Freedom
Freedom was to include three separate components: a pressurized base unit in which the crew would live and work and two automated platforms that would conduct scientific experiments and record observations of Earth's climate. At that time, designers envisioned a station that could accommodate a crew of up to ten people.
The project was plagued immediately by financial and technological problems that continued to get worse. Development costs increased even as NASA's budget shrank. Congress demanded several redesigns to save money. NASA eliminated the two automated platforms and scaled back the base unit. Each redesign resulted in a smaller station with less usable space and less electrical power available to scientists. NASA's foreign partners became increasingly annoyed about the design changes.
Meanwhile the space shuttle program was enmeshed in its own difficulties. The space shuttle was crucial to the station program, because it was to be the only means by which American flight crews could reach the station. The catastrophic breakup of the space shuttle Challenger in 1986 grounded the entire shuttle fleet for more than two years. It also raised questions about the safety and quality of NASA's operations.
Even as the space station shrank in volume, its weight increased. This required shuttle design changes to accommodate the extra weight. It was also decided to include some kind of lifeboat capability in the station in case its crew had to leave in an emergency. By December 1990 the cost of Freedom was estimated at $38 billion (approximately $58.9 billion in 2006 dollars). This included the cost of shuttle launches required to build the station.
In 1991 a Congressional committee recommended that NASA cancel the Freedom program. A vote was held on the House floor to determine its fate, and an amendment was passed to continue the program. This was the first of nearly two dozen votes that would take place over the next decade in the U.S. Congress and U.S. Senate on the fate of the space station. Each time the program was allowed to continue. However, some of the votes were very close. In a June 1993 vote the station survived on the basis of a one-vote margin.
Station Alpha
When U.S. President Bill Clinton took office in 1993 he ordered a sweeping revision to cut costs in the space station program. By that time, NASA had already spent in excess of $11 billion on design costs alone. Not one piece of hardware had been launched into space yet. NASA designers presented President Clinton with several different options for station components and functions, and the president selected a plan called Design A or Design Alpha. The new station was unofficially named Station Alpha.
By this time, the Soviet Union had collapsed. The Clinton administration began talks with the new Russian government and welcomed Russia's eagerness to participate in the space station project. According to a 2001 NASA account of the history of the space station program, President Clinton saw Russian participation as a way to improve foreign relations and put pressure on the Russians to abide by newly signed ballistic missile agreements (http://www.hq.nasa.gov/office/pao/History/smith.htm). He also wanted to provide Russian scientists with jobs to keep them from selling valuable information to America's enemies. NASA estimated that Russian participation would cut $2 billion off the $19 billion cost of completing Project Alpha and speed it up by an entire year.
On September 2, 1993, the two countries signed the Joint Declaration on Cooperation in Space. By the end of the year, NASA and the Russian space agency Rosavia-kosmos had ironed out a detailed work plan for what was now called the International Space Station (ISS).
The ISS Plan
It was decided that the ISS would comprise individual segments called modules that would dock together to form the station. Each module was to be constructed on the ground and then launched into space. The space shuttle was expected to carry the heaviest loads to the station. Russia agreed to transport supplies and propellants to the ISS aboard its unmanned Progress spacecraft. In addition, Russian Soyuz spacecraft were offered as the station's lifeboats.
A rotating schedule for the first four modules was developed in which Russia would build the first and third modules and the United States would build the second and fourth modules. NASA agreed to pay for one of the Russian modules.
The collaboration with Russia raised some concerns among U.S. politicians and scientists. They publicly expressed fears that the cash-strapped Russian government would not be able to fulfill its obligations to the program. NASA had given Rosaviakosmos responsibility for two of the most important modules in the station. Failure to deliver them would cripple the entire project. U.S. fears grew even greater during the late 1990s as problems surfaced on the Russian space station Mir.
On January 29, 1998, the U.S. government signed the 1998 Intergovernmental Agreement on Space Station Cooperation with fourteen other countries. This document outlined the agreement among the partners for design, development, operation, and utilization of the ISS. The previous year the United States had signed a separate agreement with Brazil giving that country utilization rights in exchange for supplying ISS parts. Table 5.4 lists the nations that are ISS partners.
In early 1998 it was expected that at least forty spacecraft launches spread over five to seven years would be required to assemble more than 100 components into the ISS. At that time the station was designed for a crew of seven people. The space station was expected to be
TABLE 5.4 International Space Station partner nations
ISS Assembly Begins
On November 20, 1998, a Russian Proton K rocket was launched, carrying the first module of the ISS. The module was named Zarya, which means "sunrise" in English. It is known by the Russian acronym FGB. The Russians built Zarya, but the Americans paid for it. It was to be a U.S. component of the station. The module provides control and cargo capabilities. Zarya was self-propelled and was designed to keep the station in orbit until the service module arrived. After that it would serve as a passageway, storage facility, docking port, and fuel tank. Zarya weighed 44,000 pounds at launch.
