(2 of 4)
Otherwise, the descent seemed to be continuing normally. "After aerodynamic braking in the atmosphere," reported Tass, "the parachute system was put into action and, before landing, the soft-landing engines were fired. The flight of the descending apparatus ended in a smooth landing in the preset area." These operations, however, were automatic; they did not require cooperation from the crew. Western experts speculated that whatever went wrong with Soyuz 11 occurred either during or soon after the firing of its retrorocket.
Through telemetry from the spacecraft, the Russians may well have detected a failure aboard Soyuz—or even the moment of death. But except to say that the cosmonauts' deaths were being investigated by a government commission. Soviet space officials gave no explanation of the disaster.
Penguin Suits
The record length of the Soyuz 11 mission—six days longer than any previous manned space flight—led to theorizing that the cosmonauts had exceeded man's natural limits in space. The Russians themselves had invited such speculation by repeatedly stressing the debilitating effects of weightlessness on the human body: loss of body fluids, loss of calcium from the bones, loss of heart and muscle tone. Cosmonauts Andrian Nikolayev and Vitaly Sevastyanov, for example, complained that they did not fully recover from their 17-day orbital mission aboard Soyuz 9 last year for more than a week.
Medical experts conceded that weightlessness could have played a part in the deaths, but they had doubts that the hearts of three men with different physiologies would fail simultaneously. They also pointed out that at no time during the long mission did the cosmonauts complain of any harsh reaction to zero gravity. In fact, they had spent long hours on board in their so-called "Penguin" exercise suits—tight, elastic garments designed to exert muscle-toning pressure on the body. Besides, the experience of America's astronauts seemed to demonstrate that the human body can readjust after prolonged weightlessness.
Mechanical Failure
NASA's Deputy Director George Low and most other space specialists leaned to a far simpler explanation for the deaths: a mechanical or structural failure aboard Soyuz. Because the cosmonauts were not in protective pressure suits at the time of the descent, they could have died from any number of causes—excessive heat, carbon dioxide fumes from a small fire, a nitrogen leak from the spacecraft's atmosphere system, or even a rapid drop in cabin pressure. Such theories got support from some unconfirmed reports that all radio transmissions—not only voice but also telemetry signals—stopped at the end of the braking maneuver. In fact, most speculation centered on a failure in the oxygen supply. That was based largely on the Moscow rumor that the recovery team had noted serene expressions on the faces of the cosmonauts. Such apparent composure is characteristic of hypoxia, a lack of oxygen that can lead to quick and relatively painless death.