Cosmos 111

Description

This mission was intended to orbit the Moon, and was configured identically to the later Luna 10 mission (1966-027A). It was launched on 1 March 1966 at 11:03:49 UT into Earth parking orbit, but the Blok-L upper stage lost roll control and failed to fire the spacecraft into a lunar trajectory. It was designated Cosmos 111 and reentered two days after launch.

Spacecraft and Subsystems

Cosmos 111 was designated a Ye-6S spacecraft, consisting of a Ye-6 bus attached to a cylindrical pressurized 245 kg lunar orbiter module. The module was probably taken from the Cosmos Earth-orbiting series. It was 1.5 meters tall and 75 cm in diameter at the base. The main propulsion systems for lunar orbit insertion were on the bus, and the science payload was carried on the orbiter module. The payload comprised seven instruments: a gamma-ray spectrometer for energies between 0.3--3 MeV, a triaxial magnetometer (on the end of a 1.5 meter boom), a piezoelectric micrometeoroid detector, instruments for solar-plasma studies, devices for measuring infrared emissions from the Moon, low energy X-ray detectors, and a bank of charged particle detectors. Additionally, the radio system could be used for gravitational and radio occultation studies. The lunar orbiting module was battery powered and communications were via 183 MHz and 922 MHz aerials.

Beginning in 1962, the name Cosmos was given to Soviet spacecraft which remained in Earth orbit, regardless of whether that was their intended final destination. The designation of this mission as an intended planetary probe is based on evidence from Soviet and non-Soviet sources and historical documents. Typically Soviet planetary missions were initially put into an Earth parking orbit as a launch platform with a rocket engine and attached probe. The probes were then launched toward their targets with an engine burn with a duration of roughly 4 minutes. If the engine misfired or the burn was not completed, the probes would be left in Earth orbit and given a Cosmos designation.