Two weeks later, an American shuttle, STS-88, carried the module Unity to the station. Figure 5.2 shows the two modules docked together. Zarya is on the left, and Unity on the right. Unity is an American-built module with six docking ports for attachment to other modules.
FIGURE 5.3 Service module attached to Zarya/Unity modules
Two more shuttle crews visited the ISS during 1999 and 2000 to outfit the modules with logistical equipment and supplies. On July 12, 2000, the Russians launched the service module Zvezda into space aboard a Proton K rocket. Zvezda is the Russian word for "star." This module was built and funded by the Russians and was to be the core of their segment.
It included functions for station control, navigation, communications, and life support systems (including the crew quarters). At that time, it was expected that many of these functions would be taken over by an American module to be added later. Zvezda's design was based on the core module of the Mir space station. Zvezda is forty-three feet long with a wing span of ninety-eight feet and weighed 42,000 pounds at launch. It includes docking ports for Russian Soyuz and Progress spacecraft. Figure 5.3 shows the three modules hooked together. Zvezda is on the far left.
Throughout the summer of 2000 visiting Russian and American crews continued outfitting the modules and assembling the station. The station was also visited by an unmanned Russian Progress spacecraft carrying consumables (food and water), spare parts, and propellants.
On November 2, 2000, the first crew to actually inhabit the ISS arrived aboard a Soyuz spacecraft. This is called ISS Expedition 1. It included two Russian cosmonauts and one American astronaut. Table 5.5 lists the names of all Expedition crewmembers from Expedition 1 through Expedition 12. The Expedition 1 crew lived aboard the station until March 2001. They were visited by two shuttles, one of which brought the American lab module named Destiny. Destiny was to be the primary research laboratory for U.S. payloads. It included numerous racks that could support a variety of electrical and fluid systems during the performance of experiments. Destiny also contains the control center for the ISS robotic arm.
In March 2001 the Expedition 2 crew arrived at the station aboard shuttle STS-102. The Expedition 1 crew returned to Earth aboard the space shuttle, leaving their Soyuz spacecraft at the station to serve as a lifeboat. The Expedition 2 crew included two American astronauts and one Russian cosmonaut. It had been decided to swap out the Expedition crews every four to six months and to rotate back and forth between crews that were predominantly Russian and crews that were predominantly American.
The Expedition 2 crew brought a multi-purpose logistics module (MPLM) called Leonardo. MPLMs are reusable pressurized shipping containers designed to be temporarily attached to the ISS for unloading. They are transported back and forth on space shuttles and carry a
TABLE 5.5 International Space Station expedition crews
| TABLE 5.5 | |||||
|---|---|---|---|---|---|
| International Space Station expedition crews | |||||
| Launch date | Landing date | Timein orbit | Crew members | Crew titles | |
| *ISS=International Space Station | |||||
| SOURCE: Adapted from "Mission Archives," in Space Station Expeditions, National Aeronautics and Space Administration, February 3, 2006, http://www.nasa.gov/mission_pages/station/expeditions/index.html (accessed January 31, 2006) | |||||
| Expedition 1 | 10/31/00 | 3/21/2001 | 140 days, 23 hr, 38 min | William Shepherd Yuri Gidzenko Sergei Krikalev |
Commander Soyuz Commander Flight Engineer |
| Expedition 2 | 03/08/01 | 8/22/2001 | 167 days, 6 hr, 41 min | Yury Usachev Susan Helms James Voss |
Commander Flight Engineer Flight Engineer |
| Expedition 3 | 08/10/01 | 12/17/2001 | 128 days, 20 hr, 45 min | Frank Culbertson Vladimir Dezhurov Mikhail Tyurin |
Commander Soyuz Commander Flight Engineer |
| Expedition 4 | 12/05/01 | 6/19/2002 | 195 days, 19 hr, 39 min | Yury Onufrienko Dan Bursch Carl Walz |
Commander Flight Engineer Flight Engineer |
| Expedition 5 | 06/05/02 | 12/7/2002 | 184 days, 22 hr, 14 min | Valery Korzun Peggy Whitson Sergei Treschev |
Commander NASA ISS* Science Officer Flight Engineer |
| Expedition 6 | 11/23/02 | 5/3/2003 | 161 days, 1 hr, 17 min | Ken Bowersox Nikolai Budarin Don Pettit |
Commander Flight Engineer NASA ISS Science Officer |
| Expedition 7 | 04/25/03 | 10/27/2003 | 184 days, 21 hr, 47 min | Yuri Malenchenko Ed Lu |
Commander NASA ISS Science Officer |
| Expedition 8 | 10/18/03 | 4/29/2004 | 194 days, 18 hr, 35 min | Michael Foale Alexander Kaleri |
Commander/NASA ISS Science Officer Flight Engineer |
| Expedition 9 | 04/18/04 | 10/19/2004 | 187 days, 21 hr, 17 min | Gennady Padalka Mike Fincke |
Commander Flight Engineer/NASA ISS Science Officer |
| Expedition 10 | 10/13/04 | 4/24/2005 | 192 days, 19 hr, 2 min | Leroy Chiao Salizhan Sharipov |
Commander/NASA ISS Science Officer Soyuz Commander/Flight Engineer |
| Expedition 11 | 04/14/05 | 10/10/2005 | 179 days, 23 min | Sergei Krikalev John Phillips |
Commander Flight Engineer/NASA ISS Science Officer |
| Expedition 12 | 09/30/05 | to be determined | to be determined | William McArthur Valery Tokarev |
Commander/NASA ISS Science Officer Flight Engineer |
The Expedition 2 crew also attached the station's remote manipulator system. This is a robotic arm that was nicknamed Canadarm2, because it was built by Canadian companies. The space shuttle fleet utilizes another robotic arm called Canadarm1.
