What was the first rover to operate on Mars?
Quick answer
The first rover to successfully operate on Mars was NASA’s Sojourner, part of the Mars Pathfinder mission. It landed on July 4, 1997, in the Ares Vallis region. About the size of a microwave oven and weighing 10.6 kg, it drove around the landing site for nearly three months, studying rocks and soil.
Key facts
- Rover
- Sojourner (Mars Pathfinder mission)
- Landed
- July 4, 1997
- Mass
- 10.6 kg (23 lb)
- Operated
- About 83 sols (Martian days)
A bouncy landing
Mars Pathfinder didn’t use landing legs. Instead, it was wrapped in giant airbags and bounced across the surface about 15 times before rolling to a stop. Then its petals opened and Sojourner drove down a ramp onto Martian soil.
What Sojourner did
- Traveled about 100 m in total, never far from its lander
- Studied rocks nicknamed Barnacle Bill and Yogi with an X-ray spectrometer
- Took photos showing signs that water once flowed in the area
- Proved a small wheeled robot could work on Mars
The rover’s name honors Sojourner Truth, the 19th-century abolitionist and women’s rights campaigner; see the abolitionist movement. A 12-year-old student suggested it in a naming contest.
Earlier attempts
In 1971, the Soviet Mars 3 lander carried a small rover, but the lander stopped transmitting about 20 seconds after landing, so the rover never operated. The first rover to work on another world was the Soviet Lunokhod 1 on the Moon, in 1970.
Rovers that followed
| Rover | Agency | Landed | Notes |
|---|---|---|---|
| Sojourner | NASA | 1997 | First Mars rover |
| Spirit | NASA | 2004 | Worked for about 6 years |
| Opportunity | NASA | 2004 | Planned for 90 days; lasted almost 15 years |
| Curiosity | NASA | 2012 | Car-sized; still operating |
| Perseverance | NASA | 2021 | Collecting samples; carried the Ingenuity helicopter |
| Zhurong | China | 2021 | China’s first Mars rover |
Getting there
Each mission must launch when Earth and Mars line up, about every 26 months. The trip usually takes seven months; see how long it takes to travel to Mars.
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