Mision to Mars

These future possibilities are exciting, but unmanned spacecraft have already greatly enhanced our knowledge of Mars.

Dozens of spacecraft have been sent to Mars, but only about one of every three missions has been a success. This sobering statistic underscores just how difficult it remains to send a craft to Mars and see it arrive in proper working order to transmit data back to Earth.

The first Mars missions were called flybys and involved getting a spacecraft close to the planet so that it could take images in passing.