After NASA split Hubble's third servicing mission into two parts to
allow astronauts to get to Hubble as soon as possible to replace failing gyroscopes,
which are needed to point the telescope accurately...
Servicing Mission 3A successfully got Hubble back up and running until Servicing Mission 3B
could launch and complete all of the planned upgrades to Hubble.
But, even in times of ease, the unexpected can make an appearance again.
"Houston, Columbia for EVA."
"Go ahead Columbia we're listening."
"Okay, uh, as we put on mini-workstations, I'm monitoring John's suit and there's
a large bit of water down here at the bottom of the battery I'm fixing to open up now."
Something unexpected like a spacesuit failure.
"Yeah Scooter we're gonna have to get John out of the suit."
And of course, these things always happen at the worst time, too.
"Hubble is without a heartbeat."
Servicing missions are what make Hubble, Hubble. For over two decades, servicing mission astronauts have
been able to take advantage of Hubble's malleable design. Being able to upgrade and refurbish parts
periodically is how Hubble has been able to stay on the bleeding edge of astronomical science.
And Servicing Mission 3B was no exception to that fact.
"We're providing a major upgrade in terms of science capability.
We're adding a new science instrument, and we're bringing back to life
the infrared camera, and we're making important upgrades in terms of maintenance.
We're adding new solar arrays, and we're changing out the power control unit."
"Forty percent of the highest impact
subjects that Hubble has... highest impact results that Hubble has achieved, were totally
unexpected before Hubble was launched, and I expect that five or seven years from now Hubble will be
working on subjects that we can't anticipate today. We don't even know how to ask the questions today."
And with the anticipation of those unknown discoveries building, Servicing Mission 3B
was scheduled to launch in the spring of 2002, ready to make its mark on the stars.
"Four, three, two, one, and liftoff of Space Shuttle Columbia to
broaden our view of the universe through the Hubble Space Telescope."
"Houston now controlling the flight of Columbia, the
pioneer shuttle headed for the Hubble Space Telescope..."
"Houston, we have Hubble on the arm."
With the Hubble Space Telescope fully grappled, it was time to get to work.
The servicing mission was going to encompass a wide range of upgrades and improvements,
so every minute of this 12-day mission was meticulously planned in order to
complete the five scheduled spacewalks.
First up, replace the old solar arrays with the new
and improved version three of the solar array system.
These new solar arrays were rigid, and didn't roll up like previous designs.
Being more robust, it made Hubble's power intake increase by about 20 to 30 percent.
"Solar array three has passed its functional test and ready to support."
Next on the list, replacing the Power Control Unit.
This is Hubble's power switching station, responsible for distributing
all the electricity generated by the arrays, batteries, and sending it to the other parts of the telescope.
And, in order for the Power Control Unit to be replaced, it required Hubble to
be completely powered down for the first time. And one of the cardinal
rules in the business of space is, if it's working well, don't turn it off.
During the systematic shutdown process, astronauts
John Grunsfeld and Rick Lenahan were suiting up to tackle the next spacewalk.
However, John's spacesuit began to take on water from the liquid coolant system.
Not the most ideal situation to happen right before stepping out into the cold
void of space.
With only a certain amount of time to react, since parts of Hubble were already shut down,
Grunsfeld's crew-mates quickly resized another spacesuit in order to get the spacewalker
out in time before the whole spacewalk had to be canceled.
"And a late but hopefully powerful start!"
With things back on track, the heart of Hubble, the Power Control Unit, was successfully changed out
after a meticulous seven hour spacewalk.
Next was to install the Advanced Camera for Surveys.
This camera would allow Hubble to capture wider vistas of the universe at a higher resolution than ever before,
allowing us to study weather patterns on other planets, and understand how the universe evolved.
And, finally, the astronauts of Servicing Mission 3B
were able to bring one of Hubble's most critical instruments,
called NICMOS, back to life, after it had been dormant for two years.
They achieved this by installing a cryo cooler for its infrared detectors,
once again unleashing Hubble's power to peer into the invisible infrared universe.
Servicing Mission 3B proved that NASA can take on the unexpected,
head-on, as a team, accomplishing historical strides in our understanding of the universe around us.
"And from the crew of STS-109, we wish Hubble well on its new journey
with its new tools to explore the universe. Good luck Mr. Hubble!"