Events not announced publicly at the time are shown in gray type.
May 15: The first test launch of the R-7 ICBM (failed after 20 seconds in flight).
July 16: During a meeting with government officials, Korolev and Glushko pitch the idea of developing a super-heavy rocket.
Oct. 4: The R-7 rocket launched the world's first artificial satellite -- Sputnik-1
Nov. 3: The R-7 rocket launched Sputnik-2, carrying dog Laika.
March 1: The first launch of the Jupiter missile. Failed
May 1: US Navy conducted a test launch of the Vanguard rocket.
Oct. 23: US Navy conducts a test launch of the Vanguard rocket.
Dec. 6: US Navy attempts to launch the Vanguard (TV-3) satellite. The launcher fails after 2 seconds in flight.
May 15: Sputnik-3 is launched
June 30: The Soviet Government signs a decree approving the studies of nuclear rocket propulsion.
Sept. 23: The first attempt to launch E-1 (Luna) probe fails, as its rocket explodes 93 seconds after launch.
Oct. 12: The second attempt to launch E-1 (Luna) probe fails, as its rocket explodes 104 seconds after launch.
Dec. 4: The third attempt to launch E-1 (Luna) probe fails after 245 seconds in flight.
Jan. 31: Explorer-1, the first US satellite reaches orbit.
Aug. 15: Wernher von Braun and his team in Huntsville, Ala. received an assignment to develop a heavy launcher, later designated Saturn-1.
Aug. 17: The Thor-Able rocket, carrying US Air Force's Pioneer lunar probe, explodes 77 seconds after launch.
Oct. 1: The US Congress approved the creation of NASA.
Oct. 11-12: The Thor-Able rocket failed to deliver Pioneer-1 probe to the lunar orbit.
Nov. 8: The Thor-Able rocket failed to deliver Pioneer-2 probe toward the Moon.
Dec. 6-7: The Juno-2 rocket failed to deliver Pioneer-3 probe toward the Moon.
Jan. 2: The Luna-1 (E-1), the first spacecraft to escape Earth orbit, is launched.
June 18: Launch of E-1A lunar impact mission failed at T+152 seconds due to flight control problem.
Sept. 12: The Luna-2, the first man-made object to reach the Moon is launched.
Sept. 14: The Luna-2 successfully impacts the lunar surface.
Oct. 4: The Luna-3, the first man-made object to photograph far side of the Moon is launched.
Oct. 7: The USSR obtains first photos of the Moon's far side.
Dec. 10: The Soviet Government issues a decree, authorizing a variety of space development programs, including the 8K78 (Molniya) launcher, a closed-cycle engine. The N1 program was not approved, however.
Dec. 30: Korolev approves a preliminary design of three versions of the heavy rockets with nuclear engines.
March 3-4: The Juno-2 rocket sent the Pioneer-4 probe toward the Moon.
June 8: Wernher von Braun and his group at Redstone Arsenal issue a first part of the study of a "Lunar Military Outpost" for the US Army, called Project Horizon. The Saturn-I and Saturn-II rockets were to resupply the base. (138)
Nov. 26: The Atlas-Able rocket, carrying Pioneer 5 (P-3) lunar orbiter, failed to reach orbit.
January: In a meeting with leaders of the rocket industry, Nikita Khrushchev authorizes the development of an array of projects, aimed at militarization of space, among them the N1 rocket.
Jan. 15: Korolev signed a plan for the development of the 8K78 (Molniya) launcher within next seven months. (84)
Feb. 12: Glushko proposed the R-20 super-heavy booster. (84)
March 14: Korolev reports to the government about his readiness to submit a proposal about heavy launcher. (84)
March 16: The first group of 20 pilots starts training for manned space flight. (84)
April 15: The attempt to launch the E-3 lunar probe failed due its launcher failure.
April 19: The attempt to launch the E-3 lunar probe failed on pad.
June 23: The government issued a decree, authorizing a preliminary design of the N1 booster during 1961-1963.
Sept. 9: Korolev signed an addition to the experimental project of a heavy launcher, entitled "On possible characteristics of space rockets employing hydrogen."
Sept. 27: In a letter, Korolev urges Soviet officials to develop liquid hydrogen rocketry. (84)
A US project of the Nova rocket
April 29: The first test firing of the 1st stage engines of the Saturn 1 rocket in Huntsville, Ala. (10)
Sept. 25: The Atlas-Able 5A rocket failed to deliver the Pioneer-6 (P-30) lunar orbiter on its assigned trajectory.
