Why the Reluctance to Employ Nuclear Propulsion for Interstellar Travel?

[Radrook]

Why the Reluctance to Employ Nuclear Propulsion?

If ten percent of the speed of light, which is approx. 18,600 miles per second, can be reached via nuclear propulsion, a velocity that would take the ship to Alpha centaury system in approx 44 years, then why are they hesitating in implementing it?

An unmanned exploration ship using nuclear propulsion isn’t going to harm Earth. Seems silly to shackle such a technology based on the non-nuclear proliferation into Space treaty established during the Cold war

An atomic (fission) Orion can achieve perhaps 9%-11% of the speed of light. A nuclear pulse drive starship powered by Fusion-antimatter catalyzed nuclear pulse propulsion units would be similarly in the 10% range and pure Matter-antimatter annihilation rockets would be theoretically capable of obtaining a velocity between 50% to 80% of the speed of light. In each case saving fuel for slowing down halves the max. speed. The concept of using a magnetic sail to decelerate the spacecraft as it approaches its destination has been discussed as an alternative to using propellant, this would allow the ship to travel near the maximum theoretical velocity.[18]

At 0.1c, Orion thermonuclear starships would require a flight time of at least 44 years to reach Alpha Centauri, not counting time needed to reach that speed (about 36 days at constant acceleration of 1g or 9.8 m/s2). At 0.1c, an Orion starship would require 100 years to travel 10 light years. The astronomer Carl Sagan suggested that this would be an excellent use for current stockpiles of nuclear weapons.[19]]/quote]

 

[HenryM]

Why the Reluctance to Employ Nuclear Propulsion?

If ten percent of the speed of light, which is approx. 18,600 miles per second, can be reached via nuclear propulsion, a velocity that would take the ship to Alpha centaury system in approx 44 years, then why are they hesitating in implementing it?

Because space doesn't exist.

 

[visionary]

OP has a good question.

 

[Radrook]

Because space doesn't exist.

Oh! Ok! Thank you for disabusing me of that horrendous delusion.

BTW
Care to explain what our present location is. I'm starting to feel a bit disoriented.
I assume this is a normal reaction to being exposed to such a reality-right?

 

[timewerx]

Why the Reluctance to Employ Nuclear Propulsion?

If ten percent of the speed of light, which is approx. 18,600 miles per second, can be reached via nuclear propulsion, a velocity that would take the ship to Alpha centaury system in approx 44 years, then why are they hesitating in implementing it?

An unmanned exploration ship using nuclear propulsion isn’t going to harm Earth. Seems silly to shackle such a technology based on the non-nuclear proliferation into Space treaty established during the Cold war

Nuclear rockets expel radioactive particles in their exhaust because the reactor has to be run at white-hot temperatures to achieve high thermal efficiency. These particles are heavier-than-air and can settle and contaminate the ground (including water, soil, etc.).

So even if you'll never use these rockets near Earth, the risk of radioactive fallout/contamination during development/testing on Earth is going to be high which could make development prohibitively expensive.

 

[HenryM]

Oh! Ok! Thank you for disabusing me of that horrendous delusion... I'm starting to feel a bit disoriented...

Obviously I meant space as we are told about in our mainstream culture. You can't be disoriented since space not existing as we are taught doesn't change how we live and breathe here on Earth. In fact, maybe you would be disoriented if Earth is actually spinning and moving in a spiral at breakneck speeds.

Anyway, I was presenting my conclusion. We'll see.

 

[Tolworth John]

There are a nmber of reasons, politics and the distrust between nations being one very big reason.
Cost another.
check out the site atomicrockets, its full of more maths and science than most people need, but it does explain how an atomic powered rocket could work. try Slower Than Light - Atomic Rockets

 

[Radrook]

Obviously I meant space as we are told about in our mainstream culture. You can't be disoriented since space not existing as we are taught doesn't change how we live and breathe here on Earth. In fact, maybe you would be disoriented if Earth is actually spinning and moving in a spiral at breakneck speeds.

Anyway, I was presenting my conclusion. We'll see.

So you are a Flat Earther who believes that there is an impenetrable dome preventing passage beyond and that all these claims of distances, planets and galaxies are a conspiracy-right?

 

[HenryM]

So you are a Flat Earther who believes that there is an impenetrable dome preventing passage beyond and that all these claims of distances, planets and galaxies are a conspiracy-right?

Outerspace is distinct issue to the shape of the Earth, or movement of the Earth. No need to bring Flat Earth in. I could present the same type of label-driven question back to you. Sorry for derailing the thread with this, anyhow. My original post was just a short reaction about discussing something that I think isn't real (outerspace travel).

 

[ananda]

It would be devastating to Earth if it failed while in the atmosphere of the Earth (e.g. as it ascends to leave orbit).

 

[Radrook]

Outerspace is distinct issue to the shape of the Earth, or movement of the Earth. No need to bring Flat Earth in. I could present the same type of label-driven question back to you. Sorry for derailing the thread with this, anyhow. My original post was just a short reaction about discussing something that I think isn't real (outerspace travel).

