Soyuz abort modes: Difference between revisions

The Soyuz abort systems are especially complicated because of the modular design of the vehicle; only the middle lander module is designed to survive reentry, so in an emergency the utility module and the lander module must be separated together (sometimes with the service module also attached) before the lander can be separated and orient itself for reentry. Other sovietSoviet spacecraft, like the [[TKS (spacecraft)|TKS]], attempted similar modular designs with a hatch through the heat shield to resolve this issue.<ref name="astronautix">{{cite web|title=Soyuz|url=http://www.astronautix.com/fam/soyuz.htm|website=Encyclopedia Astronautica|publisher=www.astronautix.com|accessdate=3 May 2016}}</ref> The modular design also means that the Soyuz capsule is contained within a [[payload shroud]] for much of the flight and removing the shroud without collision in an emergency was another difficult issue that needed to be addressed.<ref name = zak/>

In early Soyuz models there were two abort modes in the time ranging from the ejection of the launch escape system until orbit. One called for separation of only the upper two modules and a controlled descent and could be initiated before about t+522s, the other separated all three and underwent a ballistic descent after tT+522.<ref name = 'hall & shayler'>{{cite book|last1=Hall|first1=Rex|last2=Shayler|first2=David J.|title=Soyuz: A Universal Spacecraft|date=2003|publisher=Praxis Publishing Ltd.|location=Chichester, UK|isbn=1-85233-657-9|page=70|url=https://books.google.com/books?id=dbGchpi1HP8C&pg=PA67#v=onepage&q&f=false|accessdate=3 May 2016}}</ref>