Dec. 15: The Atlas-Able 5B rocket carrying Pioneer-6 (P-31) lunar orbiter exploded shortly after launch.
John C. Houbolt from NASA's Langley Research Center advocates a plan of lunar expedition involving a rendezvous in the lunar orbit between a mother ship and a lander. (10)
Jan. 15: Korolev writes a letter to Rudnev proposing an N1-launched military space station. (84)
Jan. 31: "Extended" Council of Chief Designers on the N1 design is held in Baikonur.
March 26: Korolev writes to Ustinov that a four-stage (Molniya) rocket can provide a soft-landing of an unmanned probe on the lunar surface. (52)
April 12: Yuri Gagarin completes world's first manned space flight.
May 13: A government decree, entitled "On Reconsideration of the Plans for Space Vehicles in the Direction of the Defense Purposes," set the first test launch of the N1 rocket for 1965.
Yuri Gagarin inside the Vostok spacecraft.
Jan. 31: The Redstone rocket launched the first Mercury spacecraft, carrying chimpanzee Ham.
Feb. 23: The Atlas-Agena rocket launched the Ranger-1 spacecraft into the Earth orbit.
May 5: Alan Shepard completes a suborbital flight.
May 25: John Kennedy, speaking at a joint session of Congress calls for the Moon landing before the end of the decade.
Fall: North American Aviation receives the contract for the development of the Apollo spacecraft.
June 11: An "ad hoc" committee chaired by William Fleming favors direct flight from the Earth to the Moon launched by a Nova rocket, as the best scenario for the lunar expedition. (10)
Oct. 27: The Saturn-1 (SA-1) rocket flies its first suborbital test mission, lasting 8 minutes 4 seconds.
Nov. 18: The Atlas-Agena rocket launches Ranger-2 spacecraft into the Earth orbit.
A NASA "ad hoc" committee chaired by Nicholas Golovin favors rendezvous of the two craft launched by Saturn C-5 rockets in the Earth orbit for the lunar expedition. (10)
March 5: In letters to the government, Korolev proposes the development of the Soyuz spacecraft and the N2 rocket, as the first step toward the bigger N1 launch vehicle. (84)
April 16: Nikita Khrushchev signs a decree, limiting the development of the N1 booster to a preliminary study and to an economic assessment of the project. At the same time, the development of the UR-500 booster has been authorized along with the development of the Soyuz complex for the circumlunar mission with the crew of two.
April 29: The Soviet government issues Decree No. 409-183 assigning OKB-52 design bureau to develop the UR-500 rocket. (210)
July 2-16: An expert commission led by Mastislav Keldysh evaluated and approved the preliminary design of the N1, scheduling the beginning of the flight tests for 1965.
August: Two manned spacecraft, Vostok 3 and 4, orbit the Earth.
Sept. 24: The government decree jump-started the N1 project and scheduled the readiness of the launch facilities in 1965. Three months are given for the formulation of military and scientific applications of the super-heavy vehicle.
Jan. 26-28: The Ranger-3 probe failed to reach the lunar surface.
February: John Glenn completes the first US manned orbital flight.
March 16: The Titan-2 ICBM, crucial for the Gemini project, flies its first test mission. (141)
March 29: McDonnell delivered the first mockup of the Gemini spacecraft for inspection to NASA.
April 23-26: The Ranger-4 probe hit the lunar surface, but failed to transmit photos.
April 25: The Saturn-1 rocket flew a suborbital test mission.
Mid-year: NASA concludes that the rendezvous in the lunar orbit between the mother craft and the lunar excursion module would the best scenario for the lunar expedition.
July 5: D. Brainerd Holmes, NASA director of manned spaceflight informed the House space committee of the US Congress that Lunar Orbit Rendezvous, LOR, was chosen as a scenario for lunar expedition. (139)
July 21: NASA announced the decision to build a launch complex for the Advanced Saturn (later Saturn-5) rocket at Merrit Island, Fla, near Cape Canaveral. (139)
Sept. 11: President Kennedy visited Redstone Arsenal in Huntsville, Ala. (10)
September: Grumman presents its proposal on the design of the lunar module (LM) to NASA.
