We cannot rule this out, but it seems very unlikely to me. The more I read about it, the less likely it seems.<p>- Laika was launched aboard Sputnik 2 in October 1957<p>- Gagarin on Vostok 1 in April 1961<p>Sputnik 2 was much lighter than the Vostok capsule (500 kg vs. 2,500 kg) and did not feature any re-entry apparatus. In just 3.5 years, the Soviets had to improve their carrier rocket and develop a man-rated capsule with a heat-shield and braking system, a guidance system and had to improve the whole life-support system.<p>We know they launched dogs on the Vostok in Dec. 1960, so it is unlikely they&#x27;d launch a cosmonaut in the time before. So the time-span between the end of 1960 and April 1961 seems like the only time they could have lost cosmonauts. That just does not seem that much time and I have a hard time believing they managed to lose <i>two</i> cosmonauts in four months.<p>After the death of Komarov in April 1967, they took 1.5 years to fix their design till the launch of Soyuz 2. Likewise, they needed 2+ years after the Soyuz 11 tragedy to launch again. I don&#x27;t believe they would have just launched a couple of cosmonauts nilly-willy after a deadly accident.