View source for Luna 16

{{short description|Soviet space probe}}
{{Use dmy dates|date=May 2020|cs1-dates=ly}}
{{italic title}}
{{Infobox spaceflight
| name                   = ''Luna 16''
| image                  = Luna 16.jpg
| image_caption          = ''Luna 16''

| mission_type           = [[Planetary science|Lunar sample return]]
| operator               = Soviet space program
| COSPAR_ID              = 1970-072A
| SATCAT                 = 4527
| mission_duration       = 12&nbsp;days

| spacecraft_bus         = [[Ye-8-5]]
| manufacturer           = [[Lavochkin|GSMZ Lavochkin]]
| launch_mass            = {{Convert|5725|kg|abbr=on}}<ref name=beyond>{{cite book|url=https://www.nasa.gov/sites/default/files/atoms/files/beyond-earth-tagged.pdf|title=Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016|last1=Siddiqi|first1=Asif|publisher=NASA History Program Office|edition=second|year=2018|isbn=9781626830431}}</ref>
| landing_mass            = {{Convert|1880|kg|abbr=on}} <ref name=Wilson>Solar System Log by Andrew Wilson (pp.60–63), Jane's Publishing Company Limited, 1987, {{ISBN|0 7106 0444 0}}</ref>
| launch_date            = {{start-date|12 September 1970, 13:25:52|timezone=yes}}&nbsp;UTC<ref name=beyond/>
| launch_rocket          = [[Proton-K]]/[[Blok D|D]]
| launch_site            = [[Baikonur Cosmodrome|Baikonur]] [[Baikonur Cosmodrome Site 81|81/23]]
| launch_contractor      =

| landing_date           = {{end-date|24 September 1970, 05:25|timezone=yes}}&nbsp;UTC
| landing_site           = {{coords|47|24|N|68|36|E}}<ref>{{Cite web|url=http://epizodsspace.airbase.ru/bibl/inostr-yazyki/sov-luna/sovets-luna.pdf |archive-url=https://web.archive.org/web/20190729155018/http://epizodsspace.airbase.ru/bibl/inostr-yazyki/sov-luna/sovets-luna.pdf |archive-date=2019-07-29 |url-status=live|title=Soviet and Russian Lunar Exploration|page=314}}</ref>

| orbit_epoch            = 18 September 1970
| orbit_reference        = [[Selenocentric orbit|Selenocentric]]
| orbit_regime           = 
| orbit_periapsis        = {{Convert|111|km|abbr=on}}
| orbit_apoapsis         = {{Convert|111|km|abbr=on}}
| orbit_inclination      = 70°
| orbit_semimajor        = {{Convert|6488.8|km|abbr=on}}
| orbit_eccentricity     = 0 
| orbit_period           = 119&nbsp;minutes
| apsis                  = selene

| interplanetary         = {{Infobox spaceflight/IP
 | type             = orbiter
 | object           = [[Moon|Lunar]]
 | orbits           = ~36
 | arrival_date     = 17 September 1970
}} {{Infobox spaceflight/IP
 | type             = lander
 | object           = Lunar
 | arrival_date     = 20 September 1970, 05:18&nbsp;UTC
 | departure_date   = 21 September 1970, 07:43&nbsp;UTC
 | location         = {{coords|0.5137|S|56.3638|E|globe:moon|display=inline,title|format=dec}}
 | sample_mass      = {{convert|101|g|oz}}
}}

| instruments            = Stereo photographic imaging system<br/>Remote arm for sample collection<br/>Radiation detector
| programme          = '''[[Luna programme]]'''
| previous_mission   = ''[[Luna E-8-5 No.405|Luna 1970A]]''
| next_mission       = [[Luna 17]]
}}

'''''Luna 16''''' was an [[uncrewed space mission|uncrewed 1970 space mission]], part of the [[Soviet Union|Soviet]] [[Luna program]]. It was the first [[robot]]ic probe to land on the [[Moon]] and return a sample of [[lunar soil]] to Earth.<ref>{{cite book |last=Burrows |first=William E. |title=This New Ocean: The Story of the First Space Age |year=1999 |publisher=[[Modern Library]] | pages=432 |isbn=0-375-75485-7}}</ref><ref>{{cite book|url=https://www.nasa.gov/sites/default/files/atoms/files/beyond-earth-tagged.pdf|title=Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016|page=1|last1=Siddiqi|first1=Asif A.|lccn=2017059404|isbn=9781626830424|publisher=NASA History Program Office|edition=second|year=2018|id=SP2018-4041|series=The NASA history series|location=Washington, DC}}</ref> The 101 grams (3.56 ounces) sample was returned from [[Mare Fecunditatis]]. It represented the first successful [[lunar sample]] return mission by the [[Soviet Union]] and was the third lunar [[sample return mission]] overall.

