The First 1,000 Days
Ghost alarms, foul odors, and a tourist season? Life aboard the International Space Station.
- By Thomas D. Jones
- Air & Space magazine, July 2004
(Page 2 of 4)
The routine is—or was, until last year’s Columbia accident—interrupted at irregular intervals by shuttles and Progress craft arriving with new station hardware and supplies, as well as planned spacewalks and unscheduled repairs.
The pace of work has varied. The Expedition One crew members had their hands full from the start, since they had to open the station and set up many of its systems. Compared to his 15 months on the Russian station Mir, says Krikalev, “the workload was pretty high, but it was expected. We knew…we were going to be busier than on average missions.” I saw this during my week-long visit in 2001. After a long day of spacewalking or outfitting the lab’s interior, I would drift off, exhausted, to my sleeping bag on Atlantis. But as I floated down through the docking tunnel, I could see Shep, Sergei, and Yuri still at work. The three were lucky to get five or six hours of sleep a night. Add in the chore of unpacking and packing the shuttle and the strain of receiving guests, and our hosts must have felt a sense of relief as they watched us pull away in Atlantis. Expedition Four’s Dan Bursch echoes a sentiment many station astronauts feel about visitors: “We were glad to see them arrive, and happier to see them leave.”
Though the second expedition crew, which arrived in March 2001, didn’t have as many setup chores, they immediately faced an annoying problem: The alarm software for the newly attached lab, which monitors the station’s critical systems, was trigger-happy. Before launch, its fault detection limits had been set too narrowly. The result was a random stream of caution and warning alarms—“false 99.9 percent of the time,” Voss recalls. On the first night, a fire klaxon jarred the astronauts out of their bunks, and repetitive alarms proved so annoying that for a time, one person had to sleep by the computer to quickly silence the noise. The crew soon grew skeptical of all alarms, which by the end of the mission totaled more than 900.
There also have been malfunctions with potentially serious consequences. During Expedition Four, the station temporarily spun out of control. Commander Yuri Onufrienko and flight engineers Carl Walz and Dan Bursch were aboard on February 4, 2002, when one of the Zvezda module’s computers failed, which stopped the flow of pointing information from Russian attitude sensors. Blinded, the U.S. guidance computers lost their ability to command attitude, and the station began to drift slowly out of orbital alignment. That meant that the solar arrays, no longer facing the sun, would stop producing power. Walz remembers the matter-of-fact call from astronaut Mario Runco in mission control: “You guys are going to lose attitude control. We’d like you to work the power-down steps.”
Wow, here we go, thought Walz as he and his crewmates waded into the emergency procedures. They began cutting off electricity to experiments and non-essential systems, and shutting down ventilation fans and all but one light in each module. Communication was lost as the S-band antenna lost track of its relay satellite. “We were sitting in this darkened tube, waiting for instructions,” Walz recalls. The three got out their flashlights and worked the procedures while waiting for a pass over a Russian ground communications site. Walz remembers thinking, How are we going to get out of this? He floated around the darkened station toting his flashlight and, of all things, a wrench. “I felt like I needed to carry a tool, something to make me feel I was doing something useful,” he says.
By now, the station had rolled about 150 degrees off its normal attitude, and the giant solar arrays were no longer catching sunlight. But Walz drew confidence from his Russian commander. “Yuri had been through this drill before on Mir,” he says. Eventually, he and Bursch worked out with Houston a way to get the solar arrays pointing properly. “Dan called out the sun’s position by looking out the lab window,” Walz says, “and I was able to use a laptop to swivel the arrays into sunshine.” Once the station batteries were recharged, ground controllers restarted the Zvezda computers and regained attitude control. The episode had lasted seven hours.
Such systems failures, though infrequent, would be impossible to overcome without the control centers looking over their shoulders, say the station astronauts. During the Zvezda failure, recalls Walz, “[mission control] essentially ran the vehicle, and we were their hands.” On such occasions, Susan Helms’ crew jokingly referred to themselves as “meat servos.” But it was more common, Helms says, and far more satisfying, for the crewmates to come up with their own solutions in the course of day-to-day work.
The first crews, particularly Expedition One, were in radio contact with mission control only 10 to 20 percent of the time, mostly via Russian ground stations. That had some advantages, according to Krikalev. Being able to talk to the ground any time he wanted was good, he says, but “having the ground able to talk to you anytime they want to is not very desirable.” Space station work can require intense concentration; controllers have since learned not to interrupt crews for a routine shift change of console operators.