Two decades have passed, this week, since one of the most remarkable instances of international co-operation ever seen in human history. For 10 days, between 27 June and 7 July 1995, six U.S. astronauts and four Russian cosmonauts—and thousands of engineers, managers, scientists, families, and friends who supported them and made their mission possible—completed the first docking between a space shuttle and the Mir orbital station. Unlike the Apollo-Soyuz Test Project (ASTP) in July 1975, this was not a “standalone” mission of détente, but the beginning of an era which would see two former foes join forces in support of a common goal. That goal bore fruit over the following years, with the construction of the International Space Station (ISS), and as noted in a proclamation signed by the 10-strong crew: “The success of this endeavor demonstrates the desire of these two nations to work co-operatively to achieve the goal of providing tangible scientific and technical rewards that will have far-reaching effects to all people of the Planet Earth.”
In yesterday’s AmericaSpace history article, the historic nature of shuttle mission STS-71 and the first docking was highlighted, as were the raft of records and empirical achievements accomplished. For the first time, the shuttle accomplished one of its original design goals—to dock with an Earth-circling space station and exchange crew members—and for the first time returned home with a different (and larger) crew than the one with which it had launched. Additionally, U.S. astronaut Norm Thagard set a new record, not only for the longest single mission ever accomplished by an American citizen (115 days), but also for the longest cumulative time spent in orbit by an American citizen (140 days), spread across his five career spaceflights. His record, to be fair, would not last long, being eclipsed by fellow astronaut Shannon Lucid in 1996, but marked the next step on the ladder as the U.S. sought to extend its long-duration experience and ultimately enabled the current One-Year Mission by Scott Kelly in 2015-2016.
Atlantis’ five days docked to Mir proved largely uneventful from a systems perspective. With the exception of a General Purpose Computer (GPC) alarm on 30 June 1995—caused by the failure to synchronize with one of its siblings—only the most minor of issues troubled the shuttle during this period. The need to reset a troublesome hydrogen valve also disturbed STS-71 Commander Robert “Hoot” Gibson’s sleep, and, early on 1 July, a temperature in one of the nose-mounted Reaction Control System (RCS) thrusters fell briefly below its temperature redline, requiring the crew to adjust Atlantis’ attitude to provide increased solar warming. “The temperature drop was not unexpected,” NASA explained, “due to the inertial attitude the Atlantis/Mir spacecraft has been flying.” Gibson and STS-71 Pilot Charlie Precourt also performed a thruster firing to test the integrity of the Orbiter Docking System (ODS) and found the hardware to be very secure.
It was already intended that Mir’s new crew of Russian cosmonauts Anatoli Solovyov and Nikolai Budarin—who had arrived at the station aboard the shuttle—would board and undock the Soyuz TM-21 spacecraft from the aft longitudinal port of the Kvant-1 module about 15 minutes prior to Atlantis’ own separation on 4 July, in order to capture still and video imagery from a station-keeping distance of about 330 feet (100 meters). In preparation for this task, on 2 July, they checked out their pressure suits and performed leak checks. Finally, on the afternoon of 3 July, the time came for the two crews to part and the returning STS-71 astronauts and cosmonauts gave Solovyov and Budarin gifts of flight pins, watches, fresh fruit, and tortillas.
The tortillas were Mission Specialist Bonnie Dunbar’s idea. Having trained with Solovyov for a long-duration Mir expedition, she knew that he loved them; in fact, both he and Budarin enjoyed American food. There was plenty left over aboard Atlantis, so she took some tortillas—“great big, soft, Mexican tortillas”—over to him, shortly before the hatches were closed. At this point, Solovyov pulled her to him. Which side of the hatch would she like to stay on, he asked. Dunbar grinned. As much as she would have loved to remain aboard Mir for a long-duration mission, she told Solovyov that she had to return on the shuttle. Solovyov secured the hatch on the Mir side at 3:32 p.m. EDT, whilst Mission Specialist Greg Harbaugh did likewise in the ODS a few minutes at 3:48 p.m.
Fittingly, the undocking between Atlantis and Mir occurred in the early hours of U.S. Independence Day, 4 July 1995. At the same time, Solovyov and Budarin deactivated several station systems, in anticipation of their own undocking and flyaround. At 6:55 a.m. EDT, Soyuz TM-21 separated from Mir and soon reached a station-keeping position of about 330 feet (100 meters), from which Budarin acquired stunning imagery as Atlantis herself undocked at 7:09:45 a.m. The undocking procedure required Harbaugh to depressurize the ODS docking base and command the unhooking of latches, after which pre-loaded separation springs pushed the two spacecraft apart at low velocity. At a distance of a couple of feet (60 cm), after clearing the respective docking mechanisms, Gibson reactivated Atlantis’ thrusters and pulsed them in a Low-Z mode to begin the relative separation. At 400 feet (120 meters), he began a steady flyaround inspection of Mir, during which time the redocking of Soyuz TM-21 was captured in still and video imagery at 7:39 a.m. The redocking occurred a minute earlier than planned when Mir’s on-board computer malfunctioned and crashed. The station had been left in free drift during the brief flight, but was about 10 degrees off its correct attitude and was becoming unstable and starting to drift. Solovyov and Budarin restored the situation to normal.