==Overview==

The spacecraft consisted of two attached stages, an ascent stage mounted on top of a descent stage. The descent stage was a cylindrical body with four protruding landing legs, fuel tanks, a landing radar, and a dual descent-engine complex.

A main descent engine was used to slow the craft until it reached a cutoff point, which was determined by the on-board computer based on altitude and velocity. After cutoff a bank of lower-thrust jets was used for the final landing. The descent stage also acted as a launch pad for the ascent stage.

The ascent stage was a smaller cylinder with a rounded top. It carried a cylindrical hermetically sealed soil-sample container inside a re-entry capsule.

The spacecraft descent stage was equipped with a television camera, radiation and temperature monitors, telecommunications equipment, and an extendable arm with a drilling rig for the collection of a lunar soil sample.

==Mission summary==
The ''Luna 16'' automated station was launched toward the Moon from a preliminary Earth orbit and after one mid-course correction on 13 September it entered a circular 111&nbsp;km with 70° inclination lunar orbit on 17 September 1970.
The lunar gravity was studied from this orbit. After two orbital adjustments were performed on 18 and 19 September the [[perilune]] was decreased to 15.1&nbsp;km, as well as the inclination altered in preparation for landing. At perilune at 05:12&nbsp;[[UTC]] on 20 September, the main braking engine was fired, initiating the descent to the lunar surface. Six minutes later, at 05:18&nbsp;UT, the spacecraft safely soft-landed in its target area at 0°41' south latitude and 56°18' east longitude, in the northeast area of [[Mare Fecunditatis]] (Sea of Fertility) approximately 100 kilometers west of [[Webb (crater)|Webb crater]] and 150&nbsp;km north of [[Langrenus (crater)|Langrenus crater]]. 

This was the first landing made in lunar night, as the Sun had set about 60 hours earlier. The main descent engine cut off at an altitude of 20&nbsp;m, and the landing jets cut off at 2&nbsp;m height at a velocity less than 2.4&nbsp;m/s, followed by vertical free fall. The mass of the spacecraft at landing was 1,880 kilograms. Less than an hour after landing, at 06:03&nbsp;UT, an automatic drill penetrated the lunar surface to collect a soil sample. After drilling for seven minutes, the drill reached a stop at 35 centimeters depth and then withdrew its sample and lifted it in an arc to the top of the spacecraft, depositing the lunar material in a small spherical capsule mounted on the main spacecraft bus. The column of [[regolith]] in the drill tube was then transferred to the soil sample container.<ref name=Wilson/>

After 26 hours and 25 minutes on the lunar surface, at 07:43&nbsp;UT on 21 September, the spacecraft's upper stage lifted off from the Moon. The lower stage of ''Luna 16'' remained on the lunar surface and continued transmission of lunar temperature and radiation data. Three days later, on 24 September, after a direct ascent traverse with no mid-course corrections, the capsule, with its 101 grams of lunar soil, reentered Earth's atmosphere at a velocity of 11 kilometers per second. The capsule parachuted down 80 kilometers southeast of the town of [[Jezkazgan]] in [[Kazakh Soviet Socialist Republic|Kazakhstan]] at 05:25&nbsp;UT on 24 September 1970. Analysis of the dark basalt material indicated a close resemblance to soil recovered by the American [[Apollo 12]] mission.<ref name=Wilson/>

According to the [[Bochum Observatory]] in [[Federal Republic of Germany|Germany]], strong and good-quality television pictures were returned by the spacecraft. ''Luna 16'' was a landmark success for the Soviets in their deep-space exploration program; the mission accomplished the first fully automatic recovery of soil samples from the surface of an extraterrestrial body.

A 0.4825&nbsp;g sample of material from a depth of 27&nbsp;cm was sent to Britain.<ref name=pillingersamp>{{cite journal |last1=Pillinger |first1= Colin Trevor |last2=Gowar |first2=A.P |date=4 January 1977 |title=The separation and subdivision of two 0.5g samples of lunar soil collected by the Luna 16 and 20 missions |journal= Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences |url=https://royalsocietypublishing.org/doi/10.1098/rsta.1977.0003 |volume=284 |issue=1319 |pages=137–143|doi=10.1098/rsta.1977.0003|bibcode= 1977RSPTA.284..137P |s2cid= 119730403 |url-access=subscription }} </ref>

