If the space shuttle is really big there would be not much difference compared to today on Earth, just that solar, wind, and hydro energies would not be an option. You would have to get energy either from nuclear or chemical reactions, and of course nuclear is much more interesting when looking at the ratio energy over weight. Energy from nuclear radioactivity or perhaps from fission chain reaction is the only options I know. Nuclear fusion has not been achieved yet for reliable energy production.

But of course when we will live in a large space shuttle far from our Sun there will be plenty of other ways to produce energy. :-)

Dear Claude Ziad El-Bayeh ,

Nuclear fusion is not yet available. But the old nuclear fission does.

There are numerous projects with nuclear fission reactors of small size and designed for spaceships. Some ships were designed 1950 with nuclear fission reactors (https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)).

However, thinking about the distance from a star, it is likely that solar panels, even very distant from a star, will still be able to produce electrical energy.

It is a fact that there are conditions for long trips with nuclear fission reactors, while controlled thermonuclear fusion is not yet a reality.

It is possible that in 2025 when ITER achieves the sustainable nuclear fusion reaction, we can think of something. However, it is still unviable given the size of a current fusion reactor, see the ITER page (https://www.iter.org).

The future always holds incredible things for us, just move on!

I wish everyone a lot of health.

Regards,

Wiltgen

Dear Doctors Dupont and Wiltgen,

I would like to thank you for your time and valuable reply. As I understood from your comments, there is no other option except nuclear fission or a small-scale nuclear power plant. However, nuclear fission is not considered a renewable energy source and could be exhausted, besides it is dangerous and may put the space shuttle in danger of radiation and explosion.

Other renewable energy sources do not exist in space, even if we are talking about solar energy, once we go further from the sun, the radiation may not be enough to supply the demand of the shuttle, since the received energy is decreasing by the square of the distance from the sun.

Does it mean that we will not be able to generate energy without using nuclear fission in the near future? Do you think that once we are able to build a nuclear fusion reactor, will it be enough to supply all our energy needs? Will there be other problems that we might face and that reduce the pace toward the exploration of space?

Thanks a lot!

Have a great day!

Solar energy is stored in space using reflectors or inflatable mirrors and is then converted to solar cells or heaters for thermal systems.

Microwave or laser-based power delivery to the Earth.

A rectenna, or microwave antenna, is used to receive power on Earth.

Dear Claude Ziad El-Bayeh,

On Earth, renewable energies (wind, hydro, photovoltaic, geothermal) are available thanks to the Sun (nuclear fusion by the way), gravity, and also residual Earth heat (with possible contribution from radioactivity). There is no such renewable energies in space far away from any Star, and to my knowledge indeed, nuclear is the only realistic option today (radioactivity or fission) and in the future (fusion).

Fusion energy is nice because the fuel is abundant on Earth (and in space). However, the nuclear fission option might be sustainable with fast breeder reactor (i.e., producing plutonium fuel from natural uranium). Nuclear (radioactivity, fission, fusion) energy is dangerous, I agree, but producing large amount of energy is not trivial anyway, even when using chemical reactions, and frankly speaking that's not more dangerous than living in a space shuttle. A least in interstellar space you can easily get rid of the nuclear waste. :-)

Concerning your final question about show-stoppers in the exploration of deep space... there are just too many! Look at the difficulties just to go to Mars... look at interstellar distances... and above all, what would be the motivations to leave Earth, the only space shuttle we have?

If you really don't like nuclear stuff ;-) another (chemical) option is hydrogen fuel cells, but you will have to find a way to harvest hydrogen in space (and oxygen also btw).

Dear Claude Ziad El-Bayeh,

About your placements:

A radioactive source of nuclear fission reactors has declined for thousands of years. Contrary to what one might think, it also doesn't explode, if there is no accident that causes damage or exposure to radioactive source, everything in engineering is subject to accidents. Contamination only occurs if the reactor is exposed, moreover, the cosmic radiation itself is actually more dangerous than the nuclear fission reactor.

You are not taking into account that light, however small, is more efficient in space than in atmosphere, so at a distance from a star (light source) it is still possible to obtain energy from a solar panel. I imagine several stars over a long journey, stored in compact capacitors or batteries, in addition a spaceship for long journeys must have more than one type of energy source.

Yes, only use of a nuclear fission reactor will allow explorations more and more distant from Earth, in near and distant future. As I said, it will take us many years to shrink the size of a future nuclear fusion reactor, regardless of technology used in process.

Do you have any idea of ​​amount of energy in a nuclear reactor, regardless of whether fission or fusion produces? In a spaceship, it would probably last for hundreds of generations of human beings living inside that spaceship.

Regards,

Prof. Wiltgen

Dear all,

this is not strictly related to the topic, so apologies to deviate, but talking about living and producing energy on an isolated space shuttle for a long period... think about nuclear submarine... in my opinion this is the closest thing ever built by man that partly answer your question.

Best regards

Dear Emmeric Dupont ,

You're absolutely right! A large nuclear submarine is largely submerged in travel for up to two years. Receives food supplies and two more years, without contributing.

Great example !!!

With fission nuclear reactor.

Regards,

Wiltgen

Dear Dr. Claude Ziad El-Bayeh,

Wow, what an interesting and futuristic question - to live in a space shuttle and produce energy.

One of the possible ways of producing energy in a space shuttle is to convert all mechanical motions (energy outputs) into some sort of energy either electrical energy to be stored in batteries (with some losses unfortunately) or heat (or cold) source. Of course, the amount energy produced with this way is least efficient. As we know that in order to be healthy and live longer we need to move and do some exercises, and perform some daily chores by which we can produce some decent amount of energy.

Another way, chemical processing (chemical reactions) of all household waste. In this case, production and use of algae species could be viable technology to produce energy.

Thanks.

A space shuttle or space ship will start of with a certain amount of mass-energy and that will be all that it can use. Once it is far from the sun the radiation received from the sun or stars will not be enough to run even a small radio. Work done by people requires input of energy rich fuel (food) which would need to be replaced . Replacing the food by any method would require more energy than the work and heat produced by the people, even if all that energy could be recovered. A long range space ship would require a store of energy, whether that is in food, chemical reactants, stored electrical energy or the stored mass-energy in atomic nucleii. The third law of thermodynamics (I think) indicates that even without energy being lost into space (some would be) a constant input of energy from this store would be required to keep things inside the ship alive and working rather than just reaching equilibrium.

Dear Claude Ziad El-Bayeh,

Greetings, Thanks for a good question!

Since the universe is living, all performed physical processes generate energy!

Regards, Saeed