A sample return mission is a spacecraft

Spacecraft

A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....

 mission with the goal of returning tangible samples from an extraterrestrial location to Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 for analysis. Sample return missions may bring back merely atoms and molecules or a deposit of complex compounds such as dirt and rocks. These samples may be obtained in a number of ways, including a collector array used for capturing particles of solar wind

Solar wind

The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...

 or cometary debris, soil and rock excavation, mining, and any other possible way for retrieving samples in the environment.

Past

The first sample return mission ever was Apollo 11

Apollo 11

In early 1969, Bill Anders accepted a job with the National Space Council effective in August 1969 and announced his retirement as an astronaut. At that point Ken Mattingly was moved from the support crew into parallel training with Anders as backup Command Module Pilot in case Apollo 11 was...

 in 1969. It returned approximately 22 kilograms of Lunar surface material. Apollo 12

Apollo 12

Apollo 12 was the sixth manned flight in the American Apollo program and the second to land on the Moon . It was launched on November 14, 1969 from the Kennedy Space Center, Florida, four months after Apollo 11. Mission commander Charles "Pete" Conrad and Lunar Module Pilot Alan L...

 was the second sample return mission which returned about 34 kilograms of material. Apollo 11 and Apollo 12 and further missions 14, 15, 16, 17 were manned missions. Perhaps one of the most significant advances in sample return missions occurred in 1970 when the robotic Soviet mission known as Luna 16

Luna 16

-External links:*...

, successfully returned 101 grams of lunar soil. Likewise, Luna 20

Luna 20

Luna 20 was the second of three successful Soviet lunar sample return missions. It was flown as part of the Luna program, also called Lunik 20, as a robotic competitor to the six successful Apollo lunar sample return missions....

 returned 30 grams in 1974 and Luna 24

Luna 24

-External links:*...

 returned 170.1 grams in 1976. Although they recovered far less than the Apollo missions, they did this fully automatically.

The Soviet Union planned for 1975 (according to plans of 1970) the first Martian sample return mission by Mars 5NM project launched by N1 superrocket

N1 rocket

N-1 was a heavy lift rocket intended to deliver payloads beyond low Earth orbit, acting as the Soviet counterpart to the NASA Saturn V rocket. This heavy lift booster had the capability of lifting very heavy loads into orbit, designed with manned extra-orbital travel in mind...

 that never flew successfully and planned for 1979 but cancelled the further Mars 5M project double-launched by Proton

Proton

The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number....

 rocket.

The Earth-Orbital Debris Collection (ODC) experiment, deployed on the Mir space station for 18 months during 1996–1997, used aerogel

Aerogel

Aerogel is a synthetic porous material derived from a gel, in which the liquid component of the gel has been replaced with a gas. The result is a solid with extremely low density and thermal conductivity...

 to capture interplanetary dust particles in orbit.

Current

After the last sample return mission by Luna 24

Luna 24

-External links:*...

 in 1976, more than twenty five years passed before another mission, known as Genesis

Genesis (spacecraft)

The Genesis spacecraft was a NASA sample return probe which collected a sample of solar wind and returned it to Earth for analysis. It was the first NASA sample return mission to return material since the Apollo Program, and the first to return material from beyond the orbit of the Moon...

 was able to return an extraterrestrial sample to Earth from beyond Earth orbit. Unfortunately, the Genesis capsule failed to open its parachute while re-entering the Earth's atmosphere, and it crash-landed in the Utah desert in 2004. There were fears of severe contamination or even total mission loss, but scientists have managed to save quite a bit of the samples—which were the first to be collected from beyond lunar orbit. Genesis used a collector array made of wafers of ultra-pure silicon

Silicon

Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...

, gold

Gold

Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

, sapphire

Sapphire

Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide , when it is a color other than red or dark pink; in which case the gem would instead be called a ruby, considered to be a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give...

, and diamond

Diamond

In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...

. Each different wafer was used to collect a different part of the solar wind

Solar wind

The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...

.

Another sample return mission is NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

's Stardust

Stardust (spacecraft)

Stardust is a 300-kilogram robotic space probe launched by NASA on February 7, 1999 to study the asteroid 5535 Annefrank and collect samples from the coma of comet Wild 2. The primary mission was completed January 15, 2006, when the sample return capsule returned to Earth...

 spacecraft which returned to earth January 15, 2006. It safely passed by Comet Wild 2 and collected dust samples from the comet's coma

Coma

In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...

 while imaging the comet's nucleus. Stardust used a collector array made of low-density aerogel

Aerogel

Aerogel is a synthetic porous material derived from a gel, in which the liquid component of the gel has been replaced with a gas. The result is a solid with extremely low density and thermal conductivity...

