[meteorite-list] Scientists Await First Call From Beagle

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:18:04 2004
Message-ID: <200312251845.KAA10272_at_zagami.jpl.nasa.gov>

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

Contact:
Gill Ormrod, PPARC Press Office
gill.ormrod_at_pparc.ac.uk, +44 (0)7818013509

Peter Barratt
Email: peter.barratt_at_pparc.ac.uk

>From 2300 hours on 24th December 2003, the Beagle 2 Media
Centre will operate from:
The Open University – Camden Offices
1-11 Hawley Crescent
Camden, London NW1 8NP
Tel: +44 (0)1908-332015 or +44 (0)1908-332017
Fax: +44 (0)1908-332016

25 December 2003

Scientists Await First Call From Beagle

Early this morning, the Beagle 2 spacecraft landed on the surface of
Mars at the end of a 250 million mile (400 million km), six-month
trek to the Red Planet.

Although the first attempt to use NASA's Mars Odyssey orbiter to
communicate with the lander three hours later was unsuccessful,
scientists and engineers are still awaiting the best Christmas
present possible -- the first faint signal to tell them that Beagle 2
has become only the fourth spacecraft to make a successful landing on
Mars.

"This is a bit disappointing, but it's not the end of the world,"
said Professor Colin Pillinger, lead scientist for the Beagle 2
project.

"We still have 14 contacts with Odyssey programmed into our computer
and we also have the opportunity to communicate through Mars Express
after 4 January."

The next window to receive confirmation that Beagle 2 has
successfully landed and survived its first night on Mars will be
between 10 pm and midnight (GMT) tonight, when its simple carrier
signal (rather than the tune composed by Blur) may be picked up
by Jodrell Bank radio observatory in Cheshire, UK. This has a
much greater chance of success because the giant telescope is able
to scan the entire side of the planet facing the Earth.

Another overflight by Mars Odyssey will take place around 18:15 GMT
tomorrow evening, followed by daily opportunities to contact Beagle 2
via the Mars Odyssey spacecraft and the radio telescopes at Jodrell
Bank and Stanford University in the United States.

There are several possible explanations for the failure of Odyssey to
pick up Beagle 2's signal. 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
lander's antenna was not pointing in the direction of the orbiter
during its brief passage over the landing site. If the onboard
computer had suffered a glitch and reset Beagle 2's clock, the two
spacecraft could be hailing each other at the wrong times.

The Beagle 2 lander entered the thin Martian atmosphere at 2:47 GMT
today. Travelling at a speed of more than 12,500 mph (20,000 km per
hour), the probe was protected from external temperatures that soared
to 1,700 C by a heat shield made of cork-like material.

As friction with the thin upper atmosphere slowed its descent, onboard
accelerometers were used to monitor the spacecraft's progress. At an
altitude of about 4.5 miles (7.1 km), Beagle's software was to order
the firing of a mortar to deploy a pilot parachute, followed one minute
later by deployment of the 33 ft (10 m) diameter main parachute and
separation of the heat shield.

At a few hundred metres above the surface, a radar altimeter was to
trigger the inflation of three gas-filled bags. Cocooned inside this
protective cushion, Beagle 2 was expected to hit the rust-red surface
at a speed of about 38 mph (60 km/h). As soon as the bags made contact
with the surface, the main parachute was to be released so that the
lander could bounce away unhindered. Like a giant beach ball, the gas
bag assembly was expected to bounce along the surface for several
minutes before coming to rest at 2:54 GMT.

Finally, a system of laces holding the three gas-bags onto the lander
was to be cut, allowing them to roll away and drop Beagle 2 about 3 ft
(1 m) onto the surface. The whole descent sequence from the top of the
atmosphere to impact was to take less than seven minutes.

The "pocket watch" design of Beagle 2 ensured that it would turn upright
irrespective of which way up the little lander fell. After the onboard
computer sent commands to release the clamp band and open the lid, the
way would be clear to deploy the four, petal-like solar panels and
initiate charging of the batteries.

Confirmation of the successful landing would be provided by a musical
"beeping" signal of 9 digitally encoded notes, composed by British
rock group Blur. This signal should be picked up by Mars Odyssey as it
passes overhead and then relayed to Earth.

Notes for editor:

Beagle 2 was targeted to land within an ellipse, 30 km long and 5 km wide,
on Isidis Planitia, a large lowland basin near the Martian equator.
However, the exact location of the landing site depended on factors such
as the angle of descent and wind speed.

The landing site (11 N, 90 E) was chosen for its low elevation, since a
greater depth of atmosphere would assist the parachute in braking the
lander's descent. Its equatorial location also means that temperatures
are warmer, minimising the amount of insulation (and hence mass) needed
to protect the lander from the cold Martian night. The relatively flat
site was also thought to be neither too dusty nor too rocky to threaten
a safe landing (but rocky enough to be interesting for the experiments).

Sunset at the Mars landing site today was at 07:15 GMT (18:35 local
solar time).

Beagle 2 is scheduled to shut down and conserve power during the cold
Martian night, when temperatures may plummet to -80 C. Sunrise will
take place at 20:02 GMT on Mars (07:02 local solar time).

Beagle 2 was launched with the European Space Agency's Mars Express
orbiter on 2 June 2003.

Beagle 2 was named to commemorate Charles Darwin's five-year voyage
around the world in HMS Beagle (1831-36). Its main objective is to
search for signs of life -- past or present -- on the Red Planet.

By the time it arrived on the Martian surface, Beagle 2 weighed 33 kg,
including 9 kg of science instruments. This is the most ambitious
experiment package ever flown in space.

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

* http://www.beagle2.com
* http://www.pparc.ac.uk/Mars
* http://www.esa.int/mars
Received on Thu 25 Dec 2003 01:45:39 PM PST