Unlike the American Shuttle, and like Soyuz, Shenzhou is equipped with a launch escape tower, which can pull the crew capsule away from the booster in case of a failure or explosion. Such an escape system has saved Russian Soyuz crews on one occasion over the years (Soyuz T-10-1). But there are many other dangers for an astronaut in a Soyuz-type spacecraft. There can be a launch booster failure after the escape tower has separated (Soyuz 18-1 - but as with the Soyuz, Shenzhou has a method of escaping in such a situation). During the landing sequence, there can be failure of the retrorockets (Salyut 6 EP-5-1 - but this is supposed to be survivable aboard Soyuz or Shenzhou due to shock absorbers in the crew seats), depressurisation of the capsule (Soyuz 11 - but the Shenzhou crew will use space suits to protect them in case of such an event and the crew can even eat while in their suits), failure of the service module to jettison (Soyuz 5 - but the Soyuz design proved itself to barely allow survival of the crew member in such an event), failure of the guidance system (ISS EP-4 - meaning an 11 G but survivable re-entry on Shenzhou), failure of the parachute system to deploy (Soyuz 1 - but Shenzhou has air bags to force the parachutes out of their containers), or landing in remote or rough terrain (Soyuz 23, Soyuz 18-1). A most serious problem would be uncommanded separation of the heat shield in orbit, a problem inherent in the Mercury, Soyuz, and Shenzhou designs (Mercury MA-6). But the cause of any future disaster is always the combination of circumstances that one has not foreseen…
Project 921 Phase 3, involving orbiting of a 20-tonne Space Station, will not occur until after 2010. Will China begin operations of a permanently-inhabited space station just as Europe and America abandon the International Space Station? An interesting scenario…