 (99% of which is empty space) which has about 1/1000 of the density

Density

The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...

 of glass. This permits the ability to collect the cometary particles without damaging them due to high impact velocities. Particle collisions with even slightly porous solid collectors would result in destruction of those particles and damage to the collection apparatus.

In June 2010 the Japan Aerospace Exploration Agency

Japan Aerospace Exploration Agency

The , or JAXA, is Japan's national aerospace agency. Through the merger of three previously independent organizations, JAXA was formed on October 1, 2003, as an Independent Administrative Institution administered by the Ministry of Education, Culture, Sports, Science and Technology and the...

 (JAXA) Hayabusa

Hayabusa

was an unmanned spacecraft developed by the Japan Aerospace Exploration Agency to return a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis....

 probe returned to Earth after a rendezvous with (and a landing on) S-type asteroid

S-type asteroid

S-type asteroids are of a stony composition, hence the name. Approximately 17% of asteroids are of this type, making it the second most common after the C-type.-Characteristics:...

 25143 Itokawa

25143 Itokawa

25143 Itokawa is an Apollo and Mars-crosser asteroid. It was the first asteroid to be the target of a sample return mission, the Japanese space probe Hayabusa.-Discovery and naming:...

. In November 2010 scientists at the agency confirmed that the probe successfully retrieved dust from the asteroid, the first ever brought back to Earth in pristine condition.

The Russian Fobos-Grunt is a sample return mission to Phobos

Phobos (moon)

Phobos is the larger and closer of the two natural satellites of Mars. Both moons were discovered in 1877. With a mean radius of , Phobos is 7.24 times as massive as Deimos...

, one of the moons of Mars

Mars

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

. It was launched on November 8, 2011. However the probe failed to leave Earth orbit. Rescuing the ship and sending it to Phobos as it was designed to is unlikely.

Future

China is planning to conduct a Lunar sample return around 2017. If successful, it would make the first lunar sample return in over 40 years.

NASA has long planned a Martian sample return mission

Mars Sample Return Mission

A Mars sample return mission would be a spaceflight mission to collect rock and dust samples from Mars and to return them to Earth for analysis...

, but has yet to successfully design, build, launch, and land a probe that would do just that. There have been mission proposals in the past, but most have not made it far beyond the drawing boards. The mission remains on NASA's roadmap for planetary science as of the 2013 Planetary Science Decadal Survey.

There were plans to launch a Mars Sample Return (MSR) mission in 2004, but following the twin-failures of the Mars Climate Orbiter

Mars Climate Orbiter

The Mars Climate Orbiter was a 338 kilogram robotic space probe launched by NASA on December 11, 1998 to study the Martian climate, atmosphere, surface changes and to act as the communications relay in the Mars Surveyor '98 program, for Mars Polar Lander...

 and Mars Polar Lander

Mars Polar Lander

The Mars Polar Lander, also referred to as the Mars Surveyor '98 Lander, was a 290-kilogram robotic spacecraft lander, launched by NASA on January 3, 1999, to study the soil and climate of Planum Australe, a region near the south pole on Mars, as part of the Mars Surveyor '98 mission...

, MSR was cancelled. A Mars Sample Return mission with collaboration with Europe (Aurora programme

Aurora Programme

The Aurora programme is a human spaceflight programme of the European Space Agency established in 2001 with the primary objectives of creating, and then implementing, a European long-term plan for exploration of the Solar System using robotic spacecraft and human spaceflight...

) may launch around 2018.

Russia has Mars-Grunt project for Mars sample return mission near 2020-2023.

Other missions may bring back samples from asteroids and comets.

The OSIRIS-REx

OSIRIS-REx

Origins Spectral Interpretation Resource Identification Security Regolith Explorer is a planetary science mission, the third selected in the New Frontiers Program. The mission will study and return a sample of a carbonaceous asteroid to Earth for detailed analyses in about 2023...

 mission will be launched in 2016 on a mission to return samples of from asteroid 1999 RQ36. The samples are expected to enable scientists to learn more about the time before the birth of our solar system, initial stages of planet formation, and the source of organic compounds which led to the formation of life.

JAXA's Hayabusa 2

Hayabusa 2

Hayabusa 2 is the follow-on mission to the Hayabusa mission as proposed by the Japanese space agency, JAXA. The goal for Hayabusa 2 is to build upon the legacy of the original mission, by strengthening the shown weak points...

 is a sample return mission to C-type asteroid

C-type asteroid

C-type asteroids are carbonaceous asteroids. They are the most common variety, forming around 75% of known asteroids, and an even higher percentage in the outer part of the asteroid belt beyond 2.7 AU, which is dominated by this asteroid type...

