ISS US roots of ISS project to Soyuz section


Russia proposes lifeboat for a US space station

From the inception of NASA's space station project in 1984, it relied on the Space Shuttle for assembly and supply missions. However, the winged orbiter could not stay docked at the station for long, mainly due to its limited consumables. As a result, a permanently occupied outpost in the Earth orbit needed a "lifeboat," providing escape for the crew in case of emergency between Shuttle missions. With the end of the Cold War and improved prospect for cooperation, Russian engineers proposed to enlarge their venerable Soyuz spacecraft to serve as a lifeboat.

Soyuz ACRV

A "space lifeboat," carrying the entire crew of the International Space Station, departs the stricken outpost, as it was envisioned around 1995. (Artist rendering of the ACRV spacecraft by Anatoly Zak; Earth backdrop and space station photo by NASA)

Purpose of the spacecraft

To develop the "lifeboat," formally known as Assured Crew Return Vehicle, ACRV, NASA created the ACRV Project Office. It was subordinated to the New Initiatives Office of the Johnson Space Center in Houston. The group identified three scenarios, which would require a dedicated spacecraft to evacuate the crew in the absence of the Shuttle:

  • Medical emergency among the crew: If one or several crew members were severely injured or fell ill and onboard facilities were not adequate to help them;
  • Technical problem on the station: An accident serious enough to require immediate evacuation of the crew from the station;
  • Technical problems with the Shuttle: Grounding of the Space Shuttle fleet long enough to require an alternative escape route from the station. (265)

Requirements for the spacecraft

NASA wanted the station lifeboat to be simple, reliable and available 24-7. The spacecraft's mass was limited to just 10,000 pounds and it had to be small enough to fit into the Shuttle cargo bay or to be launched by a regular rocket. Its main mission would be to undock from the station to reenter the Earth atmosphere and land. Finally, the "lifeboat" would use existing technology and require absolute minimum hardware for post-flight servicing.

The development

As of beginning of 1992, the ACRV program entered the development phase known as "system definition" or Phase B. Essentially, engineers had to decide on the general configuration of the spacecraft and to develop its preliminary design. At the time, this work was expected to be completed during Fiscal Year 1993. It would be followed by full-scale development beginning in Fiscal Year 1994. The ACTV had be ready to receive the crew in 1999, when Space Station Freedom was expected to reach Permanently Manned Capability. (265)

A price tag for the development of NASA's ACRV could reach up to $2 billion, while the overall program faced mounting financial pressure. In the meantime, Russian and American officials started first post-Cold War dialog on the possibility of cooperation in manned space flight.

In October 1991, during a meeting with Boeing representatives (the main station contractor) the head of NPO Energia Yuri Semenov offered the company's Soyuz spacecraft to serve as a lifeboat. In February 1992, the chairman of a congressional subcommittee on space Barbara Mikulski urged NASA Administrator Richard Truly to evaluate the feasibility of employing Soyuz as a lifeboat.

In March 1992, Russian and US space officials discussed the possibility of cooperation in manned space program, including ACRV. On June 18, 1992, after three months of negotiations, NASA Administrator Daniel Goldin and Director General of the Russian Space Agency Yuri Koptev "ratified" a contract between NASA and NPO Energia to study possible application of the Soyuz spacecraft and Russian docking port in the Freedom project. The agreement would also cover a study of the possible use of the Mir space station for the US life-science research in support of the Space Station Freedom project. The contract worth $1 million was expected to last a year. (266)

From the outset, the Soyuz was considered as a temporary solution for the ACRV issue, to be replaced by a custom-designed spacecraft sometime later.

As proposed by NASA, the initial contract studied 11 aspects of the Soyuz spacecraft as the ACRV vehicle:

  • Extension of the Soyuz mission
  • Evaluation of the spacecraft design
  • Development of the interface of the spacecraft and the station
  • Procedures of the pre-launch processing
  • Mission planning
  • Safety reliability and quality control issues
  • Landing, search and rescue issues
  • Placement of the spacecraft in the Shuttle cargo bay
  • Crew boarding and placement of medical equipment
  • Atmospheric reentry of orbital and service modules and the issues of debris impact
  • Possibility of launching a spacecraft by expendable US and Russian launch vehicles

During the study, the US aerospace industry was represented by Rockwell and Lockheed, which competed for the NASA contract to develop ACRV.

