Orbital Commuter Flights, and other fantastical mundanity

[Bricingwolf]

So, ion engines have been shooting stuff around space for us for a few decades now, with a so far perfect success rate. Seems like new breakthroughs in improving output and longevity of those engines keep coming faster and faster, too.

See; this new model for longer lasting ion engines. Great example of important improvements in the tech, leading us closer and closer to ion powered orbital ships, at the very least.

So, let's go a little nuts, and just ask some questions.

First, could you build a power plant that uses an ion reaction to generate power, assuming tech like this can make it last long enough to be worth building?

Second, assume ion engine tech increases in output at least a bit more over the next decade, and some other tech is doing the stage 1 propulsion work (the big rockets that get the thing off the ground in modern launches), such as railgun launch systems or 12 mile high launch pads, or both. I like the idea of both, personally. And, with the rail gun proposed by NASA requiring only enough juice to power a small town, that's nothing. You can get that with solar power, anywhere near the equator, which is where you'd want it anyway. Could such a launch system, combined with ion engines, lead to cheap flights in and out of orbit?

Third, could these system be put to use in terrestrial flights? Can the ion thruster tech reach enough output to keep a small passenger plane in the air, as long as something else gets it up there in the first place? Anyone know anything about aerodynamics and wingspans and all that? Could a plane with more wing use less fuel, perhaps with expandable wings, assuming we could make them durable enough?

Fourth, could we build an ion generator to power electric cars? Currently, hybrids that work that way use vastly less gasoline under normal driving conditions, but what if we could make the generator itself vastly more efficient as well?


Lastly, perhaps it's time to work out how much electrical energy the average electromancer can put out reliably without taxing themselves. Could an electromancer driver recharge their own vehicle while driving?

[Bricingwolf]

I know the scramjet thing should work, but it's still using some gnarly fuel. What about a slower climbing jet? I don't know much about aerospace, especially in terms of what it takes to get higher in the atmo, so idk.

But, I imagine that putting the rail on a mountain would put a lot of that power load onto the rail system, instead of the jet. Which, in the QFC future, just isn't' much of a problem.

[Bricingwolf]

Railgun launch platform, logistics

Crossposted from facebook: scroll down a bit for a good, detailed, breakdown on how railgun launch systems would work, with links to SCIENCE! on the subject.

Main points IMO: Launching people into orbit with railgun tech alone would require an absurdly long rail line, while launching more durable stuff would require only a mile long rail, preferably sloping up a mountainside.

However, a vertical launch platform could work as long as the vessel itself can get from high in the atmo to orbit on it's own, or using a combined/hybrid system.

Ideally, you'd want as much of the power required for Earth to Orbit launch to be on the ground in a highly reusable system, but if we can't put all of it there, putting most of it on the ground will still save thousands of dollars per launch by hugely reduce fuel usage/storage needs.

In turn, those savings would mean that smaller companies, and more of them, could be launching things into space, and a regular stream of Earth/Orbit traffic could develop as a result.

"Noone has considered having a long railgun that is miles long because it sounds crazy right off the bat, so most proposals are for small high-acceleration railguns as in the papers above. The issue is that this limits what they can launch and as soon as you do that noone is very much interested. Why is a long railgun crazy? In reality it isn't, the raw materials (aluminum rails, concrete tube, flywheels, and vacuum pumps) are all known and cheap. If they could make a railroad of iron 2000miles in the 1800s why can't we do 150miles of aluminum in the 2000s?"

Helluva good point.


Sidenote: This could also help solve the huge fuel use and emissions of terrestrial air traffic, as a lot of that fuel is used to gain altitude and full flight speed.

[Bricingwolf]

The two main proposals I've seen to deal with length of track requirements are;

A rising spiral structure, possibly looping around a mountain.

and

A circle track upon which the vessel is accelerated round and round the track until desired velocity is reached, and then released via a rising lenght of track attached to the circle.

The second is problematic because it would probably greatly increase track wear, vastly increasing the frequency with which you have to replace things, and making the system less safe as a result of that same increased wear. It also involves a bit more moving parts, increasing risk of malfunction and death.

The other option is just having a long as fuck track leading up to the rising mountain part of the track, but there are a lot of logistical problems with that, too. Not least of which the fact that in most places, this would require the track crossing national borders.

[Bricingwolf]

from wiki: "In 2003, Ian McNab outlined a plan to turn this idea into a realized technology.[27] The accelerations involved are significantly stronger than human beings can handle. This system would be used only to launch sturdy materials, such as food, water, and fuel. Note that escape velocity under ideal circumstances (equator, mountain, heading east) is 10.735 km/s. The system would cost $528/kg, compared with $20,000/kg[27] on the space shuttle (see non-rocket spacelaunch). The railgun system McNab suggested would launch 500 tons per year, spread over approximately 2000 launches per year. Because the launch track would be 1.6 km long, power will be supplied by a distributed network of 100 rotating machines (compulsator) spread along the track. Each machine would have a 3.3-ton carbon fibre rotor spinning at high speeds. A machine can recharge in a matter of hours using 10 MW. This machine could be supplied by a dedicated generator. The total launch package would weigh almost 1.4 tons. Payload per launch in these conditions is over 400 kg.[27] There would be a peak operating magnetic field of 5 T—Half of this coming from the rails, and the other half from augmenting magnets. This halves the required current through the rails, which reduces the power fourfold."

[Bricingwolf]

Elon Musk wants to start orbital commuter flights in the very near future, fueled by a carbon neutral fuel. Of course, that fuel does, IIRC, expel methane and other chemicals, but it's something.

Still seems like the best bet is to use non fuel powered methods to get initial velocity, to reduce fuel constraints.