Mars Express

Mars Express is a space exploration mission by the European Space Agency (ESA). It has been studying the planet Mars and its moons since 2003. This was the first mission of its kind by ESA. The mission has two parts: the Mars Express Orbiter and Beagle 2, a lander to study the surface of Mars. The lander did not work as planned, but the orbiter has been sending important science information since 2004.

The orbiter has helped scientists make detailed pictures of Mars. It maps minerals, studies the atmosphere, and looks at what lies under the surface. Because it provides valuable information, the mission has been extended many times. The latest extension, approved in March 2023, allows the spacecraft to keep working until the end of 2026, maybe even until 2028.

Now, more than 22 years after it reached Mars, Mars Express is the second longest-operating spacecraft around a planet other than Earth. It has also helped other missions by acting as a communication link in Mars orbit. It has worked with spacecraft from NASA, ESA, Roscosmos, China, and Japan. This makes it an important part of Mars exploration.

Name

The name "Express" means the spacecraft was built quickly and it had a fast trip to Mars. This was because Earth and Mars were very close to each other when the spacecraft was launched.

Background

The Mars Express mission was made to study Mars. It looked at Mars's inside, surface, air, and area around it. The spacecraft had seven science tools, a small lander, a lander communication system, and a Visual Monitoring Camera. These tools help solve the mystery of Mars's missing water.

Some tools on the spacecraft, like cameras and some spectrometers, came from a failed Russian mission called Mars 96 in 1996. European countries helped with tools and money for that mission. The Mars Express mission also tried to do some science goals from that failed mission, including work with Beagle-2.

The design of Mars Express was based on ESA's Rosetta mission, which saved time and money. The same design was later used for ESA's Venus Express mission. The budget for Mars Express, not including the lander, was €150 million. The main builder of the Mars Express orbiter was EADS Astrium Satellites.

Orbiter and subsystems

The Mars Express orbiter is a cube-shaped spacecraft with two large solar panel wings. It was launched with a total weight of 1,223 kg, including the main spacecraft, a small lander, and fuel for its journey. The main body is made of strong aluminium and measures about 1.5 m by 1.8 m by 1.4 m. The solar panels stretch out to about 12 m from tip to tip.

The spacecraft uses solar panels to create electricity, which powers everything on board. It still works well for its science tasks. The spacecraft keeps its instruments at the right temperatures using special blankets and heaters. It also has smart computer systems that help decide when and how to send data back to Earth.

Lander

The Beagle 2 lander was meant to study rocks, minerals, and chemicals on Mars. It also wanted to look at the atmosphere and weather and search for signs of life. Sadly, the landing did not go well, and the lander could not send back any data.

In 2015, a spacecraft called the Mars Reconnaissance Orbiter found Beagle 2 on the surface of Mars. One of its solar panels may not have opened fully, which stopped it from talking to Earth. Even though it didn’t work as planned, Beagle 2 was an important step for British and European space exploration.

Scientific instruments

The Mars Express mission has several tools to study Mars. These tools help scientists learn about the planet’s surface, atmosphere, and what lies beneath. The tools include a camera that takes detailed pictures, a spectrometer that looks at minerals, and a radar that searches for frozen water under the surface.

Other tools study the atmosphere’s composition and how it interacts with sunlight and space. There is also a radio system that helps study Mars’s atmosphere and surface using signals.

Operations of the spacecraft

Operations for Mars Express are managed by engineers from ESA's Operation Centre (ESOC) in Darmstadt. They began preparing for the mission 3 to 4 years before its launch. This included setting up equipment on Earth and planning the mission.

The Mission Control Team has several groups, like the Flight Control Team and the Flight Dynamics Team. These teams are based at ESOC, but some other teams helped design and build the spacecraft. The Flight Control Team includes a Spacecraft Operations Manager, six Operations Engineers, one Spacecraft Analyst, and six spacecraft controllers. These controllers also help with other missions like ExoMars Trace Gas Orbiter, BepiColombo, and Solar Orbiter. The team was formed four years before the launch, with engineers from different missions, mostly those that worked on satellites around Earth.

