Every Soviet and Russian manned spaceflight from Yuri Gagarin through 2002 contained the “Globus” IMP you see above. IMP is an acronym derived from the Russian term for “indicator of position in flight”. It’s purpose was to convey the spacecraft’s position relative to the Earth. However, it also transmitted its data to other systems, notably the attitude control system.
Several versions were created, with the 3rd version, which flew on the Voskhod spacecraft, being the one about which the most is known. Shortly before launch, the latitude and longitude at which the spacecraft was expected to enter orbit would be entered in using the two indicators at the top. Once the orbit was established, ground stations would measure the actual position of the spacecraft and the Globus settings would be corrected using the inner and outer black knobs. This process was repeated at regular frequencies to maintain an accurate position of the spacecraft. Once the corrected orbit was entered after launch, the activation switch on the side was turned on and the computer would continuously update the latitude, longitude and globe positions using the impulses from the flight sequencer computer converted into an analog signal then converted into mechanical movement. It would also update the orbits counter, with completed orbits shown in white and the partial orbit in red.
A variable resistor and cam-activated electric contacts would send the proper signals to other systems through out the spacecraft. Therefore, you had a nearly purely mechanical computer sending electrical signals to electronic computers, thus creating a sort of network. By 1960s technology, this was ingenious and, probably, what helped this system stick around for 40 years.
While preparing to de-orbit, the crew would monitor the automatic de-orbit process and could “fast forward” 120 degrees to see the anticipated landing site. Should that be off, or should something fail with the automatic system, the crew could take manual control and use the Globus as their “window” on where the were headed on planet Earth.
It’s an impressive system, made all the more impressive by its longevity of use. I guess if it ain’t broke, why fix it?
[Image Credit: François Guay]