Luna 9 (Луна-9), internal designation Ye-6 No.13, was an uncrewed space mission of the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...

Luna programme The Luna programme (from the Russian word "Luna" meaning "Moon"), occasionally called ''Lunik'' by western media, was a series of robotic spacecraft missions sent to the Moon by the Soviet Union between 1959 and 1976. Fifteen were successful, ...

. 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 entity, association, or structure that exists in the observable universe. In astronomy, the terms ''object'' and ''body'' are often us ...

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 A hermetic seal is any type of sealing that makes a given object airtight (preventing the passage of air, oxygen, or other gases). The term originally applied to airtight glass containers, but as technology advanced it applied to a larger categor ...

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 Sergei Pavlovich Korolev (russian: Сергей Павлович Королёв, Sergey Pavlovich Korolyov, sʲɪrˈɡʲej ˈpavləvʲɪtɕ kərɐˈlʲɵf, Ru-Sergei Pavlovich Korolev.ogg; ukr, Сергій Павлович Корольов, ...

(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 NPO Lavochkin (russian: НПО Лавочкина, OKB-301, also called Lavochkin Research and Production Association or shortly Lavochkin Association, LA) is a Russian aerospace company. It is a major player in the Russian space program, being th ...

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

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 ''Baiqoñyr ğaryş ailağy'' rus, Космодром Байконур''Kosmodrom Baykonur'' , image = Baikonur Cosmodrome Soyuz launch pad.jpg , caption = The Baikonur Cosmodrome's "Gagarin's Start" Soyuz ...

in the

Kazakh Soviet Socialist Republic ; kk, Қазақ Советтік Социалистік Республикасы) *1991: Republic of Kazakhstan (russian: Республика Казахстан; kk, Қазақстан Республикасы) , linking_name = the ...

. 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 A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never m ...

, at an altitude of and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Ea ...

of 51.8°. The fourth stage, a Blok-L, then fired to raise the

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any el ...

of the orbit to a new

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any el ...

approximately , before deploying ''Luna 9'' into a highly elliptical

geocentric orbit A geocentric orbit or Earth orbit involves any object orbiting Earth, such as the Moon or artificial satellites. In 1997, NASA estimated there were approximately 2,465 artificial satellite payloads orbiting Earth and 6,216 pieces of space debri ...

. 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 Delta-''v'' (more known as " change in velocity"), symbolized as ∆''v'' and pronounced ''delta-vee'', as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such a ...

of .

Descent and landing

At an altitude of from the Moon, the spacecraft was oriented for the firing of its

retrorocket A retrorocket (short for ''retrograde rocket'') is a rocket engine providing thrust opposing the motion of a vehicle, thereby causing it to decelerate. They have mostly been used in spacecraft, with more limited use in short-runway aircraft land ...

s 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 A radar altimeter (RA), also called a radio altimeter (RALT), electronic altimeter, reflection altimeter, or low-range radio altimeter (LRRA), measures altitude above the terrain presently beneath an aircraft or spacecraft by timing how long it t ...

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 Oceanus Procellarum ( la, Ōceanus procellārum, lit=Ocean of Storms) is a vast lunar mare on the western edge of the near side of the Moon. It is the only one of the lunar maria to be called an "Oceanus" (ocean), due to its size: Oceanus Proc ...

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

, 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 Jodrell Bank Observatory () in Cheshire, England, hosts a number of radio telescopes as part of the Jodrell Bank Centre for Astrophysics at the University of Manchester. The observatory was established in 1945 by Bernard Lovell, a radio astro ...

in England, which was monitoring the craft, noticed that the signal format used was identical to the internationally agreed

Radiofax Radiofacsimile, radiofax or HF fax is an analogue mode for transmitting monochrome images via high frequency (HF) radio waves. It was the predecessor to slow-scan television (SSTV). It was the primary method of sending photographs from remote s ...

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 ...

'' 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; 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