Oct. 18: The Ranger-5 probe fails to reach the lunar surface.
Nov. 16: The Saturn-1 (SA-3) rocket flew a 4 min. 55 sec. suborbital test mission, reaching an altitude of 167 km.
Jan. 4: The E-6 lunar lander failed in the Earth orbit.
Feb. 3: The E-6 lunar lander failed to reach orbit.
Beginning of February: Academy of Sciences and Ministry of Defense put forward proposals for the applications of the N1 heavy launcher.
April 2: The E-6 lunar lander missed the Moon. Announced as Luna-4.
June: Valentina Tereshkova, the world's first woman in space completes orbital flight onboard Vostok-6 spacecraft.
Dec. 3: A Government decree sets the first launch of the 7K Earth-orbiting spacecraft in 1964, and 9K, 11K vehicles for a circumlunar mission in 1965-1966.
Dec. 24: A Government decree distributes the assignments on the launch infrastructure for the N1 rocket.
Jan. 25: Wernher von Braun and his team starts the development of the Saturn-5 rocket. (10)
March 28: The Saturn-1 rocket flies a suborbital test mission.
April 2: NASA orders 13 flight-rated Gemini spacecraft.
Aug. 28: The Little Joe II rocket launches a mockup of the Apollo spacecraft and its escape system to an altitude of 7,320 meters from White Sands, NM, reaching the speed of 1.1 Mach and the range of 15 kilometers.
Oct. 4: McDonnell delivers the first flight-rated Gemini spacecraft to Cape Canaveral.
March 21: The E-6 lunar lander failed to reach orbit.
April 20: The E-6 lunar lander failed to reach orbit.
June 19: A Government decree, officially rescheduled the first launch of the N1 rocket to 1966.
July 27: Military Industrial Commission, VPK, considers a five-year plan for space exploration. (84)
Aug. 3: The Soviet government gives go ahead to the lunar landing effort and the LK circumlunar mission.
October 12: The first three-member crew orbits Earth onboard the Voskhod spacecraft.
December: OKB-1 completes the preliminary development of the L3 complex.
Jan. 24: The Saturn-1 rocket flies a test mission.
Jan. 30-Feb. 2: The Ranger-6 probe hit the lunar surface, but failed to transmit photos.
April 8-12: The Titan-2 rocket launches the first unmanned Gemini-1 spacecraft.
May 13: The Little Joe II rocket launches the mockup of the Apollo spacecraft and its escape system LES from White Sands, NM.
May 28: The Saturn-1 rocket flies a test mission.
July 28-31: The Ranger-7 probe hits the Moon, relaying high-resolution pictures of the lunar surface before the impact.
Sept. 18: The Saturn-1 rocket flies a test mission.
Dec. 8: The Little Joe II rocket launches the mockup of the Apollo spacecraft and its escape system LES from White Sands, NM.
Feb. 10: The plan of development of the L3 system had been approved after evaluation by the Keldysh commission from the Academy of Sciences.
March 12: The E-6 lunar lander failed to leave Earth orbit. Announced as Cosmos-60.
March 18: Alexei Leonov conducts the world's first spacewalk during Voskhod-2 mission.
April 10: The E-6 lunar lander failed to reach Earth orbit.
May 9: The E-6 lunar lander crashed into the lunar surface. Announced as Luna-5.
June 8: The E-6 lunar probe missed the Moon. Announced as Luna-6.
June 30: Chelomei approves the preliminary design of the LK complex for a circumlunar mission around the Moon.
Aug. 26: The meeting of key space officials gives go ahead to the L1 project.
Sept. 8: The Military Industrial Commission of the Presidium of the Soviet of Ministers issues Decision No. 201 allocating 18 launches of the 8K82K rocket for the L1 test flight program.
Oct. 4: The E-6 lunar lander crashes into the lunar surface. Announced as Luna-7.
Oct. 25: the Soviet government issues a decree "On the consolidation of resources of development organizations of the industry on the development of the complex of rocket and space means for the flight around the Moon," formally consolidating the effort of the industry on the circumlunar mission with the UR-500K-L1 complex.
Dec. 7, 00:51 Moscow Time: The E-6 lunar lander crashed into the lunar surface. Announced as Luna-8.
The first Proton blasts off.
