''Stardust'' was a 385-kilogram
robotic
Robotics is an interdisciplinarity, interdisciplinary branch of computer science and engineering. Robotics involves design, construction, operation, and use of robots. The goal of robotics is to design machines that can help and assist human ...
space probe
A space probe is an artificial satellite that travels through space to collect scientific data. A space probe may orbit Earth; approach the Moon; travel through interplanetary space; flyby, orbit, or land or fly on other planetary bodies; or ent ...
launched by
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
on 7 February 1999. Its primary mission was to collect dust samples from the
coma
A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to respond normally to painful stimuli, light, or sound, lacks a normal wake-sleep cycle and does not initiate voluntary actions. Coma patients exhi ...
of
comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...
Wild 2, as well as samples of
cosmic dust
Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are c ...
, and return them to Earth for analysis. It was the first
sample return mission
A sample-return mission is a spacecraft mission to collect and return samples from an extraterrestrial location to Earth for analysis. Sample-return missions may bring back merely atoms and molecules or a deposit of complex compounds such as lo ...
of its kind. En route to comet Wild 2, it also flew by and studied the
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
5535 Annefrank. The primary mission was successfully completed on 15 January 2006 when the sample return capsule returned to Earth.
A mission extension, codenamed ''NExT'', culminated in February 2011 with ''Stardust'' intercepting comet
Tempel 1
Tempel 1 (official designation: 9P/Tempel) is a periodic Jupiter-family comet discovered by Wilhelm Tempel in 1867. It completes an orbit of the Sun every 5.5 years. Tempel 1 was the target of the ''Deep Impact'' space mission, which photograph ...
, a
small Solar System body
A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, ...
previously visited by ''
Deep Impact'' in 2005. ''Stardust'' ceased operations in March 2011.
On 14 August 2014, scientists announced the identification of possible
interstellar dust
Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are c ...
particles from the ''Stardust'' capsule returned to Earth in 2006.
Mission background
History
Beginning in the 1980s, scientists began seeking a dedicated mission to study a comet. During the early 1990s, several missions to study
comet Halley
Halley's Comet or Comet Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 75–79 years. Halley is the only known short-period comet that is regularly visible to the naked eye from Earth, and thus the on ...
became the first successful missions to return close-up data. However, the US cometary mission,
Comet Rendezvous Asteroid Flyby
The Comet Rendezvous Asteroid Flyby (CRAF) was a cancelled plan for a NASA-led exploratory mission designed by the Jet Propulsion Laboratory during the mid-to-late 1980s and early 1990s, that planned to send a spacecraft to encounter an asteroid ...
, was canceled for budgetary reasons. In the mid-1990s, further support was given to a cheaper,
Discovery-class mission that would study comet Wild 2 in 2004.
''Stardust'' was competitively selected in the fall of 1995 as a NASA Discovery Program mission of low-cost with highly focused science goals.
Construction of ''Stardust'' began in 1996, and was subject to the maximum contamination restriction, level 5
planetary protection
Planetary protection is a guiding principle in the design of an interplanetary mission, aiming to prevent biological contamination of both the target celestial body and the Earth in the case of sample-return missions. Planetary protection refle ...
. However, the risk of interplanetary contamination by alien life was judged low,
as particle impacts at over 1,000 miles per hour, even into
aerogel, were believed to be terminal for any known microorganism.
Comet
Wild 2 was selected as the primary target of the mission for the rare chance to observe a long-period comet that has ventured close to the
Sun
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
. The comet has since become a short period comet after an event in 1974, where the orbit of Wild 2 was affected by the gravitational pull of
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...
, moving the orbit inward, closer to the Sun. In planning the mission, it was expected that most of the original material from which the comet formed would still be preserved.
The primary science objectives of the mission included:
*Providing a flyby of a comet of interest (Wild 2) at a sufficiently low velocity (less than 6.5 km/s) such that non-destructive capture of comet dust is possible using an aerogel collector.
*Facilitating the intercept of significant numbers of interstellar dust particles using the same collection medium, also at as low a velocity as possible.
*Returning as many high-resolution images of the comet coma and nucleus as possible, subject to the cost constraints of the mission.
The spacecraft was designed, built and operated by
Lockheed Martin
The Lockheed Martin Corporation is an American aerospace, arms, defense, information security, and technology corporation with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It ...
