Saturday, January 3, 2004 |
Calling Beagle... Where are you?
It is one law that scientists fear the most, and it isn't even a scientific law! No matter how meticulously you plan, no matter how many tests and dry runs you conduct, if things can possibly go wrong, they will. The scientists and engineers of European Space Agency's Mars Express project had left nothing to chance. They had been working and sweating for years, and just when their hour of glory arrived, things began to go wrong, at least for the time being. As the mission scientists prepared to celebrate the merriest Christmas of their lives by landing Beagle 2, a probe, on the surface of Mars on December 25, the probe lost contact with its mothership Mars Express. And as we go to press, no one knows what became of Beagle. Sod's Law or Murphy's Law appears to have struck again. Things could go wrong, and looks like they did! What happened to little Beagle? Have we just lost contact with it, or have we lost it forever? And if it is not found, will the entire mission be a failure? The team leader Prof. Colin Pillinger thinks it would be foolish to give up hope. He expects Mars Express to make contact with the probe in the first week of 2004. He believes that the UK-built lander got down safely, although the US Orbiter Mars Odyssey which flew over the assumed landing zone heard no transmission from the Beagle. The US Orbiter will keep looking for the probe in the coming days, and so will the giant radio telescope at Jodrell Bank in northwest England, another one at Stanford in California and the Westerbork radio telescope in the Netherlands. A naturally worried Prof. Pillinger put it to the Press rather poetically, "If we can contact it, we can pull this thing round. But it is very much like . . . sending somebody a love letter. You know they got it, and you are waiting for their response." The mission: The mother and its baby When we talk of space missions, we usually associate them with the United States or Russia. But now things are changing. Europe's ESA, has entered the fray with great enthusiasm and so have the Japanese, the Chinese and, of course, the Indians. Europe finally decided to catch up with the USA and Russia by setting up the European Space Agency (ESA), and their latest project is their ambitious mission to the Red Planet. The result is the spaceship Mars Express, so called because of the tight budget and breakneck speed at which it was build. The spacecraft is a wonderful example of international cooperation. The stereoscopic camera comes from Germany, the mineralogical mapping device from France and an atmospheric sounder from Italy. The radar instrument, to probe for water at depths of a few kilometres below the surface, was developed jointly by Italy and the Jet Propulsion Laboratory in California, and the 'baby' Beagle 2 landing craft was designed and built in the UK. Apart from the remote observation payload, the Orbiter carries a lander communications package to support international Mars lander missions until the year 2007. Main objectives The mission's main aim is to look for sub-surface water from orbit and, more ambitiously, land its Beagle 2 probe on the Martian soil. Seven instruments onboard the mothership will perform remote sensing experiments to learn more about the planets atmosphere, its structure, geology and composition. The lander Beagle 2, named after the ship in which Charles Darwin set sail to explore unchartered areas of the Earth in 1831, was expected not only to perform exobiology and geochemistry experiments, and also look for the possibility of life on Mars. But as David Southwood, the European Space Agency's director of science, observed earlier, "It's not looking for little green men . . . it is looking for matter that might provide evidence of life. It is looking for clues." The mission would take up from where the twin US Viking landers left in 1976 after giving inconclusive results about the prospect of finding life on Mars. To be sure, the scientists are not too optimistic about finding life there, at least not intelligent life. The best they can hope for is to find traces of extinct microscopic organisms. What they are more certain about finding is frozen water trapped in the crevices and the surface below the planet. The mission would begin taking pictures with sensitive 3D photography to understand the surface and geology of Mars. To look beneath the Martian surface, it would use radar beams. Different materials or structures will send back different radar echoes allowing scientists to produce an accurate 3D survey. One of the objectives is the precise determination of atmospheric circulation and composition to build up an accurate picture of Martian meteorology and climate. The mission would also study the interaction of the atmosphere with outer space. Why do we have to spend millions and millions to learn about a planet that is hardly capable of being colonised? The knowledge we gain from the various missions to Mars could help us in understanding our own planet and its environment better. By understanding why Martian water disappeared in the past we may learn if similar fate awaits the Earth. What ‘baby’ Beagle could do In spite of having lost contact, it is quite possible that Beagle has landed on Mars. It is designed to withstand hostile conditions and can survive temperatures down to as low as minus 100 degrees Celsius. About the size of a bicycle wheel, and weighing only 33 kg, Beagle is equipped with panoramic wide-field cameras that will be used for pictures of the landing site to guide further exploration as the mission progresses. A microscope will study the rocks and soil with a high degree of magnification. Extending its robotic arm, the Beagle will grab fragments of rocks which will be analysed for the existence of organic matter, water and aqueously-deposited minerals. Beagle will also deploy a mole capable of crawling short distances across the surface at one cm every six seconds and burrowing beneath large boulders to collect soil samples for a gas analysis system. These experiments will help us to find any evidence of past life near the landing site. But all this only if it has landed! What went wrong? Although it is too early to comment, but the scientists believe that it is most likely that Beagle 2 landed off course, in an area where communication with Mars Odyssey is not easy. It is also quite likely that the transmission from the lander's antenna is obstructed by some geological structure. Whatever the reason, the mission scientists are on pins and needles, for it is now feared that the missing baby might have tumbled down the slope of a crater. The region of Isidis Planitia, just north of the Martian equator, was selected as a landing site because it seemed to offer a compromise between safety and interesting geology in the search for life. High -resolution satellite images of the site show a 1-km-wide crater in the centre. Was Beagle unlucky enough to land right into it? Teething troubles Beagle 2 was conceived in 1997 by Colin Pillinger who gathered together a team of experts to design and build Europe's first Martian lander. But the project has been dogged by problems right from the beginning. Beagle's airbags, designed to cushion the landing on Mars, were a major technological challenge and because of technological setbacks about three weeks were lost in the 24-month timetable. The scientists did not mind the delay because they had to be absolutely certain about the probe's technical capabilities. They had to make sure that the probe landed on Mars safely. To achieve this, the scientists thought of using parachutes and airbags. The parachutes would open first and, just before impact, would jettison; the airbags would then inflate, allowing Beagle to bounce a few times before landing upright. After many trials and improvements the bags were sent to the US space agency's Plum Brook Station in Ohio to be tested. The early tests were discouraging, but after making further improvement in the design, the parachutes were given the fitness certificate. But some were still apprehensive about the modified airbags. They must be inflated at just the right time before the landing otherwise they will not have the correct pressure to cushion the probe. Scientists don't like ifs and buts. The mysterious face on Mars At some stage, the Mars Express will find time to investigate the famous face on Mars. Some of the pictures taken by NASA in the past show a formation on the surface of Mars that looks like a human face. Although scientists believe that it is just a natural formation, but looks like a human face because of the play of light, many believe it to be the work of an ancient civilisation. Is the mission doomed? Going by media reports, it appears that the entire mission would be a failure if Beagle is lost. This is an inaccurate projection, for the mothership has its own array of experiments to perform, and let's not forget that Beagle was a late addition to the programme. Although it would be a crowing glory if the 'baby' has made it safely on to the surface or Mars. Whoever likes babies getting lost? |