NASA Interstellar Options: Does NASA Have Any Practical, Real-World Options For Achieving A Manned Interstellar Flight?

Daniel Ketchum

If movies are to be believed, NASA interstellar flight capability is just around the corner. Unfortunately, the reality of the situation is a bit different. Most people seem to vastly underestimate the incredible distances between the stars, and for NASA to traverse these distances will require either remarkably advanced propulsion technologies or new ways of thinking about exploration.

At this moment, the fastest vehicles human beings have ever built are the Voyager unmanned spacecraft. These are traveling out of our solar system at 38,000 miles an hour.

In theory, at least, a functioning fusion reactor could cut the travel time to the nearest star – Alpha Centauri – to less than a single human lifetime. However, there are certain drawbacks to using fusion rockets for this purpose. One is that we don't have them yet. Another problem is that this rocket would have to carry a large amount of fuel along with it – fuel that the rocket, in turn, would have to push along with the spacecraft. An alternative to this might be the Bussard Ramjet.

This would have the benefit of allowing this theoretical NASA interstellar spacecraft to be much lighter and less expensive. Again though, we don't know how to do fusion yet. More than this, it's uncertain whether we could build a fusion reactor that could operate on the specific types of hydrogen isotopes available in the vacuum of interstellar space.

As noted by Science ABC, all of the antimatter ever created in history would be insufficient to bring a cup of tea to a boil. Yes, antimatter completely destroys an equal amount of ordinary matter – releasing "vast" amounts of energy in the process.

But the quantities of antimatter we've manufactured in particle accelerators are so tiny – basically individual particles – that it would be useless for building a propulsion system for interstellar travel. A NASA interstellar spacecraft using antimatter for propulsion would literally cost trillions of dollars just for the fuel. So that's clearly out.

The ships would go at a snail's pace compared to the previously mentioned options. This means that the people who reach Alpha Centauri – or whichever star system the spacecraft is aimed at – will be the descendants of those who originally set off from Earth. Depending on how long it takes the NASA interstellar generation ship to travel the enormous distance involved, centuries could have passed before the human colonists on board the ship reached their destination.

[Featured Image by Sean Gallup/Getty Images]