An analysis of the flight of Vostok
Purpose of the article
The purpose of this article is to summarize new facts about the flight of Vostok to see if this new information gives a new perspective on the flight. The location of both the VHF and HF ground stations are now known. They can be compared with in-flight voice contact transcripts. The text of the de-briefing of Gagarin after the flight is also available and provides interesting information. I have tried to give a synoptic view of how the flight proceeded by using an annotated map of the ground track. An attempt to understand the attitude control system of Vostok is also made.
Tracking stations used for the flight
We now know the locations of tracking stations and ground communications stations for the Vostok flights and the Sputnik test flights proceeding them. The communications system with Vostok was based on VHF communications (143.625 MHz) but also on short-wave communications using strong transmitters belonging to the USSR Ministry of Communications.( Collapse )
The dependence on HF was necessary, because the Soviet Union did not yet possess an ocean-going fleet of tracking ships. In particular for the Vostok flight, the spacecraft flew over water from the moment it left Soviet territory until retro-fire, so even if there had been VHF ground stations on foreign soil, they would not have helped, and the lack of tracking ships therefore forced the use of HF. As we shall see below, the HF system worked, but perhaps not brilliantly.
Part of our knowledge of the location of ground stations for the Vostok series is based on General Kamanin's diary (1) in which we can read for 6 March 1961:
"...the commission accepted my proposal about the organization of control points for the flight in Moscow (TsPUP), Tyura-Tam, Novosibirsk, Kolpashevo, Khabarovsk and Yelizovo (Kamchatka). Moscow will have shortwaves and VHF communications with the spacecraft (if it makes more than one orbit), Tyura-Tam, Kolpashevo and Yelizovo will have VHF only, but Novosibirsk and Khabarovsk only shortwaves. Radius of contact for shortwaves is 5000 km and 1500 km for VHF. These radii thus far have not been practically checked and it is not yet certain that communications will be reliable, especially during the phase between launch and orbital insertion. At every KP (Command Point) there will be a KP chief, a communications officer, a cosmonaut, a doctor and a representative of the Ministry of Communications. ..."( Collapse )