Jan. 19: The Titan-2 rocket launches the unmanned Gemini-2 spacecraft on a suborbital test mission.
Feb. 16: The Saturn-1 rocket launches the Pegasus-1 satellite and the Apollo "boilerplate"mockup.
Feb. 17-20: The Ranger-8 probe hits the Moon, relaying high-resolution pictures of the lunar surface before the impact.
March 21-24: The Ranger-9 probe hits the Moon, relaying high-resolution pictures of the lunar surface before the impact.
March 23: A Titan-2 rocket launches the Gemini-3 spacecraft on the first manned mission, lasting 4 hours 53 minutes.
May 19: The Little Joe II rocket launches a mockup of the Apollo spacecraft and its escape system, LES, from White Sands, NM. The launch failed.
May 25: The Saturn-1 rocket launches the Pegasus-2 satellite and the Apollo "boilerplate"mockup.
June 3-7: Edward White completes first US spacewalk during Gemini-4 mission.
July 30: The Saturn-1 rocket launches the Pegasus-3 satellite and the Apollo "boilerplate"mockup.
Aug. 21-29: Gemini-5 crew completes 8-day, 120-orbit flight.
Aug. 26: President Lyndon Johnson announced the beginning of the Manned Orbital Laboratory, MOL, project.
Dec. 4-18: Gemini-7 spends two weeks in orbit -- enough time to complete a lunar expedition.
Dec. 15-16: Gemini-6A completes a rendezvous with Gemini-7.
Jan. 14: Sergei Korolev, de-facto head of the Soviet space program, dies during a botched surgery in Moscow.
Jan. 20: The first unsuccessful attempt to conduct live test firing of the 3rd stage of the N1 rocket (Block V) at NIIKhIMMash's EU-16 facility in Zagorsk.
Feb. 3: Luna-9 completed soft landing on the lunar surface.
March 1: The E-6S lunar orbiter failed to leave Earth orbit. Announced as Cosmos-111.
March 31: Luna-10, the first spacecraft to orbit the Moon, is launched.
Aug. 24: The E-6LF lunar orbiter enter lunar orbit, under name Luna-11.
Oct. 22: The E-6LF lunar orbiter is launched; announced as Luna-12.
Nov. 28: The first attempt to test unmanned Soyuz spacecraft, announced as Cosmos-133. Destroyed on reentry.
Dec. 11: Test of emergency escape system for the Soyuz spacecraft in Vladimirovka. (52)
Dec. 21: The Luna-13 lunar lander is launched; lands successfully on Dec. 24.
Feb. 26: The first Saturn-1B rocket launches Block I of the first Apollo spacecraft on its first 15-minute suborbital test mission. The command module splashed down in the Atlantic.
March 16: Gemini-8 completes first manual docking with Agena-8.
May 30: Surveyor-1 is launched. The first US spacecraft to complete soft-landing on the surface of the Moon on June 2.
June 3-6: The Gemini-9 mission.
July 5: The Saturn-1B rocket delivers a 26.5-ton test version of the 2nd Apollo spacecraft into the low Earth orbit.
July 18-21: The Gemini-10 mission.
Aug. 10 - Oct. 19: The Lunar Orbiter-1 conducted a mission to map the Moon.
Aug. 25: The Saturn-1B rocket launches the 3rd Apollo test spacecraft on a suborbital trajectory.
Sept. 12: The Gemini-11 mission.
Sept. 20-23: The Surveyor-2 lander crashes on the lunar surface.
Nov. 3: The Titan-3 rocket launched a mockup of the MOL station.
Nov. 6, 1966 - Oct. 11, 1967: The Lunar Orbiter-2 conducts a mission to map the Moon.
Nov. 11-15: The Gemini-12 mission.
March 10: The Proton launched a prototype of the L1 circumlunar spacecraft. Announced as Cosmos-146.
April 8: The Proton launched a prototype of the L1 circumlunar spacecraft. A second firing of the Block D failed in orbit. Announced as Cosmos-154.
April 24: Vladimir Komarov dies on landing after the Soyuz-1 test flight.
May 17: The E-6LS lunar orbiter failed to leave Earth orbit. Announced as Cosmos-159.
Sept. 28: The Proton failed to deliver L1 spacecraft into orbit due to the failure of the 1st stage.
Oct. 27: A test flight of the unmanned Soyuz spacecraft, announced as Cosmos-186.
