Mars, the red planet, has fascinated astronomers for years. The possibility that liquid water once flowed on its surface makes scientists want to know whether Mars could have supported life in the past and investigate whether life could thrive there in the present. This is why they have sent dozens of spacecrafts to explore the Martian world.
While it is the most explored planet in our solar system, it is not a friendly planet to explore. The history of Mars exploration is marked with failures. Off all the attempted landings on Mars, only seven have been successful and there have never been a manned landing. Here is a list of the successful Mars Landers.
Mars Probe Program Landings
Mars 2
Mars 2, a Soviet Union’s Mars Probe Program lander, was the first artificial object to impact the surface of Mars.
It was launched on 19 May 1971 and was designed to use parachutes for landing and rockets for final braking. Mars 2’s journey from Earth to Mars was problem-free.
However, a computer malfunction caused the descent system to fail and the parachutes failed to deploy. The probe crash-landed on the Martian surface on November 27 1971. It landed when strong dust storms were blowing on the surface of Mars. Astronomers still don’t know its exact landing site.
Mars 3
Launched together with Mars 2 on 28 May 1971, Soviet Union’s Mars 3 was the second artificial object to touch down on Mars but the first spacecraft to make a successful landing.
It was supposed to capture images of the planet’s surface and clouds; measure how hot and cold it gets there; and study the surface features, atmosphere, solar wind, solar radiation, and magnetic fields.
It successfully passed through the strong dust storms that were blowing on Mars and landed on December 2 1971 in the Terra Sirenium uplands. It started operating immediately.
However, the success was short-lived. 20 Seconds after it initiated the first scan of its landing site, communication with the lander was lost forever.
Scientists suspect that its instruments stopped working but they don’t know what caused the failure. They suspect that the massive dust storms that were blowing on the Martian surface when it landed caused the failure.
The Viking Landings
NASA’s Viking Mars landers made the third and fourth successful soft landings on Mars and became the first and second successful landing missions.
The Viking Program was composed of two spacecrafts- Viking 1 and Viking 2- launched separately within months of each other. Each of the spacecrafts had an orbiter and a lander component. The lander was attached to the orbiter. The orbiter first went around Mars taking images and sending them back to Earth for use in selecting an appropriate landing site for the lander. The lander would detach from the orbiter, enter the Martian atmosphere and make a soft landing on the selected landing site.
The landers were designed to explore the surface of Mars and carry out experiments to search for microbial life. Both landers landed successfully and began their mission.
Viking 1 Mars Lander
Launched on August 20 1975, Viking 1 landed on Mars successfully on July 20 1976 in Chryse Planitia (The Plains of Golf) after separating from the orbiter and using a parachute and rocket engine to make a three-point landing. It began its 90-day mission immediately by imaging the surface of Mars.
Throughout the mission, its source of power was a plutonium decay-powered radioisotope thermoelectric generator. It carried out three biology experiments but failed to find clear evidence of microbial life on Mars. NASA lost contact with it on November 11 1982, six years after it completed its three-month mission.
Viking 2 Mars Lander
Launched on September 9 1975, Viking 2 landed on Mars on September 3 1976 in the Utopia Planitia area and began imaging the surrounding immediately.
However, it too was not successful in finding clear proof of microbial life on Mars. It found the soil there to be sterile. It went silent in 1980 when its batteries failed.
While the two Viking landers did not come across any clear evidence of the existence of microbial life, they accomplished other thing during their mission.
They carried entry science experiments during entry into the Martian atmosphere, took the first color images, collected loads of scientific data, measured temperature at their landing sites, and witnessed seasonal dust storms, pressure changes and movement of atmospheric gases between the polar caps.
While a biological experiment yielded possible proof of the existence of microbial life, other experiments did not find similar results and so the available evidence for microbial life was not clear.
Mars Pathfinder Landing
The Mars Pathfinder landing was the first mobile probe landing on Mars. It was a very popular mission with the public and its website was the most visited at the time.
Initially referred to as the Mars Environmental Survey (MESUR), the probe was composed of a stationery Mars lander and a tiny, remote-controlled surface rover known as Sojourner. Both were equipped with scientific instruments for carrying out analysis and experiments on the red planet.
Being the second of NASA’s budget planetary Discovery missions, its main purpose was to find out how feasible low-cost landings would be on Mars exploration. It was to accomplish this purpose by testing communication between the rover and lander and between the lander and earth, and testing the imaging devices and sensors.
The mission’s science objectives were to study atmospheric entry science, take long-range and close-up images of the surface and characterize the environment on Mars in preparation for further exploration.
Launched on December 4 1996, it landed on Mars on July 4 1997 in the Ares Vallis region, an ancient flood plain located in the northern hemisphere of the planet and one of the rockiest areas of Mars.
Its landing on Mars was an interesting one. It entered Mar’s atmosphere without orbiting the planet first using parachutes rockets and airbags to achieve the landing. It bounced 16 times before it finally rested about 2.5 minutes after impact. It rested about 1 km away from its initial impact site.
It then deployed Sojourner, which rolled onto the surface to explore the surrounding landscape, conditions and rocks. This deployment was a very popular event and its images received wide coverage in newspapers.
