Phil Chien wrote the following in response to Allen Thomson's question regarding the orbital inclination of USA 31: >My records indicate that the transtage (liquid bi-prop upper stage before >the IUS entered operation) failed to ignite for its second burn, stranding >the payload in a lower than planned orbit. and >What's interesting is an unclassified report from the Task Force for the >NASA Advisory Council. After the STS-49 fiasco the task force researched >whether or not satellite rescues should be done in the future. The "Report >of the Group Task Force on Satellite Rescue and Repair" a/k/a The Covert >report (29 September 1992) lists many satellites which could have >potentially be rescued and salvaged by the shuttle. >It lists the 1988 77A satellite as "VORTEX" and is my source for the >reference on the Transtage failure. What's interesting is that it lists >the satellite as one which could have _potentially_ been rescued by the >shuttle. >The report's fine print states "Please note that the determination of which >satellites could be rescued by the Shuttle is based on the best estimates >of the Group Task Force." I have noticed several mistakes in the chart, >including misidentification of some unclassified satellites, but overall >it's a fairly accurate document, so I'm assuming that its identification of >the classified satellites is correct until I get a more reliable source. >(And media speculations and sound-byte artists don't count!) I decided to consult Jonathan McDowell's compilation of debris orbits supplied by] various countries to the U.N., and low and behold it provides what seems to me to be conclusive proof that USA 31 was not stranded in a 151 x 14103 km transfer orbit: 1988-77A [USA 31] 99.8 151 x 14103 x 29.3 1C 1988-77B 99.8 151 x 14103 x 29.3 1D 1988-77C 99.8 151 x 14103 x 29.3 1D 1988-77D 708.9 465 x 39449 x 26.7 1D 1988-77E 707.7 461 x 39396 x 26.7 1D 1988-77F 669.6 385 x 37564 x 27.3 1D 1988-77G 718.8 830 x 39573 x 26.9 1D 1988-77H 718.8 830 x 39573 x 26.9 1D 1988-77J 718.8 830 x 39573 x 26.9 1D 1988-77K 718.8 830 x 39573 x 26.9 1D 1988-77L 718.8 830 x 39573 x 26.9 1D 1988-77M 717.7 807 x 39527 x 26.9 1D The debris items, 88077D - M, clearly show that at least one more manoeuvre occurred, which changed the apogee, perigee and the inclination. There would have been one more manoeuvre to circularize the orbit and reduce the inclination to zero. Although this proves that the object was not stranded in the 151 x 14103 km orbit, it does not prove that it reached its final GEO destination. So Phil's concerns about inaccuracies in the task force report he cited were justified - another example of how difficult space sleuthing is. Fortunately, in this case a reliable source of information could be found - that is more the exception than the rule. Finally, note that the orbital period of the objects 88077A-C are incorrect. McDowell has noted that many such errors are present in the U.N. data. Ted Molczan