This past Friday, January 28, a mob of space enthusiasts filled Convocation Hall for an evening entitled, “Expanding Canada’s Frontiers in Space,” organized by the U of T Astronomy and Space Exploration Society.
It was, coincidently, the 19th anniversary of the Challenger disaster, a date not forgotten by the first speaker of the evening, Mars rover scientist Dr. James Rice of the University of Arizona. “Human spaceflight is a very dangerous thing, and it’s going to be that way for a long time,” he said. “Danger goes hand-in-hand with exploration.”
It is also risky for the robotic craft that Rice and his colleagues use to explore Mars: only one-third of robotic missions have been successful. However, NASA rovers Spirit and Opportunity, which landed a year ago, have not only been successful, but have exceeded the expectations of even the most optimistic scientists.
The rovers were sent to Mars to see if water has existed on the surface and, if so, when and how much was there? Scientists believe that the search for water is key in the search for life, living or extinct, on Mars.
The Mars rovers have been remarkably successful in their search for signs of water. The first clue came with the discovery of the mineral hematite. Scientists had already suspected that the mineral would be found on the surface of Mars, but they were surprised to discover that much of it was found in small spherical globules, nick-named “blueberries.” The spherical particles, which almost always form in the presence of water, are a strong indicator that Mars had a soggy past.
But the rovers have also found that Mars may once have had not only water, but shallow lakes. “There was a body of water standing on Mars,” Rice explained, “[but] the thing we can’t answer is how long ago it was there, and how long the water existed on the surface.”
NASA had assumed that the rovers could last for 90 days on Mars, after which time the dust accumulated on the solar panels would starve the rovers of electrical power. However, after over a year on the surface, the rovers are still going strong, and engineers are still trying to figure out what is keeping the dust off the panels. “These rovers just don’t want to die,” said Rice. He said engineers believe that either wind is blowing the dust off, or frost is accumulating overnight on the solar panels and removing the dust when it boils off during the day.
Laurie Chappell of MDA Space Missions in Brampton (makers of the Canadarm) showed how a robot originally designed for use on the International Space Station (ISS) could now be used to save the Hubble Space Telescope.
The Hubble is due for a new set of batteries and gyroscopes, without which it will become unusable and eventually fall to Earth. NASA must be able to control the de-orbit to ensure that the satellite doesn’t land on a populated area. However, after the Columbia disaster a servicing mission using the Space Shuttle has been deemed too risky.
Even with a de-orbit mission the Hubble will still become unusable sometime after 2007 when either the batteries or the gyroscopes fail. After considerable public outcry, NASA was convinced to try to find a way to fix Hubble without sending any astronauts.
The challenge is being met by engineers at the Goddard Spaceflight Center and MDA who have come up with a way to use the Special Purpose Dexterous Manipulator (nicknamed Dextre), a two-armed robot, to perform the tasks that only astronauts have been able to do before.
Dextre, built for use on the ISS, would be part of the de-orbit module sent to rendezvous with Hubble. Once there, astronauts on the ground could remotely direct Dextre to connect and disconnect cables and install new batteries, gyros, and new scientific instruments.
While Canadian engineers are trying to save NASA’s Hubble Space Telescope, Jaymie Matthews of the University of British Columbia and Professor Slavek Rucinski of U of T were there to showoff the controversial results of Canada’s “Humble” Space Telescope.
MOST (Microvariability and Oscillation of Stars Telescope) has been dubbed the “Humble” space telescope because of its low cost, small size (about as big as a briefcase) and, as Matthews likes to point out, at 54 kg, “weighs less than its mission scientist [Matthews],” (though Matthews declined to say how much less).
Matthews described MOST as “the world’s most precise light meter.” It can measure the brightness of a star to the precision of 1 part-per-million-akin to being able to see somebody pull down a shade 3cm on one window on the Empire State Building.
MOST can determine how a star is vibrating. The study of stellar vibrations can give insight into the internal structure of a star, just as the study of earthquakes can help us understand the internal structure of the Earth. However, to get consistent data on the variability of brightness, the star must be constantly monitored, which is difficult for ground-based telescopes on the revolving Earth. But MOST, in orbit, can monitor stars for days at a time.
Dr. Carolyn Porco, leader of the Cassini mission Imaging Team, presented the most recent photos from Saturn and its largest moon Titan. Following a seven-year voyage, the spacecraft Cassini entered Saturn’s orbit in June 2004 in a fly-by of Saturn’s famous ring system. In December it released the European made Huygens probe, and on January 14th, Huygens descended into the murky atmosphere of Titan and became the first vehicle to land on a moon in the outer solar system, over a billion kilometres from Earth.
But Cassini isn’t finished yet. It has just started its four-year primary mission to study Saturn, its rings and 31 moons. “We are now the interlopers in the Saturn system,” Porco proudly declared. Cassini will make over 52 close fly-bys of seven of Saturn’s moons including many more fly-bys of Titan. Despite the official four-year duration of the mission, Porco is confident that Cassini will last much longer, even as long as a decade.
In an evening dominated by robotic explorers and remotely controlled telescopes, Rice stood out in his desire to see humans explore the solar system. “Astronauts are better geologists than robots,” he said. He cautioned, however, against pitting robots against humans, preferring to see robots as complimentary to human exploration. “It is a fallacy to say ‘manned vs. unmanned.’ They work better in concert [with one another].”