==Legacy==
{| class="wikitable" align="right" style="font-size:smaller"
!Lunar<br />Mission
!Sample<br />Returned
!Year
|-
|'''Luna 16'''
|align="right"|{{convert|101|g|oz|abbr=on}}<ref>{{Cite web|title = NASA - NSSDC - Spacecraft – Details|url = https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1970-072A|website = nssdc.gsfc.nasa.gov|access-date = 8 November 2015}}</ref>
|align="right"|1970
|-
|''[[Luna 20]]''
|align="right"|{{convert|30|g|oz|abbr=on}}<ref>{{Cite web|title = NASA – NSSDC – Spacecraft – Details|url = https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1972-007A|website = nssdc.gsfc.nasa.gov|access-date = 8 November 2015}}</ref>
|align="right"|1972
|-
|''[[Luna 24]]''
|align="right"|{{convert|170|g|oz|abbr=on}}<ref>{{Cite web|title = NASA – NSSDC – Spacecraft – Details|url = https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1976-081A|website = nssdc.gsfc.nasa.gov|access-date = 8 November 2015}}</ref>
|align="right"|1976
|-
|}

Three tiny samples (0.2&nbsp;grams) of the ''Luna 16'' soil were sold at [[Sotheby's]] auction for $442,500 in 1993.<ref name=nytimes>{{cite news|date=December 2, 1995|url=https://www.nytimes.com/1995/12/02/nyregion/fbi-revisits-earthly-theft-of-moon-rock.html|first=Lawrence|last=Van Gelder|page=24|work=The New York Times|title=F.B.I. Revisits Earthly Theft of Moon Rock}}</ref> The samples were resold by Sotheby's for [[United States dollar|US$]]855,000 on 29 November 2018.<ref>{{cite web |title=THE ONLY KNOWN DOCUMENTED SAMPLES OF THE MOON AVAILABLE FOR PRIVATE OWNERSHIP |url=http://www.sothebys.com/en/auctions/ecatalogue/2018/space-and-exploration-n09897/lot.63.html |website=Sothebys.com |date=29 November 2018}}</ref>

A series of 10-[[Soviet ruble|kopeck]] [[Postage stamp|stamps]] was issued in 1970 to commemorate the flight of ''Luna 16'' lunar probe and depicted the main stages of the programme: soft landing on Moon, launch of the lunar soil sample return capsule, and parachute assisted landing back on Earth.

<gallery mode=packed heights=200px>
File:The Soviet Union 1970 CPA 3951 stamp (Luna 16 in Flight (1970.09.12)).jpg
File:The Soviet Union 1970 CPA 3952 stamp (Luna 16 Leaving Moon (1970.09.20)).jpg
File:The Soviet Union 1970 CPA 3953 stamp (Capsule with Moon Rock Landing on Earth (1970.09.24)).jpg
</gallery>Replicas of Luna 16 are on display at the [[Memorial Museum of Cosmonautics]] and [[Tsiolkovsky State Museum of the History of Cosmonautics]].<gallery mode="packed">
File:Laika ac Memorial Museum of Astronautics (6995717351).jpg|Luna 16 at the [[Memorial Museum of Cosmonautics]]
File:"Луна-16".jpg|Luna 16 at the [[Memorial Museum of Cosmonautics]]
File:Kaluga Wikiexpedition (2016-06-11) 0465.jpg|Luna 16 at the  [[Tsiolkovsky State Museum of the History of Cosmonautics]]
File:Kaluga Wikiexpedition (2016-06-11) 0162.jpg|Luna 16 at the  [[Tsiolkovsky State Museum of the History of Cosmonautics]]
</gallery>

==See also==
{{Portal|Solar System|Spaceflight}}
* [[Timeline of artificial satellites and space probes]]
* [[List of artificial objects on the Moon]] (descent stage)
* [[List of missions to the Moon]]

==References==
{{reflist}}

==External links==
{{Commons}}
* [[Lunar Orbiter 4]] image showing the [http://www.lpi.usra.edu/resources/lunar_orbiter/images/aimg/iv_053_h3.jpg landing site of ''Luna 16''] in Mare Fecunditatis.
* [http://www.zarya.info/Diaries/Luna/Luna16.php Zarya – ''Luna 16'' chronology]
* [https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1970-072A NASA NSSDC Master Catalog]

{{Luna programme}}
{{Moon spacecraft}}
{{Orbital launches in 1970}}

[[Category:Luna programme]]
[[Category:Sample return missions]]
[[Category:Missions to the Moon]]
[[Category:Soft landings on the Moon]]
[[Category:1970 in the Soviet Union]]
[[Category:Spacecraft launched in 1970]]
[[Category:1970 on the Moon]]
[[Category:Successful space missions]]