Beyond our Earth, Mars is the one planet that has had the most spacecraft, research, and exploration. There have been 68 missions that have launched to Mars and they include flybys, probes, orbiters, and rovers. Mars is quite a distance from Earth and over half of the missions that were sent there have failed.
Mars has held a unique position in human folklore in that it has been known throughout the ages as the Red Planet and in the past, some even thought that there was developed civilizations that lived on it. There have been stories, poems, books, television shows, movies, and even video games devoted to Mars.
From the U.S.’s first successful voyage of the Mariner 4 in 1964, we learned that the planet is both unusual and yet strangely familiar. It shares some of the same traits of our Earth such as clouds in its atmosphere, polar ice caps, volcanoes, seasonal weather patterns, and canyons, and yet many of these are features from both past and present. Every time we think we have figured something out about this strange planet we get new information that makes us rethink all over again.
In the last thirty years we have learned from both spacecraft and high-powered Earth-based and satellite telescopes that Mars is rocky, dry, and cold beneath a sky that is a pinkish haze. We have searched over the wasteland of Mars to find a landscape that has deep craters, where volcanoes once erupted, and evidence that flood waters once raced over the surface.
The burning question that has been on the minds of every scientist is whether there is liquid water on Mars. We know that there once was water, and we continue to search to see if water exists today buried underground. If there is liquid water, the second question comes to mind if creatures could still exist below the surface?
Mars is also a location that is a priority for future manned missions so that we could set up habitats and use Mars as a space outpost. There are both government funded and private company plans for the future, so everything that we can learn about this Red Planet can be added to our bag of knowledge for those that will be staying there.
Besides learning as much as we can to understand our solar system, one of the top priorities is to also seek any signs of life. The Mars Exploration Program from NASA is using this exact term in their exploration strategy of “Seek Signs of Life.”
This transitions the previous attempts of discovery and learning about Mars in general so that it now acts as a method to locate microbial life, whether past or present.
What we have learned about Mars is that around 3.8-3.5 billion years ago, Earth and Mars were a lot alike. The various Mars missions have indicated that Mars was once a lot wetter and warmer than what we see today. The earlier Mars exploration missions included:
- 2001 Mars Odyssey
- Mars Exploration Rovers
- Mars Reconnaissance Orbiter
- Mars Phoenix Lander.
Each of these were created to find discoveries that were part of the previous NASA strategy of “Follow the Water.” Now that we have found possible evidence that liquid water once existed on Mars, we are moving to the next step of evidence of life. The creation of the Mars Science Laboratory and the rover Curiosity was the transition mark between the two themes.
Missions that are being planned for the future will continue for the search for life and will be driven by the kind of scientific questions that we ask ourselves each time we learn new information from the previous missions.
New technologies are being developed that will better equip our missions so that we have precision landings, higher resolution images, longer range surface mobility, and the ability to return rock and soil samples back to Earth for study.
History and Calendar:
The former Soviet Union took the first step in sending a spacecraft to Mars. Among the many attempts that were sent and failed, the Mars 1 mission was successful in sending data information about the Red Planet back to Earth before they lost contact with it.
Mars 2 launched safely, but the rover crashed upon landing. Their other missions of Mars 3, 4, 5, and 6 were all partially successful; and Mars 7 lander had problems with its separation and never made it to Mars’ surface.
The first mission by the U.S. that was successful was in 1964 with the Mariner 4. The spacecraft did a flyby of Mars and sent back the first-ever images of the Red Planet. Scientists were eager to study the pictures and learn even more, so NASA sent a number of other Mariner missions to Mars including Mariners 6 and 7 that were flybys that sent back both data and images.
1970s and 1980s:
NASA sent Mariner 9 to Mars in 1971 and it arrived at the worst time. The Red Planet was experiencing what we later found out was the kind of massive dust storm that often happens and is planet-wide. Mariner 9 was placed in orbit until the dust settled and then sent back 7,329 photographs that showed around 85% of the planet’s surface.
Scientists learned then that Mars had many features that we were familiar with on Earth including flood plains, volcanic features, river beds, and craters.
The two Viking landers were sent by NASA in 1976 and they successfully landed on Mars’ surface then linked back to Earth with the use of their orbiters. Both of these missions continued on for a number of years supplying atmospheric data, surface images, and orbiter mapping.
After the Viking landers, there weren’t any other missions until 1988 when the Soviets sent out the two Phobos Missions. Contact was lost with Phobos 1 and Phobos 2 did enter the Mars orbit and sent data back to Earth before the controllers lost contact with it as well.
More missions have been sent to Mars than any other planet and yet there has been a high rate that weren’t successful. In 1993 NASA set the Mars Observer and then lost communication. After an investigation it was believed that it failed due to a fuel leak. Another launch by the Soviet Union, Mars 96, also failed.
Other failures in the 90’s included the Nozomi from Japan (also known as Planet B) when it never entered the orbit of Mars, NASA’s Mars Climate Orbiter crashed into the surface in 1999, and another 1999 Mars NASA mission called the Mars Polar Lander crashed due to equipment failure.
However, there were some successes in the 1990s and they include:
NASA’s Mars Global Surveyor that spent almost ten years imaging and mapping mars from orbit.
