Re: FW: Shuttle water dump while attached to ISS

From: Vitek, Antonin (avitek@lib.cas.cz)
Date: Mon Aug 20 2001 - 15:18:35 PDT

  • Next message: Musson Bruce E: "8/18EDT 8/19 UT mystery flare"

    Bjoern Gimle wrote:
    
    > If RCS is indicative of true cross-sectional area, drag force increases with
    > RCS.
    > But the EFFECT of the force decreases with more mass of the affected object.
    
    Exactly speaking (in equations):
    spacecraft decelaration is given as
    
    a = (1/2).cx.(A/m).rho(h).v.v
    
    where cx - aerodynamic coefficient (depending on shape of object)
    A - effective cross-sectional area of spacecraft
    m - mass of spacecraft 
    rho(h) - atmospheric density at given height h
    v.v - velocity (squared)
    
    For a circular orbit with major semiaxis a, the change (decay) of 
    semiaxis per orbit is given as
    
    delta a = -2.PI.cx.(A/m).rho(h).a.a
    
    Consequences: for spacecraft of silimilar shape the decay is
    proportional to the A and inversely proportional to the m (PI is Ludolph
    number, 3.14159265....)
    -- 
    Mgr. Antonin Vitek, CSc.
    Office: Main Library, Academy of Sciences of the Czech Republic
      Narodni 3, CZ-11522 Praha 1 - Phone: +420(2)21403255, fax
    +420(2)24240611
    Home: Kytin 127, CZ-25210 Mnisek p. B., Czech Republic
    Phone: +420(305)592865 - Coord.: 14.2194 deg E, 49.8488 deg N, 442 m ASL
    My satellite home page: http://www.lib.cas.cz/www/space.40/index.html
    
    -----------------------------------------------------------------
    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 : Mon Aug 20 2001 - 06:18:18 PDT