Beagle 2

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Beagle 2 replica

Beagle 2 was the landing unit of the Mars Express mission of the European Space Agency (ESA). It was developed and designed under the direction of British universities. Beagle 2 was decoupled from its mother probe on December 19, 2003 and probably landed on the surface of Mars in the night of December 24 to 25, 2003 after a five-day flight . Since no radio contact could be established with the probe, it was declared lost on February 11, 2004. It was only possible to clearly identify it on images from the Mars orbit after more than eleven years.

The driving force and ultimate head of the project was Colin Pillinger , professor at the Open University in Milton Keynes, England . He managed to convince ESA to take the Beagle, which weighs only 57 kilograms, on board the Mars Express on the journey to Mars.

The name "Beagle" goes back to the expedition ship HMS Beagle , with which Charles Darwin carried out a five-year expedition to map the coastline of South America .

Planned course of the mission

Beagle 2 did not have its own drive and could not be steered from earth during the sinking phase. The lander received the energy for the flight from the movement of its mother probe Mars Express. After eight hours of inactivity with the probe, the decoupling took place on December 19, 2003 as planned.

The lander had a heat shield for protection while entering the Martian atmosphere. In this phase, the speed should be reduced from around 20,000 kilometers per hour to 1200 kilometers per hour. At this point in time, temperatures of up to 1700 degrees Celsius were expected on the heat shield .

The planned opening of a first parachute at a height of around seven kilometers, which was supposed to slow down the speed further to 335 kilometers per hour, could no longer be confirmed. The main parachute should then be opened 2.6 kilometers above the surface of Mars. The gas airbags should be inflated at a height between 275 meters and 200 meters above the ground . According to the plan, the lander would now have a vertical speed of 56 kilometers per hour and a horizontal speed of 129 kilometers per hour. The airbag system was supposed to protect the landing unit hitting the Martian soil at around 50 to 60 kilometers per hour during the impact. In contrast to the landing systems of the two American Mars exploration rovers Spirit and Opportunity , the British landing system did not have any brake rockets that would reduce the horizontal and vertical speed again shortly before touchdown. Having come to a standstill on the Martian surface, the airbags should be detached.

After landing, the landing unit by means of a drill should ( PLUTO , Pl anetary U Direction ground To ol) take up to three soil samples from a maximum depth of 1.5 meters and examined locally. By analyzing the combustion gases of the Martian soil, it should be proven whether there is or was life on Mars . In addition to other instruments, panoramic cameras and a stone grinder were on board.

Loss of the probe

However, after being disconnected from the mother probe, no radio signal could be received from Beagle 2. On February 11, 2004, ESA officially declared Beagle 2 lost in a press release. The ESA and the UK announced a joint investigation into the causes of the loss. The results of the investigation should feed into future missions. ESA Inspector General René Bonnefoy was chairman of the committee of inquiry.

In December 2005, the head of the project, Colin Pillinger, reported having discovered the device on images of the Martian surface and considered the "secret of Beagle 2" to be largely clear. A NASA camera captured clearly identifiable features, including the airbag and solar panel. Images from NASA's Mars Global Surveyor (MGS) would enable a reconstruction of what happened on December 19, 2003, when contact with Beagle 2 was lost. Pillinger explained that the mobile research robot of the European Mars mission from December 2003 was stuck in a crater of the planet near the intended landing site. According to Pillinger and his Mars team, the Beagle 2 landed unexpectedly hard, possibly due to considerable air pressure fluctuations at the time of landing. Instruments for communication were probably destroyed in the process.

Based on photos taken a few years later by the Mars reconnaissance satellite Mars Reconnaissance Orbiter (MRO), the reports of the discovery could not be confirmed. The suspected fragments of Beagle 2 could not be found in the suspected small crater with the HiRise camera , which is significantly more powerful than the camera of the MGS.

Beagle landing site 2

After more than eleven years in which the probe was thought to be lost, the landing site of Beagle 2 was finally located at 11.5 ° North and 90.4 ° East in January 2015 on images taken by the MRO on June 29, 2014. The images show the probe, which has apparently landed softly , and whose solar panels are at least partially open. The parachute and a discarded cover could also be identified in the immediate vicinity.

It will no longer be possible to determine with absolute certainty the reason for the failure of the Beagle 2 mission. There is no telemetry data available for the entire descent phase that could provide more detailed information about the cause of the problems. NASA had a similar problem in 1999 when the Mars Polar Lander was lost on landing. The reasons for its loss have not yet been clearly clarified. However, NASA drew conclusions from the total loss and modified the landing systems of the Mars exploration rovers Spirit and Opportunity . During the six-minute landing phase, these sent out 36 different audio signals with which they could carry out individual actions, such as B. the opening of the landing parachute confirmed. In this way, the cause of an error could have been better localized in the event of any problems.


The Beagle 2 mission was an ambitious European project that was implemented under enormous time pressure with a comparatively very small budget of only 30 million euros.

The mission was a risky project in two senses. On the one hand, ESA had no experience with landings by probes, and on the other hand, no attempt had previously been made in this form to bring an orbiter ( Mars Express ) and a lander (Beagle 2) to Mars in just one mission . During the decoupling maneuver, the mother probe Mars Express was on a collision course with Mars and could not receive commands from ESA's European Space Control Center (ESOC) because its antenna could not be aligned with the earth during this maneuver .

After the loss of radio contact with Beagle 2, the German-speaking mass media reported critical of the mission. There were headlines like “PR crash on Mars” or “Failure on Mars”. Looking at the list of missions to Mars , it becomes clear that the history of unmanned space travel to Mars has repeatedly been marked by setbacks and total losses. Only around a third of all missions have reached Mars. Beagle 2 was the first European attempt to land on Mars.

More plans

Professor Pillinger initially planned another experiment with an improved model of Beagle 2 at the time of the next "approach window" in 2007. In particular, the above-mentioned tracking of the descent phase of the lander using telemetry should be an important new element. The probe should be converted so that the antenna is on the outside and cannot, as before, only be extended when the lander is already unfolded on the ground after landing. But this attempt did not occur.

With the ESA rover mission ExoMars , which is currently Template: future / in 2 yearsplanned for 2022 , another Beagle mission would have lost its meaning.

See also

Web links

Commons : Beagle 2  - Collection of Images

Individual evidence

  1. a b Stefan Deiters: Lander Beagle 2 tracked down after eleven years. MARS EXPRESS. In: January 16, 2015, accessed March 9, 2015 .
  2. UK and ESA announce Beagle 2 inquiry ESA-News, February 11, 2004
  3. NASA:
  4. NASA: