Mars Exploration Rovers:

What is the spacecraft?

The spacecraft is separate from the launch vehicle. It is the protective "spaceship" that enables the precise cargo (that is, the rover!) to travel between Earth and Mars once the launch vehicle has already projected it outside of Earth´s atmosphere and gravity pull.

The spacecraft includes the mechanical units that safely carry and maneuver the rover as it enters the Martian atmosphere and lands on Mars. Once on the surface, like a semi-truck carrying a racecar cross-country, it lowers a ramp to let the rover drive out.

What are the main spacecraft parts?

Cruise Stage:
Configuration for travel between Earth & Mars.

Entry, Descent, & Landing System:
Configuration for entry into the Martian atmosphere. Includes the aeroshell (the heatshield and backshell), the parachute, the airbags, and a lander structure.

A wheeled vehicle with science instruments for discoveries on the Martian surface.

The spacecraft design for the Mars Exploration Rover mission is largely based on the successful Mars Pathfinder system for entry, descent, and landing. The rover design is based on the Athena Rover on the previously cancelled Mars 2001 lander mission.

How much does the spacecraft weigh?

Each system has a total launch mass of 1,063 kilograms (2,343 pounds). The mass of each primary part of the spacecraft is as follows:

   Allocated Mass in kg
Cumulative Mass in kg
185 kg
(408 lbs)
185 kg
(408 lbs)
348 kg
(767 lbs)
533 kg
(1,175 lbs)
Backshell / Parachute
209 kg
(742 lbs)
742 kg
(1,636 lbs)
Heat Shield
78 kg
(172 lbs)
820 kg
(1,808 lbs)
Cruise Stage
193 kg
(425 lbs)
1,013 kg
(2,233 lbs)
50 kg
(110 lbs)
1,063 kg
(2,343 lbs)