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Beagle 2
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Beagle 2 was an unsuccessful British landing spacecraft that formed part of the European Space Agency's 2003 Mars Express mission. It is not known for certain whether the lander reached the Martian surface; all contact with it was lost upon its separation from the Mars Express six days before its scheduled entry into the atmosphere. It may have missed Mars altogether, skipped off the atmosphere and entered an orbit around the Sun, or burned up during its descent.
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Beagle 2 was an unsuccessful British landing spacecraft that formed part of the European Space Agency's 2003 Mars Express mission. It is not known for certain whether the lander reached the Martian surface; all contact with it was lost upon its separation from the Mars Express six days before its scheduled entry into the atmosphere. It may have missed Mars altogether, skipped off the atmosphere and entered an orbit around the Sun, or burned up during its descent. If it reached the surface, it may have hit too hard or else failed to contact Earth due to a fault.
Background
Beagle 2 was conceived by a group of British academics headed by Professor Colin Pillinger of the Open University, in collaboration with the University of Leicester. Its purpose was to search for signs of Martian life, past or present, and its name reflected this goal, as Professor Pillinger explained:
- "HMS Beagle was the ship that took Darwin on his voyage around the world in the 1830s and led to our knowledge about life on Earth making a real quantum leap. We hope Beagle 2 will do the same thing for life on Mars."
A point at 10.6°N, 270°W in Isidis Planitia, a large flat sedimentary basin that overlies the boundary between the ancient highlands and the northern plains of Mars, was chosen as the landing site. The lander was expected to operate for about 180 days and an extended mission of up to one Martian year (687 Earth days) was thought possible. The Beagle 2 lander objectives were to characterize the landing site geology, mineralogy, geochemistry and oxidation state, the physical properties of the atmosphere and surface layers, collect data on Martian meteorology and climatology, and search for possible signatures of life.
Pillinger set up a consortium to design and build Beagle 2. The principal members and their initial responsibilities were:
- Open University - Consortium leader & scientific experiments
- University of Leicester - Project management, Mission management, Flight Operations Team, instrument management, and scientific experiments
- Astrium - Main industrial partner
- Martin-Baker - Entry, descent and landing system
- Logica - Cruise, entry, descent and landing software
- SciSys - Ground segment and lander software
- University of Wales, Aberystwyth - Robotic arm
In 2000, when the main development phase started, Astrium took over responsibility for program management, and Leicester assumed responsibility for mission management which involved the preparations for the operations post launch and the operations control center.
In an effort to publicize the project and gain financial support, its designers sought and received the endorsement and participation of British artists. The mission's call-sign was composed by the band Blur, and the 'test card' (Calibration Target Plate) intended for calibrating Beagle 2s cameras and spectrometers after landing was painted by Damien Hirst.
The Lander Operations Control Centre (LOCC) was located at the National Space Centre in Leicester, from which the spacecraft was being controlled, and was visible to the public visiting the center. The control center included operational systems for controlling the Beagle 2, analysis tools for processing engineering and scientific telemetry, virtual reality tools for preparing activity sequences, communications systems, and the Ground Test Model (GTM). The GTM was composed of various builds of the Beagle 2 systems, collected together to provide a full set of lander electronics. The GTM was used nearly continuously to validate the engineering and science commands, to rehearse the landing sequence, and to validate the onboard software.
Spacecraft and subsystems
Beagle 2 had a robotic arm known as the Payload Adjustable Workbench (PAW), designed to be extended after landing. The PAW contained a pair of stereo cameras, a microscope (with a 6 micrometre resolution), a Mössbauer spectrometer, an X-ray spectrometer, a drill for collecting rock samples and a spotlamp. Rock samples were to be passed by the PAW into a mass spectrometer and gas chromatograph in the body of the lander - the GAP (Gas Analysis Package), to measure the relative proportions of different isotopes of carbon. Since carbon is thought to be the basis of all life, these readings could have revealed whether the samples contained the remnants of living organisms.
In addition, Beagle 2 was equipped with a small "mole" (Planetary Undersurface Tool, or PLUTO), to be deployed by the arm. PLUTO had a compressed spring mechanism designed to enable it to move across the surface at a rate of about 1 cm every 5 seconds and to burrow into the ground and collect a subsurface sample in a cavity in its tip. The mole was attached to the lander by a power cable which could be used as a winch to bring the sample back to the lander.
The lander had the shape of a shallow bowl with a diameter of 1m and a depth of 0.25 m. The cover of the lander was hinged and folded open to reveal the interior of the craft which holds a UHF antenna, the 0.75 m long robot arm, and the scientific equipment. The main body also contained the battery, telecommunications, electronics, and central processor, heaters, and additional payload items (radiation and oxidation sensors). The lid itself further unfolded to expose four disk-shaped solar arrays. The lander package had a mass of 69 kg at launch but the actual lander would have been only 33.2 kg at touchdown.
The ground segment itself was derived from the European Space Agency software kernel known as SCOS2000. In keeping with the low cost theme of the mission, the control software was the first of its type deployed on a laptop.
