Grunsfeld Report #6
Hubble Space Telescope drifts away from Space Shuttle Columbia
after deployment on March 9, 2002.
-- After deployment of the Hubble Space Telescope it was time to
watch the Hubble slowly drift off and away from the space shuttle
and to admire its beauty. The look of the telescope has been forever
changed. Stout and strong looking panels have replaced the bird-like
solar array wings. The new solar arrays have deep blue Gallium Arsenide
solar cells, replacing the Silicon cells. On the other side of the
arrays are white reflective panels, and so the telescope will no
longer emit the golden glow so characteristic of the first 12 years
of Hubble's life on orbit.
On the aft
bulkhead of Hubble is a conduit leading to a large white radiator
mounted to handrails on the side of the telescope. Along handrails
all around the telescope are hung new cable harnesses to transfer
power and signals to new systems on the telescope.
As HST moved
off into the distance I could only watch in awe (and take an enormous
number of photographs). What an amazing telescope that we had worked
on over the previous 5 days. More remarkable is the team that developed
the new instruments. The Advanced Camera for Surveys will provide
us such remarkable views from its three cameras that I can't even
imagine the scope of the new discoveries that it will make.
HST became another star in the sky, we went back to work stowing
the space suits and space walking tools. The act of making Columbia
a space ship again is a tough one, after spending five days using
her mid-deck as a space walking staging area. Fortunately, without
a payload in the bay of Columbia we could also take time to look
out the window at the beautiful blue earth. I watched out the window
as we passed over Hawaii searching for the domes of the Kecks, UKIRT,
and the other telescopes atop Mauna Kea, with no luck. As we passed
over the Andes I desperately searched for Cerro Tellolo, but again
to no avail. My tool for these searches is a pair of Ziess 20x60
While my search
for observatory domes was not very successful, the good news is
that as we orbit the earth we see a night and day every 95 minutes
with about 35 minutes of darkness. What a joy it is to be able to
darken the cabin and with naked eyes see the broad expanse of the
Milky Way. From our vantage point above the atmosphere the stars
are steady and don't twinkle. They seem just a bit brighter and
the colors of the stars are more vibrant.
As we pass
southward the Large Magellenic Cloud is easy to discern. Using the
binoculars Jupiter is clearly resolved with light banding. The Great
Nebula in Orion is a favorite target, as well as the many open clusters.
The crescent of the moon is visible as part of a complete orb, illuminated
by the bright earth, just around the horizon.
problem with trying to find faint objects is that we are moving
so fast around the earth. As a result we only have a few minutes
to find an object before it sets or goes out of the view of a window.
As the stars
head down towards what looks like the visible horizon at night,
they first go through the airglow layer, starting at about 95 kilometers.
This greenish layer results from excited atoms releasing energy
in the form of light. During the day the atmosphere is constantly
absorbing sunlight and only in the night pass can we see the dull
glow from the atomic de-excitation. When a bright object sets it
looks like it should disappear behind the earth, but instead we
see the stars a bit longer as the go through the fog of the earth's
atmosphere. In this thin region the stars do twinkle and fade before
finally blinking out as they go behind the earth.
start turning the space shuttle into a re-entry vehicle. I hope
that before we head back home that I have more chances to look out
the window and star gaze. There will be a time, and soon I believe,
that many people will be able to view the stars as we have on this
mission. I would not be surprised to see an observatory on the moon
sometime in this century. After all, it has always been the adventurous
astronomers who brave cold nights, high altitude environments, and
even the rigors of space flight to get a better view and understanding
of our universe. I am convinced that as we push out of low earth
orbit, and on to the moon and beyond, astronomers will be there.
our own backyards, on a cold and remote mountaintop, or in earth
orbit, the beauty of the heavens is always present, and the drive
to explore and to indulge our curiosity is always strong.