Scientists Wait For Beagle 2 To Call Home (Forwarded)

Particle Physics and Astronomy Research Council
Swindon, U.K.

Contact:
Peter Barratt
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From 2300 GMT on 24 December 2003, the Beagle 2 Media Centre will operate from:

The Open University - Camden Offices
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Camden,
London NW1 8NP
Tel: +44 (0)1908-332015 or +44 (0)1908-332017
Fax: +44 (0)1908-332016

26 December 2003

Scientists Wait For Beagle 2 To Call Home

The fate of Beagle 2 remains uncertain this morning after the giant radio
telescope at Jodrell Bank in Cheshire, UK, failed in its first attempt to detect
any signal from the spacecraft.

Scientists were hopeful that the 250 ft (76 m) Lovell Telescope, recently fitted
with a highly sensitive receiver, would be able to pick up the outgoing call
from the Mars lander between 19:00 GMT and midnight last night. An attempt to
listen out for Beagle's call home by the Westerbork telescope array in the
Netherlands was unfortunately interrupted by strong radio interference.

The next window of opportunity to communicate via Mars Odyssey will open at
17:53 GMT and close at 18:33 GMT this evening, when the orbiter is within range
of the targeted landing site on Isidis Planitia.

Another communication session from Jodrell Bank is scheduled between 18:15 GMT
and midnight tonight, when Mars will be visible to the radio telescope. It is
also hoped that the Stanford University radio telescope in California will be
able to listen for the carrier signal on 27 December.

The Beagle 2 team plans to continue using the Mars Odyssey spacecraft as a
Beagle 2 communications relay for the next 10 days, after which the European
Space Agency's Mars Express orbiter will become available.

Mars Express, which was always planned to be Beagle 2's main communication link
with Earth, successfully entered orbit around the planet on 25 December and is
currently being manoeuvred into its operational polar orbit.

Meanwhile, 13 more attempts to contact Mars Odyssey have been programmed into
Beagle 2's computer. If there is still no contact established after that period,
Beagle 2 is programmed to move into auto-transmission mode, when it will send a
continuous on-off pulse signal throughout the Martian daylight hours.

The first window of opportunity to communicate with Beagle 2 took place at
around 06:00 GMT yesterday, when NASA's Mars Odyssey spacecraft flew over the
planned landing site. In the absence of a signal from the 33 kg lander, the
mission team contacted Jodrell Bank to put their contingency plan into operation.

At present, Beagle 2 should be sending a pulsing on-off signal once a minute (10
seconds on, 50 seconds off). Some 9 minutes later, this very slow "Morse Code"
broadcast should reach Earth after a journey of some 98 million miles (157
million km).

Although the Beagle's transmitter power is only 5 watts, little more than that
of a mobile phone, scientists are confident that the signal can be detected by
the state-of-the-art receiver recently installed on the Lovell Telescope.
However, a significant drop in signal strength would require rigorous analysis
of the data before it could be unambiguously identified.

Although the ground-based radio telescopes will not be able to send any reply,
the new information provided by detection of the transmission from Beagle 2
would enable the mission team to determine a provisional location for Beagle 2.
This, in turn, would allow the communications antenna on Mars Odyssey to be
directed more accurately towards Beagle 2 during the orbiter's subsequent
overhead passes.

NOTES FOR EDITORS

Beagle 2 transmits at a frequency of 401.56 MHz.

There are a number of possible explanations for Beagle's failure to call home.
Perhaps the most likely is that Beagle 2 landed off course, in an area where
communication with Mars Odyssey was difficult, if not impossible. Another
possibility is that the transmission from the lander's antenna is blocked from
reaching Mars Odyssey or the ground-based telescopes.

Beagle 2 was targeted to land in a large lowland basin called Isidis Planitia at
02:54 GMT on 25 December. The "pocket watch" design of Beagle 2 ensured that it
would turn upright irrespective of which way up the little lander fell. Soon
after, the onboard computer was expected to send commands to release the clamp
band, open the lid and begin transmission.

The next vital stage was to deploy the four, petal-like solar panels and
initiate charging of the batteries. When the Sun set below the Martian horizon a
few hours later, the lander was scheduled to go into hibernation so that it
could survive the subzero night-time temperatures.

For further details on Beagle 2 and Mars Express see the following websites:

* http://www.beagle2.com
* http://www.pparc.ac.uk/Mars
* http://www.esa.int/mars