With the space shuttle Endeavour away on its final mission today, the United States will soon have no transportation to the International Space Station of its own. Between the final launch of the Atlantis, scheduled for June 28, and until affordable commercial rockets become available to NASA, astronauts will hitch a ride on Russia's Soyuz 2 rockets, the latest version in a line of Russian and Soviet spaceships stretching back to the early 1960s. The latest Soyuz rockets are cheaper and more versatile than space shuttles, but they don't have nearly the payload and despite their emergence as the carrier of choice for near-term space missions, they don't have as extensive a history of manned flight.
By the numbers, Soyuz has a better safety record than NASA so far. NASA's history has been marred by two major disasters -- the Columbia in 2003 and the Challenger in 1986 -- both of which resulted in the deaths of the entire crew. Soyuz has not been spared from mishaps, but it has fared better overall. The Smithsonian magazine breaks down some of the safety specifics in a blog post:
Through the most recent mission, STS-130 in February 2010, the shuttle has taken 788 people to orbit (“people” includes repeat fliers—so Franklin Chang Diaz’s seven flights would count as seven people). Fourteen astronauts lost their lives on Challenger and Columbia, which leaves a ratio of one fatality for every 56 people taken to orbit. Soyuz has orbited 250 people, not including two successful aborts: Soyuz 18a in April 1975, which occurred late in a launch 90 miles high, and Soyuz T-10-1 in September 1983, on the launch pad. The program has suffered four fatalities: one on Soyuz 1 in April 1967, and the other three on Soyuz 11 in June 1971. That’s one Soyuz fatality for every 63 people delivered to orbit. Based on those ratios, Soyuz is a little safer.
But remember, with far fewer manned missions flown--only 103 manned missions to the shuttle's 130--Soyuz has had fewer chances for disaster. As The Smithsonian's Mike Klesius points out, "Who knows if Soyuz might have a critical failure in the next 27 flights?"
Safety records aside, the specifications of the two craft show two very different approaches to space flight. The Russians favor cheaper, smaller, single-use rockets that carry a recoverable capsule into orbit. The Americans have built a series of large, reusable craft that paved the way for routine manned missions. Here's a look at the Endeavor and the latest Russian model, the Soyuz 2, by the numbers:
Length: 121 feet (not including auxiliary rocket boosters)
Wingspan: 78 feet
Height: 57 feet
Engines: "Three main engines running on liquid hydrogen/liquid oxygen propellant, rated at 512,950 lb thrust each; two solid, reusable rocket boosters rated at 3,300,000 lb each at launch, running on aluminum powder, iron oxide, and ammonium perchlorate powder."
Payload: About 50,000 pounds
Successful Missions Flown: 24 (today will be no. 25)
First Mission: May 7, 1992
Pricetag: $1.7 billion
Trivia: The name of Endeavour is spelled in the British fashion instead of the American, because it takes its name from the British ship captained by 18th-century explorer James Cook.
Length: 151.2 feet
Diameter: 9.67 feet
Engines: This varies. A typical configuration is to use a three-stage rocket plus boosters. The boosters and first two stages run on liquid oxygen and kerosene, with the boosters and first stage producing about 225,000 pounds of thrust and the second stage about 66,000. The third stage, which for manned missions would typically consist of a Fregat stage powering a Soyuz capsule, has a series of small, liquid-fueled rocket thrusters fueled by liquid unsymmetrical dimethylhydrazine and nitrogen tetroxide.
Payload: About 18,740 pounds
Successful manned missions flown: 9 (per Wikipedia, apparently translated from Russian)
First mission: November 8, 2004
Pricetag: $65 million (used)
Trivia: The latest version of the manned capsule that the rocket carries, known as the Soyuz-TMA, was updated to fit larger astronauts. It now comes with adjustable couches.