Beagle Hunts for Mars
Late Monday, at a quarter to midnight in Kazakhstan, the European Space Agency successfully launched its first probe to another planet.
|Monday night, Mars Express launches from Russian Cosmodrome Credit: ESA|
The European Mars Express, along with its small autonomous research lander, is expected for Martian arrival on Christmas. Weighing in at slightly more than 1000 kilograms, the probe enterred its interim Earth orbit after the first firing of its Soyuz-Fregat upper stage. One hour and thirty-two minutes later the probe injected itself into interplanetary orbit–a step in which the probe points to the Sun, deploys its solar panels for power, and on Wednesday (two days after launch), maneuvers into a Mars-bound trajectory.
The Mars Express has 400 million kilometers [240 million miles] left to reach the Red Planet. Speeding away initially at 30 kilometers per second [65,000 miles per hour], the probe began its 6-month journey flawlessly. After all its payload operations check out, the probe will deactivate itself and hibernate to conserve power, until its first mid-journey correction scheduled for September. For the next four months, the spacecraft will wake up only once per day, just long enough contact back to Earth its continued health.
Quarter Billion Miles Later
Three months later, at the end of November, Mars Express will reactivate permanently and prepare to release a lander called Beagle 2. Further deceleration will slow the Mars Express mothership into a highly elliptical orbit. At closest approach, the orbiter will pass with 250 kilometers [150 miles] of the surface.
During each orbit, the overhead spacecraft will collect data from Mars between a half-hour to an hour, while spending the rest of its time broadcasting those results back to Earth. Its onboard camera offers high-resolution stereo views of Mars. Its comprehensive maps will feature 10 meter resolution, but some particularly interesting regions will get a close-up view to 2 meters [about the size of small car, as seen from orbit].
But below is where the main action takes place: its lander, Beagle 2, is tiny relative to previous Mars explorers and weighs only 60 kilograms. Conserving payload mass was a key cost-saving part of its design. The lander takes its name from the famous voyager, the HMS Beagle, that hosted Charles Darwin’s travels as he searched for the origin of terrestrial species.
Collision: Smart Crash Dummy
|The early fiery entry of Beagle 2 probe into the thin Martian upper atmosphere at 12,000 miles per hourCredit: ESA|
Beagle 2 has no propulsion or steering control of its own. Once released, its destination is governed– ‘bullet-like’– by the laws of physics. Protected by the same airbag system that was first demonstrated on the 1997 Mars Pathfinder mission, the research station itself will collide with Mars, more than land on its surface. Release is scheduled to begin on December 20th, followed by a fiery entry into Mars’ atmosphere on Christmas which should finally settle it near the equator in a region known as Isidis Planitia. For the lander itself, its crucial and potentially risky phase will last just ten minutes. After five days of ballistic flight, the time from its entry into the atmosphere to landing will culminate in a short moment of truth: if successful, its six-month journey will send back data to Earth on potentially rich Martian soil chemistry.
Along with the two NASA Mars Exploration Rovers launched later this month, the trio of probes aim to answer key questions about the water history of Martian geology. In contrast to the NASA rovers, Beagle 2 is more of a mining station and furnace than a wheeled car. It will collect samples using a kind of digging tool, or mole, that reaches out to explore its landing site. The mole is a wire-guided mini-robot. It will burrow to a depth of 2 meters.
|Landing ellipses centered on Mars’ third largest impact basis Credit: NASA JPL/MSSS/MOC|
One scientific milestone for Beagle 2 is an accurate, absolute dating measurement for its rock samples. To accomplish its intended task and find the age of the rocks it digs out, Beagle 2 employs a bank of twelve different furnaces. Following a programmed set of heating and cooling steps, the byproducts of this ‘bake out’ will reveal the composition, age, and ash components from Martian soil.
Around Mars in 180 Days
To complete this picture, the orbiter overhead will probe beneath the Martian surface using ground-penetrating radar. If pockets of water are found to a depth of 2 kilometers [1.2 miles], then theories of active hydrology on Mars will be borne out. Subterranean aquifers are considered one possible way in which liquid water could exist in the frigid, hostile conditions, where the atmosphere is about one percent of the Earth’s pressure. The radar, called the MARSIS instrument, uses a large 40 meter antenna to collect the return waves that bounce off any density pockets below the rusty-red soil.
The orbiter mission should last at least one Martian year (687 days), while Beagle 2 is expected to operate on the planet’s surface for 180 days.
Mars Express forms part of an international Mars exploration program, featuring also the US probes Mars Surveyor and Mars Odyssey, the two Mars Exploration Rovers and the Japanese probe Nozomi.
Using some of the same mission elements, future European explorers will head towards Venus in 2005, Mercury in 2009, and next year towards landing on a comet with the recently rescheduled Rosetta mission ‘s launch.
Related Web Pages
European Space Agency Beagle Lander (June 2003 launch)
Mars Exploration Rovers (JPL/Cornell) (June 2003 dual launch)
Mars Orbiter Camera Gallery
Mars Global Surveyor
Red Rovers: Returning to Mars
Mars Exploration Website
Two Mars Rover Sites Get Science Stamp of Approval
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