Basic Types of Space Probes

Five basic types of space probes have been sent to examine planets and other bodies in the solar system: fly-by probes, orbiters, atmospheric probes, landers and rovers.

  1. A fly-by probe makes its observations as it passes a celestial body from a distance. Fly-by missions enable a spacecraft to visit more than one object.
  2. An orbiter is designed to park itself in a stable orbit around a particular planet or moon for an extended period of time. An orbiter closely circling a body with a substantial atmosphere is gradually slowed by atmospheric friction, which causes it to lose altitude and eventually crash.
  3. An atmospheric probe is a package of instruments that descends into the atmosphere of a planet, taking readings on its way down. The probe continues to transmit data until it reaches the surface or is destroyed by heat or atmospheric pressure.
  4. A lander is designed to land safely on a planet or moon and analyze soil samples and surface conditions.
  5. A rover is a robot vehicle with wheels or treads that roams across the surface. Carried to the surface by a lander, a rover has the advantage of not being confined to one spot.