美国报废卫星今日将落向何处？_BEC初级作文

美国报废卫星今日将落向何处？

In the meantime, NASA and the U.S. Air Force will be closely monitoring the satellite and its decaying orbit.

"With re-entry we're always interested in day-by-day and hour-by-hour details," Mark Matney, a scientist with NASA's Orbital Debris Program Office, told SPACE.com. "It's very difficult to predict how it's going to happen. With our models, we try to figure out what parts of the spacecraft — what materials — will interact with the atmosphere in terms of temperature and melting, and determine which of those will survive. But it's a very dynamic environment, the force is very intense."

Current predictions of the potential impact zone cover a giant swath of the planet — anywhere between the latitudes of northern Canada and southern South America. Scientists will be able to refine these projections as the spacecraft makes its fiery journey through the atmosphere.

"It's partly a matter of not knowing enough," said Ray Williamson, executive director of the Secure World Foundation, an organization dedicated to the peaceful use of outer space. "The shape of the structure is not perfectly spherical, so when it heats up and starts to break up, it will break into odd pieces. Once it begins to break up, then they can get a better sense of where this is roughly going to hit."

Scientists at NASA's Orbital Debris Program Office estimate that at least 26 large pieces of the bus-size satellite will endure the scorching heat of re-entry. Approximately 1,170 pounds (532 kilograms) of material are expected to reach the ground, NASA officials said.