Session
Technical Session IV: Global Missions
Abstract
Long-term orbital debris is a continually growing problem that has proven challenging to overcome. A straightforward solution to the problem is to put the majority of future LEO spacecraft into Moderately Elliptical Very Low Orbits (MEVLOs) with perigees below approximately 300 km, apogees below approximately 500 km, and eccentricities in the range of 0.015 to 0.030. Orbital debris clouds cannot be sustained in this altitude regime and will decay and re-enter in times ranging from a few weeks to at most the time until the next solar maximum. This means that the debris population at this altitude is, and will remain, much lower than at higher altitudes and, of course, any satellites which explode or otherwise die in this region will not be a part of a long-term debris problem. The advantage of the elliptical orbit is that if a temporary failure causes the spacecraft to stop doing orbit maintenance burns for a moderate period of time, apogee will decay, perigee will change very little, and the orbit can be recovered with essentially no loss of total delta V. Of course, if the loss of orbit maintenance delta V is permanent, then the spacecraft will decay and re-enter, as is desirable.
Presentation Slides
Moderately Elliptical Very Low Orbits (MEVLOs) as a Long-Term Solution to Orbital Debris
Long-term orbital debris is a continually growing problem that has proven challenging to overcome. A straightforward solution to the problem is to put the majority of future LEO spacecraft into Moderately Elliptical Very Low Orbits (MEVLOs) with perigees below approximately 300 km, apogees below approximately 500 km, and eccentricities in the range of 0.015 to 0.030. Orbital debris clouds cannot be sustained in this altitude regime and will decay and re-enter in times ranging from a few weeks to at most the time until the next solar maximum. This means that the debris population at this altitude is, and will remain, much lower than at higher altitudes and, of course, any satellites which explode or otherwise die in this region will not be a part of a long-term debris problem. The advantage of the elliptical orbit is that if a temporary failure causes the spacecraft to stop doing orbit maintenance burns for a moderate period of time, apogee will decay, perigee will change very little, and the orbit can be recovered with essentially no loss of total delta V. Of course, if the loss of orbit maintenance delta V is permanent, then the spacecraft will decay and re-enter, as is desirable.
