|Image credit: NASA.|
The Soviet Union's new piloted spacecraft was a union of three modules, which together weighed about 7000 kilograms. They were, from aft to fore, the cylindrical Service Module; the 2900-kilogram Descent Module; and, linked to the Descent Module by a hatchway, the spherical Orbital Module.
The cramped Descent Module was the only part of Soyuz spacecraft meant to withstand reentry. In addition to a heat shield, parachutes, and solid-propellant rockets for soft-landing on land, it included the main control console and three cosmonaut launch and landing couches.
The Service Module carried a pair of solar array "wings" on its sides for making electricity. It included the main engine that enabled it to change its orbit; orbit-changing maneuvers included the deorbit burn performed when time came to return home. The Orbital Module provided extra living and storage space and carried a docking unit. Both the Orbital Module and the Service Module were cast off following the deorbit burn and to disintegrate high in the atmosphere.
Any joy flight controllers near Moscow felt as Kosmos 133 soared above the Earth vanished when they found that its attitude control system did not work properly. They called off the Kosmos 134 launch. Several times they tried to orient Kosmos 133 to point its main engine in its direction of orbital motion so that they could slow the spacecraft and begin reentry. On 30 November, they commanded the first Soyuz to self-destruct when it appeared that its Descent Module would land in China.
In January 1969, the piloted Soyuz 4 and Soyuz 5 spacecraft docked and two cosmonauts space-walked between them. Zond 7, a prototype circumlunar Soyuz variant without an Orbital Module, flew without a crew around the moon and landed as planned in the Soviet Union in August 1969, a month after Apollo 11 became the first mission to land men on the Moon. The two-man crew of Soyuz 9 orbited Earth for nearly 18 days in June 1970, breaking the space endurance record Gemini VII had set in 1966.
These scattered successes should not obscure the fact that, of the 16 individual cosmonauts launched on Soyuz between 1967 and 1971, one-quarter lost their lives. Of the more than 30 Soyuz-derived spacecraft launched in the same period, all but nine failed in some significant way.
Following the deaths of the three Soyuz 11 cosmonauts after they undocked from the Salyut 1 space station on 29 June 1971, Soyuz underwent a major redesign. When piloted Soyuz flights resumed in September 1973, the spacecraft could carry no more than two space-suited cosmonauts. Soyuz spacecraft suffered more malfunctions in the 1970s, often failing to reach their Salyut space station targets, but no more cosmonauts died.
The advent in 1977 of the highly reliable Progress variant, an automated cargo ship for resupplying space stations, marked a break from the past for Soyuz. Malfunctions tailed off and, after a dramatic booster explosion on the launch pad on 26 September 1983, no Soyuz failed to reach its space station target. Even the booster explosion could be seen as a sign of design maturity; despite suffering launch-escape system damage, the Soyuz-T-10a spacecraft saved its two-man crew.
Technology upgrades produced first the Soyuz-T and then the Soyuz-TM, which could transport up to three space-suited cosmonauts. By the early 1990s, Soyuz had developed a reputation for sturdy reliability.
|Forward view of Soyuz-TM spacecraft. Image credit: NASA.|
|Aft view of Soyuz-TM spacecraft. Image credit: NASA.|
The threat — and promise — of Soviet space technology soon attracted the attention of the U.S. government. Spaceflight entered the geopolitical arena in a way it had not done since the early 1970s, when the 1975 Apollo-Soyuz Test Project became the poster child for President Richard Nixon's policy of detente.
In December 1991, Congress directed NASA to study the feasibility of using the Soyuz-TM as a low-cost "lifeboat" or "escape pod" for its planned Space Station Freedom. The concept of a space station lifeboat is an old one, dating back at least to the 1960s. NASA had acknowledged the need for such a vehicle soon after the January 1986 Challenger accident killed seven astronauts and grounded the Space Shuttle fleet for almost three years.
