Johnson
Space Center STS-103
Status Report # 05
Wednesday, December, 22, 1999 - 12:00 a.m. EST
After
a 30-orbit chase, Discovery astronauts completed a successful
rendezvous Tuesday evening with the Hubble Space Telescope,
grappling it with the robotic arm and latching it into the
orbiter’s cargo bay.
Controllers at Goddard Space Flight Center had placed the
space telescope in an attitude with its closed aperture pointed
toward Earth. Commander Curt Brown guided Discovery through
an approach from below and fly-around. Then, Mission Specialist
Jean-Francois Clervoy reached out with the shuttle's robotic
arm to grip a grapple fixture on Hubble. The grapple was made
at 6:34 p.m. Central time, one day, 23 hours and 44 minutes
after Discovery’s launch from the Kennedy Space Center
in Florida.
Clervoy used the arm to rotate the space telescope and bring
its base into the cargo bay. Hubble, gleaming silver in its
Mylar insulation flanked by golden-colored solar arrays, was
firmly attached to the Flight Support System in Discovery’s
cargo by a little after 7:30 p.m. Hubble is as tall as a four-story
building. With a maximum diameter of 14 feet, it is about
the size of a railroad tank car.
The Flight Support System is a U-shaped device with a circular
platform between the U’s arms now supporting the space
telescope. The system provides power from Discovery to the
telescope and can rotate and tilt it to facilitate access
to its various compartments by space-walking astronauts. An
initial, carefully choreographed survey using a camera at
the end of the robotic arm was made. Camera surveys of
Hubble’s condition will continue during the crew’s
sleep period, scheduled to begin about 12:50 a.m. Wednesday.
The first of three planned space walks to repair and upgrade
Hubble equipment is scheduled to begin at 1:40 p.m. Wednesday,
though astronauts may get an early start. If they can get
ahead of schedule, they may be able to perform some tasks
that had been scheduled for the cancelled fourth spacewalk.
On Wednesday, Mission Specialist and Payload Commander Steve
Smith and Mission Specialist John Grunsfeld will first replace
the telescope’s three Rate Sensor Units. Each contains
two gyroscopes. The second major task is installation of six
Voltage/Temperature Improvement Kits between Hubble’s
solar panels and its six 10-year-old batteries. The cell telephone-sized
kits are designed to prevent any overheating or overcharging
of those batteries.
Discovery’s systems continue to function well as the
astronauts wind up final preparations for Wednesday’s
space walks and prepare for sleep. The spacecraft was in an
orbit with a high point of 380 statute miles and a low point
of 355 miles.
The next Mission Control Center status report will be issued
at 11 a.m. Wednesday or as events warrant.
HST
Project Update - Tuesday, December 21, 11:55 PM EST
Rendezvous
Graces the Houston Sky
At
the very moment Space Shuttle Discovery closed in on Hubble,
the drama played out in the night sky over Houston. Though
most of the team were committed to consoles in Mission Control,
several of us ran outside to witness the nighttime spectacular.
At 6:34 CST, Hubble and Discovery streaked into view from
the south and passed above Mission Control. Though actually
about 25 feet apart, the two appeared joined as a single,
barbell-shaped light. They graced the Houston sky for about
3 minutes before disappearing into shadow. What an amazing
moment!
Hubble
and Discovery will make nightly appearances over Houston for
the rest of the mission. After release, Hubble will appear
three more times before the turn of the millennium. Viewing
information is listed below:
December
22: 6:44 PM/Appearing 69 deg above SSW, moving E
December 23: 6:55 PM/Appearing 70 deg above SW, moving ESE
December 24: 7:05 PM/Appearing 67 deg above SW, moving ESE
December 25: 7:15 PM/Appearing 60 deg above SSW, moving SE
December 28: 6:04 PM/Appearing 53 deg above SSE, moving ESE
December 29: 6:14 PM/Appearing 37 deg above SSE, moving SE
December
30: 6:25 PM/Appearing 23 deg above SSE, moving SSE
HST
Project Update - Tuesday, December 21, 9:00 PM EST,
"Please
come out of the cold and stay for Christmas!"
At
7:34 PM EST, Discovery completed a sequence of ballet-like
maneuvers with Hubble that resulted in a firm mechanical link
between the two spacecraft. This operation proceeded without
a hitch even though Hubble is in an unusual orientation because
it was in safe hold. Instead of a normal approach where Discovery
would come up from the "aft end" of Hubble, it approached
from the aperture door "front end". A delicate operation by
robot arm operator Jean-Francois Clervoy rotated the Hubble
into a position for berthing with the Flight Support System
(FSS) berthing ring.
At
9:00 PM EST, the robot arm successfully placed the Hubble
on the FSS, and the three FSS latches locked on to Hubble.
Hubble's source of electrical power was then switched over
from its solar arrays to the orbiter, completing the most
visible parts of the rendezvous/grapple/berthing operation.
Hubble
looks absolutely beautiful on the Discovery's video cameras.
We feel as if we are welcoming home an old friend we have
not seen for three years.
Kennedy
Space Center Space Shuttle Status Report
MISSION:
STS-103
-- 3rd HUBBLE SPACE TELESCOPE SERVICING MISSION
VEHICLE Discovery/OV-103
LOCATION:On orbit
ORBITAL ALTITUDE and INCLINATION:317 nautical miles/28.45
degrees
Work
in progress: Space Shuttle Discovery continues to perform
very well on orbit as the flight crew prepares to rendezvous
with, grapple and service the Hubble Space Telescope. Following
Discovery's launch last night, workers completed a preliminary
walk down of Launch Pad 39B. Inspectors report only minimal
damage at the pad.
