Robot Explorers of Mars

Mariner 4 was launched on 28 November 1964 and made the first successful flyby of Mars in July 1965. Its close-up images were the first ever taken of another planet from deep space, and they showed a cratered, apparently lifeless surface. It now sits derelict in a heliocentric orbit.

Viking 1 paired an orbiter built by JPL with a lander built by Martin Marietta, and launched on 20 August 1975. Its lander touched down in July 1976 as the first spacecraft to land on and operate from the Martian surface. It was later named the Thomas Mutch Memorial Station, and contact ended on 11 November 1982 after a faulty ground command.

Mars Pathfinder, launched on 4 December 1996 as part of NASA's Discovery Program, landed a base station and a rover on Mars in 1997. The lander was renamed the Carl Sagan Memorial Station after touchdown, and it carried a 10.6 kilogram wheeled rover, which moves the trail from landers to mobile explorers.

Sojourner reached Mars on 4 July 1997 and was operational for 92 sols, about 95 Earth days. It was the first wheeled vehicle to operate on an astronomical object other than the Earth or Moon, working in the Ares Vallis channel in Chryse Planitia. The mission formally ended on 10 March 1998.

2001 Mars Odyssey was built by Lockheed Martin and orbits Mars with spectrometers and a thermal imager to detect evidence of past or present water and ice. It also relays communications for Mars rovers, so it supports the machines that follow it on this trail. It was named as a tribute to Arthur C. Clarke.

Spirit landed in Gusev crater on 4 January 2004, three weeks before its twin Opportunity. It was one of the two rovers of NASA Mars Exploration Rover Mission, managed by JPL, and operated for 2208 sols, or 3.3 Martian years, far beyond the roughly 90 sol plan.

Opportunity, nicknamed Oppy, launched on 7 July 2003 and landed in Meridiani Planum on 25 January 2004 on the other side of the planet from Spirit. It stayed operational for 5111 sols, about 14 years, until NASA declared its mission complete in 2018.

Curiosity is a car-sized rover exploring Gale crater and Mount Sharp for NASA as part of the Mars Science Laboratory mission, launched on 26 November 2011. It investigates whether Mars ever had conditions favorable for microbial life, and it has operated well past its original planned mission length.

MAVEN, launched on 18 November 2013 and built by Lockheed Martin Space Systems, studied how the solar wind strips gases from the upper atmosphere and ionosphere of Mars. The name stands for Mars Atmosphere and Volatile Evolution. NASA has since declared the spacecraft dead and its mission concluded.

InSight was a lander managed by JPL and launched on 5 May 2018, designed to study the deep interior of Mars. It confirmed marsquakes, showing that the planet has a still active interior. It operated for 1,440 sols, and its mission was declared over on 21 December 2022.

Perseverance landed in Jezero crater on 18 February 2021 as part of the Mars 2020 mission. It searches for signs of ancient microbial life and caches rock samples for a planned return to Earth. It also carried Ingenuity, a small helicopter that made the first powered flight on another planet.