QUESTION:
Would you get even better images if you flew at even higher altitudes?

ANSWER from Sean W.J. Colgan on October 25, 1995:
Yes, until we're completely above the earth's atmosphere.

The earth's atmosphere degrades images in two ways. At certain wavelengths,
or colors, the atmosphere absorbs most or all of the light.  Since
ultraviolet light is harmful to us, the absorption of this light by ozone
in the atmosphere is good for people. However, if astronomers want to look
at stars or galaxies in ultraviolet light, they can't do it from the
earth. Astronomers have to use a telescope in a satellite in this
case. This is also why the Kuiper Airborne Observatory flies at such high
altitudes: to see infrared light requires that we get above as much of the
water in the earth's atmosphere as possible. Sometimes we are doing an
experiment which requires us to fly even higher than the normal 7.8 mile
altitude. In this case, we can fly 3/4 of a mile higher, but one in every
three people on the airplane has to put on an oxygen mask. This is just in
case something bad happens, the people with oxygen masks will be able to
help the people without masks. The second way in which the earth's
atmosphere degrades images is through winds. This is exactly the same
effect which causes stars to twinkle. If you get above the entire
atmosphere, the stars don't twinkle. This is why the Hubble Space Telescope
was launched into orbit and why it makes such sharp pictures - better than
anything we can get down here on earth.