COLLEGE PARK – University of Maryland scientists are confident that their new spacecraft is going to crash. In fact, they’re counting on it.
Deep Impact, a space exploration project led by Maryland professor Michael A’Hearn, is designed to slam a spacecraft into the Tempel 1 comet 80 million miles from Earth next summer, with the hope that resulting crater will reveal more about the origins of the universe.
Most comets, A’Hearn said, formed at the edge of the solar system at the same time as the planets. Ice contained in the middle of the comet could tell scientists more about what space was like at the time the solar system formed.
The trick, he said, is “to get down to a depth where the ices are relatively unprocessed.”
To do that, the spacecraft will position itself in front of the 4-mile-wide pickle-shaped comet and release an “impactor” — essentially an 820-pound piece of copper about 4 feet in diameter — that will move directly into the comet’s path, hitting it at about 23,000 mph.
The explosive force of the impact will be equal to about 4 tons of TNT, and should create a crater about the size of a football field and anywhere from 65 to 100 feet deep, A’Hearn said.
The $311 million project is scheduled for a Dec. 30 launch from the Kennedy Space Center in Florida and it should reach the comet by July 4, A’Hearn said.
Plans to engrave the face of the impactor with the university’s mascot, Testudo, were scrapped due to cost, but the “fly-by” vehicle will carry a CD listing more than 500,000 people who signed up to have their names launched into space, including University of Maryland President Dan Mote, said Lucy McFadden, a research scientist in the University of Maryland Department of Astronomy.
The “fly-by” part of the spacecraft will remain about 310 miles away from Tempel 1, McFadden said. After the impact, it will have only about 13 minutes to look into the crater and take readings before the comet passes by, she said.
The concept for Deep Impact was proposed by A’Hearn and his team in 1998 and selected by the National Aeronautics and Space Administration in 2000. The spacecraft was built by Ball Aerospace in Boulder, Colo.
Despite several highly publicized failures by NASA spacecraft, most recently Genesis, the solar-wind collector that crashed in the Utah desert earlier this year, A’Hearn said he is “99.9 percent sure” that Deep Impact will hit its target, based on computer simulations.
He admitted that experts are unsure exactly what the comet is made of and how dense it is. But A’Hearn said that is part of the reason NASA is spending millions on what is a grand version of the most basic scientific experiment: “Hit it and see what happens.”
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