Spaceflight Now STS-100

Station to grow two-handed robot arm during shuttle visit

Posted: April 16, 2001

The crew patch for Endeavour's STS-100 mission. Photo: NASA
The shuttle Endeavour stands poised for blastoff Thursday on the most complex space station assembly flight yet attempted, a two-spacewalk mission to install a $900 million Canadian robot arm able to move around the station's exterior like a 58-foot-long mechanical inchworm.

Endeavour's seven-man crew also will deliver six tons of equipment and supplies in a new Italian-built cargo carrier, including two experiment racks bound or the Destiny laboratory module, critical spare parts and a two-month supply of food for the station's full-time crew.

But the top priority of the 104th shuttle mission is installation and checkout of the Canadarm 2 space crane, a billion-dollar piece of complex, high-tech hardware that must be checked out and operational for subsequent assembly missions to proceed.

"We're going to be delivering on orbit what I consider to be the mechanical cornerstone, if you will, of the international space station," said spacewalker Scott Parazynski. "It's going to support all the assembly activities from here through the life of the station."

The spacewalks and the assembly and checkout of the space station remote manipulator system, or SSRMS, "really usher in a whole new level of integrated operations," said lead flight director Phil Engelauf.

Endeavour's payload bay is loaded with the station's robot arm folded up on a Spacelab pallet and the Raffaello cargo module. Photo: NASA
The shuttle crew will be operating Endeavour's Canadian-built robot arm at the same time the station crew is putting the new SSRMS through its paces. Adding to the complexity, shuttle and space station flight controllers will be simultaneously commanding both vehicles.

That level of coordination has really "made this a very, very complex mission to choreograph, to train for and to have all of our procedures in place," Engelauf said. "It's taken a great deal of work to get there and it really redefines integrated operations for us."

Endeavour is scheduled for launch from pad 39A at the Kennedy Space Center at 2:40:41 p.m. Thursday.

Strapped in on the shuttle's flight deck will be commander Kent Rominger, pilot Jeffrey Ashby, flight engineer John Phillips and Canadian astronaut Chris Hadfield.

Seated below on Endeavour's lower deck will be Parazynski, Italian Umberto Guidoni and Russian cosmonaut Yuri Lonchakov. Phillips and Lonchakov are both rookies while their crewmates are all shuttle veterans.

Endeavour's liftoff is timed to coincide with the moment Earth's rotation carries the launch pad into the plane of the international space station's orbit.

To catch up with its quarry, the shuttle will climb into an initially elliptical orbit with a perigee, or low point, of just 98 statute miles and an apogee, or high point, of 204 miles, slightly lower than the space station.

A series of rocket firings over the next two days will fine-tune Endeavour's approach, setting up a docking Saturday morning.

As with the most recent shuttle visit in March, the flight plan calls for Rominger to approach the station from behind and below, looping up directly in front of the outpost before beginning the final push to dock.

Flying tail down with its cargo bay facing the station, Rominger will manually guide Endeavour to a linkup with a docking port known as PMA-2 on the forward end of the new Destiny laboratory module.

Just like this view from the last shuttle mission, Endeavour will approach the station in the same fashion along with Velocity Vector. Photo: NASA
But the crew will not actually enter the station for the first time until after a spacewalk Sunday by Hadfield and Parazynski to install the new robot arm on the hull of the Destiny module.

The station currently is made up of four pressurized modules connected end to end. NASA's Destiny module is bolted to the multi-hatch Unity node. Unity, in turn, is connected to the Russian-built NASA-financed Zarya module, which is attached to the Russian Zvezda command module.

Unity's port hatch is occupied by a spare shuttle docking port while its starboard hatch is vacant. Unity's upward-facing port is occupied by a boxy structural truss that houses the station's four stabilizing gyroscopes.

Bolted to the top of the Z1 truss is the huge P6 solar array, which provides most of the station's electrical power. The two panels making up the P6 array stretch 240 feet from tip to tip, oriented like two huge wings extending to either side of the station's central axis.

The day before Endeavour's launch, the station's on-board crew - Expedition Two commander Yuri Usachev, Susan Helms and James Voss - will strap into a Russian Soyuz spacecraft docked to a downward-facing port on the Zarya module and fly it around to the Zvezda module's aft port.

Computer animation shows the Soyuz beginning its trek from Zarya to Zvezda. Photo: Spaceflight Now/NASA TV
It is the same Soyuz that carried the station's first full-time crew into orbit Oct. 31 and it is nearing the end of its certified on-orbit lifetime of 180 days. A fresh Soyuz is scheduled for launch April 28 - the day Endeavour undocks - carrying a three-man crew expected to include U.S. millionaire Dennis Tito.

The so-called taxi crew will return to Earth May 6 in the old Soyuz, leaving the station crew with a fresh lifeboat good for another six months in space. The new Soyuz will remain docked to the Zarya module's Earth-facing, or nadir, port. A Progress supply ship will dock at Zvezda's aft port late next month.

In general, the Russians want to use Zarya's nadir port for Soyuz vehicles to keep Zvezda's docking port free for use by Progress supply ships. Progress vehicles can reboost the station's altitude from the aft port, but not from the Zarya port.

Usachev and his crewmates will move the 2R Soyuz before Endeavour's launch primarily to get the work out of the way.


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