Oct. 30: A test flight of the unmanned Soyuz spacecraft, announced as Cosmos-188. Docked with Cosmos-186.
Nov. 22: The Proton failed to deliver the L1 spacecraft into orbit due to the failure of the 2nd stage.
Jan. 27: Three astronauts died in a fire during training inside the command module of the the Apollo spacecraft on the launch pad at Cape Canaveral.
Feb. 5-Oct. 9: The Lunar Orbiter-3 conducts a mission to map the Moon.
April 17-20: The Surveyor-3 lander reaches the lunar surface.
May 4-Oct. 6: The Lunar Orbiter-4 conducts a mission to map the Moon.
July 14-17: The Surveyor-4 lander crashes on the lunar surface.
Aug. 1-Jan. 31, 1968: The Lunar Orbiter-5 conducts a mission to map the Moon.
Sept. 8-11: The Surveyor-5 lander reaches the lunar surface.
Nov. 7-10: The Surveyor-6 lander reaches the lunar surface.
Nov. 9: The first Saturn-5 rocket launches an unmanned Apollo-4 spacecraft into the Earth orbit.
Feb. 7: The E-6LS lunar orbiter failed to reach the Earth orbit.
March 2: The Proton rocket launched the L1 spacecraft, announced as Zond-4 into a test flight. Its reentry capsule self-destructed during the reentry.
April 7: The launch of the Luna-14 lunar orbiter to test DRK long-range communications system.
April 14: A test flight of the unmanned Soyuz spacecraft, announced as Cosmos-212.
April 15: A test flight of the unmanned Soyuz spacecraft, announced as Cosmos-213.
April 23: The Proton rocket failed to deliver the L1 spacecraft into orbit, after its emergency escape system self-ignited
July 14: An on-pad explosion of the upper stage killed one person. Craft damaged.
Aug. 28: A test flight of the unmanned Soyuz spacecraft, announced as Cosmos-238.
Sept. 15-21: The Zond-5, a prototype of the spacecraft for manned circumlunar flight flew around the Moon and splashed down in the Indian Ocean.
Oct. 26-30: The Soyuz-3 spacecraft conducted a rendezvous with the Soyuz-2 spacecraft.
Nov. 10-17: The Zond-6 flies around the moon and lands in the USSR.
Zond-5 (L1) craft
Earth as viewed from Apollo-8 circling the Moon.
Jan. 7-10: The Surveyor-7 lander reaches the lunar surface.
Jan. 22-Feb. 11: The Saturn-1B rocket launches an unmanned Apollo-5 mission, testing the first lunar module in the Earth orbit.
April 4: The second Saturn-5 rocket launched an unmanned Apollo-6 spacecraft.
August: In the wake of the Soviet Zond flights, and due to the delays with the development of the lunar module (scheduled to fly during the Apollo-8 mission in the Earth orbit), NASA considered instead to send the Apollo-8 spacecraft on a mission around the Moon (a circumlunar mission). The flight test of the lunar module in the Earth orbit would be then deferred to the Apollo-9 mission. (140)
Oct. 11-22: Apollo-7 carried a crew of three into the Earth orbit.
Nov. 12: In the wake of the Apollo-7 success, NASA publicly disclosed its decision to send the Apollo-8 spacecraft on a circumlunar mission in December 1968. (139)
Dec. 21-27: Apollo-8 with the crew of three completes the world's first manned mission around the Moon.
Jan. 14-18: The Soyuz-4 and 5 spacecraft docked in the Earth orbit. Two cosmonauts transfer from one craft to another during the EVA.
Jan. 20: The Proton failed to deliver the L1 spacecraft into orbit due to the failure of the 2nd stage.
Feb. 19: The E-8 lunar rover failed to reach Earth orbit.
July 13: The E-8-5 spacecraft designed to return lunar samples before the Apollo-11 expedition, launched toward the Moon. Crashed on the lunar surface. Announced as Luna-15.
Aug. 8-14: The Zond-7 flew around the moon and landed in the USSR.
Sept. 23: The E-8-5 spacecraft designed to return lunar samples failed to leave Earth orbit. Announced as Cosmos-300.
Oct. 11-18: The Soyuz-6, -7, -8 conducted simultaneous orbital flight.
