would have been an historic mission even without the added assignment
of the first-ever Shuttle-Mir rendezvous. This was the first Space Shuttle
mission to be piloted by a woman—Eileen Collins. The crew performed
20 experiments in the SPACEHAB science module, and they deployed, rendezvoused
with, and then retrieved the Spartan-204 free-flying astronomy package.
Two astronauts—Mike Foale and the first African-American spacewalker,
Bernard Harris—conducted an extravehicular activity (EVA) that tested
new equipment and demonstrated how well an astronaut could manipulate
a large object in space. These accomplishments, plus the crew’s many
other duties, would have made STS-63 one of the busiest Shuttle missions
But, the rendezvous with the Russian space station became STS-63’s
primary mission and on the success of this rendezvous hinged the future
of the Shuttle-Mir Program. Although the orbital physics of rendezvous
were well understood, many techniques were undemonstrated and the stakes
were high. Discovery had a mass of 87 tons; Mir weighed 103 tons;
and each measured more than 100 feet long. Even a small human error
or mechanical glitch could be magnified by the mass and momentum of
the spacecraft, jeopardizing the nine lives aboard Discovery
and Mir as well as the future of human spaceflight.
Lifting off just past midnight on the morning of February 3, 1995,
Discovery’s launch lit up the night sky as it roared up America’s
Atlantic coast so that it could match Mir’s orbital inclination of 51.6
degrees. Pilot Collins has said that a night launch is like being "in
a room that’s on fire." Light from the rockets poured through the
windows as the spacecraft roared and shook. Observers on the ground
watched the light from the Orbiter’s main engines for the full eight-and-a-half
minutes until the engines shut down.
Regardless of spectacle, a problem occurred almost immediately. As
NASA Flight Director William Reeves said, "We launched, and, lo
and behold … we had a leaking jet. One of the thrusters on the Shuttle
was leaking propellant … and the Russians didn’t know what to think
of it. They were concerned about fuel contamination on their vehicle;
and if we couldn’t arrest the leak, they didn’t want the Shuttle coming
too close to the Mir." Among other worries, if contamination got
onto some of the Soyuz capsule’s surfaces, the Mir crew could not use
it as an escape vehicle.
Early in the flight the propellant spewed in a conical pattern, "like
a snowstorm for five miles up into space," according to Commander
Jim Wetherbee. The Russians didn’t want Discovery to come within
1,000 feet of Mir. But NASA flight controllers and the Discovery
crew "worked the problem," at times rolling the Orbiter to
warm the thrusters in the Sun. As Reeves tells the story, the Russian
engineers were "very sharp and astute … and asked all the right
questions." They changed the minimum separation to 400 feet, still
not close enough for meaningful data.
According to Flight Director Phil Engelauf, "[It] wasn’t until
the morning of the rendezvous that we had finally gotten an agreement
from the Russians that we were going to be able to go ahead and make
the close approach." Onboard Discovery, Wetherbee told veteran
cosmonaut Vladimir Titov that, if the leak was still a problem, he would
not bring the Orbiter close to Mir—no matter what the flight controllers
said. But, when the shuttle crew woke up on the morning of the rendezvous,
the leak had diminished.
Another concern was whether Discovery might actually bump Mir.
The Russians remembered the Apollo-Soyuz docking mission in 1975 when
the Apollo capsule docked with the Soyuz with a much bigger bump than
the Russians had expected, said Wetherbee. But, he said, the Space Shuttle
is "like a big ocean liner coming in, and things are done more
slowly. It’s a very good system designed by really good engineers, and
the handling qualities are perfect…. I think a lot of people are surprised
at how stable the vehicle looks, how motionless it looks as it’s coming
in, and it’s very controllable. So, that was another thing that gave
the Russians a lot of confidence on [STS]-63 …"
The Discovery crew brought the Orbiter up to within 35 feet
of Mir. "Oh, beautiful, beautiful, beautiful!" Titov reported.
According to Wetherbee, the Orbiter crew was "just blown away by
the sight … of that huge, giant space station out the window … Mir looked
so brilliant and white and bright." They saw the Mir crew at the
windows; Valeri Polyakov and Aleksandr Viktorenko waved, and Elena Kondakova
held up a little cosmonaut doll.
STS-63 validated several precision-control techniques; performed an
inspection of Mir by eye, photo, and video; and tested the joint operations
capabilities of the Mission Control Centers in Houston and Moscow. Discovery
then left the vicinity of Mir.
Titov used the Shuttle’s arm to release the Spartan-204 package. It
flew free for two days to study far ultraviolet radiation. The crew
conducted science in the SPACEHAB module and shot footage for an IMAX
movie. Harris and Foale conducted their EVA to test the spacesuits’
thermal properties. Harris also manipulated the Spartan-204 package
to test a spacewalker’s ability to work with large objects in space.
more about the STS-63 mission and crew.