The launch of the US space shuttle has sparked Soviet warnings that the arms race may be going galactic -- and it has also rained on a long-planned celebration of Soviet space accomplishments.
The timing of the shuttle launch -- exactly 20 years after the Soviets orbited the world's first manned spacecraft --could hardly have been more symbolic of a renewed superpower race for space.
In the six years since the United States last launched a manned craft, the Americans has largely squatted on the sidelines. Now, to the Soviets' evident concern, they are back.
Should the reported loss of some of the shuttle's heat-resistance tiles not interfere with successful completion of the US mission April 14, Soviet commentaries suggest, Washington will have taken a potentially dangerous step toward militarizing outer space.
Some Western experts here agree. They note that the US Air Force already has reserved roughly one-third of the shuttle's first 60 or so missions. Though cargoes may include navigation, communications, weather, and surveillance satellites, observers believe the craft could play a valuable role in developing and deploying laser or particle-beam weapons capable of destroying missiles in midair.
Both the Americans and, Western analysts say, the Soviets have been exploring such a weapons system.
US officials have maintained that Moscow is also working on a shuttle program but lags considerably behind the Americans in that area.
At a news conference late last month, the director of Soviet cosmonaut-training brushed such suggestions aside, saying Moscow was satisfied that its own orbital space stations were "capable of working much longer in space."
Whatever Soviet intentions in the shuttle field are, Moscow has done little to hide its concern over the US program.
This concern was seen by diplomats here as one explanation for the flurry of Soviet space activity in recent weeks.
On March 12, the Soviets launched two cosmonauts on a linkup with the orbital space station Salyut, the sixth such Soviet station and now aloft for more than three years.
Ten days later came the latest in a series of joint flights by the USSR and allied states, this one including a Soviet and a Mongolian cosmonaut who briefly joined their two colleagues aboard the space station and then returned to earth.
Amid US focus on the shuttle mission this month, the official Soviet news media have been playing up the Soviets' own space accomplishments.
These are considerable. While the Americans launched their shuttle, the Soviets celebrated the 20th anniversary of space pioneer Yuri Gagarin's one-orbit flight in space.
The Soviets have also pioneered use of the space station, and have far outstripped the Americans in keeping their cosmonauts aloft for long periods of time -- a full 185 days in one flight last year.
Moscow can also draw on a far larger group of experienced astronauts than can the Americans, and says it has marked "2.5 times the number of man-hours spent in space."
But the Soviets lag in some technological areas, Western experts maintain. One example: Moscow has only recently perfected full computer guiding for its spacecraft.
Moscow news reports have played up setbacks in the US shuttle program and said "serious difficulties" delayed the originally scheduled April 10 launch of the craft.
The Soviets announce their own space shots only after they have taken place. Some Western diplomats argue there may, for instance, have been a technical delay in the most recent Soviet launching originally intended to take place on Mongolia's national day. It occurred several days later.
Amid tributes to the 1961 Gagarin flight, Moscow television April 12 showed a brief film clip of the US shuttle launching. The Communist Party newspaper Pravda April 13 carried a straightforward, two-paragraph account of the launching. But both reports were followed by a longer commentary stressing the fundamentally "military" nature of the shuttle program.