 (162173) 1999 JU3

(162173) 1999 JU3

162173 1999 JU3 is an Apollo asteroid. It is the proposed target of the Japanese space probe Hayabusa 2.-Discovery and naming:The asteroid was discovered in 1999 by the LINEAR project, and given the provisional designation .- References :...

. It is planning to launch in 2014 or 2015.

Collector array

A collector array may be used to collect millions or billions of atoms, molecules, and fine particulates by using a number of wafers made of different elements. The molecular structure of these wafers allows for the collection of various sizes of particles. Collector arrays, such as those flown on Genesis are ultra-pure in order to ensure maximum collection efficiency, durability, and analytical distinguishability.

Collector arrays are useful for collecting tiny, fast-moving atoms such as those expelled by the Sun through solar wind, but can also be used for collection of larger particles such as those found in the coma

Coma

In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...

 of a comet. The NASA spacecraft known as Stardust

Stardust (spacecraft)

Stardust is a 300-kilogram robotic space probe launched by NASA on February 7, 1999 to study the asteroid 5535 Annefrank and collect samples from the coma of comet Wild 2. The primary mission was completed January 15, 2006, when the sample return capsule returned to Earth...

 implements this technique. However, due to the high speeds and size of the particles that make up the coma and the area nearby, a dense solid-state collector array was not viable. As a result, another means for collecting samples had to be designed as to preserve the safety of the spacecraft and the samples themselves.

Aerogel

Aerogel

Aerogel

Aerogel is a synthetic porous material derived from a gel, in which the liquid component of the gel has been replaced with a gas. The result is a solid with extremely low density and thermal conductivity...

 is a silicon-based

Silicon

Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...

, porous, solid with a sponge-like structure in which 99.8% of its volume is composed of empty space. Aerogel has about 1/1000 of the density

Density

The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...

 of glass. An aerogel was implemented for use with the Stardust spacecraft because the collision of a particle smaller than the size of a grain of sand would have an impact velocities of about six times the speed of a rifle bullet, and hence a collision with a dense solid could alter its chemical composition, and perhaps vaporize it completely.

Since the aerogel is mostly transparent, it is extraordinarily easy for the scientists to find and retrieve the particles since they leave a carrot-shaped path once they penetrate the surface. Since its pores are on the nanometer scale, the particles do not merely pass through the aerogel completely. Instead, they slow to a stop and then are embedded within it.

The Stardust spacecraft has a tennis racket shaped collector with aerogel fitted to it. The collector is retracted into its capsule for safe-storage and delivery back to Earth. One thing that makes aerogel a good choice for missions such as Stardust is that it is quite strong and easily survives both launching and outer space

Outer space

Outer space is the void that exists between celestial bodies, including the Earth. It is not completely empty, but consists of a hard vacuum containing a low density of particles: predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, and neutrinos....

 environments.

Excavation and rocket return

Some of the most risky and difficult types of sample return missions are those that require landing on an extraterrestrial body such as an asteroid, moon, or planet. It takes a great deal of time, money, and technical ability in order to even initiate such plans. It is a difficult feat that requires that everything from launch to landing to retrieval and launch back to Earth be planned out with high precision and accuracy.

This type of sample return, although having the most risks, is the most rewarding for planetary science. Furthermore, such missions carry a great deal of public outreach potential, which is an important attribute for space exploration

Space exploration

Space exploration is the use of space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft....

 when it comes to publicity.

NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 is considering launching an international sample return mission of this type to Mars around the year 2018, depending on its budget. Previous attempts to launch this type of sample return mission have been scrubbed due to technical difficulty, budget constraints, and other factors such as recent mission failures (e.g.: Mars Climate Orbiter

Mars Climate Orbiter

The Mars Climate Orbiter was a 338 kilogram robotic space probe launched by NASA on December 11, 1998 to study the Martian climate, atmosphere, surface changes and to act as the communications relay in the Mars Surveyor '98 program, for Mars Polar Lander...

 and Mars Polar Lander

Mars Polar Lander

The Mars Polar Lander, also referred to as the Mars Surveyor '98 Lander, was a 290-kilogram robotic spacecraft lander, launched by NASA on January 3, 1999, to study the soil and climate of Planum Australe, a region near the south pole on Mars, as part of the Mars Surveyor '98 mission...

). The only successful robotic sample return missions of this type have been the former U.S.S.R. Luna landers

Luna programme

The Luna programme , occasionally called Lunik or Lunnik, was a series of robotic spacecraft missions sent to the Moon by the Soviet Union between 1959 and 1976. Fifteen were successful, each designed as either an orbiter or lander, and accomplished many firsts in space exploration...

.

