| STS-63 | Crew | Payload | Mission | Snowball in the Fax |


Space Shuttle Discovery

February 3, 1995, 12:22 a.m. EST
Kennedy Space Center, Pad 39-B

STS-63 patchOrbit:
213 nautical miles

51.6 degrees

February 11, 1995, 6:51 a.m. EST
Kennedy Space Center

8 days, 6 hours, 28 minutes

Back to


| STS-63 | Crew | Payload | Mission | Snowball in the Fax |

STS-63 Crew

STS-63 crewCommander James D. Wetherbee
Third Shuttle flight

Pilot Eileen M. Collins
First Shuttle flight

Mission Specialist Bernard A. Harris, M.D.
Second Shuttle flight

Mission Specialist C. Michael Foale, Ph.D.
Third Shuttle flight

Mission Specialist Janice E. Voss, Ph.D.
Second Shuttle flight

Cosmonaut Vladimir G. Titov
Russian Space Agency
First Shuttle flight and fourth space mission

STS-63 Crew Biographies

Read the Shuttle-Mir Oral Histories (PDF)


| STS-63 | Crew | Payload | Mission | Snowball in the Fax |


Space Habitation Module-03 Experiments
Cryo Systems Experiment
Orbital Debris Radar Calibration System
IMAX Cargo Bay Camera
Air Force Maui Optical Site
Solid-Surface Combustion Experiment

Read more about Shuttle-Mir Science


| STS-63 | Crew | Payload | Mission | Snowball in the Fax |

Mission: Feb. 3 - 11, 1995

Mir Space Station as viewed from the Space Shuttle DiscoverySTS-63 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 ever.

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.

Read more about the STS-63 mission and crew.


| STS-63 | Crew | Payload | Mission | Snowball in the Fax |

The Snowball in the Fax

As the "go/no-go" decision for the STS-63 rendezvous approached, NASA Flight Director William Reeves was in Moscow and had to explain the thruster propellant leak situation "one more time." According to Reeves, "All of [the Russian] systems experts and safety people were there…. They all sat there and they looked at me and they said, ‘We understand what you’re saying, but what about the 180-gram snowball?'

"And, I’m sitting there with this blank look on my face, and I said, ‘What are you talking about?’

"And, they said, ‘Well, the 180-gram snowball in your fax.’

"I said, ‘What fax?’"

It turned out that some NASA engineers had worked out an extremely remote, worst-case scenario of a thruster jet freezing and getting packed with ice. Communications were poor at this time between Moscow and Houston; when the engineers sent this scenario in a fax, it went straight to the Russians. Reeves had never seen it.

The Russian space officials said to Reeves, "Well, you know, this piece of ice could form in the jet and it could come loose and all of a sudden this big chunk of ice could hit the Mir."

Reeves said, "Oh, no, it’s not going to happen…. You’ve got to give me time to go figure out what’s going on here and explain this."

Reeves got to the bottom of the story, and he explained it to the Russians. Reeves then consulted with Houston and waited. Time was getting short.

Finally, Russian operations chief Victor Blagov came out of his office. According to Reeves, "He grabbed me…. And, between my broken Russian and his broken English, we [could] carry on a conversation. And, he says, ‘You know, we’re getting very close to making a decision, and we’re going to allow you all to come to 30 feet.’

"And then he just grinned at me."

The rendezvous was approved.

Next Chapter - NASA-1 Norm Thagard:
    An End and a Beginning!