From the 1960s on, spacecraft bound for Mars have been regularly launched to explore our closest planetary neighbor and assess its potential as a host planet for life. But only half have succeeded so far.
Last summer, two cutting-edge missions arrived at Mars orbit: Hope from the United Arab Emirates and Tianwen-1 from China. Both orbiters carried cutting-edge instruments.
NASA’s Phoenix probe successfully landed at Mars’ north pole to study water ice and alkaline soil conditions, carrying along a chemical laboratory for analysis that may provide clues into how Earth could have been similar to Mars in past times.
Orbiter
NASA orbiters orbiting Mars serve two purposes, relaying data back to Earth for surface missions as well as performing their own scientific research. Their orbiters have assisted mission teams with selecting landing sites, monitored weather systems and dust storms and helped define Mars’ geology.
MRO played an essential role in pinpointing Europe’s failed ExoMars Schiaparelli lander in 2016 as well as gathering data which indicated liquid water may have existed on Mars in its ancient past.
MRO employs aerobraking, or gently brushing against the atmosphere, to adjust its orbit and save fuel. As of 2016, it transmits 34 Terabits annually via two 34-meter Deep Space Network antennas located here on Earth – more than 20 times as much data than previous planetary missions did! Electra’s communications package facilitates these inter-spacecraft data links with protocols.
Lander
A lander is designed to land at a specific spot on Mars and equipped with instruments to study its environment, such as cameras that take panoramic images and sensors for studying atmospheric, surface and interior characteristics of Mars.
Once the lander has disengaged from its parachute and back shell, thrusters would be used for controlled descent while inertial gyroscopes and accelerometers would provide orientation during this stage.
Once on Mars’ surface, the spacecraft would deploy solar panels for power. Furthermore, data would begin being transmitted back from its MVACS surface stereo imager and meteorology package back to Earth.
JPL’s New Millennium Deep Space Project had developed two 3.5 kg penetrators designed to penetrate up to one meter into Martian soil and send acceleration data back to an orbiter, in order to test Europe’s capabilities of landing controlled on Mars – their intended target being Chryse Planitia near Mars’ equator.
Rover
Mars Exploration Rovers Spirit and Opportunity use rovers to explore the surface of Mars, searching for any signs of past life on its surface and studying climate, geology and other characteristics which would allow researchers to determine whether life ever developed there.
This rover also collects rock samples for examination, sealing and caching some on Mars as part of NASA’s Mars Sample Return Campaign; future missions could then bring these rocks back home for study on Earth.
The instruments aboard the rover use an array of instruments to analyze chemicals, isotopes and minerals in rocks it collects. A drill collects samples for closer examination as well as making holes to conduct chemical analyses on surface rocks. Two cameras aboard include PIXL which finds microscopic details in rocks while Mastcam-Z provides zoomable color images for education and outreach activities.
Other Spacecraft
NASA and its international partners are taking steps toward sending humans to Mars. Their Mars Exploration Program uses a carefully chosen fleet of robotic orbiters, landers and rovers that continually explore this Red Planet for scientific discoveries.
Venera 7 from the Soviet Union became the first free-moving rover to land on Mars in 1970, followed by Spirit and Opportunity from US MER (Mars Exploration Rover) missions. These missions were designed to search for signs of past life on the Red Planet but instead brought stunning imagery until dust storms destroyed their solar panels in 2010s.
American Mars 2020 mission carried the Curiosity rover to search for signs of life on Mars and collect samples to be returned back to Earth, along with a drill designed to collect them for later return. China sent their Tianwen-1 Lander/Zhurong Rover into Mars orbit in 2021 as did Hope from United Arab Emirates, along with missions visiting Phobos and Deimos moons of Mars; Hera visited Asteroid Didymos while DART collided with Dimorphos.