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> We have developed an understanding of what propulsion systems enable missions to Mars in 90 days or less, and to otherwise reduce the trip times to the outer

> We have developed an understanding of what propulsion systems enable missions to Mars in 90 days or less, and to otherwise reduce the trip times to the outer planets and beyond by a factor of three. - Dr. Jason Cassibry, Associate professor - Mechanical and aerospace engineering Wow, this seems tremendous. The article itself is behind a paywall. (Abstract: http://arc.aiaa.org/doi/abs/10.2514/6.2014-3520 http://arc.aiaa.org/doi/abs/10.2514/6.2014-3520) Before this article, I'd only dreamed of using nuclear propulsion for interplanetary travel. TIL others have been researching how to make real this technology before I was born. Finding diamonds like this among life's rough sand dunes and rocky hills makes me wonder how many other gems are out there; working theories for components that could be combined to build amazing new devices. And the idea of reaching Mars in months instead of years is too positive to coherently express. This must be what it felt like for travelers settling the American Old West when the First Transcontinental Railroad was completed. Suddenly trips that took months now took weeks, or even days. Cities that were out of reach were now close enough to visit on vacation. Not to mention the benefits from trade - food and other perishable goods (including viruses) could be transported much further, and very large equipment went from being untransportable to being only difficult to transport. Surely, this will be like exploring the solar system in a covered wagon.

vilhelm_s 12y ago
The book "Project Orion: The True Story of the Atomic Spaceship" by George Dyson is really fascinating. The Orion project was all done before the Apollo project was planned, so it is kindof an alternative way the US space program could have gone. Rather than launching dinky little space capsules, they were planning on launching thousands of tonnes into orbit. The spaceship would be a literal spaceship, build similarly to how you construct submarines. The scientists involved kindof assumed that they personally would get to go on a voyage to Saturn (why not, there's plenty of space in the ship...). Compared to what we actually got, with chemical rockets, it was way more impressive!
- TeMPOraL 12y ago
  The simple thought of having that much Δv in a craft that heavy pretty much blows my mind...
  - TheLoneWolfling 12y ago
    That much Δv at a decent TWR, too...
ChuckMcM 12y ago
Stay out of the backwash though :-) The Dyson paper is excellent. Unfortunately, for now at least, it is hard to launch a nuclear RTG without a lot of resistance, imagine how hard it is going to be to launch what is essentially a retriggerable hydrogen bomb into orbit. Does solve a lot of 'time of flight' problems, but adds a few shielding problems of its own.
- Symmetry 12y ago
  Project Orion had much more thrust than this proposal but also came attached to a very heavy lifter plate and set of shock absorbers. That meant that the only feasible way to get Orion up to orbit was for it to fly there under its own power. That means that all the radioactive byproducts were going to end up in the atmosphere. Each bomb is tiny but you'll need a lot of them and it adds up. By contrast this drive is designed to be used in space and once you're outside the Van Allen belt you're pretty much fine to use nuclear drives. The fact that there aren't any critical masses involved also means that you're not violating the Outer Space Treaty.
ValleyOfTheMtns 12y ago
> And the idea of reaching Mars in months instead of years is too positive to coherently express. I don't think getting to Mars has ever taken years. The typical numbers given are 6-8 months, depending on where Earth and Mars are in relation to each others' orbits around the Sun. More than halving the amount of time from 8 to 3 months is still impressive though.
- TeMPOraL 12y ago
  > More than halving the amount of time from 8 to 3 months is still impressive though. That also suggests lots of spare Δv that could be used for going places.

vilhelm_s 12y ago

The book "Project Orion: The True Story of the Atomic Spaceship" by George Dyson is really fascinating. The Orion project was all done before the Apollo project was planned, so it is kindof an alternative way the US space program could have gone. Rather than launching dinky little space capsules, they were planning on launching thousands of tonnes into orbit. The spaceship would be a literal spaceship, build similarly to how you construct submarines. The scientists involved kindof assumed that they personally would get to go on a voyage to Saturn (why not, there's plenty of space in the ship...). Compared to what we actually got, with chemical rockets, it was way more impressive!

TeMPOraL 12y ago
The simple thought of having that much Δv in a craft that heavy pretty much blows my mind...
- TheLoneWolfling 12y ago
  That much Δv at a decent TWR, too...

ChuckMcM 12y ago

Stay out of the backwash though :-) The Dyson paper is excellent. Unfortunately, for now at least, it is hard to launch a nuclear RTG without a lot of resistance, imagine how hard it is going to be to launch what is essentially a retriggerable hydrogen bomb into orbit. Does solve a lot of 'time of flight' problems, but adds a few shielding problems of its own.

Symmetry 12y ago
Project Orion had much more thrust than this proposal but also came attached to a very heavy lifter plate and set of shock absorbers. That meant that the only feasible way to get Orion up to orbit was for it to fly there under its own power. That means that all the radioactive byproducts were going to end up in the atmosphere. Each bomb is tiny but you'll need a lot of them and it adds up. By contrast this drive is designed to be used in space and once you're outside the Van Allen belt you're pretty much fine to use nuclear drives. The fact that there aren't any critical masses involved also means that you're not violating the Outer Space Treaty.

ValleyOfTheMtns 12y ago

> And the idea of reaching Mars in months instead of years is too positive to coherently express. I don't think getting to Mars has ever taken years. The typical numbers given are 6-8 months, depending on where Earth and Mars are in relation to each others' orbits around the Sun. More than halving the amount of time from 8 to 3 months is still impressive though.

TeMPOraL 12y ago
> More than halving the amount of time from 8 to 3 months is still impressive though. That also suggests lots of spare Δv that could be used for going places.