Mission profile
Mars Express launched from Baikonur at 17:45 UTC (18:45 British Summer Time) on 2 June 2003. The Beagle 2 was a Mars lander initially mounted on the top deck of the Mars Express Orbiter. It was released from the Orbiter on a ballistic trajectory towards Mars on 19 December 2003 at 8:31 UT. Beagle 2 coasted for six days after release and was scheduled to enter the Martian atmosphere, at over 20,000 km/h, on the morning of 25 December. The lander was protected from the heat of entry by a heatshield coated with NORCOAT, an ablating material made by EADS. Compression of the martian atmosphere and radiation from the hot gas are estimated to have led to a peak heating rate of around 100 W/cm², comparable to the heat flux experienced by Mars Pathfinder.
After deceleration in the Martian atmosphere, parachutes were to be deployed and about 1 km above the surface large airbags were to inflate around the lander and protect it when it hit the surface. Landing was expected to occur at about 02:45 UT on 25 December (9:45 p.m. EST 24 December). After landing the bags were supposed to deflate and the top of the lander was to open. A signal was supposed to be sent to Mars Express after landing and another the next (local) morning to confirm that Beagle 2 survived the landing and the first night on Mars. A panoramic image of the landing area was then supposed to be taken using the stereo camera and a pop-up mirror, after which the lander arm would have been released. The lander arm was to dig up samples to be deposited in the various instruments for study, and the "mole" would have been deployed, crawling across the surface to a distance of about 3 meters from the lander and burrowing under rocks to collect soil samples for analysis.
The British government spent more than £22 million (US$40 million) on Beagle 2, with the remainder of the total £44 million (US$80 million) coming from the private sector.
Mission progress
Although the Beagle 2 craft successfully deployed from the Mars Express "mother ship", confirmation of a successful landing was not forthcoming. Confirmation should have come on 25 December 2003, when the Beagle 2 should have contacted NASA's 2001 Mars Odyssey spacecraft that was already in orbit. In the following days, the Lovell Telescope at Jodrell Bank also failed to pick up a signal from Beagle 2. The team said they were "still hopeful" of finding a successful return signal.
Attempts were made throughout January and February of 2004 to contact Beagle 2 using Mars Express. The first of these occurred on 7 January 2004, but ended in failure. Although regular calls were made, particular hope was placed on communication occurring on 12 January, when Beagle 2 was pre-programmed to expect the Mars Express probe to fly overhead, and on 2 February, when the probe was supposed to resort to the last communication back-up mode: Autotransmit. However, no communication was ever established with Beagle 2.
On 31 December 2003, it was reported that a crater was photographed in the center of the target landing site. It was originally believed that this could have been the final resting place of Beagle 2, the craft unable to transmit from the shadow of the crater walls; however, higher-resolution imagery later disproved this theory.
Beagle 2 was declared lost on 6 February 2004, by the Beagle 2 Management Board. On 11 February, ESA announced an inquiry would be held into the failure of Beagle 2.
Failures in missions to Mars are common. As of 2006, of 37 launch attempts to reach the planet, only 18 have succeeded. See the so-called Mars Curse for details.
Search for a possible crash site
On 20 December 2005, Professor Pillinger released specially-processed images from the Mars Global Surveyor which suggested that Beagle 2 came down in a crater at the landing site on Isidis Planitia. It was claimed that the blurry images show the primary impact site as a dark patch and a short distance away, Beagle 2 surrounded by the deflated airbags and with its solar panels extended. . Mars Reconnaissance Orbiter's HiRISE camera observed the area in February 2007, revealing that the crater was empty.
ESA/UK Inquiry report
In May, 2004, the report from the was submitted to ESA and the UK's science minister Lord Sainsbury. Initially the full report was not published on the grounds of confidentiality, but a list of 19 recommendations was announced to the public.
Professor David Southwood, ESA's director of science, provided the following scenarios on how the landing might have failed:
Beagle entered an atmosphere that was not predicted by scientists and could have burnt up. It may even have "bounced off into space". The amount of dust in the atmosphere often varies widely, changing its density and temperature characteristics.The probe's parachute or cushioning airbags failed to deploy or deployed at the wrong time;Beagles backshell tangled with the parachute preventing it from opening properly;Beagle became wrapped up in its airbags or parachute on the surface and could not open.
In February 2005, following comments from the House of Commons Select Committee on Science and Technology, the report was made public, and Leicester University independently published a detailed mission report, including possible failure modes, and a "lessons learned" pamphlet.
Beagle 2 in fiction
The concept for the Beagle 2 mission appears in the Transformers motion picture released in 2007, which inaccurately depicts the Beagle 2 as a NASA-launched rover. The mission's failure is attributed to the rover's destruction by a Decepticon. In the movie, Beagle 2 reportedly functioned for 13 seconds, before being destroyed by the Decepticons. A picture of the extraterrestrial being was taken and the incident was kept secret from the public. Beagle 2 is incorrectly portrayed in the film as a wheeled rover, rather than a stationary probe. Director Michael Bay had always wanted to incorporate the incident into one of his films.
In the novel Sunstorm by Arthur C. Clarke and Stephen Baxter a Mars rover is named for Beagle 2.
See also
External links
- by
- (BBC News Online 20 December 2005)
- (New Scientist, 8 March 2004 )
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