Flight profile

The primary mission scenario for the Soyuz-based ACRV called for its launch from Kennedy Space Center in Florida, onboard Shuttle. However an option of launching the Soyuz by the Proton rocket equipped with Block D from Baikonur was also under consideration. Due to geographic location of Baikonur, the spacecraft had to enter the initial parking orbit with the inclination 51.6 degrees toward the Equator and then change to 28.5 degrees with the help of Block D. The unmanned spacecraft would then dock to the station automatically. The analysis showed that the latter scenario would not be possible without considerable upgrades of the spacecraft, the rocket and its upper stage due to mass limitations.

Landing in the outback

Both flight scenarios made it impossible for the Soyuz to land in the traditional areas in Kazakhstan, since space station's orbit was located much farther south. After studying various landing regions, including the US territory, Australia was chosen as preferred location. In November 1992, a NASA team, including a Russian expert, visited desolated areas of the continent, which were recommended by Australian officials. Locations included Coober Pedi in the South, Mikaterra in the West, Tennant Creek in the North and suburbs of Charleville in the East of the continent. The first three areas were certified as acceptable for landing, the fourth, located in the wooded area was found least acceptable. Overall, the landing in Australia was considered possible and from that time, coordinates of Australian sites were included in the planning of the ACRV missions.

NASA efforts to minimize the cost of the ACRV program prompted the analysis of possible mission extension for Soyuz up to one year and three years.

As an alternative to the launch onboard the Shuttle, Russian and American specialists considered such rockets as Zenit, Soyuz, Proton, Atlas and Titan.

Initial Soyuz/ACRV studies were completed in November 1992 and in March 1993, NASA and NPO Energia renewed the agreement for additional in-depth study of the Soyuz ACRV. By December 1993, partners were ready to take the project to the next stage, however other events in the Russian-American cooperation in space had overtaken the ACRV issue. In the wake of the historic agreement to replace Space Station Freedom with the International Space Station, ISS, NASA made a decision to put off the ACRV program until 1997.

Enlarged Soyuz

In 1995, RKK Energia in cooperation with Rockwell International resumed studies of the ACRV vehicle, in anticipation of a contract from NASA. This time, designers proposed a radical upgrade of the Soyuz to accomodate eight people. The spacecraft would be launched exclusively onboard the Shuttle. The 12.5-ton vehicle could remain docked to the station for five years. By the end of 1995, Khrunichev enterprise, the developer of the venerable TKS transport ship, joined the project.

In June 1996, NASA made a decision to use a modified Soyuz spacecraft as a lifeboat for the American crew members during the construction of the station. (52) The development of a dedicated ACRV vehicle would eventually shift back to US-based contractors and the program would ultimately be killed due to lack of funds. NASA would continue purchasing Soyuz missions to provide rescue capabilities for US astronauts. However the concept of the enlarged Soyuz reentry capsule would find new application in the 21st century.


Known specifications of the enlarged Soyuz for the ACRV role:

Launch vehicle Space Shuttle
Flight duration 5 years
Crew 8 people
Total mass 12.5 tons
Reentry capsule mass 8 tons
Reentry capsule diameter 3.7 meters
Total length 7.2 meters


Writing, photography and illustrations by Anatoly Zak. All rights reserved

Last update: November 28, 2021


insider content


ACRV concept

One of the early concepts of a lifeboat for Space Station Freedom.

Below: Various concepts of "lifeboats," which were considered for Space Station Freedom as of beginning of 1992:

Winged ACRV

Lifting-body/winged configuration...

Scram ACRV

"SCRAM" configuration...

Apollo ACRV

"Apollo-derived" configuration...

Discoverer ACRV

"Discoverer-derived" configuration...

Hermes ACRV

A European concept of a rescue vehicle circa 1993, considered as a replacement to the ill-fated Hermes space place. Click to enlarge. Credit: ESA


The X-38 reusable vehicle, designed to serve as a rescue ship for the station, drops away from NASA's NB-52B aircraft during its eight test flight on Dec. 13, 2001. The program was cancelled before any piloted missions could be attempted. Credit: ESA


Rep. Barbara Mikulski, D-Md., played a key role in making first steps toward US-Russian cooperation on the International Space Station. Copyright © 2002 Anatoly Zak