[HN Gopher] NASA, DARPA will test nuclear engine for future Mars...
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NASA, DARPA will test nuclear engine for future Mars missions
Author : 1970-01-01
Score : 52 points
Date : 2023-01-24 19:52 UTC (3 hours ago)
(HTM) web link (www.nasa.gov)
(TXT) w3m dump (www.nasa.gov)
| 1bent wrote:
| Sounds like the system in Heinlein's Rocket Ship Galileo
| wkat4242 wrote:
| Nice, at least this doesn't seem like one of those horrible 60s
| designs that spewed radiation everywhere by basically detonating
| a small nuclear bomb against a pusher plate.
|
| I think nuclear propulsion is there only way forward for
| interplanetary colonisation because we've long reached the limits
| of chemical. And ion is too slow.
| Scalene2 wrote:
| NERVA in the 1960s operated under a similar principal to the
| one just announced. Orion (what you're describing) was not the
| only proposal in the 1960s.
|
| As for nuclear propulsion being the only way forward, I doubt
| that, I suspect that chemical will be more cost efficient for a
| lot of the trips, especially for unmanned cargo trips.
| NegativeLatency wrote:
| Probably easier to generate chemical fuel on the moon/mars
| too then to refine nuclear fuel, although if you could carry
| enough nuclear fuel in the first place maybe that would be
| moot.
| comprambler wrote:
| Good video on the NERVA project.
|
| https://www.youtube.com/watch?v=eDNX65d-FBY
| kneebonian wrote:
| So I've been working on a sci-fi book that involves
| interplanetary governance, and one of the things I've
| realized is that if one wanted to have a civilization that
| worked on an interplanetary scale nuclear is probably the
| only way to go for meaningful power production.
|
| Chemical means, based on carbon products that we've used up
| till now, would be very rare on remote planets, solar
| wouldn't work because planets could be various distances from
| a star they orbit, or could have different atmospheric, or
| magnetospheric conditions that would make that impractical,
| wind suffers a similar issue.
|
| The only power source that could be guaranteed to work at the
| large scale, both in terms of space and time, reliably, and
| is likely to be available is nuclear power. With your other
| options being the quantum vacuum energy or anti-matter, but
| both fall more into the fiction part of sci-fi right now than
| the science part.
|
| it was just a fun interesting little thought exercise. I'd
| love to hear if anyone has a criticism of the reading though.
| blisterpeanuts wrote:
| Isaac Arthur on YouTube has some interesting commentary on
| antimatter, and other advanced proposed propulsion systems.
| It seems that for the moment, at least, antimatter is
| strictly in the realm of science fiction, until some very
| difficult problems are solved.
| blisterpeanuts wrote:
| It sounds like you're referring to nuclear pulse propulsion, a
| proposed method of reaching Mars from the Earth's surface in 2
| weeks.[1]
|
| I'm not sure what's "horrible" about it. Research was halted
| because of the Test Ban Treaty, but if a safe way could be
| found to get the nuclear material into orbit, why not try it?
|
| 2 weeks is far better than 45 days which is what Nasa estimates
| nuclear thermal propulsion would achieve.
|
| Zero gravity and space radiation are deadly to humans, and the
| more exposure we can cut, the better.
|
| 1. https://en.m.wikipedia.org/wiki/Nuclear_pulse_propulsion
| allenrb wrote:
| Personally I am excited to see this, but I wonder if the optics
| will kill it?
|
| People get upset enough about reactors that don't move and live
| inside huge structures of reinforced concrete. Can we convince
| this segment of the population that launching a small device
| (with necessarily less shielding) is safe?
|
| Even the most reliable launch vehicles (Falcon 9, Atlas V) are
| probably not more than ~99% likely to succeed. Can the payload be
| made safe in the event that it fails to make orbit?
| geijoenr wrote:
| Definitely a common sense step in the right direction. Humans
| going anywhere beyond the moon using chemical propulsion seems
| quite problematic due to all the unsolved issues related to
| radiation and micro-gravity.
|
| Now talking speculative fiction, the real breakthrough will come
| if we figure out a way to induce acceleration without an action-
| reaction process. Just an energy source, and no propellant. Being
| able to sustain 1g for a few months on a heavy spacecraft means
| interstellar travel (proxima centaury) would be within grasp.
| eddsh1994 wrote:
| How does your initial point of 1g for a few months on a heavy
| spacecraft lead to traveling 4.246 light years? Genuine
| question!
| gpm wrote:
| It would take 6 years to get there (earth time) or 3.6 years
| (spacecraft time) if you could have constant 1G acceleration
| (in the opposite direction for the second half of the
| journey).
|
| https://cosmicreflections.skythisweek.info/2019/09/04/space-.
| ..
| geijoenr wrote:
| With a spacecraft big enough to live in, we are talking of
| a time frame not too different from the one from the age of
| exploration by sea. I have no doubt many people would want
| to take such a trip even if it takes 10 years to get back
| to earth.
|
| Unmanned spacecrafts would be able to go much faster,
| sustaining more dramatic accelerations. So getting cargo
| and robots there for support would be way faster.
| eddsh1994 wrote:
| This takes you to 0.99C, how feasible is that (thinking
| materials more than anything)
| credit_guy wrote:
| It's not feasible. It would require more fuel than the
| Earth is heavy, even if we had nuclear propulsion.
| geijoenr wrote:
| Yeah well, we don't really know what happens at high
| speeds. Probably biochemistry stops working at 0.3c? It
| doesn't seem structural materials would remain solid at
| 0.95c... who knows.
| protokultur wrote:
| Kerbal Space Program right again
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