Feb.
24, 2002
Dr. Edward Cheung (Jackson & Tull)
HST Principal Engineer
Inside Columbia's Bay
 It
is finally launch week. With only a few more days to go, our hardware
along with their carriers has been installed into the Orbiter. Most
of the components in the Bay need little attention except for some
minor work.
Access to our hardware while it is installed in the Orbiter occurs
via the Payload Changeout Room (PCR). One whole side of this room
is taken up by the Cargo Bay and the two large open doors that cover
it. Using multi-level platforms, we can gain close access for final
preparations.
It is quite an awesome sight to see all the hardware that the team
has been working on all these years. Looking at all the widgets
and enclosures on the carriers shows the great attention to detail
our team has paid to all the hardware that will be needed during
the mission. It has come as a result of close work among ourselves,
and with the astronaut crew. There is a great deal of excitement
among our team members, as we know that the big payoff is around
the corner. It will be great to know you had a small part in making
HST better and more powerful.
 At
the top of the PCR is the front of the orbiter. Going there one
can see the egress hatch the crew will use to exit the orbiter and
perform their space walks. If you then go down one level, you can
see the front most carrier, called the Rigid Array Carrier (RAC),
which holds the new Solar Arrays. I have designed most of the circuitry
inside the Diode Box Controller that is part of that system. It
is also at this level that you can see the attachment point of the
Shuttle robot arm (RMS). It will be used during the mission to gently
pluck HST out of its orbit.
The next level down is the SAC, which is the carrier for the ACS
instrument, and the NCC. I have worked on that cooler since 1997,
and am proud to finally see it ready for flight.
The next carrier down is the FSS, which has hardware to hold and
park HST during the mission. Three clamps (called down-locks), grab
and lock down the Telescope after the robot arm pulls it down into
the bay. The FSS is the only carrier with motors, some of which
rotate and pivot HST so the crew has easy access to all parts. The
FSS is also the only carrier on which I have no flight hardware.
Finally, at the bottom of the room, and the back of the orbiter
is the MULE carrier (yep that is its name), which holds the NCC
radiator, the NCC computer (ESM), and the Reaction Wheel Assembly.
The radiator prominently shows a recent addition, called the ARUBA
(ASCS/NCS Relay Unit Breaker Assembly). I named it after my country
of origin to stimulate interest in this mission among people from
my country of birth. This has had its desired effect, and interest
from Aruba has been extremely high. A small group of three reporters
from the island will be viewing the launch with us.
More from Ed at: http://www.edcheung.com/job/sm3b/sm3b.htm
Click here for
more pictures inside Columbia's bay...
Feb.
24, 2002
Dr. Edward Cheung (Jackson & Tull)
HST Principal Engineer
Bad Weather and High Wire Work
 Since
our arrival in Florida, the weather has been excellent. This all
turned sour yesterday when we had very strong winds and rain. The
wind was so heavy that some reported the top of the External Tank
swaying by an inch. The platforms in the Payload Changeout Room
(PCR) were also moving, and we could see motion with respect to
the Orbiter. The Orbiter and PCR are not rigidly attached to each
other, and the gaps is closed by inflating seals to keep the elements
out. Some water did seep in, and dripped down the Orbiter doors.
As I write this, a high crew is climbing along the scaffolding to
wipe off the residue.
Walking in the high winds was very difficult, especially outside
the, where one is exposed to the elements. I have a dreadful fear
of heights, and my co-workers often kid me about walking outside.
The levels are built from steel grating, allowing clear vision down
to the ground. I feel like I am walking in mid-air, and can plummet
to the ground 135 feet below at any time when I need to make that
'death walk' back to the elevator.
Today (Sunday) will be the last day that we staff the vacuum pumps.
We disconnect tonight, and the multi-level platform, called the
PGHM (or "pig'm") will be slowly rolled back and away from the Orbiter.
At that point, we will have the first opportunity to see the whole
Orbiter bay in its full glory. I intend to take plenty of pictures
for that.
Then the Orbiter and PCR doors are closed, and the entire structure
holding the PCR will be rolled away, revealing the Shuttle for full
view again for the first time in weeks. I expect that to occur on
Tuesday. We then tank on Wednesday, and launch on Thursday. A last
minute problem can still cause a hold-up, and a 'go' from the tanking
meeting on Wednesday will be the clearest indication all is proceeding
well. I can't wait.
More from Ed: http://www.edcheung.com/job/sm3b/sm3b.htm
Click here for more pictures
of Columbia at the launch pad...
Feb.
16, 2002
Dr. Edward Cheung (Jackson & Tull)
HST Principal Engineer
Hubble Payload -> Orbiter Columbia
 After
our hardware undergoes final processing at the Vertical Processing
Facility, it is packaged for the trip to the Orbiter. This occurs
with a container called the 'Canister'. This vehicle is the same
size as the Orbiter, and even has two arched doors, that are similar
to the pair of arched Orbiter doors. The Canister is driven into
the VPF clean room, and parked along side our carriers, which hold
the hardware that will fly into space. The carriers are transferred
into the Canister one at a time, in the precise spacing that they
will have in the Orbiter.
