January 6, 1999

Construction of the International Space Station
Mating of the First Two Modules--Zarya and Unity

The International Space Station is an unprecedented undertaking in scientific, technological, and international experimentation. Whether the research improves our industrial processes, increases fundamental knowledge, helps us to look after our health, or enables us to take the next steps in the exploration and development of space, research onboard the International Space Station should bring enduring benefits for life on Earth and in space.

Daniel S. Goldin
NASA Administrator

Zarya (with solar panels) and Unity, the first two modules of the International Space Station, orbiting Earth after undocking from space shuttle Endeavour. December 13, 1998.

Additional Images

Image Credits: National Aeronautics and Space Administration (NASA).

On November 20, 1998, a three-stage Russian Proton rocket lifted off from the Baikonur Cosmodrome in Kazakhstan and carried the first module of the International Space Station (ISS), Zarya, into a 114- by 225-mile-high Earth orbit. After deploying its solar arrays and communications antennas and undergoing several days of operational tests, Zarya's own engines raised it to a circular orbit 240 miles above Earth. The 42,600-pound, 41.2-foot-long module will serve as the station's initial source of electrical power and provide communication with Earth, orientation control, and propulsion.

Two weeks later, the space shuttle Endeavour (STS-88), with the space station's second module, Unity, in its cargo bay, was launched from NASA's Kennedy Space Center into an elliptical orbit between 118 and 202 miles above the Earth. After gradually raising its orbit to match that of Zarya, Endeavour rendezvoused with Zarya on December 6. Its crew captured the Russian module with a 50-foot-long robotic arm and, at 8:48 CST that evening, Zarya and Unity were successfully mated to form a tightly sealed, 35-ton, 76-foot-tall structure--the embryonic beginning of the International Space Station.

During three subsequent spacewalks, Endeavour's crew connected power and communications cables between the two modules, unjammed two stuck antennas on Zarya, entered Unity and turned on the lights, and then opened the hatch to Zarya. They unstowed hardware and logistical supplies brought up by Zarya, completed the assembly of an early S-band communications system, checked out Unity's videoconferencing capability, and downlinked greetings to the station flight control room at the Johnson Space Center in Houston.

None of Endeavour's crew stayed in the station. The first residence will be taken up by a three-member crew early in 2000 after one additional module, the Russian-built Service Module, other needed capabilities, and more supplies have been added to the station.

The construction of the International Space Station is an enormously complex and costly undertaking. It is also a symbol of international cooperation and goodwill, involving, besides the US and Russia, 11 European nations, Japan, Canada, and Brazil.

The station is scheduled to be completed in 2004, after a total of 45 assembly flights have lofted more than 100 modules, various other components, and supplies into orbit. It will then stretch out longer than a football field, weigh nearly 500 tons, and provide pressurized living and working space comparable to the interior volume of a 747 jumbo jet. For at least 15 years, it will be the orbital home for visiting astronauts and cosmonauts.

More Cool Stuff

NASA's new, consolidated human spaceflight homepage, from which pages on the ISS, shuttle, exploring Mars, images, space station history, and other related topics can be accessed, is at:

http://station.nasa.gov/index-n.html

Another informative ISS Web site is maintained by The Boeing Company, the ISS prime contractor:

http://www.boeing.com/defense-space/space/spacestation/

We have our own spaceflight pages with both factual and entertaining content:

http://observe.ivv.nasa.gov/nasa/spacefly/spacefly_index.shtml

The above quote by NASA Administrator Daniel Goldin can be found on the ISS Web site of NASA Headquarters:

http://www.hq.nasa.gov/office/olmsa/ISS/

The acronym "STS" followed by a number refers to specific space shuttle missions and derives from "Space Transportation System," NASA's name for the overall space shuttle program. For information on the STS, go to:

http://www.ksc.nasa.gov/shuttle/technology/sts-newsref/sts_overview.html#sts_overview

As part of its Learning Technologies Project (LTP), NASA supports a number of educational Web sites that have excellent material on the space sciences:

http://observe.ivv.nasa.gov/nasa/education/edu/edudocs/topic_space.html