Европейская орбитальная станция на Марсе Mars Express

European Mars orbiter

the space exploration mission

Mars Express is a space exploration mission being conducted by the European Space Agency (ESA). The Mars Express mission is exploring the planet Mars, and is the first planetary mission attempted by the agency. "Express" originally referred to the speed and efficiency with which the spacecraft was designed and built. However, "Express" also describes the spacecraft's relatively short interplanetary voyage, a result of being launched when the orbits of Earth and Mars brought them closer than they had been in about 60,000 years. Mars Express consists of two parts, the Mars Express Orbiter and Beagle 2, a lander designed to perform exobiology and geochemistry research. Although the lander failed to fully deploy after it landed on the Martian surface, the orbiter has been successfully performing scientific measurements since early 2004, namely, high resolution imaging and mineralogical mapping of the surface, radar sounding of the subsurface structure down to the permafrost, precise determination of the atmospheric circulation and composition, and study of the interaction of the atmosphere with the interplanetary medium. Some of the instruments on the orbiter, including the camera systems and some spectrometers, reuse designs from the failed launch of the Russian Mars 96 mission in 1996

Arriving at Mars in 2003, ago (and counting), it is the second longest surviving, continually active spacecraft in orbit around a planet other than Earth, behind only NASA's still active 2001 Mars Odyssey.

The Mars Express mission is dedicated to the orbital (and originally in situ) study of the interior, subsurface, surface and atmosphere, and environment of the planet Mars. The scientific objectives of the Mars Express mission represent an attempt to fulfill in part the lost scientific goals of the Russian Mars 96 mission, complemented by exobiology research with Beagle 2. Mars exploration is crucial for a better understanding of the Earth from the perspective of comparative planetology. The spacecraft originally carried seven scientific instruments, a small lander, a lander relay and a Visual Monitoring Camera, all designed to contribute to solving the mystery of Mars' missing water. All of the instruments take measurements of the surface, atmosphere and interplanetary media, from the main spacecraft in polar orbit, which will allow it to gradually cover the whole planet. The total initial Mars Express budget excluding the lander was €150 million. The prime contractor for the construction of Mars Express orbiter was EADS Astrium Satellites.

The spacecraft was launched on June 2, 2003, at 23:45 local time (17:45 UT, 1:45 p. m. EDT) from Baikonur Cosmodrome in Kazakhstan, using a Soyuz FG/Fregat rocket. The Mars Express and Fregat booster were initially put into a 200 km Earth parking orbit, then the Fregat was fired again at 19:14 UT to put the spacecraft into a Mars transfer orbit. The Fregat and Mars Express separated at approximately 19:17 UT. The solar panels were then deployed and a trajectory correction manoeuvre was performed on June 4 to aim Mars Express towards Mars and allow the Fregat booster to coast into interplanetary space. The Mars Express was the first Russian launched probe to successfully make it out of low Earth orbit since the Soviet Union fell.

The Near Earth commissioning phase extended from the separation of the spacecraft from the launcher upper stage until the completion of the initial check out of the orbiter and payload. It included the solar array deployment, the initial attitude acquisition, the declamping of the Beagle 2 spin up mechanism, the injection error correction manoeuvre and the first commissioning of the spacecraft and payload (final commissioning of payload took place after Mars Orbit Insertion). The payload was checked out one instrument at a time. This phase lasted about one month.

This five month phase lasted from the end of the Near Earth Commissioning phase until one month prior to the Mars capture manoeuvre and included trajectory correction manoeuvres and payloads calibration. The payload was mostly switched off during the cruise phase, with the exception of some intermediate check outs. Although it was originally meant to be a "quiet cruise" phase, It soon became obvious that this "cruise" would be indeed very busy. There were star Tracker problems, a power wiring problem, extra manoeuvres, and on October 28, the spacecraft was hit by one of the largest solar flares ever recorded.

The Beagle 2 lander was released on December 19, 2003, at 8:31 UTC (9:31 CET) on a ballistic cruise towards the surface. It entered Mars' atmosphere on the morning of December 25. Landing was expected to occur at about 02:45 UT on December 25 (9:45 p. m. EST December 24). However, after repeated attempts to contact the lander failed using the Mars Express craft and the NASA Mars Odyssey orbiter, it was declared lost on February 6, 2004, by the Beagle 2 management board. An inquiry was held and its findings were published later that year.