List of unmanned sample return missions

Date launched	Name	Sample	Sample origin	Date recovered	Result
July 13, 1969	Luna 15 Luna 15 -External links:*...		The Moon Moon The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...		failure crash-landed on the Moon
September 12, 1970	Luna 16 Luna 16 -External links:*...	101 grams (3.6 oz) of lunar rock	The Moon Moon The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...	September 24, 1970	success
September 2, 1971	Luna 18 Luna 18 Luna 18 was an unmanned space mission of the Luna program, also called Lunik 18.Luna 18 was placed in an earth parking orbit after it was launched and was then sent towards the Moon. On September 7, 1971, it entered lunar orbit. The spacecraft completed 85 communications sessions and 54 lunar...		The Moon Moon The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...		failure crash-landed on the Moon
February 14, 1972	Luna 20 Luna 20 Luna 20 was the second of three successful Soviet lunar sample return missions. It was flown as part of the Luna program, also called Lunik 20, as a robotic competitor to the six successful Apollo lunar sample return missions....	55 grams (1.9 oz) of lunar rock	The Moon Moon The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...	February 25, 1972	success
November 2, 1974	Luna 23 Luna 23 Luna 23 was an unmanned space mission of the Luna program, also called Lunik 23.Luna 23 was a Moon lander mission which was intended to return a lunar sample to Earth. Launched to the Moon by a Proton SL-12/D-1-e booster, the spacecraft was damaged during landing in Mare Crisium...		The Moon Moon The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...		failure drilling device damaged on Moon landing, mission abandoned
August 9, 1976	Luna 24 Luna 24 -External links:*...	170 grams (6 oz) of lunar rock	The Moon Moon The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...	August 22, 1976	success
February 7, 1999	Stardust Stardust (spacecraft) Stardust is a 300-kilogram robotic space probe launched by NASA on February 7, 1999 to study the asteroid 5535 Annefrank and collect samples from the coma of comet Wild 2. The primary mission was completed January 15, 2006, when the sample return capsule returned to Earth...	over 1 million comet particles	81P/Wild 81P/Wild Comet 81P/Wild, also known as Wild 2 , is a comet named after Swiss astronomer Paul Wild, who discovered it in 1978 using a 40-cm Schmidt telescope at Zimmerwald....	January 15, 2006	success
August 8, 2001	Genesis Genesis (spacecraft) The Genesis spacecraft was a NASA sample return probe which collected a sample of solar wind and returned it to Earth for analysis. It was the first NASA sample return mission to return material since the Apollo Program, and the first to return material from beyond the orbit of the Moon...	Solar particles	Solar wind Solar wind The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...	September 8, 2004	partial success parachute failure led to return capsule crash and heavy damage some usable samples recovered
May 9, 2003	Hayabusa Hayabusa was an unmanned spacecraft developed by the Japan Aerospace Exploration Agency to return a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis....	1,500 grains of asteroid particles	25143 Itokawa 25143 Itokawa 25143 Itokawa is an Apollo and Mars-crosser asteroid. It was the first asteroid to be the target of a sample return mission, the Japanese space probe Hayabusa.-Discovery and naming:...	June 13, 2010	partial success several hundred milligrams of sample material were planned
November 8, 2011	Fobos-Grunt	200 grams (7.1 oz) of Phobos soil	Phobos Phobos (moon) Phobos is the larger and closer of the two natural satellites of Mars. Both moons were discovered in 1877. With a mean radius of , Phobos is 7.24 times as massive as Deimos...	August 2014 (planned)	mission in progress
2016 (planned)	OSIRIS-REx OSIRIS-REx Origins Spectral Interpretation Resource Identification Security Regolith Explorer is a planetary science mission, the third selected in the New Frontiers Program. The mission will study and return a sample of a carbonaceous asteroid to Earth for detailed analyses in about 2023...	Asteroid regolith Regolith Regolith is a layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, some asteroids, and other terrestrial planets and moons.-Etymology:...	1999 RQ36	2023 (planned)	TBD

External links

• Mars Exploration: Sample Returns Jet Propulsion Laboratory Mars Exploration Program on sample return missions.
• Stardust Homepage Jet Propulsion Laboratory Stardust mission website.
• Genesis Mission Homepage Jet Propulsion Laboratory Genesis mission website.
• Stardust: Aerogel Stardust website on aerogel technology.
• JAXA Hayabusa JAXA Hayabusa project update.
• MarsNews.com: Mars Sample Return MarsNews.com on Mars Sample Return missions.
• Texas Space Grant Consortium: Missions to the Moon A list of missions to the Moon from 1958 to 1998.
• Evaluating the Biological Potential in Samples Returned from Planetary Satellites and Small Solar System Bodies The National Academies, Space Science Board 1998