in , ,

‘Follow Our Dreams’: 20 Years Since Zarya Launched the International Space Station Era (Part 1)

Twenty years ago, this month, the grandest engineering endeavor in human history got underway with the dawn of the International Space Station (ISS). Photo Credit: NASA

Twenty years ago, this month, a new era began. On 20 November 1998, a Russian Proton-K rocket—descendent of a family of heavylift boosters which had already launched a half-dozen Soviet space stations and numerous scientific and technological research modules into low-Earth orbit—blasted off from Site 81 at the Baikonur Cosmodrome in Kazakhstan, laden with the first component of the International Space Station (ISS). Measuring 41 feet (12.5 meters) in length and 13.5 feet (4.1 meters) wide, the Zarya (“Dawn”) module would provide power, storage, propulsion and guidance for an infant station which, in time, would grow to become the largest artificial satellite ever launched into space and the grandest and most complex engineering accomplishment in human history.

Mounted atop the Orbiter Docking System (ODS) in shuttle Endeavour’s payload bay in December 1998, the first two elements of the International Space Station (ISS), the US-built Unity Node (lower) and the Russian-built Zarya (upper), bring the dreams of a dozen nations together at last. Photo Credit: NASA

Within hours of emplacement into a 250-mile-high (400 km) orbit, inclined 51.6 degrees to the equator, Zarya’s twin solar arrays were deployed and the module lingered for two weeks, ahead of the launch of shuttle Endeavour with the first U.S.-built ISS element, the Unity node. Fundamentally, the purpose of Zarya—also known as the Functional Cargo Block, or “FGB” in Cyrillic letters—was to act as a junction between the station’s Russian Orbital Segment (ROS) and U.S. Orbital Segment (USOS). However, the union of East and West which began in space that cold November day, twenty winters ago, had come about only after many years of political and economic difficulty and on more than one occasion had teetered on the brink of collapse.

Its story began on 25 January 1984, when then-President Ronald Reagan formally declared that the United States would build a permanent space station, “and do it within a decade”, perhaps tapping into his predecessor John F. Kennedy’s vaunted goal of landing a man on the Moon by the end of the 1960s. Reagan had already discussed the concept at length with the NASA administrator at the time, Jim Beggs, and declared that the nation should “follow our dreams to distant stars, living and working in space for peaceful economic and scientific gain”. Within weeks, in April 1984, former NASA flight director Neil Hutchinson was appointed as the first space station program manager at the Johnson Space Center (JSC) in Houston, Texas, and it was under his leadership that the first blueprints emerged for what America’s next space station might look like.

The “Power Tower” concept, unveiled in April 1984, was the earliest incarnation of what later became Space Station Freedom. Image Credit: NASA

Those early designs were impressive in their scope and capability. With a total pressurized volume of 31,000 cubic feet (878 cubic meters), the station would be assembled, module by critical module, in low-Earth orbit, by a succession of shuttle crews. The “power tower” design in April 1984 envisaged a station with a long, central keel, a cluster of modules at one end and a giant set of articulating solar arrays and a satellite servicing bay at the other end. Contracts for preliminary design and definition studies were awarded in early 1985 and expectations were strong that construction would begin by 1992.

By the time shuttle Challenger was lost in the spring of 1986, the station’s design had changed again, this time featuring a pair of keels and shifting the cluster of modules to a central truss to make the center-of-gravity positioning more suitable for quiescent microgravity research. At around the same time, the number of U.S. pressurized scientific modules was reduced from two to one, as the European and Japanese space agencies came aboard with their own home-built modules. In September 1986, this “dual-keel” station was costed at $14.5 billion and, with the shuttle fleet grounded, no one anticipated the launch of its first element anytime before 1994. The cost caused concern in Congress and NASA was obliged to investigate other station designs, ranging from a Skylab-like monolith to a gradual, phased assembly of a dual-keel facility, the latter of which decreased the cost marginally to around $12.2 billion.

