[meteorite-list] Scientists Wait For Beagle 2 To Call Home

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:18:04 2004
Message-ID: <200312261547.HAA02618_at_zagami.jpl.nasa.gov>

http://www.beagle2.com/news/index.htm

Scientists Wait For Beagle 2 To Call Home
26-Dec-03 11:15 GMT

Summary

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.
Received on Fri 26 Dec 2003 10:47:35 AM PST