Mission timeline

Mission preparation

Before it launched, many experts worked together to get the spacecraft ready. They tested the control system, checked the satellite, and did many practice runs to make sure everything was ready for launch.

Launch

The spacecraft launched on June 2, 2003, from Baikonur Cosmodrome in Kazakhstan using a Soyuz-FG/Fregat rocket. It first went into a circle around Earth, then the rocket fired again to send it toward Mars. The solar panels opened, and the spacecraft began its journey to Mars. This was the first successful Russian-launched probe to leave Earth’s orbit since the Soviet Union.

Near Earth commissioning phase

After launch, the spacecraft went through checks to make sure everything worked. This included opening the solar arrays and checking the instruments one by one. This phase lasted about one month.

The interplanetary cruise phase

For five months, the spacecraft traveled toward Mars. This phase had some problems, like star tracker issues and a big solar flare, but it kept going.

Lander jettison

The Beagle 2 lander was released on December 19, 2003, to land on Mars. It entered the atmosphere on December 25 but could not be contacted after landing.

Orbit insertion

Mars Express arrived at Mars after traveling 400 million km. On December 20, it fired its engines to start orbiting the planet. The orbit was adjusted several times to get the right path around Mars. After 100 days, the orbit was changed again to make the spacecraft’s path around Mars shorter.

Routine phase: science return

Since entering orbit, Mars Express has been doing science work. It points toward Mars to collect data and then turns to send the information to Earth. Some instruments can work even while the spacecraft points toward Earth.

Timeline of notable discoveries and events

For more than 20,000 orbits, the Mars Express payload instruments have been regularly operating. The HRSC camera has been consistently mapping the Martian surface with very clear pictures and has taken many images.

First decade

2004

• January 23: ESA announced the discovery of water ice in the south polar ice cap, using data from the OMEGA instrument.
• January 28: Mars Express orbiter reached its final orbit around Mars.
• March 17: Orbiter found polar ice caps that contain mostly carbon dioxide ice and some water ice.
• March 30: A report said the orbiter found methane in the Martian atmosphere. The amount is small, but scientists are interested because methane on Earth comes from living things. They want to learn more about where it comes from on Mars.
• April 28: ESA announced that deploying the boom for the radar-based MARSIS antenna was delayed because of safety concerns.
• July 15: Scientists using the PFS instrument reported they found signs of the compound ammonia in the Martian atmosphere. Like methane, ammonia does not stay in the atmosphere for long, so something must be making it.

2005

• In 2005, ESA scientists said the OMEGA instrument showed the presence of certain minerals on Mars.
• February 8: ESA approved the delayed deployment of the MARSIS antenna for early May 2005.
• May 5: The first part of the MARSIS antenna was deployed successfully, but one part did not lock properly. Deployment of the next part was delayed for more checks.
• May 11: Using the Sun's heat, the last part of the MARSIS antenna locked in place successfully.
• June 14: The second part of the antenna was deployed, and on June 16 ESA said it worked.
• June 22: ESA said MARSIS was fully working and would soon start collecting data. This followed the deployment of the third part on June 17 and a test on June 19.

2006

• September 21: The High Resolution Stereo Camera (HRSC) took images of the Cydonia region, where the "Face on Mars" was photographed in 1976 by the Viking 1 Orbiter.
• September 26: Mars Express entered a special low-power mode called 'Sumo' to save energy during a difficult time.
• October: Mars Express passed through a time when Earth, the Sun, and Mars were lined up. Special steps were taken to protect the spacecraft.
• December: After NASA's Mars Global Surveyor was lost, Mars Express tried to find it using its HRSC camera, but was not successful.

2007

• January: Mars Express began supporting NASA's landing of the Phoenix lander in May 2008.
• February: The small camera VMC was turned back on to let students help take pictures of Mars.
• February 23: The Science Program Committee extended the mission until May 2009.
• June 28: The HRSC took images of important features in Aeolis Mensae.

2008

• In March 2008, the Mars Express Team won an award for their work.
• In July 2008, during a flyby of Phobos, Mars Express observed something at Phobos that had been seen at Earth's Moon before.

