NASA to revive the NERVA engine concept.

[plz delete account]

With the Artemis program underway, NASA has once again turned to nuclear engines for far off Mars manned missions; specifically, a concept that was last listed in the 60s called NERVA.

NERVA, like it's brother Orion, was canned in the mid 1960s as proof of concept tests proved they could in fact be used to propel a spacecraft.

How do you feel about rockets irradiating hydrogen and then propelling them outside the back of a rocket engine in the next 15-20 years?

[smityx]

How do you feel about rockets irradiating hydrogen and then propelling them outside the back of a rocket engine in the next 15-20 years?

If they use more conventional rockets to get the craft into space using the NERVA after being in space this would not be a issue.

[I Push Buttons]

With the Artemis program underway, NASA has once again turned to nuclear engines for far off Mars manned missions; specifically, a concept that was last listed in the 60s called NERVA.

NERVA, like it's brother Orion, was canned in the mid 1960s as proof of concept tests proved they could in fact be used to propel a spacecraft.

How do you feel about rockets irradiating hydrogen and then propelling them outside the back of a rocket engine in the next 15-20 years?

I prefer Orion.

Space travel via propelling the ship with literal nuclear explosions sounds metal AF.

[Tuor]

With the Artemis program underway, NASA has once again turned to nuclear engines for far off Mars manned missions; specifically, a concept that was last listed in the 60s called NERVA.

NERVA, like it's brother Orion, was canned in the mid 1960s as proof of concept tests proved they could in fact be used to propel a spacecraft.

How do you feel about rockets irradiating hydrogen and then propelling them outside the back of a rocket engine in the next 15-20 years?

If they don't blow those things in the atmosphere, and if they manage to build a spacecraft with enought radiation isolation, anyway, we would still need conventional rockets to proppel stuff into orbit, also, might not be a good idea to detonate a nuke on orbit as its effects can be measured at the surface.

we need to find faster ways to move within the solar systhem, if properly tested, this could provide us with speed, that conventional rockets don't allow.

[Daedius]

What does it use for trust off the nuclear power?

[I Push Buttons]

What does it use for trust off the nuclear power?

Gas, the same as other rocket engines.

Nuclear thermal is just far more efficient because the nuclear reactor makes the fuel much much hotter before it gets to the nozzle (thousands of degrees), which causes much more expansion and pressure, which allows for a specific impulse that is twice as long as traditional chemical rockets (IE: with a given amount of fuel, the rocket can burn at full thrust for twice as long). This allows for rockets to carry much more payload weight, as less of their launch mass will be taken up by fuel and it also allows them to travel moderately faster since they can continue generating thrust longer, thus achieving a higher final velocity.

[Hammerfest]

With the Artemis program underway, NASA has once again turned to nuclear engines for far off Mars manned missions

What's a "nuclear engine" and how would that propel a vessel through a vacuum?

[Thekri]

What's a "nuclear engine" and how would that propel a vessel through a vacuum?

Something that is fundamentally unnecessary on a flat earth.

[Logwyn]

We need to be going to the Moon already and Mars. Whatever gets us there the fastest would be awesome.

[Calfredd]

I feel like another moon landing would sort of help remind everyone what we can accomplish and reaffirm our space goals.

[Shakadam]

What's a "nuclear engine" and how would that propel a vessel through a vacuum?

Basically, a turbopump forces fuel (generally liquid hydrogen) through a nuclear reactor where it's heated to very high temperatures and then expelled through a nozzle like on conventional rockets. The heated fuel expands and produces thrust, it's at least twice as efficient as the best chemical rockets we can currently make.

[plz delete account]

We need to be going to the Moon already and Mars. Whatever gets us there the fastest would be awesome.

I feel like another moon landing would sort of help remind everyone what we can accomplish and reaffirm our space goals.

It's like NASA is trying to get back to the Moon by 2024 to prepare for Mars landings in the 2030s...

[smityx]

I just fear what a disaster in the upper atmosphere could do.

Probably much less than the air detonations of large nuclear weapons testings during the 50s 60s etc. This would probably more equivalent of a dirty bomb.

[Hammerfest]

Basically, a turbopump forces fuel (generally liquid hydrogen) through a nuclear reactor where it's heated to very high temperatures and then expelled through a nozzle like on conventional rockets. The heated fuel expands and produces thrust, it's at least twice as efficient as the best chemical rockets we can currently make.

How does it do that in a vacuum?

[plz delete account]

How does it do that in a vacuum?

Because the movement of hydrogen produces thrust.
Video below was produced before the Apollo program really got going.

[I Push Buttons]

How does it do that in a vacuum?

Newton's third law... For every action there is an equal and opposite reaction.

Imagine you and a copy of yourself are floating next to each other in the vacuum of space. If you reach out and push your copy, you aren't just going to sit still while your copy floats away, both you and and your copy will float away in opposite directions... The force you exert on your copy will be equally and oppositely exerted back on yourself in the opposite direction.

In the case of rockets... Force is expelled out of the rocket engine via fuel, which causes an equal opposite force to propel the rocket the rocket engine is strapped to in the opposite direction. No atmosphere is necessary, in fact an atmosphere is detrimental to this process via atmospheric drag and rockets are more efficient in the vacuum of space.

[Nihilist74]

It would be good to use one in orbit. Probably not good to use to get to orbit unless it doesn't cause a lot of radioactive exhaust. It would be great to have a rocket with the nuclear-powered vehicle as payload to carry it into orbit. Then the nuclear-powered craft could start its journey towards Mars. It would be great like nuclear submarines. Nuclear submarines can stay out at sea for years. They only need to come back for food. In a rocket, they would still run out of hydrogen though.

[Hammerfest]

Because the movement of hydrogen produces thrust.

In a weightless vacuum?

[Eviscero]

How does it do that in a vacuum?

The same way all rockets generate propulsion in a vacuum... The expanding gas exerts a force on the inside of the engine as it is expelled because "equal and opposite reaction." That force results in acceleration of the ship forward. Or are you someone who thinks jets push off the atmosphere to move forward, hahahah!

[Tuor]

It would be good to use one in orbit. Probably not good to use to get to orbit unless it doesn't cause a lot of radioactive exhaust. It would be great to have a rocket with the nuclear-powered vehicle as payload to carry it into orbit. Then the nuclear-powered craft could start its journey towards Mars. It would be great like nuclear submarines. Nuclear submarines can stay out at sea for years. They only need to come back for food. In a rocket, they would still run out of hydrogen though.

This isn't even closely related to a submarine. A nuclear submarine uses radioactive material to produce electricity, the concept its the same as any other nuclear plant. Electricity can then be used to power the submarine, for example, provide electricity to the eletrical engines.

This concept o nuclear rockets is totaly diferent, as the idea is to turn energy not in electricity, but in mechanical energy, in this case thrust.