Zond 4
| Launch Date | Mar. 2, 1968 |
| Launch Site | Baikonur Cosmodrome, Kazakhstan, Russia | Launch Site 81L |
| Destination | Solar System (Earth’s Moon Test) |
| Type | Flyby (Deep Space) |
| Status | Unsuccessful |
| Nation | Soviet Union |
| Alternate Names | 1968-013A, 03134 |
Goals
To flight-test a vacant 2-person spacecraft in preparation for sending cosmonauts to the Moon and back. It may also have been intended to investigate near-Earth space.
Accomplishments
It flew about 300,000 to 350,000 km from Earth in the direction opposite that of the Moon, possibly to avoid the Moon's gravitational influence, but possibly because of a malfunction in the attitude-control system. It returned to Earth but was deliberately destroyed about 10 km over the Gulf of Guinea when a system malfunctioned.
Key Dates
Mar. 2, 1968: Launch
In Depth
The Soviets decided to send this next 7K-L1 spacecraft, not on a circumlunar flight, but about 330,000 kilometers into deep space in the opposite direction of the Moon in order to test the main spacecraft systems without the perturbing effects of the Moon (much like the Surveyor model test flights in 1965 and 1966).
The spacecraft was successfully boosted on its trajectory and reached an apogee of 354,000 kilometers. During the flight, although a key attitude-control sensor worked only intermittently, controllers managed to aim the spacecraft for a guided reentry back into Earth's atmosphere. Unfortunately, the same sensor failed at reentry, preventing the vehicle from maintaining stable orientation. Instead, Zond 4 began to carry out a direct ballistic reentry for landing in the Indian Ocean. An emergency destruct system, however, destroyed the returning capsule over the Gulf of Guinea to prevent foreign observers from recovering the wayward spacecraft.
Spacecraft
Launch Vehicle: 8K82K + Blok D (Proton-K no. 232-01)
Spacecraft Mass: About 5,375 kg
Spacecraft Instruments: Unknown
Spacecraft Dimensions: Cylindrical capsule approx. 4.5 m in length and 2.2 to 2.72 m in diameter, with 2 solar panels on opposite sides of the body spanning a total of about 9 m
Spacecraft Power: Solar panels
Additional Resources
Selected References
Siddiqi, Asif A. Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, NASA, 2002.
