Luna 13

Goals: Luna 13 was to land on Moon and characterize the lunar surface.

Accomplishments: Like January's Luna 9, December's Luna 13 came to a rough but survivable landing in the Ocean of Storms region of the Moon. The scientific capsule was ejected less than one second before the main spacecraft crashed at 30 km/h. Equipped with instruments its predecessor did not carry, Luna 13 not only returned 5 panoramic photos of the landscape at different sun angles, but also measured the soil's physical and mechanical properties and its radiation characteristics. One of the two cameras intended to create stereo images failed, but the pictures the working camera provided were good.

21 Dec 1966: Launch

Mission Type: Lander
Launch Vehicle: Modified SS-6 (Sapwood) with second-generation upper stage + escape stage; 8K78M (no. N103-45)
Launch Site: Tyuratam (Baikonur Cosmodrome), USSR; NIIP-5 / launch site 1
Spacecraft Mass: 1,620 kg at launch, 112 kg surface capsule
Spacecraft Instruments: 1) TV cameras; 2) infrared radiometer; 3) penetrometer; 4) radiation densitometer; and 5) radiation detector
References:
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi

National Space Science Data Center, http://nssdc.gsfc.nasa.gov/

Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.

Luna 13 became the second Soviet spacecraft to successfully soft-land on the surface of the Moon. The probe landed in the Ocean of Storms at 18:01 UT on 24 December 1966, between the Krafft and Seleucus craters at 18°52' north latitude and 62°3' west longitude.

Unlike its predecessor, the heavier Luna 13 lander (113 kilograms) carried a suite of scientific instruments in addition to the usual imaging system. A three-axis accelerometer within the pressurized frame of the lander recorded the landing forces during impact to determine the soil structure down to a depth of 20 to 30 centimeters. A pair of spring-loaded booms was also deployed. Both were equipped with titanium-tipped rods that were driven into the ground with a powerful force by small explosive charges to measure soil density (found at roughly 0.8 grams per cubic centimeter).

Four radiometers recorded infrared radiation from the surface, indicating a noon temperature of about 117°C, while a radiation detector indicated that radiation levels would be less than hazardous for humans. The lander returned a total of five panoramas of the lunar surface, showing a smoother terrain than seen by Luna 9.

One of the two cameras (intended to return stereo images) failed, but this did not diminish the quality of the photographs. After a fully successful mission, contact was lost at 06:13 UT on 28 December when the onboard batteries were exhausted.

- Credit: NASA