STS 81 and MIR Docking

Philip Chien (
Sun, 29 Dec 1996 02:54:51 -0500

Nick Budd <> asked:

>I know it's not for a while yet....... but here's the problem:
>I'm hoping to be at the KSC for the launch of STS 81 on Jan 11 (yes, even at

Actually it's January 12th at approximately 4:17 am local, with roughly a 7
minute launch window.

>but I shall not have access to either elements or a computer for a couple of
>days and I would like to see it in orbit later on that evening. What I can do
>in advance is to plot Mir's orbits.

Good idea, but I don't believe Mir or the shuttle will be making many
visible passes in the Central Florida region for those couple of days.

>What I need to know is (a) will STS 81 go "straight" to a 51 degree orbit
>and, if so, (b) roughly how far behind or in advance of Mir is it likely to be,
>say, 16 hrs after launch?

Mir will pass over the KSC area shortly before the STS-81 launch (they may
even get to see it!).  Atlantis will launch directly in to the 51.6 degree
inclined orbit in Mir's orbital plane.  But it will be far behind Mir and
in a very elliptical orbit with a very low perigee.  Over a couple of days
Atlantis will 'catch up' with Mir and raise its orbit at the appropriate
point to match Mir's orbit.  Depending on when Atlantis launches within its
window, the exact burns would vary, and the actual rendezvous and docking
would occur on either the 3rd or 4th flight day.

In simple - it is rocket science!

Philip Chien, KC4YER
Earth News - space writer and consultant
note new E-mail address -