Live data from Hacker News

Questions about Nasa's space drive answered

wired.co.uk

11–20 of 205 posts

Re: Questions about Nasa's space drive answered

#12

Please be true, please be true! How big is a two megawatt nuclear power source anyway? A quick search showed nuclear power plants are in the hundreds to low thousands of megawatt range, and RTGs are in the tens to hundreds of watt range. I have no idea what something that lies between those two would be.

http://en.wikipedia.org/wiki/Micro_nuclear_reactor

Toshiba 4S gives 10 MW.

"a 50 MW version [will be] available in the future"

Re: Questions about Nasa's space drive answered

#13

Please be true, please be true! How big is a two megawatt nuclear power source anyway? A quick search showed nuclear power plants are in the hundreds to low thousands of megawatt range, and RTGs are in the tens to hundreds of watt range. I have no idea what something that lies between those two would be.

Wikipedia gives the generator of Loss Angeles class nuclear submarines to be 26 MW [1]. I don't know whether you can make them as successful in space without the access to ambient water.

[1]http://en.wikipedia.org/wiki/Los_Angeles_class_submarine

Re: Questions about Nasa's space drive answered

#15

Besides the frequency of the electromagnetic waves , is this the same concept as the "Pioneer Anomaly" - where they eventually figured out it was thermal radiation emitted from its satellite dish which slowed down the spacecraft ?

As far as I can tell it wouldn't matter what the cause of the apparent effect is. Not requiring reaction mass is what makes it interesting.

Re: Questions about Nasa's space drive answered

#16

Deep breaths. Probably experimental error. Extraordinary claims require extraordinary proof... God DAMN this is exciting.

Indeed.

As to the whole "we don't actually understand how it works" - we still can't make up our minds as to how wings work, so this isn't overly novel. Sure, we can explain the outcome, but whether it's Navier-Stokes or Bernoulli or something else, we can't make up our minds.

I suspect this will be similar for a long while - although puts physics hat on I think this is likely a relativistic temporal quantisation effect.

Re: Questions about Nasa's space drive answered

#17
post #13

Please be true, please be true! How big is a two megawatt nuclear power source anyway? A quick search showed nuclear power plants are in the hundreds to low thousands of megawatt range, and RTGs are in the tens to hundreds of watt range. I have no idea what something that lies between those two would be.

Wikipedia gives the generator of Loss Angeles class nuclear submarines to be 26 MW [1]. I don't know whether you can make them as successful in space without the access to ambient water. [1] http://en.wikipedia.org/wiki/Los_Angeles_class_submarine

The principle problem to be overcome with this tech is going to be cooling - both for the power source and for the drive. It's going to require radiators the with a stonkingly huge area and Peltier shunts, unless we come up with a cunning means of dumping excess heat - potentially turning it into more energy to drive with, even, using the seebeck effect.

Re: Questions about Nasa's space drive answered

#18
post #15

Besides the frequency of the electromagnetic waves , is this the same concept as the "Pioneer Anomaly" - where they eventually figured out it was thermal radiation emitted from its satellite dish which slowed down the spacecraft ?

As far as I can tell it wouldn't matter what the cause of the apparent effect is. Not requiring reaction mass is what makes it interesting.

What? Of course the apparent affect matters. If the underlying physical principles can be understood, there is a possibility of increasing its efficiency for larger throughput. And if the underlying process isn't understood, there is no way to rule out something that isn't actually producing thrust or some other fluke.

Finally, the whole point of science is to discover things. Not make magic :|

Re: Questions about Nasa's space drive answered

#19
post #13

Earlier quoted context omitted.

Wikipedia gives the generator of Loss Angeles class nuclear submarines to be 26 MW [1]. I don't know whether you can make them as successful in space without the access to ambient water. [1] http://en.wikipedia.org/wiki/Los_Angeles_class_submarine

The principle problem to be overcome with this tech is going to be cooling - both for the power source and for the drive. It's going to require radiators the with a stonkingly huge area and Peltier shunts, unless we come up with a cunning means of dumping excess heat - potentially turning it into more energy to drive with, even, using the seebeck effect.

Isn't space pretty cool?
Post reply on HN