Oct. 22: The E-8-5 spacecraft designed to return lunar samples failed to leave Earth orbit. Announced as Cosmos-305.
February: President Nixon established a Space Task Group, STG, considering the future of the US space program. (10)
March 3-13: Apollo-9 conducts a test mission in the Earth orbit, including the autonomous flight of the lunar module.
May 18-26: Apollo-10 flies toward and around the Moon in a "dress rehearsal" of the lunar landing.
July 16-24: The Apollo-11 astronauts land and walk on the surface of the Moon.
August: The MOL project was officially canceled.
September: Space Task Group, STG, proposed an aggressive post-Apollo program.
Nov. 14-24: The Apollo-12 expedition to the Moon.
6: The E-8-5 spacecraft designed to return lunar samples failed to reach
Sept. 12: The Luna-16 blasted off toward the Moon on a mission to return lunar samples.
Oct. 20: The Zond-8 (L1) spacecraft flew around the Moon and landed in the Indian Ocean.
Nov. 17: Luna-17 delivers Lunokhod-1 on the surface of the Moon.
Nov. 24: A test of the LK lunar lander in the Earth orbit. Announced as Cosmos-379.
Dec. 2: A flight test of the Block D upper stage version developed for the N-1 launcher. Fired seven times in orbit. Announced as Cosmos-382.
April 11-17: The Apollo-13 fails to reach the Moon due to an in-flight anomaly, however its crew returns safely to Earth.
July 28: NASA Administrator Thomas O. Paine announced his resignation from the agency. (10)
November: Dr. George Low, acting NASA Administrator, told Congress that the Soviet program of developing of a super heavy-lift vehicle continued despite all failures.
Feb. 26: A test of the LK lunar lander in the Earth orbit. Announced as Cosmos-398.
April 19: Salyut-1, the first orbital station is launched. Its first crew of three dies on landing.
June 27: The 3rd launch of the N1 rocket (Vehicle Number 6L) fails at 50.1 seconds after liftoff.
Aug. 12: A test of the LK lunar lander in the Earth orbit. Announced as Cosmos-434.
Sept. 2: The E-8-5 lunar sample return mission launched. Crashed during landing on the Moon. Announced as Luna-18.
Sept. 28: The E-8LS lunar orbiter launched toward the Moon. Announced as Luna-19.
Jan. 31-Feb. 9: The Apollo-14 expedition to the Moon.
July 26-Aug. 7: The Apollo-15 expedition to the Moon.
Feb. 14: The Luna-20 blasted off toward the Moon on a mission to return lunar samples.
Nov. 23: The 4th launch of the N1 rocket (Vehicle Number 7L) failed about 107 seconds after liftoff.
April 16-27: The Apollo-16 expedition to the Moon.
June 10: Wernher von Braun left NASA. (10)
Dec. 7-19: The Apollo-17, the 6th and last expedition to visit the Moon in the 20th century.
Jan. 16: Luna 21 delivered the Lunokhod-2 rover on the surface of the Moon.
May 14: The last Saturn-5 rocket launches the Skylab station.
May 25-June 22: The 1st expedition to the Skylab space station.
July 29-Sept. 25: The 2nd expedition to the Skylab space station.
Nov. 16-Feb. 8, 1974: The 3rd expedition to the Skylab space station.
May: The Vehicle Number 8L is modified for the fifth N1 test flight scheduled for the fourth quarter of 1974.
May 21-22: Valentin Glushko replaces Vasili Mishin as a head of TsKBEM.
May 29: The E-8LS lunar orbiter launched toward the Moon. Announced as Luna-22.
Oct. 28: The E-8-5M lunar sample return mission failed during landing on the Moon. Announced as Luna-23.
|1974||Feb. 8: The 3rd and final expedition to the Skylab space station returns to Earth.|
|Oct. 16: The attempt to launch the E-8-5M #412 soil sample return mission failed to reach Earth orbit due to Block D failure.||1975||July 15: The 9th and last Saturn-1B rocket launches the Apollo spacecraft to rendezvous with the Soviet Soyuz-19 spacecraft.|
February: A government decree officially canceled the N1-L3 program.
Aug. 9: The E-8-5M soil-sample return mission is launched successfully. Announced as Luna-24.
Aug. 18: Luna-24 lands on the surface of the Moon to collect soil samples, which then returned to Earth.