By Bob Granath
NASA's Kennedy Space Center, Fla.
The first elements of the International Space Station now have been in orbit for 15 years. Assembly of the largest spacecraft ever built was a global, cooperative effort and began with the STS-88 space shuttle mission in December 1998.
The orbiting outpost now serves as a unique laboratory where teams from around the world are performing scientific research only possible in the microgravity environment of space.
Kennedy Space Center Director Bob Cabana, a former space shuttle astronaut, commanded the flight that began one of history's landmark engineering achievements.
"STS-88 was a phenomenal mission," said Cabana. "It was just perfect from start to finish. Everything just flowed, and it set the tone for the whole space station assembly."
The first module placed in orbit was the functional cargo block, named "Zarya" -- Russian for dawn. It was built by Boeing and the Russian Federal Space Agency and launched by a Proton rocket from the Baikonur Cosmodrome in Kazakhstan on Nov. 20, 1998.
Two weeks later, on Dec. 4, 1998, the space shuttle Endeavour lifted off from Kennedy with Cabana, pilot Rick Sturckow, mission specialists Nancy Currie, Jerry Ross, Jim Newman and Russian cosmonaut Sergei Krikalev. They carried with them the first American-launched station element, node 1, called "Unity." The 12-day STS-88 shuttle flight was highlighted by connecting Unity to Zarya.
"We had to take Unity out of the payload bay and attach it to the orbiter docking station," Cabana said. "Then, we had to rendezvous with the Russian functional cargo block."
Next, came one of the most challenging portions of the operation. Mission specialist Nancy Currie used the remote manipulator system robotic arm to capture the Zarya module even though the view for Endeavour's crew was partially obscured by the large Unity module.
"Here's this 45,000 pound mass (Zarya), and you can't see it out the window because Unity was there," Cabana said. "There's a point where you lose sight of it in the overhead windows and you're relying on the centerline television cameras (in the payload bay) and on the end of the arm and two TV monitors to keep us precisely positioned. So when it is about three feet from the end of the arm, Nancy Currie can move in and grab it."
Once Zarya and Unity were joined together, mission specialists Jerry Ross and Jim Newman conducted three spacewalks to begin activation of systems between the two modules.
"The spacewalks were designed to attach all the electrical and data connectors before we went inside," said Cabana. "Part of what they did was to ensure the pieces could never come apart."
Flight day eight was a historic milestone as the International Space Station was opened for the first time.
"I think it was really special when we got to go inside the space station," Cabana said. "When it came time to actually go through the hatch, I waved Sergei up and opened the hatch and the two of us went in side by side -- a Russian and an American into a space station. It was an International Space Station and international crew. We were setting the tone for the future. It was one team working together."
Together with other members of the crew, they started unpacking gear to activate the station to prepare it for the inhabitants of the first expedition.
After 12 days in space, the STS-88 crew returned to Kennedy, landing Dec. 15, 1998. According to Cabana, teamwork was the key to the highly successful mission.
"It went so well because of the team -- the crew working together with the ground, the engineers, everybody," he said.
Permanent occupancy of the space station began with the Expedition 1 crew launched Oct. 31, 2000, establishing a continuous human presence in space that endures today.
While ISS expedition crews came and went, assembly continued through the final space shuttle mission, STS-135, in July 2011. During that time the station grew from two modules to having more livable room than a conventional five-bedroom house, with two bathrooms, a gymnasium and a 360-degree bay window.
"It is truly incredible when you think about when Zarya launched fifteen years ago and where it is now," said current station resident Mike Hopkins, an Expedition 37/38 flight engineer. "It is a testament to the work of people from all the participating countries, all the crews, all the flights from shuttles to Soyuz to resupply vehicles."
Cabana considers international cooperation an essential element of space exploration going forward.
"I believe it's the model for how we are going to explore beyond planet Earth," he said. "Right now we've got the United States, Japan, Canada, Russia, ESA and all its partners working together as one up there. When we leave planet Earth, we're not going to leave as any one nation, we're going to leave as the people from planet Earth."
The 11 members of ESA -- the European Space Agency -- include Belgium, Denmark, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland and the United Kingdom. More than 100,000 people in space agencies and contractor facilities in 37 U.S. states and throughout the world are involved in this massive endeavor.
Before returning to the space station as a member of the Expedition 1 crew, Krikalev also spoke of being a part of a global effort.
"We not only represent our hometown or even our countries in space, it's more like international adventure," he said.
Beginning with Expedition1, the multi-national effort already is achieving important scientific results ranging from studies of diseases to materials research.
One of the most compelling results reported is the confirmation that the ability of common germs to cause disease increases during spaceflight, but that changing the growth environment of the bacteria can control this ability to overcome the human body’s defense mechanisms.
Among the early results investigators learned that Salmonella grows rapidly in microgravity, helping scientists better understand the disease. The Effect of Spaceflight on Microbial Gene Expression and Virulence experiment identified increased virulence (ability to overcome bodily defenses) of space-flown Salmonella typhimurium, a leading cause of food poisoning. Research on subsequent station missions are targeting development of a vaccine for this widespread malady.
Cabana also notes the importance of the space station as part of our exploration strategy.
"In addition to being just a phenomenal scientific laboratory, it is a superb engineering test bed," he said. "We're proving the systems that we need to explore beyond our own planet will work as designed, giving us the ability to stay in space for extended periods of time in that microgravity environment and the harsh void of space."
One of the most prolific series of investigations aboard the space station tests how spacecraft materials withstand the harsh space environment. The results of the Materials International Space Station Experiment is aiding in developing new satellite system components such as insulation materials and solar cells for future commercial station cargo ships.
One of the next important milestones for the space station will be a year-long mission. In an expedition slated to begin in 2015, NASA astronaut Scott Kelly and Russian Space Agency cosmonaut Mikhail Kornienko will collect scientific data important for human exploration to asteroids and planets.
"In order for us to eventually move beyond low-Earth orbit, we need to better understand how humans adapt to long-term spaceflight," Michael Suffredini, NASA's International Space Station program manager said last year in announcing the mission. "The space station serves as a vital scientific resource for teaching us those lessons, and this yearlong expedition aboard the complex will help us move closer to those journeys."
Expedition 38 commander Oleg Kotov believes the space station's value goes well into the future as an inspiration to the next generation of space explorers.
"I want to show and tell children on Earth what life in space looks like, how space is wonderful, how our planet is wonderful," he said in a preflight interview.
Krikalev sees the station as part of a logical progression in explorations beyond Earth.
"Bringing our efforts together to build the International Space Station, I would say, is just the next step to joint exploration of the universe," he said,
Cabana agrees that the space station can be a stepping stone in venturing beyond humankind's current reach.
"We still have a lot to learn about human physiology in extended periods of time in microgravity, how to protect from radiation," he said. "We've been to the moon, we know how to operate in low-Earth orbit, now let's go to another planet. Our ultimate goal is to put boots on Mars and, one day, explore beyond our solar system."