York-CUNY Prof Explains Curiosity Rover's Mission
By Timothy Paglione, Ph.D.
Unlike its smaller cousins, which all landed by bouncing on the surface in protective airbag cocoons, Curiosity is the size and weight of a small car, so no airbag could have saved it from a devastating crash. Instead, it was dramatically lowered to the surface on cables suspended from a rocket-powered platform called the Sky Crane. This novel (and might I add, awesome) landing technique provided an exciting, if harrowing, completion to Curiosity’s eight-month trip to Mars. But the landing marked just the beginning of its two-year mission to explore the rich geology of Gale Crater. The amazing landing sequence, referred to by Jet Propulsion Labs scientists and engineers as “seven minutes of terror,” was caught on camera by Curiosity’s Mars Descent Imager for all to see. Its initial parachuted descent was also imaged by NASA’s Mars Reconnaissance Orbiter, which later snapped pictures of the landed rover and the rest of the scattered descent equipment such as the heat shield, parachute, and inimitable Sky Crane.
Besides the fantastic landing, Curiosity is a major advance over the recent, incredibly successful rovers, Spirit and Opportunity. Not to knock these rovers in any way – Opportunity is still running strong after an incredible eight years at Mars – but Curiosity carries a dozen instruments and tools for analyzing the surface geology and atmosphere throughout a full Martian year (about two Earth years). Of course Curiosity has cameras and spectroscopes, but its suite of tools also includes scoops, drills, and brushes mounted on a robotic arm that can feed samples to instruments mounted on the chassis. What if an interesting sample lies out of reach of the arm? Then Curiosity can blast it with its ChemCam laser and analyze the resulting puffs of gas and plasma from up to twenty feet away. Some of the sampling equipment was made right here in New York City by Honeybee Robotics. Veterans of three previous Mars lander missions, Honeybee literally took the City to Mars, incorporating Twin Towers steel in their Spirit and Opportunity instruments. Weighing in at nearly a ton, over twice the mass of the previous rovers combined, Curiosity’s instruments are designed to critically examine the carbon and hydrogen content of the rocks. These may signal present or past traces of biological activity, as well as measure the water content of the rocks and soil.
The point of Curiosity’s mission is to investigate the habitability of Mars. That is, are the surface conditions today or in the past conducive to supporting life, and is there any evidence of past or present biological activity? Some experiments follow on the controversial, inconclusive, and/or ambiguous results of the Viking lander missions of the 1970s. One Viking experiment showed tantalizing hints of active biological processes in Martian soil, while another showed no evidence of life-like molecules. Neither experiment alone was a smoking gun or nail in a coffin, and they varied in sensitivity and scope, fueling nearly forty years of debate. Curiosity may finally settle the issue while providing a wealth of information on the geological history and composition of the Martain surface in Gale Crater.
Tim Paglione is a professor of Astronomy & Physics and Chair of the Dept. of Earth & Physical Sciences at York College, CUNY. He is also a member of the Physics graduate faculty at the CUNY Graduate Center, and a Resident Research Associate in the Astrophysics Dept. at the American Museum of Natural History. He holds a Ph.D. in Astronomy from Boston Univ., and BS in Physics from Stevens Institute of Technology.