2009

• February 4: ESA extended the mission of Mars Express until the end of 2009.
• October 7: ESA extended the mission until the end of 2012.

2010

• March 5: Mars Express flew by Phobos to study its gravity.

2011

• August 13: Mars Express went into a safe mode after a problem with its memory system.
• August 23: Mars Express had another memory problem.
• September 23: Mars Express went into safe mode again after a memory problem.
• October 11: Mars Express had a memory problem.
• October 16: Mars Express went into safe mode after a memory problem.
• November 24: Science work resumed using different files instead of the memory system that had problems.

2012

• February 16: Mars Express resumed full science work. There is still fuel for up to 14 more years.
• In March 2012, a report showed a faint glow above Mars's winter poles using data from Mars Express.
• July: Mars Express studied the Sun's outer layer using radio waves.
• August 5/6: Mars Express helped US probes Mars Odyssey and Mars Reconnaissance Orbiter with the landing of Mars Science Laboratory.

2013

• Mars Express made a detailed map of Mars's surface.
• On 29 December, Mars Express made its closest flyby of Phobos to date.

Second decade

2014

• In October 2014, ESA said Mars Express was healthy after a comet passed close to Mars.

2015

• January: Beagle 2 was found by another orbiter.

2016

• In January 2016, Mars Express observed something at Phobos again.
• October 19: Mars Express helped with the landing of the Schiaparelli EDM lander.

2017

• On 19 June, the spacecraft took an image from the North Pole to Alba Mons and beyond. The image was released in December 2017.

2018

• Mars Express got new software to help its instruments last longer.
• In July 2018, studies using MARSIS found a lake under the ice at Mars's south pole. It was the first time a stable body of water was found on Mars.
• December 2018: Mars Express sent images of Korolev Crater, which has ice inside it.

2019

• Data from the HRSC camera showed signs of an old system of underground water on Mars.

2020

• Between March and April 2020, Mars Express turned off its instruments because of changes caused by the COVID-19 pandemic.

2021

• Studies showed that water on Mars may escape into space more during dust storms and when Mars is close to the Sun.
• A study found a problem with how we understand the climate on Mars that might also help us understand Earth's climate.
• In November 2021, Mars Express tested a new way to send information from a lander on Mars.

2022

• In February 2022, a report said that salty water is the best explanation for what MARSIS saw in 2018, which looked like liquid water under Mars's south pole.
• On 14 February 2022, Mars Express saw the moon Deimos pass in front of Jupiter and its moons, helping scientists learn more about Deimos.
• In June 2022, the software for the MARSIS instrument was updated to work better.
• On 23 September 2022, Mars Express flew very close to Phobos and studied its underground structure.
• In November 2022, Mars Express helped another spacecraft send information from a rover on Mars.

2023

• In January 2023, a map of minerals that need water to form was made using data from Mars Express.
• June 3: To celebrate the 20th anniversary of the launch, images from the Visual Monitoring Camera were shown online for the first time.

Third decade

2024

• In January 2024, a report said that a feature on Mars called the Medusae Fossae Formation has a lot of water ice.

• In May 2024, Mars Express and another mission had computer problems during a big solar flare.

• During May 2024 solar storms, Mars Express and another orbiter studied how the Martian atmosphere changed.

• In June 2024, a report showed evidence of frost near Mars's equator using data from Mars Express.

• In July 2024, a report showed the first routine use of a new method to study Mars's atmosphere using Mars Express and another orbiter.

• In September 2024, a new picture book of clouds on Mars was published using images from Mars Express over 20 years.

2025

• In February 2025, a report said the red color of Mars is caused by a type of iron that contains water.
• In May 2025, ESA updated software to help Mars Express work longer.
• In June 2025, data from Mars Express was made public in a new report.
• In September 2025, scientists showed how to predict a type of light show on Mars using data from Mars Express.
• In October 2025, scientists listed many spinning wind events on Mars seen by Mars Express and another orbiter.

2026

• In April 2026, ESA shared a new picture of Utopia Planitia showing changes on Mars's surface.