NASA’s nanosatellite NanoSail-D is slowly descending after successfully orbiting the Earth’s upper atmosphere for 95 days since deploying its 100-square-foot sail on Jan. 20. The small satellite demonstration experiment continues its descent towards Earth, lending key sail data to the design of de-orbit mechanisms for future satellites.
One of NanoSail-D’s main mission objectives is to demonstrate and test the de-orbiting capabilities of a solar sail for possible use in de-orbiting decommissioned satellites and space debris. The NanoSail-D engineering and science team at NASA’s Marshall Space flight Center in Huntsville, Ala., have been monitoring the satellite’s orbital characteristics since initial sail deployment. The team has learned that the satellite’s attitude dynamics is causing it to orbit the Earth in a flat spin as opposed to a random tumble, or facing into the direction of flight. This flat spin attitude causes the spacecraft to encounter less atmospheric drag, or particles, keeping it in orbit longer than originally estimated.
“NanoSail-D has lowered its altitude above the Earth by approximately 28 miles (45 kilometers) from its original altitude of 400 miles (640 kilometers), and continues to descend,” said Dean Alhorn, principal investigator for the NanoSail-D mission at Marshall. “Prior to launch, our original de-orbit analysis was based on a maximum drag attitude, which meant NanoSail-D would de-orbit in 70-120 days. Based upon NASA’s current analytical assessments of the NanoSail-D tracking data, the team predicts NanoSail-D will continue to descend and eventually re-enter Earth’s atmosphere and disintegrate six months to one year from sail deployment.”