The acceleration (in the ring) will be a killer. a = v^2/r. For an 8 km/s speed with a 10-km-diameter circle, the acceleration will still be ~1300G. Typical satellites are designed for the 6-8G range.
I'll bet this would win the "Pumpkin Chuckin" contest hands-down!
Sounds kinda like a exotic weapon.
1300 G`s,wow
Niven used this launch system in Ringworld,or
was it for landing
You got that right. As the article said...
...could fling satellites into space, or perhaps weapons around the world...
I wonder if they could aim that thing at things in orbit with any accuracy?
Sounds like a Gerard K. O'Neill idea.
For example, if this thing has a 10 meter circular cross-section, you'd need to be able to evacuate about 2.5 million m3 to a very good vacuum, similar to what's found in space -- in a structure that's flexing in response to a 1300 G point load. Good luck with that.
Next, when you open the door to let this thing out, there's gonna be that nice shock wave caused by air racing in to fill the vacuum. Whole lotta buffeting going on there -- launch accuracy will suck, assuming that the thing doesn't just tumble and fragment.
And don't forget the part about screaming through the atmosphere at Mach 20+. The thermal requirements are gonna be killer.
Imagine a power plant (nuclear would be ideal -- it's a good base-load provider) built in the center of the ring. During peak hours, the plant sends juice over the wires as usual. Off peak, the plant feeds excess power into the ring's accelerator magnets. Instead of lofting a spacecraft into orbit, the ring magnets use the juice to accelerate a conductive body (say an iron slug) to the maximum speed mentioned in the article, 10 km/sec. Since Ek=mv2/2, a 10 kg slug traveling at 10000 m/sec will have a instantaneous kinetic energy of five hundred million Joules. The power plant then closes off the power to the ring magnets. Due to induction, the speeding slug will then cause a current to flow back through the circuit, converting its energy of motion into about 139 kW/h of instantaneous electrical energy. Figure 50% loss through the system and that's roughly 70 kW/h of tappable electrical power per slug -- enough power to meet an American home's electrical needs for several weeks!
Now imagine the entire ring filled with such slugs. At a diameter of 10km, the power ring would have a circumference of 31.4 km, give or take a few centimeters. Assume the slugs are of equal size (90 cm, say); with a 10 cm gap between slugs, the ring could hold 34, 906 slugs, making its total instantaneous electrical energy storage potential an astounding 2,443,400 kW/H (2.44 gW/h) -- enough stored energy to power a city of seventeen thousand homes for a month!
In addition, the power ring would (through losses) generate a good deal of heat energy. By careful design, the cooling system could make use of this "waste" heat to provide cogeneration energy for other uses.
Of course, if the levitation magnets fail or the physical structure of the ring is compromised, the slugs will impact the ring walls, depositing all 17,453,000,000,000 Joules into the surface of the earth — the equivalent of a nuclear explosion of a little over four kilotons. Ouch!
All this is just a thought experiment, of course. I am no kind of engineer and I may be overlooking one or more important objectons to the use of high-speed magnetic-levitation rings as power storage devices. (And I also may have the math wrong.) Still, it's an interesting idea, I think.
Dude, that really doesn't seem right. 1.96 RPS across a 10km circle is not going to give you 1300G's. Are you talking about centrifugal or centripedal accelerations?
OMG! That's right!
Figured that in your head, didn't you? :-)