After that, the doors are closed, and the Canister is driven out
of the VPF to the Canister Rotation Facility. In this facility,
the Canister is rotated from a horizontal position to a vertical
position using cranes. This matches the orientation of the Orbiter
on the pad.
A little known aspect of the Shuttle Launch Pad is the Rotating
Service Structure (RSS). It is essentially a huge rotating scaffolding
that covers the orbiter for servicing and protection against the
weather. Once the RSS is rotated over the Shuttle, a large clean
room covers the Orbiter Payload Bay, called the Payload Changeout
Room (PCR). The PCR allows free access to the Orbiter Bay to prepare
it for the mission.
 After
rotation, the Canister is driven to the launch pad. With the RSS
rotated back away from the Shuttle, the Canister is lifted and fastened
in place in front of the PCR. The doors of the PCR and the Canister
are opened, revealing our hardware to the interior of the PCR.
When standing in the PCR, the view is just like you were looking
at our hardware sitting in the Shuttle.
A massive structure called the Payload Ground Handling Mechanism
(nick-named the "pig-em") moves forward, grabs the carriers, and
pulls them out of the Canister into the PCR. The Canister is then
lowered and removed, and the RSS is rotated to cover the Shuttle.
The PCR doors and the Orbiter doors are then opened, and the pig-em
rolls forward to insert our carriers into the Orbiter.
We then do our final electrical and mechanical hook-ups and final
end-to-end tests before launch.
More from Ed at the launch pad: http://www.edcheung.com/job/sm3b/sm3b2.htm
Click here for more
pictures of the payload transfer at the launch pad...
Jan.
31, 2002
Dr. Edward Cheung (Jackson & Tull)
HST Principal Engineer
Visit to the VAB
 I
was present at the Kennedy Space Center when the orbiter Columbia
was scheduled to roll out to the launch pad. A group of us decided
to go over to the VAB to see the orbiter being prepared for the
event. This is a short account of the visit.
South of the two shuttle launch pads at KSC is one of the world's
largest buildings, known as the Vehicle Assembly Building (VAB).
It was built in the Apollo days to accommodate the enormous Saturn
V rocket, but has been retrofitted for the Shuttle program. The
Shuttle is assembled in the VAB from its constituent parts (External
Tank, Solid Rocket Booster, and the Orbiter).
It is difficult to tell how large the VAB is when you drive up to
it, as there is nothing nearby for comparison. A portion of the
side of the building is painted with a huge American Flag. It boggles
the mind to know that the flag is so big that the road you arrive
on is about as wide as one of the red stripes on the flag. The height
of the building is about 525 feet!
As you enter the VAB's central hallway and look up, you realize
how large an expanse this building is. A building of this size sometimes
has some odd aspects. For example, I have been inside the VAB on
a bright summer day, and see it "rain" inside the VAB. Water vapor
condenses on the inside of the roof, and rains back down on humid
days. One year, I was in the VAB with Atlantis parked in one of
the bays, and they had to suspend a huge tarp over the Orbiter to
protect it from the moisture raining down.
 Leaving
out certain details of the security arrangement, one is required
to check in at another station to get close to the Shuttle. There
is a check of your clothing and the items you are carrying. To prevent
any objects from accidentally falling on the Shuttle while you are
walking overhead, anything that can come loose such as eye-glasses
are required to be tethered. If you are wearing a watch, you are
required to cover that with tape in case a part should fall off.
If you are wearing a ring with a stone, that needs to be taped too,
and no cell phones or pagers are allowed.
 After
going thru this gauntlet, you are finally able to take the elevator
and see the Shuttle up close. It is difficult to describe how impressive
this sight is. It is a thrill that always excites me, no matter
how many times I come here. Many details become visible that are
blurred when viewed on a TV screen. One can see the individual markings
on the thermal tiles, and see their individual differences. You
also realize that the entire tank, booster, and orbiter stack is
essentially held to the launch pad by eight bolts, four on each
Booster. After the main engines are lit, and the Boosters are fired,
these bolts are blown apart, and the Shuttle accelerates upwards.
Columbia did not roll out to the pad that day, as there were problems
with the steering mechanism. She would roll out the week after I
visited. Going back two years, I was present for the rollout of
the previous HST mission in 1999, a very impressive sight in itself.
That, however, is a story for another day...
See more from Ed at: http://www.edcheung.com/job/sm3b/sm3b.htm
Click here for more
pictures of the shuttle and VAB...
Dec.
20, 2001
D.H. :: SM3B Site Webmaster
Enter the Hubble Project
 Webmaster
here - just thought I'd start these chronicles off with the launch
of the website. I started working for NASA in the summer of 2000.
So it's over a year later, and I realize how fortunate I am to be
working on the Hubble Project.
To tell the truth, I had never been a real "space-guy"
- more interested in Rembrandt's and Wyeth's than Armstrong's and
John Glenn's. But I've come a long way. Hubble truly is one of NASA's
crown jewels. Fantastic images, insights into the creation of the
Universe, evidence suggesting the laws of physics being turned upside
down - how can these things not spark a sense of wonder?
And now I get to witness my first shuttle launch in February. They
tell me it's like nothing else - seven million pounds of rocket
thrust to propel the shuttle into space. The ground will shake and
the sky will scream. I wait with anticipation and a sense of wonder.
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