Why do we do this? Sending probes to the other planets of the solar system that take about a decade of time and half a dozen swing-by's of earth and other planets to build up speed from gravitational catapult manouvers... yeah, I'm bloody impatient. If I were in charge, these things would be launched into earth orbit with one rocket, while a big fuckoff rocket stage was lifted into orbit by a shuttle, while another launch or launches carried up fuel to be pumped into the rocket. This would be followed by bolting the now-fueled rocket onto the payload and then, hey presto, you fire that up and your probe is really fucking going right from day one. Low resource efficiency, but much quicker transit times, and no need (or greatly reduced need) for all that dancing around from one planet to the other in order to get where you're going.
Ion drives are the fastest deepspace engines we have, it just takes time to build up a head of steam.
You just said it yourself, low resource efficiency. So long as there are a steady stream of missions launching, it doesn't matter if they are taking a decade, since there will at that time be other missions arriving at their destination to pay attention to. What would you prefer? Constant action where you might have to wait 10 years for your favourite mission to arrive at it's destination, or bigger, more expensive missions, where you favourite mission doesn't even happen because all it's budget was spent just getting the preious project to it's destination? You also have to appreciate how goddamn big space is, even our solar system. edit: also not sure if you are aware, but the current mission to Pluto, which is going to take around a decade to arrive, is still the fastest spacecraft ever launched. It is taking the direct route.
I'm pretty sure those guys at the space agencies have thought about that. I hear most of them are not complete morons.
They should build a freaking Saturn V stack in orbit and then bring up fuel for it. The most powerful rocket that was ever made.. putting out about four thousand tons of thrust from its main stage.. then imagine all that from a starting point already in space instead of having to heave itself up out of Earth's gravity well. Going to pluto would be the work of a year or two. Of course, if I was truly in charge, we'd be using orion propulsion. That'll get you out to pluto in well under a year, and with a pretty big spacecraft to boot. A very large orion drive ship, similar in mass to large ocean vessels of 60,000 - 100,000 tons, would be able to thrust up to about 10% of C. That would get you a probe to the Centauri system in about 40 years. Well, closer to 50 years, accounting for time spent accelerating and decellerating.
#1 The Solar system has no atmosphere to warm #2 A tiny, tiny, tiny human spaceship burning fuel doesn't hold a candle to the eight hundred thousand mile wide nuclear furnace blasting away 24/7 in the middle of the solar system. But I think you knew these things
Yeah, for about as long as 150 seconds. I'd rather imagine an ion drive spacecraft, powered by a nuclear reactor. This drive kicks ass. Undoubtedly. Might be a bumpy ride, though. Seriously, regardless of specific drive design, we're stuck with the rocket equation. The rocket equations says, if you want to lower the reaction mass the spacecraft has to carry, you have to lower either the end mass/payload of the craft, it's velocity change (goes exponentially here) or you have to increase exhaust speed (also goes exp.) In the end, the propulsion system with the most efficient power/mass ratio wins. My guess is that a nuclear reactor is more efficient than a bomb.
Actually, I think Orion would get you more bang for the mass. IIRC a nuclear or fusion reactor would still need reaction mass.
Perhaps you are right, as there will be some losses when transforming the heat of a nuclear reactor into electric energy. On the other hand I wonder, if all fissible material in a bomb will go into chain reaction? As soon as you reach critical mass, the thing explodes, thus stopping the chain reaction. In a reactor you've got more control about this. Project Orion test flight video In 1959 a test vehicle called the Hot Rod reached an altitude of 104 m (300 ft). It was of course driven by conventional explosives. http://www.youtube.com/watch?v=uQCrPNEsQaY