NASA foresaw three scenarios in which a Space Station lifeboat might save lives. First, a medical emergency on board Space Station Freedom might require the rapid evacuation of a sick or injured astronaut. Second, a disaster — for example, a fire — might render Freedom uninhabitable. Finally, another Shuttle accident might ground the Orbiter fleet, stranding a crew on board Freedom with no resupply.
|A NASA-designed ACRV for eight astronauts shortly after touchdown. Image credit: NASA.|
As part of the preliminary Soyuz ACRV feasibility study for Congress, NASA engineers traveled to Moscow in March 1992 to meet with Russian government and NPO Energia officials. The space agency completed its study the following month.
In its study report, NASA portrayed Soyuz-TM as an interim lifeboat for the period when Space Station Freedom's crew numbered no more than three astronauts. Use of Soyuz-TM would, it was hoped, bring nearer the day when Freedom could be staffed continuously. In about the year 2000, as Freedom's population grew to six or eight astronauts, an "optimized" U.S.-built ACRV would take over from Soyuz-TM.
|June 1992: U.S. President George H. W. Bush (right) and Russian President Boris Yeltsin. Image credit: National Archives.|
It had, of course, already become evident that Soyuz-TM would need modifications before it could serve as an ACRV for Freedom. Its Russian language control panel labels would, for example, need to be replaced with labels in English. More significantly, its on-orbit endurance would need to be stretched from 180 days to three years and its docking unit would need to be made compatible with Freedom's docking ports. In addition, NPO Energia would need to find a way to squeeze NASA's tallest astronauts into the cramped Soyuz Descent Module.
Even more challenging was Space Station Freedom's planned orbit about the Earth. NASA expected to assemble its station in an orbit inclined 28.5° relative to Earth's equator. It would orbit over an equator-centered, globe-girdling band of Earth's surface spanning from 28.5° north latitude to 28.5° south latitude. Freedom's planned inclination meant that a Shuttle Orbiter launched from Kennedy Space Center, located on Florida's east coast at 28.5° north latitude, would in theory be capable of reaching the station bearing its maximum possible payload.
Space Station Freedom's orbit meant that, if Soyuz-TM were launched from Baikonur Cosmodrome on the usual Soyuz launch vehicle, then it could not reach the U.S. station. The sprawling Central Asian launch site is located in Kazakhstan at 46° north. The Soyuz launcher normally propels Soyuz and Progress spacecraft toward an orbit inclined 51.6° relative to the equator to avoid flying over China during ascent. This meant that, upon reaching orbit, the Soyuz-TM ACRV would need to change its orbital plane by a whopping 23.1° to rendezvous with Freedom.
Each degree of plane change would demand hundreds of kilograms of propellants. If the Soyuz ACRV were launched to Space Station Freedom from Baikonur, then the larger, more powerful, and more costly four-stage Proton launcher would have to do the job. Its entire fourth stage, suitable for boosting spacecraft out of Earth orbit toward the Moon and planets, would be expended to accomplish the required plane change.
NASA envisioned that a Shuttle Orbiter launched from Kennedy Space Center would deliver the Soyuz ACRV to Space Station Freedom. Once there, Orbiter or Station robot arms would pluck the Soyuz ACRV from the Orbiter payload bay and berth it at a waiting Freedom docking port. Alternately, the Soyuz ACRV might be launched minus a crew from Florida on a U.S. expendable rocket such as Atlas and perform an automated rendezvous and docking with Freedom.
Space Station Freedom's 28.5° orbital inclination would limit where the Soyuz ACRV's Descent Module could land after it evacuated a crew. The normal Soyuz landing area is located at about 50° north, far beyond the range of a Soyuz ACRV returning from Freedom.
In a June 1993 report, the ACRV Project Office at NASA Johnson Space Center in Houston, Texas, summed up a study of potential Soyuz ACRV landing zones. It noted that, because of Space Station Freedom's orbital inclination, a Soyuz ACRV could land on U.S. soil only in south Texas and south Florida. (The report made no mention of Hawaii, the southernmost U.S. state, over which Freedom would pass regularly.)
The ACRV Project Office then looked abroad to friendly countries with wide-open spaces. Australia appeared ideal. The northern two-thirds of the country lies between 28.5° and 10° south latitude and much of its interior is flat, arid, and sparsely populated.
