January 4, 2004
Beagle 2
Team Congratulates NASA
At a press briefing in London today, Professor
Colin Pillinger and Dr. Mark Sims -- the head scientist and mission
manager of the European Space Agency team still hoping to communicate
with their own mars lander, which has been missing since Dec.
25, 2003 -- congratulated their colleagues at NASA's Jet Propulsion
Laboratory on the successful landing of the Spirit rover on Mars.
"I'd like to give congratulations to NASA and the Spirit
team for getting the lander down safely," Pillinger said.
"We wish them every luck."
Adding his congratulations, Sims said,
"I'd like to reiterate the international cooperation we've
been getting in terms of looking for Beagle. In particular, the
JPL team which has been working very strange hours supporting
the Odyssey passes, Lockheed Martin, who've been running the
Odyssey spacecraft, Jodrell Bank, Westerborg, the British Astronomical
Association and Malin Space Science Systems. Mike Malin is looking
at imaging the landing site potentially from tomorrow."
Meanwhile, the search for Beagle 2 goes
on.
Computer Generated Image of
Beagle 2 Lander Leaving Mars Express Orbiter
Click
for larger image
All Rights Reserved Beagle 2 - www.beagle2.com
"We haven't in any shape or form given
up on Beagle 2," Pillinger said.
"We have realised that Mars Express
is not in the orbit we originally expected, so our communication
strategy is now different from the one that we explained at the
beginning of last week."
Describing the ongoing work at the Lander
Operations Control Centre, Sims explained that teams from the
University of Leicester, SciSys and Astrium are continuing their
efforts to identify possible failure modes that can be addressed.
"We're still concentrating on both
the communications and timing/software issues, and working our
way through the logic and fault tree on the basis that Beagle
2 is on the surface of Mars and for some reason is failing to
talk to us," Sims said.
"There are six or seven scenarios
that we're still working through and we still can't eliminate
any of those."
However, possible failure scenarios involving
a reset of the clock hardware and a problem with a tilted antenna
seem to have been ruled out. Today's successful transmission
of signals from the Spirit rover via Mars Odyssey also indicates
that the radio on board NASA's orbiter is working properly.
Meanwhile, an attempt to send blind commands
to Beagle 2 via Mars Odyssey on Dec. 31 also resulted in no obvious
response from the lander.
There has also been no response from the
Beagle 2 transceiver during 11 programmed passes. Unfortunately,
the last four contact opportunities pre-programmed into Beagle
2's computer no longer coincide with Mars Express on its current
orbit, so the team is now relying on the spacecraft switching
to various back-up communication modes.
The mission team is now waiting for their
little lander to switch to one of its backup communication modes.
Beagle 2 could already be operating in 'communication search
mode 1', during which it listens for 80 minutes during both the
Martian day and night in an effort to establish contact with
an available orbiter at Mars Odyssey overflight times.
If no link is established by this method,
'communication search mode 2' should eventually be activated.
The earliest date by which this mode could become operational
was on Jan. 3. In this mode, the receiver is on for 59 minutes
out of every hour throughout the Martian day, and the spacecraft
sends a carrier signal five times in each daylight hour. During
the Martian night, Beagle 2's receiver will be on for one minute
out of every five, but there is no carrier signal.
Although Mars Odyssey will continue to
search for the lander, Mars Express will soon become the prime
communication link with Beagle 2. After reaching its operational
polar orbit today, ESA's orbiter should pass over the Beagle
2 landing site regularly from Jan. 7 onwards. Various modes of
communication can be attempted during passes by Mars Express,
although the team anticipates starting on Jan. 7 - 8 with the
standard 'hail and command' which has been used with Mars Odyssey.
The first four passes with Mars Express
(Jan. 7 - 10) are almost directly over the landing site and only
5 to 8 minutes long, so they are not ideal for communication,
whereas the opportunities on Jan. 12 and 14 are potentially much
longer.
Source: Particle
Physics and Astronomy Research Council press release
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