No I am not complaining. I am simply trying to get a clear view of your viewpoint. No need to be sorry. I appreciate your feedback.

 

[Greg J.]

Why the Reluctance to Employ Nuclear Propulsion?

If ten percent of the speed of light, which is approx. 18,600 miles per second, can be reached via nuclear propulsion, a velocity that would take the ship to Alpha centaury system in approx 44 years, then why are they hesitating in implementing it?

An unmanned exploration ship using nuclear propulsion isn’t going to harm Earth. Seems silly to shackle such a technology based on the non-nuclear proliferation into Space treaty established during the Cold war

Nuclear reaction is a method of creating heat. You may just as well have asked why we don't use a steam engine. The burning of fuel is valuable because it is a weight-efficient way to create propulsion (for current technology). For a nuclear reaction to be valuable in space, the heat must be used to propel matter in the opposite direction the ship must go. Where does that matter come from? It would have to be carried on board just like any fuel is. It's why the Bussard Ramjet is a clever (fantasized) solution (imagined by SF author Larry Niven). It only works because it gathers the matter it needs from space as it moves along, then it is heated to be vigorously propelled out the back (ala a turbine engine).

 

[durangodawood]

It would be devastating to Earth if it failed while in the atmosphere of the Earth (e.g. as it ascends to leave orbit).

That didnt stop us launching Cassini with its 33kg of plutonium energy source.

If that blew up in atmosphere it would have been.... a mess.

 

[RDKirk]

'Cuz they is nooooooks!

Real talk: Cassini uses nuclear propulsion. We believe the Russians have used small ones all along in satellites during the Space Race (although the Soviets did lots and lots of stupid nuke stuff that has left many thousands of square miles of Russia uninhabitable).

The first thing we need to do toward any further human activity in space is to build a permanent major space station in earth orbit, a torus station or something along the lines of Babylon 5. It would be permanently staffed, and largely used as a platform to assemble deep-space ships--including nuclear powered ships.

No future manned program that is proposed without building a permanently manned orbiting "shipyard" first is anything more than a political stunt.

 

[Radrook]

It would be devastating to Earth if it failed while in the atmosphere of the Earth (e.g. as it ascends to leave orbit).

It was planned to be lifted into orbit conventionally and then the nuclear part would kick in after it reached outer space. No need to use it when it was close to Earth at all. We cannot reach one-tenth the speed of light with chemical rocket engines. The amount of fuel that would be needed is impractical.

 

[FrumiousBandersnatch]

Real talk: Cassini uses nuclear propulsion.

For propulsion, Cassini uses conventional hydrazine rocket fuel and hypergolic nitrogen tetroxide/monomethylhydrazine fuel - and gravity assist. The power for electronics, etc., is supplied by three standard plutonium-238 radioisotope thermoelectric generators.

 

[Aldebaran]

It was planned to be lifted into orbit conventionally and then the nuclear part would kick in after it reached outer space. No need to use it when it was close to Earth at all. We cannot reach one-tenth the speed of light with chemical rocket engines. The amount of fuel that would be needed is impractical.

I'm not sure the reluctance is purely with using nuclear power for interstellar travel. I think it's interstellar travel itself. Heck, we're reluctant to even do interplanetary travel with humans on board. A manned trip to Mars is questionable as to whether or not it will happen in our lifetime. We'd have to accomplish a trip to Mars and be able to do it very easily before considering a manned trip to another star system.

 

[Aldebaran]

For propulsion, Cassini uses conventional hydrazine rocket fuel and hypergolic nitrogen tetroxide/monomethylhydrazine fuel - and gravity assist. The power for electronics, etc., is supplied by three standard plutonium-238 radioisotope thermoelectric generators.

The latest Mars rover (Curiosity) is also powered with a nuclear source. The Curiosity Rover Nuclear Battery Explained To All

 

[FrumiousBandersnatch]

The latest Mars rover (Curiosity) is also powered with a nuclear source. The Curiosity Rover Nuclear Battery Explained To All

Yes, apparently they updated the old RTG model for Curiosity.

 

[Radrook]

I'm not sure the reluctance is purely with using nuclear power for interstellar travel. I think it's interstellar travel itself. Heck, we're reluctant to even do interplanetary travel with humans on board. A manned trip to Mars is questionable as to whether or not it will happen in our lifetime. We'd have to accomplish a trip to Mars and be able to do it very easily before considering a manned trip to another star system.

Yes, I am, aware of the reluctance to send people out there and it's perfectly understandable and I think it has been a wise decision to use probes in our initial exploration of the solar system. When I proposed interstellar I had such an unmanned probe in mind.

Just recently the discovery of a planet around a red dwarf star in the Alpha Centaury system was discovered. Such a planet could be reached in approx. 48 years at one-tenth the speed of light. Four years later information sent back to us such as images would begin to arrive as they did with Pluto.