Just
before noon today, the solid rocket booster recovery ships
began towing operations and are expected to arrive at Hangar
AF Tuesday at about 4:30 a.m. Both boosters are reported to
be in good condition following last night's splashdown in
the Atlantic Ocean.
HST
Project Update - Tuesday, December 21, noon EST
Discovery
is performing extremely well in orbit. We hear that "it is
the best it has ever been."
The
new color printer is still having problems. New software drivers
are being sent up to Discovery to try to solve the problem.
All Discovery and Hubble systems are ready for rendezvous
and berthing late this afternoon.
The
Hubble Team is making some final cable clearance checks for
a contingency case during the computer installation tomorrow.
Johnson
Space Center STS-103 Status Report # 04 Tuesday, December,
21, 1999 - 11:00 a.m. EST
Discovery
is on track for its rendezvous with the Hubble Space Telescope
this afternoon, culminating in the planned capture of the
12.5-ton observatory at 6:41 p.m. CST. In recognition of today's
activities, the seven astronauts aboard Discovery were awakened
at 9:20 a.m. today to the song "Rendezvous" by Bruce
Springsteen.
While
the crew slept, the Shuttle continued to close in on the Hubble
Space Telescope at a rate of about 125 statute miles with
each 90 minute long orbit of Earth. At the time the crew woke
this morning, Discovery trailed the telescope by about 330
statute miles.
The
crew will fire the Shuttle's thrusters at 12:38 p.m. today
to slightly raise Discovery's orbit and slow the closing rate
on Hubble. Another engine firing will be conducted about 48
minutes later to further adjust the closing rate and aim Discovery
to reach a point eight nautical miles behind the telescope
-- the starting point for the final phase of the rendezvous
-- about three hours later. Just before Discovery reaches
that point, European astronaut Jean-Francois Clervoy will
power up the robotic arm and lift it to a position just above
its latches along the left edge of the Shuttle cargo bay.
At
4:28 p.m., Discovery will reach the starting point and fire
its thrusters again to begin the final phase of rendezvous,
putting the Shuttle on a course to directly intercept the
telescope on the next orbit of Earth. As Discovery closes
the final distance to Hubble, four small course correction
engine firings will fine-tune the approach and Clervoy will
raise the arm high above the payload bay, poised to latch
onto the Hubble's grapple fixture.
When
Discovery reaches a point about half a mile away and directly
beneath the telescope, Commander Curt Brown will take over
manual control of the Shuttle. Brown, assisted by Pilot Scott
Kelly, will gently maneuver the 110-ton Shuttle to within
35 feet of the orbiting observatory to allow Clervoy to capture
it with the arm. After the arm has latched onto the telescope,
Clervoy will lower it into a cradle in the aft cargo bay.
Using controls in the aft cockpit of Discovery, Payload Commander
Steve Smith will then latch the telescope in place, where
it will remain for the next four days. Hubble is planned to
be latched into the bay at about 7 p.m. Once the telescope
has been secured in the payload bay, Clervoy will release
the arm and use it to perform a television survey of the Hubble's
exterior.
The
first of three planned Hubble maintenance spacewalks is planned
to begin at 1:40 p.m. Wednesday.
The
next Mission Control Center status report will be issued at
11 p.m. central time or as events warrant.
GSFC
Space Telescope Operations Control Center Update
Controllers spent a quiet night in the STOCC monitoring Hubble's
systems. They report ground systems here in the STOCC continue
to perform flawlessly, and work is proceeding as planned for
this evening's capture of the Telescope.
Anticipation
is growing here in the STOCC for tonight's grapple and berthing
of the Telescope. It has been three years since engineers
got their last up-close look at the Telescope, and they are
anxious to see and hear from the crew on the condition of
the orbiting observatory.
Controllers
in the STOCC will perform a number of key steps today in preparation
for tonight's capture of Hubble. About 6 hours prior to grapple,
controllers will power up Hubble's backup computer. This backup
computer controls a set of 3 mechanical gyroscopes, completely
different from the gyroscopes that are being replaced during
this servicing mission. These backup gyros cannot be used
for the extremely precise pointing required for Hubble to
stay locked on to its stellar targets, but they will keep
the Telescope stable for the delicate rendezvous and capture
activity tonight.
Though
the Telescope has been in orbit nearly 10 years, these backup
gyroscopes were turned on and checked out for the first time
two weeks ago in preparation for the mission, and they operated
perfectly.
Immediately
after grapple, the astronauts will send commands to Hubble
to place it in a drift mode. This will prevent the Telescope
from using its onboard attitude control systems to compensate
for any small movements placed on the Telescope after the
astronauts grab it with Discovery's robot arm.
Once
berthed in Discovery's payload bay, controllers will disconnect
the Hubble solar arrays. During the servicing mission, Hubble
will receive its electrical power from the orbiter's fuel
cells.
Discovery
also will provide a relay for data from the Hubble while it
is berthed in the payload bay. Normally, these data are down-linked
to Goddard directly, via the Tracking and Data Relay Satellite
system. But while the Hubble is being worked on, the data
stream will flow to Goddard via the orbiter. The onboard portion
of this communications loop was successfully checked out yesterday.
Also
completed yesterday was the visual inspection of the Space
Support Equipment. These are the two major fixtures in Discovery's
payload bay - the Flight Support System and the Orbital Replacement
Unit Carrier. The Flight Support System, which is the platform
the Hubble sits in during the servicing mission, has been
moved into position to accept the Telescope.
After
capture, as the astronauts install new equipment on Hubble,
the STOCC team will immediately test it. Later, while the
crew sleeps, ground controllers will perform more detailed
checkouts.
At
the end of the mission, the STOCC team will deploy Hubble's
high gain antennas and open its aperture door. They will reactivate
and check out all Hubble equipment powered off during the
servicing call. Then, Discovery's robot arm will release Hubble
and normal science operations will resume.
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