Editing Vostok programme (section)

===Vanguard Six===
At the [[Gromov Flight Research Institute]], a spacecraft simulator had been built, called the ''TDK-1''. Owing to the inefficiency of training all 20 cosmonauts in the simulator, it was decided they would select six men who would go through accelerated training.<ref name=p249>Siddiqi, p.249</ref> This group, which would be known as ''The Vanguard Six'', was decided on May 30, 1960, and initially consisted of Gagarin, Kartashov, Nikolayev, Popovich, Titov, and Varlamov.<ref name=p249/> Alexei Leonov recalls that these six were the shortest of the group of 20.<ref>Burgess and Hall, p.100</ref>

In July, shortly after relocation to Star City, two of the six were replaced on medical grounds. Firstly, during a centrifuge test of 8&nbsp;[[g-force|''g'']], Kartashov experienced some internal damage, causing minor [[Bleeding|hemorrhaging]] on his back.<ref>Burgess and Hall, p.101; and Siddiqi, p.249</ref> Despite Gagarin's requests for him to stay, the doctors decided to remove Kartashov from the group of six. Later in July, Varlamov was involved in a swimming accident. During a dive into a lake near the training center, he hit his head on the bottom, displacing a [[Cervical vertebrae|cervical vertebra]].<ref>Siddiqi, p.249; for a detailed account of this incident, see Burgess and Hall, p.102-107</ref> So by the end of July, the Vanguard Six were: Gagarin, Bykovskiy, Nelyubov, Nikolayev, Popovich, and Titov.<ref name="p249"/>

By January 1961, these six had all finished parachute and recovery training, as well as three-day regimes in simulators.<ref name=p261>Siddiqi, p.261</ref> On January 17, the six participated in their final exams, including time spent in a simulator, and a written test. Based on these results, a commission, supervised by Kamanin, recommended the use of the cosmonauts in the following order: Gagarin, Titov, Nelyubov, Nikolayev, Bykovskiy, Popovich.<ref name=p261/> At this stage Gagarin was the clear favorite to be the first man in space, not only based on the exams, but also among an informal peer evaluation.<ref name=p262>Siddiqi, p.262</ref>