re: ISS decay

From: FrankEReed@aol.com
Date: Sat Apr 29 2000 - 16:14:51 PDT

  • Next message: Brian Webb: "Apollo Navigation/Maneuvers"

    DEHB asked:
    "   Does anyone know what the approx. height, in both standard and knautical 
    miles, the Station or ANY object decays; AS OF NOW, considering the solar 
    max. "
    
    Decay is a continuous process which depends exponentially on altitude since 
    atmospheric density decreases exponentially with altitude. For an object like 
    ISS whose mean altitude is presently about 345 kilometers, the total time 
    until burning up assuming absolutely no orbital adjustments, is a year or so. 
    The current rate of orbital decay is 2km per week. This rate continues almost 
    linearly down to about 300km. So in some 23 weeks, ISS will have dropped down 
    to 300km (again, assuming no maneuvering at all --an unrealistic assumption). 
    Below 300km, the decay rate begins to increase noticeably. Only another 22 
    weeks or so would be required to drop the next hundred kilometers down to 
    200km orbital altiude. At this height, the end is very near. Really rapid 
    decay occurs around 170km about three weeks later. 
    
    These are rough estimates only.
    
    -FER
    PS: My estimates are based on a simple program I wrote years ago, and I'll be 
    curious to see how they stand up under the scrutiny of the experts on this 
    list.
    
    -----------------------------------------------------------------
    Unsubscribe from SeeSat-L by sending a message with 'unsubscribe'
    in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org
    http://www2.satellite.eu.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Sat Apr 29 2000 - 16:15:43 PDT