The probe started the mission by making atmospheric measurements during its descent.
By the time the mission ended, the lander had beamed back 16, 500 images and the rover 550 images, performed over 15 chemical analyses of rocks and soils, and transmitted extensive data on the Martian winds and weather. The two robotic explorers found signs that the red planet was once warm and wet, had water in liquid form and had a thicker atmosphere in the past.
The ground teams received the last contact from it on 27 September 1997. The mission ended a success. The reason for the failure remains a mystery.
Spirit and Opportunity Landings
The success of the Mars Pathfinder Mission inspired NASA to embark on a bolder landing mission on the red planet. Spirit and Opportunity, the twin Mars Exploration Rovers, went to Mars on a three-month mission in search of evidence of water existence in Mars past. The mission was part of NASA’s Mars Exploration Program.
The rovers examined soil and rock for signs of water activity and present in the past. They conducted surface experiments, took images, and performed science experiments through the instruments onboard.
Both rovers achieved their objective when they found strong evidence that indeed Mars once had water flowing on its surface.
Spirit Mars Lander
Launched on June 10 2003, Spirit landed on Mars on January 4 2004 in Gusev Crater, which is thought to have been a crater lake in the past. It bounced then rolled along the surface before coming to a stop. The airbags deflated and retracted, the petals opened and the rover deployed its solar arrays. An initial communication glitch delayed operations for a few days.
NASA lost contact with the rover in March 2010 long after it completed its 90-day mission and surpassed expectations after operating for more than six years. It was declared failed in May 2011.
Opportunity Mars Lander
Lunched on July 8 2003, Opportunity landed on Mars on January 25 2004 in the Meridiani Planum area. The area is also known as the `Hematite Site’ because of the presence of iron-rich mineral deposits that are formed in water and referred to as hematite. It was also considered a smooth and safe landing site.
It bounced then rolled along the surface before coming to a stop in a small crater. The airbags deflated and retracted, the petals opened and the rover deployed its solar arrays. The rover found evidence that water once present in this area. It is currently exploring the rim of Endeavour crater.
Phoenix Mars Landing
The Phoenix Mars Lander, a NASA Mars Scout lander, was launched on August 4 2007 from Cape Canaveral and landed on the red planet on Mar 25 2008 near the North Pole of the planet, an area with a high ratio of ice to rock. It descended into the Martian atmosphere suspended from its parachute. After 15 minutes allowance for the dust to settle, the solar panels that were to provide power were deployed and it took the first images of itself and the surrounding.
It was to study the surface, near-surface environment, climate, weather, atmosphere, geomorphology, active processes, regolith, history of water, ice, and climate of the Northern region of Mars. It was to investigate the potential of the surface and subsurface environment in this region to support biological life. Some of its spare instruments and equipment were recovered from the lost Mars Polar Lander project.
Using a scoop mounted on its robotic arm, it burrowed into Mar’s surface, examined the soil beneath and found evidence of water ice buried beneath the surface. Its instruments investigated whether the area may have once accommodated microbial life. It is most famous for being the first lander to be captured by another spacecraft as it landed onto a planetary body.
Mars experiences very harsh winters and its solar panels were damaged during this period leading to a loss of communication with it on 2 November 2008 because of power failure when summer ended. After trying to reestablish communication in vain, the lander was declared failed and dead in May 2010. The mission operated for about 7 months.
Mars Science Laboratory/Curiosity Rover
Following the Phoenix Mars lander, NASA launched the Curiosity rover also referred to as the Mars Science Laboratory. It was a very ambitious mission even more powerful than Spirit and Opportunity.
Curiosity rover is the latest rover to land on Mars. It is a 1-ton robotic rover, the size of a car. It is exploring Mars looking for signs of potential for life now or in the past.
The initial schedule was to launch it in 2009 but it was launched much later on November 26, 2011. Curiosity landed on Mar’s surface on August 5 2012 in the Gale Crater region on Aeolis Palus that is between Peace Vallis and Aeolis Mons (Mount Sharp). This site was picked because there is a high chance that it has or had potential to support life now or in the past. Its entry into the Martian atmosphere, descent and landing was so complicated and nerve-wracking that it was dubbed the `seven minutes of terror’.
Because it was too large, airbags could not be used to cushion its landing. A rocket powered sky crane was used to lower the 1-ton lander to the surface on cables. After landing, the sky crane flew off and crash-landed a safe distance away.
After performing a number of S-curve maneuvers to slow it down during descent, a parachute was deployed about three minutes before its landing. Near the end of the descent, retrorockets were used and then the rover was lowered to the surface from the descent stage on a tether. This kind of landing had not been accomplished before.
During its mission, it is investigating organic carbon compounds, chemical necessities of life, signs of biological life and processes, mineral composition of the surface and near-surface materials, geological processes that have shaped the rocks and soils, atmospheric evolution processes, water and carbon dioxide, and surface radiation.
It is studying the mountain at its landing site that has exposed rock faces representing various periods in the history of Mars.
It is expected to last one Martian year, that is, 687 Earth days. During its mission, it is expected to travel 5-20 km gathering and analyzing rock and soil samples.