MOSCOW — The Soviet Union's Energia rocket, the most powerful in the world, will be completely reusable, Soviet officials disclosed for the first time in interviews here Saturday.
American experts have suspected that the Energia, fired for the first time earlier this year, could be at least partially recovered, but details about the rocket, including the fact that the entire vehicle is designed to be reused, were disclosed in interviews with officials attending a major international symposium here sponsored by the Soviet Union.
U.S. experts who were told of the Soviet disclosures said that the Soviets had achieved a major breakthrough in their space program.
"It's very significant because it could reduce the cost while still giving a heavy lift capability," said John Logsdon, director of the Space Policy Institute at George Washington University in Washington, D.C.
"That's a very powerful combination," added Logsdon, because it means the Soviets should be able to do something economically that the United States cannot do at all at the present time--boost giant payloads into space with a single rocket.
The Energia is similar to the Saturn 5 rockets that the United States used to send astronauts to the moon. Those powerful rockets were abandoned by the United States after the Apollo program when the National Aeronautics and Space Administration won congressional approval to make the space shuttle the nation's only access to space. That decision is now viewed by most experts as a disaster, especially in the wake of the explosion of the shuttle Challenger in January, 1986, that killed all seven crew members.
The Energia can carry a payload of about 200 tons, more than three times the maximum load that can be carried aboard the shuttle.
And it became clear during interviews here that the Soviets have big plans for their new powerhouse, including launching unmanned probes to Mars in 1992.
Leonid Kasperovich of Moscow's Space Research Institute said the Energia is designed to be separated into seven sections after burning its fuel, and each section is to descend to Earth by parachute, where it is to be recovered. The four booster rockets strapped to its side will each descend separately, and the main section of the vehicle will break into three separate parts for the return to Earth, he said.
"All the elements can be used again," Kasperovich said in an interview.
He said the vehicle will pick up speed very gradually during its ascent, despite the fact that all four boosters and the four main liquid engines will fire simultaneously, channeling their energy through 20 nozzles on the vehicle's tail.
The Soviets have fired off only one Energia so far, but Kasperovich said a second will be launched before the end of this year.
And sometime next year, he added, the Soviet Union will launch its space shuttle for the first time, although that flight will be unmanned and the entire mission will be controlled from the ground. The Soviets have not yet disclosed details about their "space plane," which is believed to be very similar to the U.S. shuttle.
The fact that the Soviets plan to use an Energia for one of their six unmanned expeditions to Mars over the next few years caused a stir among American scientists.
The Americans concluded that the 1992 mission, which will use the Energia, must have a much larger payload than the other missions, which will use the far less powerful Proton rocket.
Soviet officials insisted, however, that they are still many years away from a manned expedition to Mars, and they said that if they were to try it now, they would not hesitate to say so.
"We are open about it," Vladimir Shalatov, commander of the Soviet Union's cosmonauts, said during a discussion involving an astonishing number of 41 active and retired cosmonauts and U.S. astronauts.
Shalatov had been asked when the Soviets would consider a manned expedition to Mars.
"We make no secrets about it. We are sending probes to Mars," he said, emphasizing the word probes. A manned expedition, he suggested, is beyond the reach of any single nation.
"A project like that, in those dimensions, is a problem for all the nations of the world to do through cooperation," he said to the applause of other cosmonauts and astronauts--believed to be the largest group of international space veterans ever assembled.
The theme of cooperation in space has been prominent throughout the conference, which concludes today. At one point, Shalatov gestured toward the packed stage of space veterans and said he would like to see them "as members of a joint crew to Mars."
Although several had been invited, no top-ranking official of NASA was even present to discuss the offer. NASA sent only a middle-management delegation, contending the Soviets were exploiting the 30th anniversary of Sputnik, the first man-made satellite placed in orbit, for propaganda purposes.