Why we should embrace the end of human spaceflight?

[lustatopia]

What if you want to sail towards the sun? How does a sailing-spaceship tack -- where's the second force-vector (analogous to the resistance of the water, for a sailing-ship with a rudder and keel)?

The ship would still need a nuclear power plant. The solar wind wouldn't be the only power source. The point is why be farting around the inner planets and not harvest whatever energy you can to reduce the amount of fuel you'll need?

 

[Frisco_Slug_Esq]

Whatever you say, Rosenkreutz. Maybe I should have the coffee and you the single malt.

Deal!




Something to take the edge off a 100° day...

 

[stephen55]

The ship would still need a nuclear power plant. The solar wind wouldn't be the only power source. The point is why be farting around the inner planets and not harvest whatever energy you can to reduce the amount of fuel you'll need?

A problem with nuclear power plants is that they are heavy. They don't have to be, if you don't mind being bathed in radiation. Many space craft have had a nuclear power plant on board. All of those amazing images we've gotten from the Cassini craft are due to the nuclear power plant it carries. But putting a nuke on a manned craft does pose some basic problems.

 

[lustatopia]

A problem with nuclear power plants is that they are heavy. They don't have to be, if you don't mind being bathed in radiation. Many space craft have had a nuclear power plant on board. All of those amazing images we've gotten from the Cassini craft are due to the nuclear power plant it carries. But putting a nuke on a manned craft does pose some basic problems.

No problemo amigo in Zero grav. Just put El nuko on the end of a very long boom, plus shielding only has to be on one side. Not only can no one hear you scream in space but aerodynamics don't matter either....plus there ain't no stinkin' EPA regulations since there ain't no stinkin' environment to pollute..... That'll cut down on the weight and increase efficiency.

 

[seniyajw]

I know that near-Earth objects. I know there are many of them. I know they do hit the Earth. I also know that the relationship between the size of these objects in relation to the incidence rate (from hitting the Earth) follows a power law distribution that convinces me not to worry about it.

 

[stephen55]

No problemo amigo in Zero grav. Just put El nuko on the end of a very long boom, plus shielding only has to be on one side. Not only can no one hear you scream in space but aerodynamics don't matter either....plus there ain't no stinkin' EPA regulations since there ain't no stinkin' environment to pollute..... That'll cut down on the weight and increase efficiency.

The problem is that the nuke, and the rest of the craft start off at one G. Even if a craft is assembled out there somewhere, everything still starts off down here.

That said, it's still feasible to have a nuclear power plant on board. Shielding the crew from the reactor is similar to shielding the crew from ionizing cosmic radiation. All it takes is enough mass between tissue and radiation. And therein lies the rub. It still costs about $10,000 to lift one kilogram of anything into low-Earth orbit orbit and considerably more to get it out into inter-planetary space.

Recently, the Russians came up with a plan for a Mars mission and one configuration has a nuclear plant on board to provide the electricity to power an electric rocket (ion thrust) engine.

Their proposed Mars Piloted Orbital Station (or MARPOST), which would not include an actual human landing on Mars, weighs in at about 400 metric tons. (400,000 kilograms)

http://upload.wikimedia.org/wikipedia/en/thumb/b/b2/MEK_MOK_advanced_design.jpg/800px-MEK_MOK_advanced_design.jpg