Mars Pathfinder mission was the first successful rover that was placed on Mars. It lasted for 3 months and was the first mission to drill and get a sample of the rocks to figure out what they are made of.
In the first twenty years of the 21st century there were more successful missions including:
NASA’s Mars Odyssey
The European Space Agency’s (ESA) Mars Express
The Mars Exploration Rovers A and B. Spirit and Opportunity landed in 2004 and began searching for evidence that there was ever water on Mars. Although only designed for about a three month tour, Spirit lasted for seven years and Opportunity stopped in June, 2018 when a dust storm overtook it. Opportunity lasted around 14 years.
Both rovers were critical in gaining information about Mars’ surface, trying to find evidence of past water, and sending valuable data and images back to Earth regarding the surface, climate, and weather.
In 2005, the Mars Reconnaissance Orbiter launched with the purpose of imaging and mapping Mars in high resolution. It, combined with other orbiters, have supplied a useful radio link back to Earth.
Mars Phoenix landed on the Red Planet for the purposes of cataloging the norther pole region conditions.
In 2003, the Russians, British, and in 2011, the Chinese all had back luck with their launched spacecraft. The Beagle Rover did arrive at Mars but then failed when it landed. The Fobos-Grunt and Yinghuo-1 missions both fell back to Earth after a launch failure.
The U.S. rover Mars Curiosity has been one of the most successful, roaming all over the planet and sending images and data about rock mineralogy.
September, 2014, the Indian Space Research Organization Mars Orbiter Mission (nicknamed “Mom”), and NASA’s MAVEN mission were successfully launched and arrived. MOM is sending back images and data about the atmosphere of Mars.
MAVEN was designed as an atmospheric satellite that is taking samples of the upper atmosphere to figure out why the planet is losing its atmosphere. The atmospheric information may give an idea as to why Mars may have lost water in the past.
Types of Missions:
The various missions that have been sent to Mars have followed three different types:
Flybys: The first startup missions sent out to explore the solar system. The flybys took as many pictures of Mars as they could. These missions included: Mariner 3-4, Mariner 6-7.
Orbiters: The more information that we collected, the more we needed the increased technology to put a spacecraft in orbit for a longer period of time around Mars so that we could do a global study. These missions included: Mariner 8-9 | Viking 1-2 | Mars Observer | Mars Global Surveyor | Mars Climate Orbiter | 2001 Mars Odyssey | Mars Express | Mars Reconnaissance Orbiter | Mars Atmosphere and Volatile Evolution | NASA In ESA’s ExoMars Orbiter| InSight
Landers and Rovers: As our technology improved the design of crafts that could be sent to the surface of Mars included those that would land and collect data in a stationary condition and the rovers that would move across the planet’s surface and make use of more high tech onboard laboratories. These missions included: Viking 1-2 | Pathfinder | Polar Lander/Deep Space 2 | Mars Exploration Rovers | Phoenix | Mars Science Laboratory | NASA In ESA’s ExoMars Rover | 2020 Mission Plans
Of all of the space missions sent to Mars, those with the highest publicity have been the landers and the rovers. Just getting a probe to land safely to a surface that is millions of miles away from Earth is an incredible accomplishment.
Beyond that, the surface presents hazards that include mountains, craters, sand dunes, boulders, and deep canyons. Finding a safe place to land is a combination of scientific analysis and luck.
Landers are usually barreling down starting at 13,000 mph and have only a few minutes to decelerate. For the landers that contain rovers they have airbag landing systems that have to inflate and then bounce like gigantic bouncing balls, over and over again, while protecting the rover inside.
Additionally, they have internal sensing technologies that keep the ball from rolling down into steep surfaces once it does land.
Part of the landing gear includes a structure that acts like a shock absorber so that it protects the lander’s main body. This absorber has legs to assist in stabilizing it after it lands. If either of these are damaged or crushed, the main lander would be jeopardized.
Mobility is the key to getting the most information and the rovers allow us to explore beyond just the touchdown spot. The first rover that we sent was Sojourner and it traveled about 109 yards/100 meters in an entire month. We made excellent progress with the twin rovers of Spirit and Opportunity that continued for 7 years and 14 years
Rovers have sophisticated onboard laboratories as well as extendable “arms” that can be used to drill down into the surface rocks to get samples and then analyze what they are made of. One of the challenges that the design team faced was creating a tire system that could move around and not get stuck in the sand and dirt.
In the future, rovers will be able to travel to locations where they will meet up with other surface vehicles as well as make use of smart technologies so that they know where they are in relation to the planet’s surface.
- The late Dr. Carl Sagan once wrote: “Mars has become a kind of mythic arena onto which we have projected our Earthly hopes and fears.”
- Missions to Mars have to be planned very carefully so that they happen when Mars and Earth are at their closest point in orbit. Doing this saves around 7 months of traveling time.
- Of all of the failed missions to Mars, Russia (then the USSR) has the most.
- The Rovers Spirit and Opportunity were only designed to last 90 Martian days. Spirit became trapped in a sand trap 5 years and 3 months after landing and continued to transmit for a total of 7 years. Opportunity last 14 years.
- The rover Curiosity was on Mars and took a picture of Earth that is only the second one taken from such as incredible distance. The first was the “Pale Blue Dot” taken by the Voyager spacecraft from the outer edges of the solar system.