The History of Mars Exploration

Mars has long fascinated humans. Even in ancient times, people watched the planet and created legends about it. While the planet has long been the source of fantasy and fiction, it is also the target of intense scientific study. Researchers have used telescopes and unmanned spacecraft to explore the planet and try to understand its climate, geology, and potential for life.

Since the launch of the first successful Mars flyby by NASA's Mariner 4 in 1965, our knowledge of the planet has expanded. NASA has discovered evidence of ice, seasons, and surface features that suggest an evolving geology.

Robotic explorers like Curiosity and Perseverance have provided data and samples, but many aspects of Mars remain mysteries. Here is a look at the history of the exploration of Mars, what we know, and what still remains unknown.

When Was the First Mission to Mars?

The first successful mission to Mars was NASA's Mariner 4. It took off on November 28, 1964. This unmanned spacecraft was the first to take close-up images of Mars, providing NASA with its first glimpse of the Martian surface.

The Mariner 4 images showed a cratered, lifeless surface, and fundamentally changed scientists' understanding of Mars.

More importantly, Mariner 4 laid the groundwork for all subsequent Mars missions. It collected data on Mars' atmosphere and surface conditions. This information was critical in planning future missions. For instance, NASA used the information to develop more sophisticated instruments and equipment

Mariner 4 paved the way for the complex missions that followed, such as the Viking Project and the Mars rovers.

The Mars Global Surveyor

Launched in 1996, the Mars Global Surveyor (MGS) was a specialized orbiter with advanced mapping equipment. Its primary goal was to map the entire Martian surface with as much accuracy as possible.

It focused on the planet's topography but also collected information on its composition, geology, and magnetic field. The MGS monitored the climate, collecting data on Martian weather and the makeup of its atmosphere.

By the time it was over, the MGS mission significantly advanced our understanding of Mars and brought new insights about its history. By looking at the planet's surface features, scientists were able to find dried riverbeds and mineral deposits. These served as evidence that the Martian surface once contained water.

This discovery supported theories that Mars once had a natural environment capable of supporting life. This evidence was enough to gain support for future missions that looked more closely at the surface.

Rover Missions to Mars

Rover missions to Mars involved sending unmanned craft to the Martian surface to deliver vehicles that could collect samples and conduct experiments directly on the planet's surface.

Wheeled rovers were capable of collecting samples and conducting analysis. They could also capture detailed images and transmit them back to Earth. Additionally, the knowledge of the Martian surface from past aerial expeditions helped NASA design vehicles that could navigate the terrain of Mars.

The biggest advantage of these visits to the surface was the ability to take daily readings of atmosphere, radiation, and weather while also collecting samples that provided new information about geology, chemistry, and the environment on Mars.

Here is a closer look at the discoveries of the different rover missions.

Sojourner

The Sojourner rover was part of NASA's Mars Pathfinder mission, which launched on December 4, 1996, and landed on Mars on July 4, 1997. Its main goal was to take the first step of landing on the Martian surface.

Sojourner proved that landings and surface exploration on Mars were possible.

Once it landed, it was able to provide up-close images of the surface and collect and analyze rock and soil samples.

This proof-of-concept mission laid the groundwork for future rover missions to explore the surface of the planet more in-depth.

Spirit and Opportunity

NASA's twin rovers, Spirit and Opportunity, launched in 2003 and landed on Mars in early 2004. Their mission was to take a deeper look at Martian geology and search for more concrete evidence of water.

The rovers traversed the Martian landscape collecting and analyzing a variety of rock and soil samples.

Both rovers found some evidence that Mars once contained water. Spirit discovered evidence of past hydrothermal activity, which means liquid from beneath the planet's crust heated and came to the surface. Geysers and hot springs are examples of hydrothermal activity on Earth.

Opportunity found signs of ancient water in the form of small, round mineral deposits that became known as Martian blueberries.

Curiosity

The evidence of water meant that it was possible that Mars once supported or could still support life. The Curiosity rover, part of NASA's Mars Science Laboratory mission, launched on November 26, 2011, and landed on Mars on August 6, 2012. Its main goal was to search for evidence of past life on the planet.

The research did not involve seeking alien creatures. Instead, the mission focused on evidence of microbial life. Curiosity was successful in finding organic molecules, identifying chemical processes in the soil and atmosphere, and uncovering evidence of ancient environments that could have contained water.

Recent Missions to Mars

Exploration of Mars is ongoing, with other countries now joining the U.S. in the race to learn more about the planet. Each mission builds on past knowledge and adds to what we know about Mars.

Here are four recent and ongoing efforts.

• Tianwen-1: Launched by China on July 23, 2020, Tianwen-1 includes an orbiter, lander, and rover. It analyzed soil, looked for signs of ancient life, and took readings of the atmosphere. China's first surface vehicle, the Zhurong rover, landed successfully in May 2021 and transmitted environmental data back to Earth.
• MMX Mission: Japan's Martian Moons eXploration (MMX) mission, set for launch in 2024 and arrival near Mars a year later, has a different aim. It will explore Mars' moons, Phobos and Deimos. It will collect samples from the moons and return them to Earth for analysis.
• ExoMars: This collaboration between the European Space Agency and NASA began almost a decade ago with the 2016 launch of a Trace Gas Orbiter. The project will also send a surface rover to the planet in 2028. These missions focus on taking gas readings in the atmosphere in the Martian atmosphere and searching for signs of past life.

Exploration continues, with other countries attempting to send orbiters and rovers to collect samples and search for evidence of life.

Will There Ever Be a Manned Mission to Mars?

Manned missions to Mars could provide further insights into the planet and allow for more dynamic missions and exploration. For instance, scientists on the planet could design and conduct experiments based on specific findings instead of relying on the programmed activities of rovers. Also, they would be able to pursue specific types of exploration, such as searching for life on Mars without having to wait years for subsequent missions.

Ultimately, such missions could explore ideas like terraforming, which could pave the way for humans to one day colonize the planet or at least have permanent scientific bases there.

The Challenges of Sending Humans to Mars

Sending humans to Mars is challenging. Rovers and orbiters allow some room for uncertainty, but manned missions would require taking steps to ensure the safety and health of the crew.

Here are some challenges mission planners would have to deal with before sending humans to Mars.

• Microgravity: Prolonged exposure to low-gravity environments can cause muscle atrophy, bone weakness, and other health issues for astronauts. Effective countermeasures, such as detailed exercise plans, will be essential during the journey.
• Cosmic radiation: Mars missions expose astronauts to higher levels of radiation compared to Earth. This increases the risk of cancer and other health problems. Effective shielding and monitoring techniques would be critical for protecting crew members.
• Isolation: The psychological impact of long-term space travel is another potential issue. Planners would need strategies for morale and mental health and would need to ensure good team dynamics during the years-long mission.

Overall, addressing these challenges is crucial for enabling safe and sustainable human exploration of Mars in the future.

Mars exploration has come a long way since the 1960s. We know a lot more than we did about the Red Planet, but our understanding remains limited. Exploration continues and scientists are busy planning future missions that could uncover more details about Mars.