Tito Comes Aboard
In April 2001 the Russians sent the first taxi to the station to replace the Soyuz lifeboat left by the Expedition 1 crew. The taxi crew included a U.S. millionaire named Dennis Tito (1940–). A year earlier Tito had paid $20 million for a visit to the Mir space station. He immediately began training in Russia. When the Russians decided to deorbit Mir, they rescheduled Tito for a trip to the ISS. They hoped he would be the first of many "space tourists" to pay to fly on ISS taxis. Rosaviakosmos desperately needed the money.
NASA and the European partners in the ISS were not happy with the decision. When Tito and two cosmonauts showed up at the Houston Space Center for training, NASA refused to allow Tito entry. The cosmonauts responded by refusing to undergo training. The standoff resulted in a flurry of negotiations between NASA and Rosaviakosmos. The Americans finally agreed reluctantly to allow Tito to train in the United States. They continued to argue that Tito posed a safety risk to the station and banned him from the American segments of the ISS. NASA repeatedly asked Rosaviakosmos to postpone Tito's flight, but the Russians would not agree.
On April 28, 2001, a Soyuz blasted off with Tito and two cosmonauts aboard. Two days later it docked with the ISS. Tito spent his time aboard ISS in the Russian segment taking pictures of Earth and listening to opera. The crew stayed at the station for four days before returning to Earth aboard the old Soyuz lifeboat. After landing Tito told reporters, "I've finally had my dream."
The Price Goes Up
In April 2001 NASA announced that the U.S. cost to complete the ISS by 2006 was going to be $4 billion more than expected. The Clinton administration responded by setting up the ISS Management and Cost Evaluation Task Force to assess the project. In November 2001 the Task Force released a forty-page report that called for serious downsizing of the ISS.
The report recommended that the ISS be configured for only a three-person crew. Previous plans had called for a seven-person crew. The Task Force noted that scientists were not happy with this proposal and feared it would "have a significant adverse impact on science." However, the report noted that the cutback was necessary to save money and suggested that some of the research planned for the ISS could take place aboard space shuttle flights instead.
The report recommended many management changes within NASA to save money and suggested that the agency prioritize its research goals for the station. One goal considered crucial was installation of a centrifuge. A centrifuge is a machine commonly used in research to separate different substances, to remove moisture, or to simulate certain gravitational effects. The report noted that NASA kept putting off centrifuge installation on the ISS, much to the disappointment of the scientific community.
The Task Force called for NASA to establish a specific "end state" for station construction that could be achieved within NASA's existing budget. At that point, station construction would be complete and a much cheaper operation stage could begin. The task force recommended that several planned ISS features be eliminated: a crew return vehicle; Node 3, a habituation module; and a propulsion module.
The report was issued only days before the United States election that ended with George W. Bush being declared the new president by the Supreme Court. The ISS project had now fallen under the terms of four U.S. presidents. The Bush administration agreed wholeheartedly with the findings of the Task Force. The end state recommended by the report came to be called the "core complete" point. Bush appointed a new NASA administrator, Sean O'Keefe (1956–), and charged him to achieve core complete as soon as possible. NASA estimated that construction could be completed by 2004.
America's international partners were not happy with the plan for a smaller crew size because it meant fewer chances for their personnel to visit the station. Many scientists were disappointed with the reduction in research potential afforded by the smaller station.
The Expeditions Continue
By the end of 2001 the station had been visited by Expedition 3 and Expedition 4 crews, which included three members each. These crews installed a new Russian docking and airlock module called Pirs ("Pier" in English) and began construction on the truss. The truss is a long girder-like structure that is perpendicular to the row of existing modules. The truss is designed to hold the solar panels that power the station and to hold any new modules constructed in the future.
