Shizuoka University and other institutions will conduct the first test in space this month as part of a project to build a space elevator, Japan's The Mainichi reported last week. The space elevator essentially ferries people and cargo shipments in an elevator car travelling on a cable connecting Earth to a space station.
This test is the first exploring the movement of a container on a cable in space. Two ultra-small cubic satellites measuring 10 centimeters on each side connected by a steel cable about 10 metres long will be carried from Kagoshima's Tanegashima Space Center to the International Space Station on Sept. 11.
From there, the connected satellites will be launched and a motorised container acting as an elevator car will travel along the cable and have its journey recorded via a camera attached to the satellites.
The project's technical advisor, Japan's construction giant Obayashi Corporation, is also working on a similar project, though it previously said it expects to deliver a space elevator by 2050.
(Score: 2) by c0lo on Tuesday September 04 2018, @07:40PM (1 child)
Not gonna cut it. Rationale - the cable isn't going to sit in balance without a tension, the equilibrium is unstable, any perturbation is subject to positive feedback. And gosh, those cyclones/hurricanes/typhoons just can't wait to provide some perturbations.
Besides, I suspect the cable is going to need some controlled oscillations, be it only to get some hundred metres out of the way of some satellites or near-earth asteroids now and then. Too risky to control those oscillations without tethering one end.
Interesting, never thought about. But won't be a single exponential... Need to grow exponential up to geostationary (where the cable tension is max) then it can decrease exponentially to the distal end.
(Score: 2) by Immerman on Wednesday September 05 2018, @01:42PM
Yes, cyclones, hurricanes, etc. are going to provide some pertubations - quite possibly terminal ones. That's why most plans have the base of the beanstalk well inland and atop a high mountain - up above the worst of atmospheric disruptions. For maximum reliability you wouldn't want it to touch the ground at all - if it simply stops 40 or 50 miles above ground any hurricanes, etc. will simply pass harmlessly beneath it. Of course that means you'll have to take a high-altitude capable aircraft up to the base, which makes it a bit less convenient. On the other hand, that would also let you get a bit out of geostationary, so that the bottom end could slowly sweep across the globe to serve a much greater area,albeit only periodically.
And yes, it's only exponential up to geostationary, which is the point of maximum tension. As to whether it extends much beyond that - it might, it would come in handy as a "snap the whip" style interplanetary launch system. On the other hand a 36,000km cable made of exotic materials is already going to be incredibly expensive without making it twice as long, and there's *lots* of alternative interplanetary launch systems once you're in orbit. The cable might just end at a small moon (large captured asteroid) a bit above geostationary - makes for a much cheaper counterweight, and a well-shielded base of orbital operations.