Mars Exploration Rovers - Quick Facts | Public Outreach | Mars Institute - To further the scientific study, exploration, and public understanding of Mars

Spacecraft

Cruise vehicle dimensions: 2.65 meters (8.7 feet) diameter, 1.6 meters (5.2 feet) tall Rover dimensions: 1.5 meter (4.9 feet) high by 2.3 meters (7.5 feet) wide by 1.6 meter (5.2 feet) long
Weight: 1,062 kilograms (2,341 pounds) total at launch, consisting of 174-kilogram (384- pound) rover, 365-kilogram (805-pound) lander, 198-kilogram (436-pound) backshell and parachute, 90-kilogram (198-pound) heat shield and 183-kilogram (403-pound) cruise stage, plus 52 kilograms (115 pounds) of propellant
Power: Solar panel and lithium-ion battery system providing 140 watts on Mars surface
Science instruments: Panoramic cameras, miniature thermal emission spectrometer, Mössbauer spectrometer, alpha particle X-ray spectrometer, microscopic imager, rock abrasion tool, magnet arrays

Spirit Mission

Launch vehicle: Delta II 7925
Launch: June 10, 2003, from Cape Canaveral Air Force Station, Fla.
Earth-Mars distance at launch: 103 million kilometers (64 million miles)
Mars landing: Jan. 4, 2004, at about 2:30 p.m. local Mars time (signal received at Earth 8:35 p.m. PST Jan. 3)
Landing site: Gusev Crater, possible former lake in giant impact crater
Earth-Mars distance on landing day: 170.2 million kilometers (105.7 million miles)
One-way speed-of-light time Mars-to-Earth on landing day: 9.46 minutes
Total distance traveled Earth to Mars (approximate): 487 million kilometers (303 million miles)
Near-surface atmospheric temperature at landing site: -100 C (-148 F) to 0 C (32 F)
Primary mission: 90 Mars days, or "sols" (equivalent to 92 Earth days)

Opportunity Mission

Launch vehicle: Delta II 7925H (larger solid-fuel boosters than 7925)
Launch: July 7, 2003, from Cape Canaveral Air Force Station, Fla.
Earth-Mars distance at launch: 78 million kilometers (48 million miles)
Mars landing: Jan. 25, 2004, at about 1:15 p.m. local Mars time (signal received at Earth 9:05 p.m. PST Jan. 24)
Landing site: Meridiani Planum, where mineral deposits suggest wet past
Earth-Mars distance on landing day: 198.7 million kilometers (123.5 million miles)
One-way speed-of-light time Mars-to-Earth on landing day: 11 minutes
Total distance traveled Earth to Mars (approximate): 456 million kilometers (283 million miles)
Near-surface atmospheric temperature at landing site: -100 C (-148 F) to 0 C (32 F)
Primary mission: 90 Mars days, or "sols" (equivalent to 92 Earth days)

Program

Cost: Approximately $820 million total, consisting approximately of $645 million spacecraft development and science instruments; $100 million launch; $75 million mission operations and science processing