To The Moon and Back
The Zond series was a line of unmanned Soviet spacecraft that were designed to be capable of interplanetary flight, deployed by the Soviet Union from 1964 to 1970. The first prototype Zonds (not truly part of the Zond series) were used in conjunction with Sputnik 7 and 8 in 1961, attempting to launch space probes to Venus from an Earth orbital platform. The Zond program did not have a designated target, and included flights to Venus, Mars and the Moon. Indeed, one Zond rocket became the first human spacecraft to ever successfully make a flight to the Moon and back. All the Zond craft were launched from orbital platforms that in turn were launched from Baikonur Cosmodrome.
Zond 1 (April 2nd, 1964)
Zond 1, a 890 kg rocket carrying scientific instruments, was launched towards Venus, although its announced mission objective was simply to perform a test of its onboard systems. Unfortunately, all communication with the craft was lost after May 14th, 1964, leaving it completely silent as it flew by Venus on July 14th. It then entered an orbit around the Sun, where it is presumably still orbiting.
Zond 2 (November 30th, 1964)
The successor to Zond 1 was mostly similar to its predecessor, except for a few adjustments and improvements to the probe itself. It had the same dry mass as Zond 1, 890 kg. It was launched towards Mars to carry out various investigations of the red planet. Zond 2 carried a descent craft and the same instruments as the older Soviet Mars 1 flyby craft: A magnetometer, photographic equipment, a spectroreflectometer, radiation sensors, a spectrograph and a micrometeoroid instrument. The craft carried experimental low-thrust electrojet plasma ion engines that could be used instead of the gasoline-driven engines to maintain orientation. It was powered by dual solar panels. Unfortunately, one of the solar panels failed, and the craft lost its communications subsystem in May 1965, leaving it silent as it flew by Mars on the 6th of August the same year. Its experimental orientation jets were successfully tested, and while its Mars mission failed, it provided a precious boost to Soviet rocket science.
Zond 3 (July 18th, 1965)
A heavier, more advanced Zond, the 960 kg Zond 3 was launched so that it would fly by the Moon and continue into interplanetary space. Its primary instruments consisted of a camera and TV system that allowed it to perform automated film processing before sending pictures back to Earth. On the 20th of July 1965, it took 25 pictures (described by both Baikonur and NASA astronomers as "very good quality") of the Moon, covering approximately 19,000,000 square kilometers of lunar surface. It continued exploration after flying by the moon, achieving a heliocentric orbit. It still occasionally broadcasts signals back to Earth (from a distance equivalent to Mars' orbit), although judging from the current state of affairs in Russia, it's a safe bet that nobody's listening anymore....
Zond 4 (2nd March, 1968)
A much larger and heavier Zond, this 5.1 ton giant was primarily intended as a test flight for some new, experimental Soviet systems and instruments. It was launched in an opposite direction from the Moon, to avoid giving it complications due to lunar gravity. Its new instrumentation included proton detectors, and one of its purposes was an attempt to detect particle matter in space. It was intended to return to Earth using a skip re-entry, although an error in its attitude control system caused it to enter at a too steep angle, entering the atmosphere at dangerously high speeds, headed towards impact in West Africa. Baikonur set off its self-destruct mechanism over the Gulf of Guinea at an altitude of 10 kilometers, and it exploded without any ground casualties.
Zond 5 (September 15th, 1968)
Slightly larger than Zond 4, this probe weighed approximately 200 kilograms more than its predecessor. It served two purposes, primarily it was supposed to fly to the Moon and make a successful return flight, and secondly it was to test the effects of long space flight on Earth life. It carried a payload of turtles, wine flies, mealworms, and various plants, seeds and bacteria. It successfully performed a flight around the moon on September 18th, and returned to the Earth on September 21st, both in 1968. Its re-entry capsule landed as planned in the Indian Ocean and was successfully recovered. The turtles had lost about 10% body weight, but had suffered no loss of appetite. Zond 5 had the prestige of becoming the first Earth spacecraft to fly to the moon and actually come back, and in related news, scaly critters around the world spoke (or, hissed and performed creative colour changes, I guess) in hushed tones of the legendary first reptiles in space carried by this flight.
Zond 6 (November 10th, 1968)
Similar in weight and size to Zond 5, Zond 6 was a lunar flyby mission, carrying scientific probes intended to monitor micrometeoroids and cosmic rays. It was intended as a precursor to Soviet manned long space flight, and carried a similar biological payload as its predecessor. It took high quality pictures of the dark side of the moon, and returned to Earth on November 17th, 1968. It landed in the Soviet Union, and tested an experimental landing technology employing gliding, airbrakes and aerodynamic updraft. Its ground landing went according to plan.
Zond 7 (August 8th, 1969)
Some of the steam of the Soviet Zond program had been taken out by the successful US lunar landing performed by the Apollo 11 astronauts on the 20th of July the same year. Apollo 11 ended a long-standing Soviet record-breaking streak, including first man-made satellite, first living creature in space, first successful space return flight, first man in space, first woman in space and first space flight with more than one human crewmember. The 5979 kg Zond 7 was mainly a photographic vessel, and brought back the first Soviet color photographies of Earth and the Moon, taken one day after its launch. Zond 7 conducted two automated picture taking sessions of the Moon on August 11th, and re-entered the Earth atmosphere on August 14th, 1969. It achieved a soft landing in the Soviet Union, utilizing the same landing technology as Zond 6.
Zond 8 (October 20th, 1970)
The last vessel in the Zond program, the 5375 kg Zond 8 took pictures of the moon and performed some tests of new Soviet space technology (including some crude miniaturization of instruments and systems on earlier Zond flights, hence the slightly lighter weight). It re-entered Earth atmosphere on October 27th, 1970 after a successful flight to the Moon and a three day photo survey of the Earth, landing in the Indian Ocean from where it was successfully recovered.
After the Zond project was discontinued, some of the technology developed during its lifetime was included in the Soviet Union's more advanced, manned Soyuz spaceships.
- Lademanns Astronomi Leksikon, ISBN 87-15-07429-3