QUESTION:
I want to know when you are at 41,000 feet do you stay at a certain speed
or do you change speeds from time to time? 

ANSWER from Terry Rager, Project pilot, KAO, on October 12, 1995:
That's a good question. If you look at the question called "Highest Speed",
you see I discussed the difference between Airspeed and
Groundspeed. If the airplane stayed at the same airspeed but turned in a
different direction the wind would effect the airplane in either a faster
or slower way. Therefore the airplane is going through the air at the same
speed but is going across the ground at a different speed. Ask your
teacher to demonstrate. 

We do have to change speed (groundspeed) for the astronomer because the
telescope must be a specific spot on the earth at a specific time so all
of the selected objects can be seen that flight. 

Terry Rager, Project Pilot, KAO