The research will aid in planning for future human missions to the Red Planet.

The first human mission to Mars is now probably too expensive for any one nation to pull off by itself.

But all this can be accomplished without human missions to Mars.

Another is to survey the geology and resources that might be used to support future human missions to the planet.

Few scientists are calling for a human mission to the Moon or Mars.

Beech knew I there'd already been at least one human mission to the planet.

Grant drove himself fiercely to make certain that the next human mission into Jupiter's ocean would not end the same way.

These discoveries will help lay the foundation for future human missions to Mars.

In my novel Mars, I needed to show some of the political background that led up to the first human mission there.

But three years ago Alex was killed on the first human mission to Venus.