PHOTO: NASA

7 May 2008—What should have been a routine return from the International Space Station (ISS) on 19 April 2008 quickly turned into a heart-stopping drama for ground controllers and the three astronauts aboard a Soyuz TMA-11. The craft had disappeared during the descent and was then found on a scorched steppe some 400 kilometers from where it was supposed to land. Now the incident is a technological puzzle to space engineers and a potential political challenge to the international partnership behind the ISS.

Although the technical investigation will take weeks to resolve, NASA and Russian engineers have come to several credible preliminary conclusions. And internal NASA documents, such as “15S Ballistic Entry Outbrief” by George Kafka, chief of the Safety & Mission Assurance Directorate for the ISS program, reveal a plausible idea of what probably happened.

During the landing, space officials at mission control in Moscow and at the recovery site seriously worried for at least half an hour—and some even believed, briefly, that the crew had been killed. The landing seemed to be a replay of a near disaster from almost 40 years ago, and it threatened to have the first Russian in-flight fatalities since 1971.

Although the officials’ worries soon turned out to be ill-founded, an examination of the craft’s flight path indicates that catastrophe had not been far off. Total disaster was avoided not by any real-time actions of the crew or ground teams but instead by the ingenious design and robust construction of the spacecraft.