From his perspective, Gibson described the maneuvers of Soyuz TM-21, Mir, and the shuttle as “a cosmic ballet.” With eight crew members now aboard Atlantis, this was the joint largest crew ever carried aboard the shuttle in orbit during independent flight. Whilst the medical research continued aboard the Spacelab module, the pilots continued to maintain a steady separation distance from Mir. By the end of 5 July, they were 230 miles (370 km) “behind” the station and increasing their separation distance by about 10 miles (16 km) with each orbit, although Gibson was still able to see Mir as a far-off point of light.
With landing scheduled for early on the 7th, Mission Specialist Ellen Baker set to work assembling three recumbent seats in Atlantis’ middeck for the returning Mir crew of Russian cosmonauts Vladimir Dezhurov and Gennadi Strekalov and U.S. astronaut Norm Thagard. Having the Russians aboard was a pleasant experience for the shuttle crew … and presented the opportunity for Dezhurov to prank at Precourt’s expense. One day, Precourt was working with a volt ohm meter on the aft flight deck, repairing a broken circuit, when the cosmonaut floated up behind him and whispered “Pfftt” in his ear. “You can’t jump in space, but you can sure go reeling in zero-gravity,” Precourt told the NASA oral historian, “and I could’ve choked him, but he had this big grin on his face! It was just a neat experience to bring him on the shuttle, show him around and let him feel at home.”
In the meantime, most of the Spacelab hardware was deactivated and Gibson, Precourt, and Harbaugh prepared the shuttle’s systems for re-entry. Two opportunities existed to land at the Kennedy Space Center (KSC) on 7 July, the first occurring a few seconds before 10:55 a.m. EDT and the second at 12:31 p.m. In contrast to the difficulties in getting Atlantis off the ground, her return to Earth was charmed, and at 9:45 a.m. the twin Orbital Maneuvering System (OMS) engines were fired for the irreversible deorbit to begin an hour-long hypersonic plunge into the “sensible” atmosphere. Seventy minutes later, at 10:54:34 a.m., Gibson executed a perfect landing on KSC’s Runway 15, wrapping up a 10-day voyage and one of the most spectacular human spaceflights ever accomplished.
A normal homecoming came as a great pleasure for Dezhurov and Strekalov, for two reasons. Obviously, they were relieved that they had returned to Earth safely, but secondly they were pleased that they were not challenged by the U.S. authorities for lacking passports and visas upon landing in Florida. During their final days aboard Mir, Strekalov pulled Thagard to one side and, in all seriousness, expressed concern that he had no passport or travel visa. Would he be arrested?
“I kept trying to allay Gennadi,” said Thagard in his oral history. “Of course, he comes from a different culture, but knowing what I know of bureaucracy, I should have been worried a little bit for him, but I couldn’t believe that in a million years they were going to arrest Veloga or Gennadi because they arrived in the United States with no passport. I hadn’t even thought about it, but Gennadi obviously had been thinking about it quite a lot.”
After 115 days, eight hours, and 43 minutes in flight, Dezhurov, Strekalov, and Thagard could have been forgiven for being a little unsteady on their feet. However, Thagard was one of the first of them to unstrap and stand up after landing. His recumbent couch was on the starboard side of Atlantis’ middeck, farthest from the hatch, so he had to wait until Dezhurov, Strekalov, and—in a normal, upright seat—Bonnie Dunbar had departed before he could leave the orbiter. “I walked off with no assistance,” Thagard recalled. “I didn’t have that much of a problem.” In fact, the biggest issue was the amount of monitoring equipment, including an electrocardiograph and an irritating blood pressure cuff, which rhythmically pumped itself up every few minutes, leaving his arm bruised and little feeling in his hand.
Within an hour or two of landing, after medical tests, he no longer felt “heavy,” but it took a few days for him to return to his normal self. Nevertheless, the three men were flown back to Ellington Field in Houston, Texas, aboard an Air Force C-9 Medevac aircraft for several weeks of medical tests and readaptation to normal terrestrial gravity. The remainder of the STS-71 crew returned to Houston later on 7 July. “I still didn’t feel totally gainly,” Thagard said later. “I felt a little awkward; more so than on my shorter shuttle flights. I had a real sensation that if I were to bend forward, if I weren’t careful, I’d continue to go forward, and if I bent back, if I weren’t careful, I’d continue to go back.”
Walking down hallways and turning, he felt the tendency to overshoot the corner, brushing his shoulder against a wall. “You just don’t turn sharply enough,” he said, “and that’s all because of the gains that change in the vestibular system while you’re there.” By his own admission, after each of his four previous shuttle flights, Thagard had felt back to normal within about 24 hours of landing; after his Mir mission, it took around five days, which still represented a remarkably rapid readaptation to gravity. On 12 July, he went jogging with Charlie Precourt and Ellen Baker. “It was the hardest three miles I ever did,” he said, “but I did it.”
This is part of a series of history articles, which will appear each weekend, barring any major news stories. Next week’s article will focus on STS-4, the first U.S. space mission to end on Independence Day, way back in 1982.