Re: Mir or Atlantis?

DJLaszlo@aol.com
Sun, 31 Mar 1996 11:30:28 -0500

Dan Laszlo wrote:
>> However, on the previous STS-Mir mission, within a few hours of 
>> separation, Mir was clearly ahead of the Shuttle when it made its pass 
>> for us in Colorado. 

 Walter Nissen replied:
>I don't remember this.  What do you mean by "clearly ahead"?  There have 
>been fly-arounds, which I ignored.  Could you fill in some details? 

Phil Chien replied:

>err - not unless you were viewing it from a *really* strange angle (like
>from above and upside down?)  When the shuttle departs Mir the shuttle will
>*ALWAYS* appear to be travelling ahead of Mir.


No, Phil, there was nothing unconventional about my perspective in space or
time.  Since my observation has been questioned by two sages, I'll do my best
to oblige with the files I still have from the STS-74 mission.  The pass in
question happened within a few hours of separation on the morning of November
18, 1995.  Here is a snip of the projected timeline, from the time of
undocking.  All times are CST per NASA convention:
---------------------------------------------------------
11/18/95 02:16AM 
ATLANTIS UNDOCKS FROM THE MIR SPACE STATION, LEAVING BEHIND THE 
DOCKING MODULE PERMANENTLY ATTACHED TO THE KRISTALL MODULE 
11/18/95 02:18AM 
At a distance of two feet from the Mir 10 seconds after undocking, Cameron
initiates a 2/10 of a foot per second seperation maneuver with Atlantis'
upward firing jets disabled 
11/18/95 02:32AM 
At a distance of about 400 feet below the Mir, Cameron begins the flyaround
of the Space Station to conduct a photographic survey of the Complex 
11/18/95 02:34AM 
Atlantis crosses the +V-Bar in front of the Mir 
11/18/95 02:38AM 
Atlantis crosses the -R-Bar above the Mir 
11/18/95 02:50AM 
Atlantis crosses the -V-Bar about 400 feet behind the Mir 
11/18/95 03:01AM 
Atlantis crosses the +R-Bar below the Mir 
11/18/95 03:13AM 
Atlantis crosses the +V-Bar for the second time in front of Mir 
11/18/95 03:25AM 
Atlantis crosses the -R-Bar for the second time above the Mir 
11/18/95 03:45AM 
Atlantis crosses the -V-Bar behind the Mir for the second time 
11/18/95 04:01AM 
ATLANTIS SEPERATES FROM THE MIR SPACE STATION AT THE +R-BAR ABOUT 600 
FEET UNDERNEATH MIR AS CAMERON CONDUCTS A 3 FOOT PER SECOND 
RETROGRADE BURN 
------------------------------------------------------------------
I gather the retrograde burn sent the STS temporarily trailing.  The pair
rose for us in Northern Colorado about 0640 CST.  Location is about 40.5
degrees N latitude, 105 degrees west Longitude.  I was primed to expect STS
to lead, and I'll admit initial disbelief at the sight, with a dimmer, yellow
tinged object leading the brighter white object.  Based on 35mm slides of the
pass, they appear to be separated at culmination like the nearby Eta and
Gamma Leonis.  This is about 4 degrees, considerably more than expected for
the flyaround.  I thought I might have NASA TV videotape confirmation, but no
such luck.

Therefore, to the best of my knowledge, and most contrary to my expectations
;-)  Mir led the Shuttle in orbit within a few hours of the (presumed)
completion of the flyaround.  The magnitude of separation would apparently
preclude the flyaround as an explanation for the trailing STS.   I do
recognize that the constraints of orbital mechanics should rapidly bring the
STS ahead  :-)  Nobody at my site was more puzzled than I, since I "knew" STS
should always lead.  As advised by a certain sage, I'm calling what I saw,
not what I know should happen :-)  :-)
Regards, Dan Laszlo