Until recently, this website, sponsored by the The Aerospace Corporation, was devoted to monitoring the orbit decay and presenting information and the results of analyses pertaining to the reentry of the Russian space station Mir. Russia's controlled reentry plan for Mir is described on this site, and weekly predictions of its reentry date and time for an uncontrolled reentry are posted as well.
Mir reentered Earth's atmosphere on March 23, 2001 as a result of both natural orbit decay and a sequence of three braking burns commanded by the Russian Mission Control Center (TsUP). The reentry of the station was observed from the south Pacific island of Fiji. Observers there saw five extremely bright objects, glowing with a blue-white light, crossing the sky, leaving trails of smoke behind them. A series of sonic booms followed their passage. These objects were the component modules of Mir, separated by the reentry breakup of the station at an altitude of approximately 40 nmi (74.1 km). For accounts, pictures, and video of Mir's fiery passage over Fiji, see Space.com's Mir deorbit page.
With Mir's demise, the focus of this page will now turn to analyzing data from the station's reentry in order to better understand the breakup dynamics of reentering spacecraft, spent rocket stages, and other man-made space debris. The data obtained from Russian and U.S. ground tracking stations, eyewitness accounts, and other sources will be analyzed by Aerospace engineers and scientists, sponsored by CORDS. The goal of these analyses will be to reconstruct as closely as possible Mir's reentry breakup sequence and trajectory during the station's final minutes.
Although the events leading up to and including the breakup and impact of reentering spacecraft and other orbital debris are generally known, the exact times at which they occur are difficult to predict due to
- Variations in Earth's atmosphere
- Over and under performance by spacecraft propulsion systems executing braking burns for controlled reentries
- Errors in spacecraft attitude (orientation) or loss of stability during braking burns
- Attitude uncertainties during reentry
- Uncertainty in how the complex structures of reentering spacecraft and other man-made debris will behave under the extreme aerodynamic forces and heating of reentry
The reentry of the 140 ton Mir (including the docked Progress M1-5 spacecraft), the largest man-made object to reenter Earth's atmosphere, has provided scientists and engineers with an excellent subject for continued investigation, leading to better characterizations of reentering space debris trajectories and hence greater safety for people and property on the surface of the earth.
The following links provide information on the plan TsUP used for Mir's controlled March 23 reentry/deorbit and the reentry breakup dynamics that lead to the formation of the debris footprint for the station.
