Such information is needed before humans can safely travel to Mars and beyond in the next century.

The first humans to travel so far out into space, visiting new planets.

Indeed, a constant 1 g acceleration would permit humans to travel through the entire known Universe in one human lifetime.

A more likely use of this effect would be to enable humans to travel to nearby stars without spending their entire lives aboard the ship.

What we learn from each of these missions helps us build a future where humans travel throughout the solar system.

There's a good chance that humans will travel to Mars before we see the beginning of a new century.

Navigation devices such as the treadmill and bicycle make use of the natural ways that humans travel in the real world.

The Brainians could see the long, thin arteries along which the humans travelled.

As humans traveled around the world they brought with them many foreign animals which disturbed these island species.

Jet lag is a physiological condition, often occurring when humans travel from one time zone to another.