Vostok rocket

The Vostok rocket (Russian Восток, translated as "East") was a derivative of the Soviet R-7 ICBM designed for the human spaceflight programme but later used for other satellite launches.

The major versions of the rocket were:

• 8K72 - used to launch the prototype Vostok spacecraft
• 8K72K - a refined version of the above. This was the version actually used for human spaceflight
• 8A92 - used for launching Zenit spy satellites throughout the 1960s
• 8A92M - modified version for launching Meteor weather satellites into high orbits.

On March 18, 1980 a Vostok-2M rocket exploded on its launch pad at Plesetsk during a fueling operation, killing 48. An investigation into a similar -- but avoided -- accident revealed that the substitution of lead-based for tin-based solder in hydrogen peroxide filters had resulted in the breakdown of the H2O2 and the resulting explosion.