Using today’s technology, is it possible to build something analogous to 2001: A Space Odyssey’s Discovery, or Space:1999’s Eagles?
Discovery in 2001 used nuclear propulsion. We’ve got nothing like that, but a nuclear propulsion initiative ( Project Prometheus ) is still alive in congress.
The Discovery? Sure. We could have done it in the 1960s when the film was made. (Heck, read some of RAH’s novels like Space Cadet or The Rolling Stones. He describes nuclear powered spaceships which would have been possible in the 1950s, IIRC.)
As for the Eagles, I don’t think anyone’s come up with a spaceship design that can crash one week, and be fully repaired by the following week.
A large, nuclear powered spacecraft capable of transversing interplanetary distances within a reasonable time frame while carrying a human crew (I would reccomend submariners for the job) is quite feasible with today’s technology. No HAL though. It would just be really really expensive, tens of billions of dollars at the minimum, and take a couple years to assemble in orbit. Unless you built it on the ground in one piece and “Project Orioned” it into space.
Nuclear propulsion?
Simple.
Store a sizable amount of liquid hydrogen, pass it over a nuclear pile,and expel the superheated gas out a rocket nozzle.
Nah, drop nuclear bombs out the bottom of your ship, detonate them, so that the force of the explosion propels your ship.
Think I’m kidding? This was the basis of Project Orion, on which noted physicist Freeman Dyson and other scientists and engineers worked from about 1957 to 1965.
Although it sounds nuts, it was in fact very well thought-out and probably remains the only effective way to send substantial payloads to the outer solar system. They even calculated that it would take about four million bombs to get to Alpha Centuri. (Oh yeah, and another four million if you want to stop there.)
You’re laughing, but this is serious. Read Dyson’s son George’s book, Project Orion. Fascinating, and not nearly as nuts as it sounds.
Well, yeah. The propulsion problems are licked, pretty much, as far as theory goes. And mathematically, it would work.
…but there’s the matter of what we’re going to feed the boys along the trip. Oh, and what they’re going to breathe.
Regarding Orion:
<Army of Darkness mode>
This…is my BOOM-SHIP!
Yes, it has not been possible to find a way of recycling water and oxygen in a way which is small enough to cram into a small interplanetary craft; and the production of food in an artificial biosphere would take up vast amounts of volume and mass.
So if we were to build an Orion type boom ship to go to Mars and Jupiter now we would probably have to accompany it with a fleet of supply craft, especially if they want to come back as well.
Of course experience with Mir and the ISS has shown that long term survival in space is possible, and so is periodic resupply of spacecraft. So no biggie-
it would be nice to get recycling worked out, though.
These aren’t exactly starships, by the way…
…hence my point.
Sure, we could put a space station in orbit around Jupiter. Nuclear-powered spacecraft would be a peachy way to do it, too. And we’d need the ships that built it to resupply it.
…but the idea of setting up a supply train to Alpha Centauri and back frankly kind of frightens me. I don’t want the job until we get this E=mc-squared stuff straightened out…
I seem to recall that the Discovery in “2001” was essentially a nuclear-powered ion rocket, electrically accelerating ionized plasma as exhaust. The Marshall Space Center in Huntsville is working on something like that; it has the potential for combining a fairly high acceleration with the ability of an ion rocket to maintain thrust for a long time.
Actually, we could go anywhere in the Solar System with chemical rockets. First, teleport a fully loaded Saturn 5 into orbit…
As far as actually achieving interstellar travel with today’s technology… well, hope you don’t mind a long trip.
Well, that’s a problem for any long-term space mission, regardless of how it’s powered, right? So basically, you send an entire ecosystem, with plants to clean the air and provide food, etc.
One of the beauties of Orion (unlike virtually all other propulsion systems) is that it scales up very well (but not down). Use megaton hydrogen bombs, and you can have a ship with a mass of 1 million tons that can reach speeds of 10,000 km/sec and get to Alpha Centauri in 150 years. (I was wrong about 4 million bombs–it would take 25 million.)
The high specific impulse (the measure of how much boost you get per mass unit of fuel) is so much higher for bomb propulsion than chemical rockets or nuclear ion propulsion that it makes taking lots of people and stuff no practical barrier.
Okay, so going to another star system is way, way out in the future, but trips to the farther reaches of our solar system are not impossible.
True.
But first we’ve got to lick the problem of “balanced ecosphere.” Hell, we haven’t managed to do that just yet even when equipped with a gigantic freakin’ building and a humungous selection and supply of plants and animals. Last I heard, each of the “biodome” experiments had failed, requiring a massive input of oxygen and other items necessary to maintain life in a sealed environment.
Not saying it’s impossible… only that we haven’t licked the problem yet. It’s either that, or we finally perfect the cryogenic freezing process.
Not necessarily. If you have enough power, you just carry enough supplies to last the length of your trip, assuming it’s not a one-way immigration ship. A two-man crew on a 5-year round trip mission will require around 100 tons of supplies. That includes food and oxygen but it’s mostly the water. If you have a good water reclamation system you can probably cut it down to about 20 tons.
Why do other systems not scale up very well?
Two men for five years? Are there any missions seriously considering sending two men out for five years? I thought the Mars missions were five or six at least.
Besides, I was talking about sending good size communities out for centuries.
It’s the specific impulse and the mass ratio. Your ship has to carry the weight of the payload and the fuel. The more fuel you need, the bigger the ship has to be and the more fuel you need, and so on.
The mass ratio of the Apollo system–the pad weight vs. the amount that returned to earth–was 600:1. The Orion project physicists estimated that the mass ratio for an Orion ship to go to Saturn would have been about 5:1. That’s because nuclear bombs are so much more efficient in converting mass to energy than chemicals.
Several years ago, an engineer in Whole Earth Review, wrote an article detailing exactly what went wrong with Biosphere II. The gist of it is that the thing was built to look cool and wasn’t built to work. One of the really big problems with it was that it wasn’t orientated correctly, thus the plants weren’t able to get enough sunlight. So, Biosphere II isn’t an example of us building a self-contained environment.
I recently read an article about a class of weapons being researched that use Stimulated Gamma Decay and thought that it sounded ideally suited for spacecraft propulsion. Apparently if you take Hafnium 178m2, an excited isomer of Hafnium 178 and bombard it with low energy x-rays it will rapidly revert to it’s low energy state by emitting a gamma-ray photon. The energy densities are such that one gram of this stuff is equal to 50 kilograms of TNT, with much much less fallout or contamination than is involved in a fission bomb. Could this be used to power an Orion type spacecraft? Just using a little math (which I hope is correct) you could get a one megaton explosion from about 18,500 kilograms of Hafnium which is a fraction of the weight of fuel the space shuttle uses in one launch.
There is one huge problem with sending a manned mission not mentioned in 2001 - the radiation. The immediate environment of Jupiter is insanely radioactive. Unmanned probes survive, but keeping a human alive there would take some major advances in shielding.
Of course, if you’re using nuclear bombs to propel your ship, you’ve probably had to solve the radiation shielding problem anyway.