The Soyuz/Fregat launcher provided most of the thrust Mars Express needed to reach Mars. The final stage of the Fregat was jettisoned once the probe was safely on a course for Mars. The spacecraft's on board means of propulsion was used to slow the probe for Mars orbit insertion and subsequently for orbit corrections. During routine phase, the spacecraft's power consumption is in the range of 450–550W.

Attitude control (3 axis stabilization) is achieved using two 3 axis inertial measurement units, a set of two star cameras and two Sun sensors, gyroscopes, accelerometers, and four 12 N·m·s reaction wheels. Pointing accuracy is 0.04 degree with respect to the inertial reference frame and 0.8 degree with respect to the Mars orbital frame. Three on board systems help Mars Express maintain a very precise pointing accuracy, which is essential to allow the spacecraft to use some of the science instruments.

The communications subsystem is composed of three antennas: A 1.6 m diameter parabolic dish high gain antenna and two omnidirectional antennas. The first one provide links (telecommands uplink and telemetry downlink) in both X band (8.4 GHz) and S band (2.1 GHz) and is used during nominal science phase around Mars. The low gain antennas are used during launch and early operations to Mars and for eventual contingencies once in orbit. Two Mars lander relay UHF antennas are mounted on the top face for communication with the Beagle 2 or other landers, using a Melacom transceiver.

Although communications with Earth were originally scheduled to take place with the ESA 35 meter wide Ground Station in New Norcia (Australia) New Norcia Station, the mission profile of progressive enhancement and science return flexibility have triggered the use of the ESA ESTRACK Ground Stations in Cebreros Station, Madrid, Spain and Malargüe Station, Argentina. In addition, further agreements with NASA Deep Space Network have made possible the use of American stations for nominal mission planning, thus increasing complexity but with a clear positive impact in scientific returns. This inter agency cooperation has proven effective, flexible and enriching for both sides. On the technical side, it has been made possible (among other reasons) thanks to the adoption of both Agencies of the Standards for Space Communications defined in CCSDS.

Thermal control is maintained through the use of radiators, multi layer insulation, and actively controlled heaters. The spacecraft must provide a benign environment for the instruments and on board equipment. Two instruments, PFS and OMEGA, have infrared detectors that need to be kept at very low temperatures (about −180 °C). The sensors on the camera (HRSC) also need to be kept cool. But the rest of the instruments and on board equipment function best at room temperatures (10–20 °C). The spacecraft is covered in gold plated aluminium tin alloy thermal blankets to maintain a temperature of 10–20 °C inside the spacecraft. The instruments that operate at low temperatures to be kept cold are thermally insulated from this relatively high internal temperature, and emit excess heat into space using attached radiators. The primary purpose of the AI tool is the scheduling of when to download various parts of the collected scientific data back to Earth, a process which used to take ground controllers a significant amount of time. The new AI tool saves operator time, optimizes bandwidth use on the DSN, prevents data loss, and allows better use of the DSN for other space operations as well. The AI decides how to manage the spacecraft's 12 gigabits of storage memory, when the DSN will be available and not be in use by another mission, how to make the best use of the DSN bandwidth allocated to it, and when the spacecraft will be oriented properly to transmit back to Earth.

The Beagle 2 lander objectives were to characterize the landing site geology, mineralogy, and geochemistry, the physical properties of the atmosphere and surface layers, collect data on Martian meteorology and climatology, and search for possible signatures of life on Mars. However, the landing attempt was unsuccessful and the lander was declared lost. A Commission of Inquiry on Beagle 2 identified several possible causes, including airbag problems, severe shocks to the lander's electronics which had not been simulated adequately before launch, and problems with parts of the landing system colliding; but was unable to reach any firm conclusions. The spacecraft's fate remained a mystery until it was announced in January 2015 that NASA's Mars Reconnaissance Orbiter, using HiRISE, had found the probe intact on the surface of Mars. It was then determined that an error had prevented two of the spacecraft's four solar panels from deploying, blocking the spacecraft's communications. Beagle 2 was the first British and first European probe to achieve a landing on Mars.

The Mars Express Team was the winner of the Sir Arthur Clarke Award for Best Team Achievement.

Based on data from the HRSC camera, there is geological evidence of an ancient planet wide groundwater system.

Sept 2020, a discovery is reported based on MARSIS radar studies, of a three more subglacial lakes on Mars, below the southern polar ice cap. The size of the first lake found, and the largest, has been corrected to wide. It is surrounded by 3 smaller lakes, each a few kilometres wide.

The onboard software of the MARSIS experiment was upgraded in order to improve the performance of the instrument.