Deliveries of food, water, and supplies to the ISS continued to occur every few months aboard automated Russian Progress spacecraft. These vehicles were loaded up with ISS trash and disposed of during reentry to Earth's atmosphere.
The Russian Soyuz lifeboat docked to the ISS was exchanged every six months by taxi crews. In April 2002 the taxi crew again included a space tourist. This time it was a South African Internet entrepreneur named Mark Shuttleworth (1973–). He paid approximately $20 million to visit the ISS.
After two years of negotiation, the ISS partners had worked out an agreement specifying who could visit the station. It was titled Principles Regarding Processes and Criteria for Selection, Assignment, Training and Certification of ISS (Expedition and Visiting) Crewmembers. The agreement listed very strict requirements regarding the personal character and communication skills of any visitors. It disqualified anyone found to have a drinking or drug problem, those with poor employment or military records, convicted criminals, people who had engaged in "notoriously disgraceful conduct," and anyone known to be affiliated with organizations that wished to "adversely affect the confidence of the public" in the space program. Visitors also had to speak English.
Shuttleworth passed the review process and launched aboard a Russian Soyuz rocket on April 25, 2002, with a Russian cosmonaut and an Italian flight engineer. Two days later they entered the station. Shuttleworth performed some simple scientific experiments while on board and conducted numerous interviews with school children. During his flight he said, "I have truly never seen anything as beautiful as the Earth from space." Shuttleworth and the taxi crew spent eight days aboard the ISS.
Throughout the remainder of 2002 the station was visited by the crews of Expedition 5 and Expedition 6 who continued construction of the ISS truss. A Soyuz taxi flight launched in October of that year included a visiting astronaut from the European Space Agency. Frank DeWinne (1961–) and two taxi cosmonauts spent eight days at the station before returning to Earth.
The last visitors of the year came aboard space shuttle flight STS-113. The orbiter Endeavour docked at the ISS in late November to deliver the Expedition 6 crew and a new truss segment. In early December the shuttle returned safely to Earth carrying the Expedition 5 crew. It was the sixteenth American shuttle flight to the ISS. It was to be the last for a long while.
TABLE 5.6 The International Space Station construction statistics as of February 2006
| TABLE 5.6 | |
|---|---|
| The International Space Station construction statistics as of February 2006 | |
| International Space Station: | |
| SOURCE: "Vital Statistics," in The ISS to Date (11/07/05), National Aeronautics and Space Administration, November 7, 2005, http://spaceflight.nasa.gov/station/isstodate.html (accessed December 28, 2005) | |
| Major elements: | |
| Zarya: | Launched Nov. 20, 1998 |
| Unity: | Attached Dec. 8, 1998 |
| Zvezda: | Attached July 25, 2000 |
| Z1 truss: | Attached Oct. 14, 2000 |
| P6 integrated truss: | Attached Dec. 3, 2000 |
| Destiny: | Attached Feb. 10, 2001 |
| Canadarm2: | Attached April 22, 2001 |
| Joint airlock: | Attached July 15, 2001 |
| Pirs: | Attached Sept. 16, 2001 |
| S0 Truss: | Attached April 11, 2002 |
| S1 Truss: | Attached Oct. 10, 2002 |
| P1 Truss: | Attached Nov. 26, 2002 |
| Weight: | 404,069 pounds (183,283 kg) |
| Habitable volume: | 15,000 cubic feet (425 cubic meters) |
| Surface area (solar arrays): | 9,600 square feet (892 square meters) |
| Dimensions: | |
| Width: | 240 feet (73 meters) across solar arrays |
| Length: | 146 feet (44.5 meters) from Destiny Lab to Zvezda; 171 feet (52 meters) with a Progress resupply vessel docked |
| Height: | 90 feet (27.5 meters) |
ISS Assembly Halts
On February 1, 2003, the space shuttle Columbia broke apart as it entered Earth's atmosphere over the western United States. The shuttle had been on a research mission and did not visit the ISS. The catastrophe killed the seven crewmembers and shook the U.S. space program to its core. An investigation revealed that the shuttle's thermal protection tiles were likely damaged by a foam strike shortly after launch. During reentry, hot gases seeped past the tiles into the orbiter structure. The resulting turbulence tore it apart.
The entire shuttle fleet was grounded. Flights planned to the ISS during 2003 to deliver truss segments and research facilities were cancelled. There was no other way to transport these heavy components to the ISS. The Russian Soyuz spacecraft can carry only around 5,000 pounds, compared to the approximately 36,000—pound capacity of a shuttle. Russia's automated Progress spacecraft can carry even less weight, only 1,000 pounds. ISS assembly came to a halt. As shown in Table 5.6, the last major element of the ISS was attached in November 2002.
User Comments Add a comment…