Design and Test of a Modified Passive Orbital Disconnect Strut (PODS-IV)

  • Iran E. Spradley
  • Richard T. Parmley
Part of the A Cryogenic Engineering Conference Publication book series (ACRE, volume 33)


Passive Orbital Disconnect Struts (PODS) can potentially reduce the support conductance a factor of 10 over state-of-the-art tension band nondisconnect supports and can significantly reduce helium dewar weights without reducing lifetime. A series of thermal and structural tests have demonstrated this performance improvement. The major shortcoming of the PODS-III design is lack of side-load resistance to thermal shorting. This paper describes a design modification (PODS-IV) that dramatically increases the side-load resistance to shorting without significantly degrading thermal performance.


Side Load Length Adjustment Differential Shrinkage Support Conductance Launch Tube 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    R. T. Parmley, “Feasibility Study for Long Lifetime Helium Dewar,” NASA CR 166254 (Dec 1981)Google Scholar
  2. 2.
    R. T. Parmley, “Passive Orbital Disconnect Strut (PODS-III) Structural and Thermal Test Program,” NASA CR 166473 (Mar 1983)Google Scholar
  3. 3.
    R. T. Parmley, “Passive Orbital Disconnect Strut (PODS-III) Structural Test Program,” NASA CR 177325 (Jan 1985)Google Scholar
  4. 4.
    R. T. Parmley et al., “Test and Evaluate Passive Orbital Disconnect Struts (PODS-III),” NASA CR 177368 (Aug 1985)Google Scholar
  5. 5.
    I. E. Spradley, “Passive Orbital Disconnect Strut (PODS-IV) Development,” NASA CR 177426 (Sep 1986)Google Scholar
  6. 6.
    D. Bushness, “Optimum Design of Dewar Supports,” J. Spacecraft and Rockets, Vol. 22, 4:432 (Jul-Aug 1985 )Google Scholar
  7. 7.
    D. Bushnell, “Improved Optimum Design of Dewar Supports,” AIAA 28th SDM Meeting, Monterey, CA, (6–8 Apr 1987 )Google Scholar
  8. 8.
    G. N. Vanderplaats and F. Moses, Structural Optimization by Methods of Feasible Directions, Computers & Structures 3: 739–755 (1973)Google Scholar
  9. 9.
    G. N. Vanderplaats, “COMNIN-A FORTRAN Program for Constrained Function Minimization: User’s Manual,” NASA TM X-62,282, Ames Research Center, Moffett Field, CA (Aug 1973); version updated Mar 1975Google Scholar
  10. 10.
    G. Zoutendijk, “Methods of Feasible Directions,” Elsevier Publishing Co., Amsterdam (1960)Google Scholar

Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • Iran E. Spradley
    • 1
  • Richard T. Parmley
    • 1
  1. 1.Research & Development DivisionLockheed Missiles & Space Company, Inc.Palo AltoUSA

Personalised recommendations