[FPSPACE] Buran.Ru news - Polyus vs Mir-2
Sat, 16 Dec 2000 23:39:47 +0100
Jim Oberg wrote :
>Especially for those of us finishing up a book on the US/Russian space
>partnership. Bart, once again, my sincerest appreication for you sharing
>these insights with us.
Thanks, but the credit for the information on the heritage of Polyus should
go to Konstantin Lantratov, who I think was the first to uncover it in an
article in "Rossiyskaya Gazeta" in 1997.
Incidentally, I referred to Skif-D as a "dynamic analogue" of Skif that was
supposed to be launched into orbit, but it may just as well have been
intended for ground tests. That was not really specified in the articles
Phil Clarke wrote :
>I have not done any orbital _plane_ calculations for this, but Soviet
>statements after the event said that Polyus was due to fly at 65 deg
I've checked on the intended inclination for Skif-DM/Polyus. Konstantin
Lantratov wrote in a 1997 article in "Novosti Kosmonavtiki" that the payload
was targeted for a 280 km circular orbit at 64.6 degrees. Interestingly,
Boris Gubanov (chief designer of the Energiya rocket) now says in his
memoirs that it was 50.7 degrees (with a launch azimuth of 63.5 degrees).
He says that at some point there *was* talk of shifting to a higher
inclination orbit to avoid the risk of parts falling down on foreign
case of a launch failure (more particularly Mongolia, China and Japan). Two
possibilities were studied :
- launching directly into an orbit with an inclination higher than 55
- performing a "side maneuver" during launch (what I think is called a
"dog-leg maneuvre" in English terminology)
The direct launch option was considered the best, with preference being
given to a 65 degree inclination orbit. However, that would have decreased
the mass of the payload by 5 tons and would have required all sorts of other
modifications. According to Gubanov a launch into a 65 degree inclination
orbit would also have made it impossible to fly the mission from mid-May to
August, because that would have placed the impact zone of
the strap-ons and the payload fairing right in the middle of the nesting
area of the pink flamingo (a level of concern for the natural environment
usually not displayed by the Russians with other launch vehicles....).
Because of all these factors and the fact that a launch failure resulting in
an impact on foreign territory was considered unlikely, it was decided to
stick with the 50.7 degree inclination.
I should caution that Gubanov only talks about the planned inclination while
describing the events leading up to the launch of Energiya. Perhaps it *was*
changed to 65 degrees at a later stage (and I'm inclined to believe what
Konstantin Lantratov wrote). There seem to have been several delays in the
launch that could have given the time to make the necessary
modifications required for the inclination change. And with the launch
having taken place on 15 May 1987, that would have been just in time before
the closing of the "flamingo window"!