As part of the June 1992 contract activities, NASA engineers and officials, a U.S. State Department representative, and NPO Energia engineer Valentin Ovciannikov traveled to Australia in November 1992 to conduct a preliminary assessment of four candidate Soyuz ACRV landing zones. The Australian Space Office (ASO), working with the Australian Geological Survey Organization and the National Resource Information Center, chose the zones based on NPO Energia and NASA selection criteria.
|November 1992: The NASA ACRV Project Office team's route through Australia during its tour of prospective Soyuz ACRV landing zones. Image credit: David S. F. Portree/NASA.|
On 11 November the team began a whirlwind eight-day, 9800-kilometer tour of the proposed landing zones. Team members flew first to Adelaide, the capital of South Australia. There they met with state police to describe the Soyuz ACRV mission and learn about Search and Rescue (SAR) capabilities in the Coober Pedy-Oodnadatta region. Coober-Pedy, "the Opal Capital of the World," is a town of about 2000 people in the Australian Outback north of Adelaide.
The team learned that the police were responsible for SAR operations throughout Australia, and that Australian SAR personnel and equipment were concentrated in capital cities, not scattered among small Outback communities. In South Australia, the state police had four elite rescue teams and three small airplanes that could reach Coober Pedy's 1400-meter-long asphalt runway in two and a half hours. They leased a single helicopter that could reach the area in four hours.
The next day (12 November), the team flew to Coober Pedy in a small chartered plane. There they learned that the local police and mine rescue service had at their disposal several four-wheel-drive vehicles and an ambulance. They found that much of the area was dry and flat with red, gravel-covered soil of good bearing strength. The hard surface would enable four-wheel-drive vehicles to reach points throughout the area and would help to ensure that the Soyuz ACRV land-landing system would operate properly.
As an aside, the team noted in its report that NASA could learn a great deal by participating in a Soyuz-TM landing. NASA engineers subsequently observed the Soyuz-TM 16 landing in Kazakhstan on 22 July 1993.
It was an appropriate landing for them to observe, for the spacecraft had been used to test a Russian-built APAS-89 universal docking unit of the type U.S. Shuttle Orbiters would use to dock with the Mir station during Shuttle-Mir missions (1994-1998). The APAS-89 system, which was based on the U.S.-Soviet APAS-75 system developed jointly for ASTP, had been built originally to enable the Soviet Buran shuttle to dock with Mir and its planned successor, Mir-2.
In the south part of the Coober Pedy zone, the survey team gathered data on the "moon plain," a large area where trees — gidgee and acacia — grew along dry watercourses and the soil had "fair to poor" bearing strength. They also noted a field of small sand dunes. NPO Energia's Ovciannikov worried that the Soyuz ACRV Descent Module might roll between two dunes and become stuck with its top-mounted crew hatch buried in the sand. Using a hand-held anemometer and historical weather data from the Australian Bureau of Meteorology, the team determined that wind speeds near Coober Pedy would be acceptable for Soyuz ACRV landings.
The team spent the night in Coober Pedy listening to the distant howls and barks of dingoes, then flew on to Perth, the capital of Western Australia. On 13 November they discussed with state police the SAR capabilities in the area of Meekatharra, about 1240 kilometers to the northeast.
They also learned of the Royal Flying Doctor Service (RFDS), which had one of its 14 bases in Perth. RFDS provided rapid medical response to two-thirds of the Australian continent, including all four of the candidate Soyuz ACRV landing zones. In their report, the team suggested that NASA doctors should begin to coordinate with the RFDS as soon as possible.
The police in Perth made it clear that present-day local needs had priority over any future NASA needs. They asked to be alerted 24 hours before an expected Soyuz ACRV landing. In its report, the team noted that this would not be possible for a medical or emergency evacuation, though it would be possible for a crew returning from Freedom during a prolonged Shuttle stand-down.
