I guess we'll have to see what information is
available on the net about
that January 1986 event. I do seem to recall that the flight was about 2
minutes 10+ seconds underway when the ship hit the fan, so to speak. The
entire trip into orbit only required about 8.5 minutes, so they were a fair
piece of the way along.
Orbit:
Altitude: 150nm (planned)
Inclination: 28.5 degrees (planned)
Orbits: 0
Duration: 01 min 13 seconds
Distance: 18 miles
Source:
http://www.ksc.nasa.gov/shuttle/missions/51-l/mission-51-l.html