||This article includes a list of references, but its sources remain unclear because it has insufficient inline citations. (December 2011)|
|Major contractors||EADS Astrium|
|Launch date||2 June 2003 17:45:00 UTC|
|Launch site||Baikonur Cosmodrome
|Mission duration||2003-12-25 03:54:00 UTC
Mission failure on day 206
|Data rate||2 or 8 kbit/s, 2 to 128 kbit/s|
Beagle 2 was an unsuccessful British landing spacecraft that formed part of the European Space Agency's 2003 Mars Express mission. All contact with it was lost upon its separation from the Mars Express six days before its scheduled entry into the atmosphere. The Beagle 2 was named after HMS Beagle, which twice carried Charles Darwin during expeditions which would later lead to the theory of natural selection.
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 life on Mars, 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 2's 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 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 and methane. 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. Atmospheric methane is another signature of existing life, although geological processes can also be a source.
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 20 mm per second 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.
Mars Express launched from Baikonur on 2 June 2003, at 17:45 UTC (18:45 BST). 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 the 19th of 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 the 25th of 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 200 m 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 metres from the lander and burrowing under rocks to collect soil samples for analysis.
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 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 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. 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.
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. However, Mars Reconnaissance Orbiter's HiRISE camera subsequently observed the area, in February 2007, and revealed that the crater was empty. While that mission ended in disaster, the Mars Express Orbiter that carried the Beagle 2 to Mars has been a success.
Failures in missions to Mars are common. As of 2010, of 38 launch attempts to reach the planet, only 19 have succeeded - failures are attributed to the Mars Curse.
ESA/UK inquiry report
In May 2004, the report from the Commission of Inquiry on Beagle 2 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 four scenarios of possible failures:
- Beagle entered in atmospheric conditions outside the range assumed by its designers and could have burnt up. The scenario that it may have "bounced off into space" has been put forward but this does not stand up to close technical scrutiny. The amount of dust in the atmosphere often varies widely, changing its density and temperature characteristics. However, the chosen margins on the design of the heat shield and the thermal loads it can withstand are such that the burn-up scenario is unlikely, and even the worst case density variations certainly are not such that, given the steep entry flight path angle at entry, the craft could conceivably have left the atmosphere again (see also Section 6.1 of the Inquiry Report, which states explicitly: "the Commission concludes that deviation of the atmospheric entry conditions is not a probable failure mode of the mission");
- The probe's parachute or cushioning airbags failed to deploy or deployed at the wrong time. This is supported by the observation that throughout the transfer to Mars, the outgassing of some substance and subsequent condensation on optical components of the Mars Express spacecraft carrying the Beagle lander was observed. This observation would be consistent with a leak in the gas generators of Beagle's airbags;
- Beagle's backshell tangled with the parachute preventing it from opening properly. It is not clear whether the difference in air drag between the probe with the parachute deployed and the back shell of the heat shield is sufficient to guarantee a safe separation distance (see Section 5.4.4 of the Inquiry Report);
- Beagle became wrapped up in its airbags or parachute on the surface and could not open. Entanglement with the parachute appears plausible in view of the fact that the parachute's strop was shortened from the original design to save mass. Assuming that the airbags deployed, Beagle would, in the scenario, have bounced off the surface right back into the descending parachute (see also Section 5.4.6 of the Inquiry Report).
In addition, further scenarios appear plausible and consistent with the available body of data:
- Beagle may have jettisoned its airbags too early, before it had come to a complete rest on the surface. For mass and cost reasons, the airbag jettison device was designed to be triggered by a timer rather than by acceleration sensors that would have discerned when the lander package had stopped moving. Given that the landing package of NASA's Spirit rover mission rebounded off the surface in Gusev crater numerous times before coming to a standstill – taking much more time than anticipated – Beagle's timer may have been set to a too short time (see Section 5.4.8 of the Inquiry Report);
- The parachute deployment sequence was designed to be triggered by three accelerometers. The system was not designed for a "best out of three" logic. Rather, the first accelerometer to compute that a safe deployment velocity had been reached would trigger the parachute deployment sequence, even if the accelerometer readout were faulty.
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
Beagle 2 was inaccurately portrayed as a rover and a JPL and NASA project in the 2007 Transformers movie. After landing on Mars, it was revealed it was destroyed by a Decepticon 13 seconds after being activated. Afterwards, the incident was classified above Top Secret by the US government, and declared a complete failure to the public (saying it crashed on Mars instead) but later became a warning that the Transformers were coming to Earth.
In the Facebook game Assassin's Creed: Project Legacy, Chapter 1 of the Holiday Set involves Beagle 2 being secretly co-opted by an unspecified organization, a freelance spy having hidden the lander's survival from everyone else at Mission Control while rerouting its controls to a laptop that she handed over to her handler.
In the 2005 BBC Doctor Who Christmas special, 'The Christmas Invasion', a 'British Martian lander', not directly identified, is lost close to the planet Mars on Christmas Day - inspired by the story of the Beagle 2 which had been lost exactly 2 years before the episode's broadcast date. In the story the lander is captured by an alien species, the Sycorax, who use its contents of A+ blood (put in the lander in case alien life were to come across the probe and enquire about its makers) to control everyone on Earth with that blood type.
- Atmospheric reentry
- Beagle 3 (rejected proposal)
- Life on Mars
- Unmanned space missions
- Viking program
- Sims, M. R. (2004). Beagle 2 Mission Report. Leicester UK: University of Leicester. p. 1. ISBN 1898489351.
- Jane Wardell (24 May 2004). "Beagle Mission Hampered by Funding, Management Problems". Associated Press. Archived from the original on 23 May 2009. Retrieved 2009-04-22.
- "UK and ESA announce Beagle 2 inquiry". ESA. 11 February 2004.
- "Possible evidence found for Beagle 2 location". ESA. 21 December 2005. Retrieved 2009-04-22.
- Pallab Ghosh (20 December 2005). "Beagle 2 probe 'spotted' on Mars". BBC News. Retrieved 2009-04-22.
- "Portion of Beagle 2 Landing Ellipse in Isidis Planitia (PSP_002347915)". HiRISE. University of Arizona. 26 January 2007. Retrieved 2009-04-22.
- R. Bonnefoy et al. (5 April 2005). Beagle 2 ESA/UKCommission of Inquiry (.PDF). ESA and UK Ministry of Science and Innovation. Archived from the original on 27 March 2009. Retrieved 2009-04-22.
- Official website
- Mars Express
- Beagle 2 Mission Profile by NASA's Solar System Exploration
- BBC guide to Beagle 2
- Beagle 2 may have sped to its death (New Scientist, 8 March 2004 )
- University of Leicester Mission Report and Lessons Learned
- NSSDC - Beagle 2