The team flew to Meekatharra on 14 November. Of great interest was a 2180-meter-long, 45-meter-wide asphalt runway at the Meekatharra Airport. In their report, the team suggested that the runway, built originally for emergency Boeing 707 landings, might be used to land cargo planes bearing rescue equipment, four-wheel-drive vehicles, and helicopters.
The team judged that Meekatharra's soil had "excellent" bearing strength. Acacia and munga trees stood over less than 10% of the area, which was very flat. There were, however, scattered bedrock outcrops protruding from the windswept plain. In addition to presenting a minor impact hazard, the outcrops included naturally radioactive "uraniferous" deposits. Ovciannikov expressed concern that these might interfere with the Descent Module's altimeter, which relied on a radioactive source.
Meekatharra is only about 500 kilometers from Australia's west coast, a fact that had both pluses and minuses for Soyuz ACRV landings. On the one hand, it meant that debris from discarded Orbital Modules and Service Modules would not fall on land. On the other hand, the Descent Module might fall short of land if it followed a ballistic reentry path; that is, if it failed to rotate about its center of gravity to generate lift. Following a ballistic reentry, quick crew recovery might be crucial; a ballistic reentry would subject the astronauts, who might be weak after a long stay in weightlessness, to deceleration equal to 10 times Earth's surface gravity.
The team flew on to Darwin, capital of the Northern Territory, on 15 November. There territorial police described their 30-member Police Task Force, which was trained to deal with situations as diverse as riot control, bomb disposal, and cliff rescue.
The proposed Soyuz ACRV landing zone in the Northern Territory, the largest of the four candidates, was centered on the town of Tennant Creek (population 3200). The territorial police explained that their SAR resources were based both in Darwin, 970 kilometers from Tennant Creek, and in Alice Springs, 480 kilometers away.
The team visited the Tennant Creek zone on 16 November. They learned that the Tennant Creek police force included 25 officers but only one four-wheel drive vehicle. The police worried that the Soyuz ACRV soft-landing rockets might start brush fires. Ovciannikov assured them through an interpreter that they would not.
The team noted that the proposed landing zone was in the sprawling Barkley Tableland, a region of black-earth raised plains covered with gold-colored Mitchell grass. Ovciannikov observed that the area resembled the Soyuz-TM "landing grounds" around Dzhezkazgan, Kazakhstan.
Unlike the other landing zones, Tennant Creek had distinct wet and dry seasons, with the former occurring in the southern-hemisphere summer/early autumn months (December through March). Located just 19.5° south of the equator, it was also the hottest of the four zones, with an average of 22 days per year above 40° Celsius (104° Fahrenheit). Flooding from seasonal rains would not interfere with a Soyuz ACRV landing, Ovciannikov explained, though it might impede surface vehicles dispatched to recover the astronauts.
The team flew to Charleville in Queensland on 17 November without stopping in Brisbane, the state's capital. They found that the local airport included two asphalt runways, the largest of which was more than 1500 meters long and 30 meters wide. Though they met with local police, the team's report on the Charleville zone included no SAR data.
Charleville's rolling plains, or downs, differed from the other zones the team surveyed in that they included many large trees (briglow and sandalwood) interspersed with "square" and "circle" treeless areas used for grazing and farming. Charleville police told the team that local ranchers knocked down and burned the trees to create grazing land; if left alone, however, the trees grew back within a few years.
Ovciannikov compared Charleville to the "wooded steppe" on the north edge of the Soyuz-TM landing zone near Arkalyk, Kazakhstan. The open areas would make acceptable landing sites, he judged, though the bearing strength of the black and brown loamy soils could be rated only as "fair."
The team returned to Canberra late on 18 November. After another meeting with Australian government officials, during which they signed a document that summarized what the parties had learned and what had been agreed, its members departed Australia on 20 November 1992.
|Soyuz-TM Descent Module on the treeless steppe in Kazakhstan. Image: NASA.|
Clinton did not in fact support Space Station Freedom; that did not mean, however, that he failed to find value in a space station. On 9 March 1993, he ordered NASA to produce three low-cost station designs in 90 days. Aided by an advisory committee, he would then select one design for development.
