Building a brand new space station is a big job.
Just ask the assembly crews of the International Space Station
(ISS). They have to attach modules weighing tons, extend solar
panels longer than a bus, and haul equipment to and from the
space shuttle. It sounds like these hardworking astronauts could
use a hand!

Now, thanks to the Canadian Space Agency (CSA), they’re going
to get one.

When the space shuttle Endeavour blasts off on mission STS-100,
one of its passengers will be a new assistant for the crew of
the International Space Station — an extraordinary robotic arm
called Canadarm2.

"Canadarm2 is a bigger, smarter and more grown-up version
of the shuttle’s robotic arm," said Chris Lorenz, CSA’s
manager of mission operations. "It’s part of Canada’s investment
in the space station program."

Weighing 1640 kg (3620 lb), Canadarm2 is 17.6 meters
(57.7 feet) long when fully extended and has seven motorized
joints. It’s capable of handling large payloads and helping dock
the space shuttle.

Canadarm2 is surely big and strong, but it’s not just a brute.
This next-generation robotic arm has some amazing tricks up its
sleeve. Consider, for example, the way it moves. Unlike the original
Canadarm, which is mounted just outside a shuttle’s payload bay,
Canadarm2 won’t be tied down to one spot. Each end of the new
arm has a hand that can grasp an anchor on the space station.
By flipping end-over-end between anchor points, Canadarm2 can
move around the ISS like an inchworm.

With seven joints, Canadarm2 is more maneuverable than its
predecessor on the shuttle and even more agile than a human arm.
This is important because the space station is a larger and more
complex environment than the shuttle’s payload bay.

Astronauts will install Canadarm2 during
a series of spacewalks beginning on Day 4 of the STS-100 mission.
From inside Endeavour, pilot Jeff Ashby will use the shuttle’s
robotic arm to lift Canadarm2’s pallet from the payload bay.
He’ll maneuver it toward the Destiny Lab module where the pallet
will latch on to a special cradle.

Next, mission specialists Chris Hadfield (a Canadian) and
Scott Parazynski will leave the shuttle’s airlock and begin their
space walk. The pair will unwrap Canadarm2 from its insulating
blankets, attach power to the arm and loosen its restraining
bolts. By the end of the day, Canadarm2 will be ready to step
out of its pallet.

On Day 6 of the mission, the two space walkers will venture
out again. This time they will install a Power Data Grapple Fixture
(PDGF) — that is, a handhold for Canadarm2– on Destiny itself.
When the PDGF is ready, Canadarm2 will reach out from its pallet
and grab the space station. It’ll be one small step for Canadarm2,
and an impressive leap for space robotics!

After a few limbering up exercises, Canadarm2 will hand its
pallet back to Canadarm — a maneuver that scientists have dubbed
"the first-ever robotic handshake in space."

Once
deployed, Canadarm2’s primary job will be space station assembly.

"On the very next mission, Canadarm2 will be used to
install the airlock," said Ken Podwalski, a CSA scientist
working with Lorenz. "So we are going from arrival to immediate
use on the subsequent mission. This is really the critical piece
to continue construction of the space station."

For the next few years, the space station’s crew will control
Canadarm2 from two identical consoles (called "Robotic Workstations")
located inside the Destiny Lab. Eventually one of those workstations
will move to The Cupola — a module tentatively scheduled for
launch in 2005. Like the window-studded "Ten Forward"
lounge on Star Trek‘s USS Enterprise, the Cupola –with
eight windows– will provide astronauts a stunning view of the
space around the ISS. It’s the perfect spot for direct viewing
of the robotic arm and shuttle payload operations.

The Canadian Space Agency has also built a ground control
center for Canadarm2 at the CSA’s Saint-Hubert, Quebec, headquarters.
That facility is linked directly to NASA’s Mission Control at
the Johnson Space Center in Houston, Texas. Crewmembers on board
the ISS will be the ones who actually control the arm. Personnel
in Quebec and Houston will offer real-time support and troubleshooting
while Canadarm2 operations are underway in space.

Canadarm2
is only the first installment of what the CSA refers to as the
space station’s "Mobile Servicing System." The next
piece (slated for launch no earlier than 2002) will be the Mobile
Base System, or MBS — literally a small truck that moves along
rails covering the exterior of the ISS.

"After the MBS is in place, we’ll be able to move the
Canadarm up and down the length of the space station," said
Lorenz. Compared to inchworming, riding the MBS will be a less
entertaining way to travel — but much faster.

The final piece of the Mobile Servicing System will be the
Special Purpose Dexterous Manipulator, an attachment for one
end of Canadarm2. This so-called "Canada Hand" is itself
a highly advanced robot with two arms and sophisticated feedback
mechanisms that allow it to touch and feel much like a human
hand. Equipped with lights, a video camera and four tool holders,
the Hand will perform sophisticated operations like installing
batteries, power supplies and computers.

After
it arrives in orbit (no sooner than 2003) the Canada Hand will
be controlled by the ISS crew using one of the Robotic Workstations.
The Hand, which can wield very specialized tools and execute
delicate servicing tasks, could substantially reduce the amount
of time astronauts spend working "outdoors" in the
dangerous environment of space.

An inchworming space arm equipped with a robotic super-Hand?
It sounds like a wonderful Lego kit! Indeed, Canadarm2 consists
of many Lego-like "on-orbit replaceable units" (ORUs).
"You can basically take the arm apart in Lego fashion and
replace units as needed," added Podwalski.

It would seem to be a case of life imitating toys, but that
shouldn’t come as a surprise. The designers of Canadarm2 –the
same engineers who built Dino the Dinosaur at Universal
Studios– must be kids at heart to develop something so wonderful.

To learn more about Canadarm2 and to follow the progress of
its installation on the ISS, visit http://spaceflight.nasa.gov.