Rescoped version of Space Station Freedom, following the March 1991 redesign. Image Credit: NASA/Tom Buzbee

In August 1988, on the eve of the shuttle’s return to flight after Challenger, and in his final months as president, Reagan announced that the station would be called “Freedom”. A month later, NASA signed ten-year contracts to kick off its development and a Space Station Intergovernmental Agreement allocated resources between the U.S. and its European, Japanese and Canadian partners. Under the language of the agreement, NASA would receive 97 percent of resources in the U.S. lab, with the remainder allocated to Canada, in return for having its robotic assets on station. Europe and Japan would each retain 51 percent of their modules, with the United States taking 46 percent and Canada 3 percent of the rest. In terms of crewing, it was expected that Freedom would initially have a long-duration staff of four, rotating through 90-120-day increments. At a later date, station crews would expand to eight people: six Americans and two international astronauts from Europe, Japan or Canada.

Politics conspired heavily against Freedom in its early years, as harsh budgetary realities hit home. Congress reduced NASA’s Fiscal Year 1988 allocation for the station from $767 million to $525 million and virtually halved what the space agency had requested for 1989. Further cuts occurred in 1990, by which time the troubling realization reared its head that Freedom was 23 percent overweight, offered only 66 percent of the electrical power for its scientific requirements and was becoming excessively complex. An external maintenance task team estimated in September that between 2,282 and 3,276 hours of Extravehicular Activity (EVA) would be required, per year, to assemble and maintain Freedom, a far cry indeed from the 500 hours initially planned by NASA.

In the words of President Ronald Reagan, America’s new space station was expected to provide a gateway to explore deeper into the cosmos. Image Credit: Great Images in NASA

Further redesigns took place over the following months, in response to continuing budgetary cuts, and in March 1991 NASA unveiled its new plan for Freedom, with slimmed-down laboratory and habitation modules—40 percent shorter in length—as well as simplified radiators and attitude-control systems and a smaller number of shuttle flights to build. The massive solar arrays and trusses would be prefabricated and tested on the ground, contributing to a halving of the predicted number of EVA hours. “We’ve cut costs, simplified the design and reduced the complexity of the project,” explained former shuttle astronaut Bill Lenoir, then serving as NASA’s associate administrator for spaceflight. “At the same time, Freedom will be a quality facility, providing a research laboratory unsurpassed in the world for life sciences and microgravity research and a stepping stone into the future.”

Under the provisions of the new plan, construction would begin early in 1996, allowing the station to be “man-tended” by mid-1997, with astronauts performing research for about two weeks at a time, whilst a shuttle was docked. By the turn of the millennium, it was expected that Freedom—by then equipped with U.S., European and Japanese modules, Canadian robotic assets and three sets of solar arrays, with an output totalling 65 kilowatts—would be permanently occupied by a staff of four astronauts. There were also discussions to add another U.S. module and a further set of solar arrays to boost electrical power to 75 kilowatts, which would comfortably allow the crew size to expand to eight.

In June 1992, newly-inaugurated NASA Administrator Dan Goldin stood before the National Space Club, frustration clear in his voice as the delays dragged on. The United States, he said, had “waited long enough” for a space station, that the nation “must have a permanent presence in space” and that “we need Space Station Freedom…and we need it now.” Despite much pessimism, the development test article for the station’s propulsion module was successfully static-fired in December 1992, prompting Dick Kohrs, head of the station program at NASA Headquarters in Washington, D.C., to observe that “Freedom is no longer a paper station.” And yet 1993 would bring America’s dream of having its first space station since Skylab closer to cancelation than ever before.


FOLLOW AmericaSpace on Facebook and Twitter!



Written by Ben Evans

One Comment

NASA’s Lucy Mission to the Trojans Is a GO!

SpaceX Ties Personal Best, Launches 18th Mission of 2018 With Qatari ComSat