The new President then handed off supervision of NASA to his Vice President, Al Gore. On 25 March, Gore appointed members to the Advisory Committee on the Redesign of the Space Station. MIT's Charles Vest became its chair.
That same month, in a letter to NASA Administrator Daniel Goldin, Russian Space Agency director Yuri Koptev and NPO Energia director Yuri Semenov proposed what would become the NASA station program's salvation: a merger of the financially strapped, politically troubled Freedom and Mir-2 programs. They proposed that the joint station be assembled in an orbit inclined more than 50° relative to Earth's equator. The following month, the Russians provided NASA with a straw-man assembly sequence for the joint station.
On 11 May 1993, Vest advised the White House that, regardless of the design selected, the U.S. station should be built in what he called a "world orbit" inclined between 45.6° and 51.6° so that Russian — and Chinese and Japanese — rockets could easily reach it. This would, he explained, ensure that redundant means of reaching and returning from the station would exist. He added that "the shuttle will likely be grounded during the operational life of the station."
Vest presented the Advisory Committee's report to the Clinton White House on 10 June 1993. Barely two weeks later, on 23 June 1993, the U.S. station program had a near-death experience: the U.S. House of Representatives approved Fiscal Year 1994 station funding by a margin of a single vote (215-216). The close vote, which showed how politically vulnerable Space Station Freedom had become, clearly conveyed to many in NASA that station program reform was essential.
President Clinton soon approved Option A, or Alpha, the redesign option most like Space Station Freedom. Meanwhile, the proposal to merge the U.S. and Russian station programs gained momentum. Engineers and managers in Moscow, Washington, and Houston began to refer to "Ralpha," which was short for "Russian Alpha."
On 2 September 1993, Vice President Gore and Russian Prime Minister Viktor Chernomyrdin released a joint statement on U.S.-Russian space cooperation. In it, they announced a dramatic expansion of the space cooperation outlined in the June 1992 Bush-Yeltsin agreement. Russia became a full partner in the space station; minus Russian participation, it simply would not fly.
At the same time, however, NASA would pay Russia for its involvement, which put the Russian Space Agency (and through it, NPO Energia) in the role of a NASA contractor. Though ambiguous and controversial in some quarters, the expanded Russian role reinforced the station's geopolitical justification, helping to ensure that the U.S. Congress would support it.
In November 1993, NASA and the Russian Space Agency completed an addendum to NASA's August 1993 Alpha Station Program Plan. It amounted to a blueprint for merging the Alpha and Mir-2 programs. The resulting International Space Station would be assembled in a 51.6° orbit, which meant that Soyuz spacecraft returning from it could land in their long-established recovery zones in central Asia.
Mir Hardware Heritage, NASA RP-1357, David S. F. Portree, NASA Lyndon B. Johnson Space Center, March 1995.
Alpha Station Addendum to Program Implementation Plan, RSA/NASA, 1 November 1993.
Australian Landing Sites Evaluation and Survey, JSC-34045, Assured Crew Return Vehicle (ACRV) Project Office, NASA Lyndon B. Johnson Space Center, 22 June 1993.
Assured Crew Return Vehicle (ACRV): Technical Feasibility Study on Use of the Soyuz TM for the Assured Crew Return Vehicle Missions, JSC-34048, Assured Crew Return Vehicle (ACRV) Project Office, NASA Lyndon B. Johnson Space Center, June 1993.
Letter with Attachment, C. Vest to J. Gibbons, 11 May 1993.
Mir-Freedom Assembly Sequence, NPO Energia, April 1993.
Letter, Y. Koptev and Y. Semenov to D. Goldin, 16 March 1993.
Assured Crew Return Vehicle (ACRV): Preliminary Feasibility Analysis of Using Soyuz TM for Assured Crew Return Vehicle Missions* *Includes Evaluation of Automated Rendezvous and Docking System, JSC-34023, Assured Crew Return Vehicle Project Office, NASA Lyndon B. Johnson Space Center, April 1992.
Skylab-Salyut Space Laboratory (1972)
SEI Swan Song: International Lunar Resources Exploration Concept (1993)