|Lunokhod 1 / Ye-8-LS - |
Credit: © Mark Wade. 14,787 bytes. 340 x 237 pixels.
The basic Ye-8 was deigned to soft land on the Moon and deliver an automatic, self-propelled lunar vehicle, Lunokhod, for purposes of surveying sites for later manned landings and lunar bases. It was also intended that the spacecraft would provide a radio homing beacon for precision landings of later manned spacecraft. The design had its origins in Korolevís L2 project of 1963. This evolved within OKB-1 to the globular Ye-8 of 1965 before further development of unmanned planetary spacecraft was passed to the Lavochkin bureau. There the design was refined and modified for a single launch by a Proton launch vehicle. By the time the spacecraft flew, America had won the manned moon race and mission objectives were to collect images of the lunar surface, examine ambient light levels to determine the feasibility of astronomical observations from the Moon, perform laser ranging experiments from Earth, observe solar X-rays, measure local magnetic fields, and study mechanical properties of the lunar surface material.
The lander had dual ramps by which the Lunokhod descended to the lunar surface. The lander and rover together weighed 1814 kg on the lunar surface.
The Lunokhod itself consisted of a tub-like compartment with a large convex lid on eight wheels. It stood 135 cm high, 170 cm long and 160 cm wide, with a mass of 840 kg. The 8 wheels each had an independent suspension, motor and brake. The rover had two speeds, ~1 km/hr and ~2 km/hr. Lunokhod was equipped with four TV cameras, three of them panoramic cameras. The fourth was mounted high on the rover for navigation, and could return high resolution images at different rates (3.2, 5.7, 10.9 or 21.1 seconds per frame). These images were used by a five-man team of controllers on Earth who sent driving commands to the rover in real time. Communications were through a cone-shaped omni-antenna and a highly directional helical antenna. Power was supplied by a solar panel on the inside of a round hinged lid which covered the instrument bay. A Polonium-210 isotopic heat source was used to keep the rover warm during the lunar nights. Scientific instruments included a soil mechanics tester, solar X-ray experiment, an astrophotometer to measure visible and UV light levels, a magnetometer deployed in front of the rover on the end of a 2.5 m boom, a radiometer, a photodetector (Rubin-1) for laser detection experiments, and a French-supplied laser corner-reflector. Lunokhod was designed to operate through three lunar days (three earth months) but greatly exceeded this in operation.
Total Mass: 5,590 kg.
Central Committee of the Communist Party and Council of Soviet Ministers Decree 655-268 'On Work on the Exploration of the Moon and Mastery of Space--piloted LK-1 circumlunar and L3 lunar landing projects and the Ye-6M lunar lander' was issued.
Credit: NASA. 48,079 bytes. 500 x 401 pixels.
Former Lavochkin bureau, part of Chelomei, regained status of a separate design bureau with former Korolev deputy GN Babakin as its head. By the end of 1965 all materials on the E-6, Ye-8, and planetary probes were passed by Korolev to the Lavochkin Bureau, who took over responsibility for all future lunar and planetary unmanned probes.
Central Committee of the Communist Party and Council of Soviet Ministers Decree 19-10 'On Work on Research of the Moon, Venus and Mars by Automatic Stations--work on automated lunar and interplanetary spacecraft' was issued.
Luna 17 was launched from an earth parking orbit towards the Moon and entered lunar orbit on November 15, 1970. Luna 17 landed on Moon 17 November 1970 at 03:47:00 GMT, Latitude 38.28 N, Longitude 325.00 E - Mare Imbrium (Sea of Rains). The payload, the Lunokhod 1 unmanned rover, rolled down a ramp from the landing stage and began exploring the surface. Lunokhod was intended to operate through three lunar days but actually operated for eleven lunar days (earth months). The operations of Lunokhod officially ceased on October 4, 1971, the anniversary of Sputnik 1. By then it had traveled 10,540 m and had transmitted more than 20,000 TV pictures and more than 200 TV panoramas. It had also conducted more than 500 lunar soil tests. Parameters are for lunar orbit.
|Lunokhod bus - Lunokhod bus / Ye-8-LS|
Credit: NASA. 13,827 bytes. 214 x 224 pixels.
George M. Low, Acting NASA Administrator, discussed the significance of unmanned lunar probes Luna XVI and XVII launched by the U.S.S.R. September 12 and November 10. Luna XVI had brought lunar samples back to earth and Luna XVII had landed an unmanned Lunokhod roving vehicle on the moon's surface. Low stated in a letter to Chairman Clinton P. Anderson of the Senate Committee on Aeronautical and Space Sciences that while the two launches were impressive their contributions to science and technology were relatively minor. Low suggested that the main lesson to be learned from the two launches specifically and the U.S. and U.S.S.R. space programs in general was that while the Soviet launch rate was increasing that of the United States was decreasing. These trends in the two countries' space programs should be a cause of concern if the United States was interested in maintaining a position of leadership in space.
The Proton / Block D launcher put the spacecraft into Earth parking orbit followed by translunar injection. On 12 January 1973, Luna 21 braked into a 90 x 100 km orbit about the Moon. On 13 and 14 January, the perilune was lowered to 16 km altitude. On 15 January after 40 orbits, the braking rocket was fired at 16 km altitude, and the craft went into free fall. At an altitude of 750 meters the main thrusters began firing, slowing the fall until a height of 22 meters was reached. At this point the main thrusters shut down and the secondary thrusters ignited, slowing the fall until the lander was 1.5 meters above the surface, where the engine was cut off. Landing occurred at 23:35 GMT in LeMonnier crater at 25.85 degrees N, 30.45 degrees E. The lander carried a bas relief of Lenin and the Soviet coat-of-arms. After landing, Lunokhod 2 took TV images of the surrounding area, then rolled down a ramp to the surface at 01:14 GMT on 16 January and took pictures of the Luna 21 lander and landing site. It stopped and charged batteries until 18 January, took more images of the lander and landing site, and then set out over the Moon. The rover would run during the lunar day, stopping occasionally to recharge its batteries via the solar panels. At night the rover would hibernate until the next sunrise, heated by the radioactive source. Lunokhod 2 operated for about 4 months, covered 37 km of terrain including hilly upland areas and rilles, and sent back 86 panoramic images and over 80,000 TV pictures. Many mechanical tests of the surface, laser ranging measurements, and other experiments were completed during this time. On June 4 it was announced that the program was completed, leading to speculation that the vehicle probably failed in mid-May or could not be revived after the lunar night of May-June. The Lunokhod was not left in a position such that the laser retroreflector could be used, indicating that the failure may have happened suddenly.