LATE LAST YEAR, Russia's S.P. Korolev Rocket and Space Corporation Energia (known as RKK) revealed detailed plans for a next-generation, reusable space orbiter, dubbed the Kliper (Clipper in English). The project would be the first Russian attempt to build a manned transport spacecraft since the Buran, the Soviet equivalent of the U.S. space shuttle, was abandoned in 1992 as the Soviet economy was collapsing. And the Kliper could be, in effect, the successor to the U.S. space shuttle—perhaps as the vehicle of choice in a joint Russian-European space program.

The existence of the Kliper project had been disclosed a year earlier, though not in as much detail. What was really new and surprising was the announcement that it would be launched aboard a Ukrainian Zenit rocket.

The proposed reliance on Zenit reverses a standing Russian policy of shifting all space and defense subcontracting in the former Soviet republics into the Russian Federation. RKK's move was especially startling against the backdrop of the political turmoil roiling Ukraine as 2004 came to a close. But Zenit's proponents argued—persuasively, it seems—that the use of the existing launcher, rather than the development of the brand-new Onega booster originally proposed for the Kliper, would make the whole program much more technically and financially realistic.

THE 13-TON KLIPER, shaped like a flatiron [see illustration, "Space Wedge"], will be capable of making 25 flights. It is designed to carry two pilots, four passengers, and up to 700 kilograms of cargo. (By comparison, the Soyuz spacecraft, also developed by RKK, can carry no more than three people.) The Kliper's skin, its "thermal protection system," is based on material developed for the Buran.

A reusable crew cabin with a volume of 20 cubic meters was designed as a separate module. It can be coupled with two possible variations of the aerodynamic shell: a shuttle-like winged glider or a so-called lifting body, whereby the shape of the vehicle itself (rather than the wings) would provide effective aerodynamic lift, necessary for control during reentry into the atmosphere [see diagram, "Exploded View"].

In the shuttle form, the craft could maneuver up to 2000 kilometers away from its designated landing path; in its lifting-body form, it could go only 500 km away. The winged version of the Kliper would land on a runway like a regular aircraft; the wingless version would touch down under a trio of parachutes.

While in orbit, the Kliper would be capable of delivering crew and cargo to the space station or, alternatively, of carrying six people, including tourists, on a 10-day excursion. A detachable habitation module, borrowed from the Soyuz and able to accommodate part of the crew, is to be mounted behind the main crew cabin. The habitation module carries a docking port, a toilet, and life-support systems.

The habitation module would be surrounded by a torus-shaped service module containing propulsion systems. The habitation module/service module combination would be jettisoned from the 8.8-ton reentry capsule immediately after the braking maneuver to return to Earth, as is done today on the Soyuz.

Unlike the U.S. shuttle, the Kliper will be equipped with an emergency escape system, enabling the craft and its crew to fly away from the failing rocket booster at any stage of the launch. If launch goes well, the escape rockets would be fired anyway, to complete the orbital insertion.

THE KLIPER EVOLVED from many years of trial and error on the part of RKK. Despite unstable funding in the post-Soviet era, the company quietly continued to study prospective space transportation systems and new propulsion technologies, even contemplating expeditions to Mars. Although the latest effort to find a replacement for the Soyuz had started as early as 2000, the company remained tight-lipped about the project until early last year.

Perhaps not coincidentally, the Russian Aviation and Space Agency, which oversees RKK, disclosed the Kliper last February, weeks after President George W. Bush called for the U.S. return to the Moon. The new U.S. strategy in space was conceived in the wake of the February 2003 Columbia accident, and the anticipated retirement of the space shuttle was a central point of the plan. The administration's decision left NASA with little choice but to develop a capsule-like spacecraft, reminiscent of those used in the Apollo era.

Russia's banking on a "minishuttle" design for its future space transport appears to create a role reversal with the United States. Russian officials stressed that the primary purpose of the Kliper would be the support of the International Space Station, which NASA now plans to abandon.

The engineering design that went into the Kliper has met with good reviews in the space technology community, and RKK is considered technically capable of building the craft. But where will the money for its development and construction come from? Right now the project is essentially a pile of paper studies and a hollow metal mock-up.

One possible source of funds is the European Union, which greeted the Kliper announcement with cautious optimism. Interestingly, the Kliper concept—especially its winged configuration—looks remarkably similar to the Hermes, an ill-fated European minishuttle, which was a victim of budget cuts a decade ago. The proponents of the new spacecraft hope that combined funds and technical expertise will make the minishuttle a reality.