Luna 9 (Луна-9), internal designation Ye-6 No.13, was an

uncrewed space mission Spaceflight (or space flight) is an application of astronautics to fly spacecraft into or through outer space, either with or without humans on board. Most spaceflight is uncrewed and conducted mainly with spacecraft such as satellites in or ...

of the Soviet Union's Luna programme. On 3 February 1966, the Luna 9 spacecraft became the first spacecraft to achieve a survivable landing on a

celestial body An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical object, physical entity, association, or structure that exists in the observable universe. In astronomy, the terms ''object'' and ''bod ...

Spacecraft

The lander had a mass of and consisted of a spheroid ALS capsule measuring . It used a landing bag to survive the impact speed of . It was a hermetically sealed container with radio equipment, a program timing device, heat control systems, scientific apparatus, power sources, and a television system. The spacecraft was developed in the design bureau then known as

OKB-1 PAO S. P. Korolev Rocket and Space Corporation Energia (russian: Ракетно-космическая корпорация «Энергия» им. С. П. Королёва, Raketno-kosmicheskaya korporatsiya "Energiya" im. S. P. Korolyov ...

, under Chief Designer Sergei Korolev (who had died before the launch). The first 11 Luna missions were unsuccessful for a variety of reasons. At that time the project was transferred to Lavochkin design bureau since OKB-1 was busy with a human expedition to the Moon. ''Luna 9'' was the twelfth attempt at a soft-landing by the Soviet Union; it was also the first successful deep space probe built by the Lavochkin design bureau, which ultimately would design and build almost all Soviet (later Russian) lunar and interplanetary spacecraft.

Launch and translunar coast

''Luna 9'' was launched by a Molniya-M rocket, serial number 103-32, flying from Site 31/6 at the

Baikonur Cosmodrome The Baikonur Cosmodrome ( kk, Байқоңыр ғарыш айлағы, translit=Baiqoñyr ğaryş ailağy, ; russian: Космодром Байконур, translit=Kosmodrom Baykonur, ) is a spaceport in an area of southern Kazakhstan leased to R ...

in the Kazakh Soviet Socialist Republic. Liftoff took place at 11:41:37 GMT on 31 January 1966. The first three stages of the four-stage carrier rocket injected the payload and fourth stage into low Earth orbit, at an altitude of and an inclination of 51.8°. The fourth stage, a Blok-L, then fired to raise the perigee of the orbit to a new apogee approximately , before deploying ''Luna 9'' into a highly elliptical geocentric orbit. For thermal control, the spacecraft then spun itself up to 0.67 rpm using nitrogen jets. On 1 February at 19:29 GMT, a mid-course correction took place involving a 48-second burn and resulting in a delta-v of .

Descent and landing

At an altitude of from the Moon, the spacecraft was oriented for the firing of its retrorockets and its spin was stopped in preparation for landing. From this moment the orientation of the spacecraft was supported by measurements of directions to the Sun and the Earth using an optomechanical system. At above the lunar surface, the radar altimeter triggered the jettison of the side modules, the inflation of the airbags and the firing of the retro rockets. At from the surface, the main retrorocket was turned off by the integrator of an acceleration having reached the planned velocity of the braking manoeuver. The four outrigger engines were used to slow the craft. About above the lunar surface, a contact sensor touched the ground triggering the engines to be shut down and the landing capsule to be ejected. The craft landed at . The spacecraft bounced several times before coming to rest in Oceanus Procellarum west of Reiner and Marius craters at approximately 7.08 N, 64.37 W (other sources indicate ) on 3 February 1966 at 18:45:30 GMT.

Surface operations

left, Luna 9 lander model The first photo ever taken from the surface of the Moon. Approximately 250 seconds after landing in the Oceanus Procellarum, four petals that covered the top half of the spacecraft opened outward for increased stability. Seven hours after (to allow for the Sun to climb to 7° elevation) the probe began sending the first of nine images (including five panoramas) of the surface of the Moon. Seven radio sessions with a total of 8 hours and 5 minutes were transmitted, as well as three series of TV pictures. After assembly the photographs gave a panoramic view of the immediate lunar surface, comprising views of nearby rocks and of the horizon, away. The pictures from ''Luna 9'' were not released immediately by the Soviet authorities, but scientists at Jodrell Bank Observatory in England, which was monitoring the craft, noticed that the signal format used was identical to the internationally agreed Radiofax system used by newspapers for transmitting pictures. The ''

Daily Express The ''Daily Express'' is a national daily United Kingdom middle-market newspaper printed in tabloid format. Published in London, it is the flagship of Express Newspapers, owned by publisher Reach plc. It was first published as a broadsheet i ...

'' rushed a suitable receiver to the Observatory and the pictures from ''Luna 9'' were decoded and published worldwide. The BBC speculated that the spacecraft's designers deliberately fitted the probe with equipment conforming to the standard, to enable reception of the pictures by Jodrell Bank Observatory. The radiation detector, the only dedicated scientific instrument on board, measured dosage of 30 millirads (0.3 milligrays) per day.NSSDCA ID: 1966-006A-02
/ref> The mission also determined that a spacecraft would not sink into the

lunar dust Lunar soil is the grain size, fine fraction of the regolith found on the selenography, surface of the Moon. Its properties can differ significantly from those of Soil, terrestrial soil. The physical properties of lunar soil are primarily the r ...

; that the ground could support a lander. The last contact with the spacecraft was at 22:55 GMT on 6 February 1966.

Sources

External links