Astronautics as a Discovery-class mission in Denver, Colorado. JPL provided mission management for the NASA division for mission operations. The principal investigator of the mission was Dr. Donald Brownlee from the University of Washington.
Spacecraft design
The spacecraft bus measured in length, and in width, a design adapted from the SpaceProbe deep space bus developed by
Lockheed Martin Astronautics. The bus was primarily constructed with
graphite fiber panels with an aluminum honeycomb support structure underneath; the entire spacecraft was covered with polycyanate,
Kapton
Structure of poly-oxydiphenylene-pyromellitimide
Kapton insulating pads for mounting electronic parts on a heat sink
Kapton is a polyimide film used in flexible printed circuits (flexible electronics) and space blankets, which are used on spac ...
sheeting for further protection. To maintain low costs, the spacecraft incorporated many designs and technologies used in past missions or previously developed for future missions by the Small Spacecraft Technologies Initiative (SSTI). The spacecraft featured five scientific instruments to collect data, including the ''Stardust'' Sample Collection tray, which was brought back to Earth for analysis.
Attitude control and propulsion
The spacecraft was
three-axis stabilized
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle/satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, et ...
with eight 4.41
N hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine ...
monopropellant
Monopropellants are propellants consisting of chemicals that release energy through exothermic chemical decomposition. The molecular bond energy of the monopropellant is released usually through use of a catalyst. This can be contrasted with biprop ...
thrusters, and eight 1-
Newton thrusters to maintain
attitude control
Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc.
Controlling vehicle ...
(orientation); necessary minor propulsion maneuvers were performed by these thrusters as well. The spacecraft was launched with 80 kilograms of propellant. Information for spacecraft positioning was provided by a
star camera using FSW to determine attitude (stellar compass), an
inertial measurement unit, and two
sun sensors.
Communications
For communicating with the
Deep Space Network
The NASA Deep Space Network (DSN) is a worldwide network of American spacecraft communication ground segment facilities, located in the United States (California), Spain (Madrid), and Australia (Canberra), that supports NASA's interplanetary ...
, the spacecraft transmitted data across the
X-band
The X band is the designation for a band of frequencies in the microwave radio region of the electromagnetic spectrum. In some cases, such as in communication engineering, the frequency range of the X band is rather indefinitely set at approxi ...
using a parabolic
high-gain antenna
A directional antenna or beam antenna is an antenna which radiates or receives greater power in specific directions allowing increased performance and reduced interference from unwanted sources. Directional antennas provide increased performanc ...
, medium-gain antenna (MGA) and low-gain antennas (LGA) depending on mission phase, and a 15-watt
transponder
In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend word, blend of ''transmitter'' and ''responder''.
In air navigation or radio frequency identification, a T ...
design originally intended for the
''Cassini'' spacecraft.
Power
The probe was powered by two
solar arrays
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and c ...
, providing an average of 330 watts of power. The arrays also included
Whipple shield
The Whipple shield or Whipple bumper, invented by Fred Whipple, is a type of hypervelocity impact shield used to protect crewed and uncrewed spacecraft from collisions with micrometeoroids and orbital debris whose velocities generally range be ...
s to protect the delicate surfaces from the potentially damaging cometary dust while the spacecraft was in the coma of Wild 2. The solar array design was derived primarily from the Small Spacecraft Technology Initiative (SSTI) spacecraft development guidelines. The arrays provided a unique method of switching strings from series to parallel depending on the distance from the Sun. A single
nickel–hydrogen () battery was also included to provide the spacecraft with power when the solar arrays received too little sunlight.
Computer
The computer on the spacecraft operated using a
radiation-hardened
Radiation hardening is the process of making electronic components and circuits resistant to damage or malfunction caused by high levels of ionizing radiation ( particle radiation and high-energy electromagnetic radiation), especially for environ ...
RAD6000
The RAD6000 radiation-hardened single-board computer, based on the IBM RISC Single Chip CPU, was manufactured by IBM Federal Systems. IBM Federal Systems was sold to Loral, and by way of acquisition, ended up with Lockheed Martin and is ...
32-bit processor card. For
storing data when the spacecraft was unable to communicate with Earth, the processor card was able to store 128
megabyte
The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB. The unit prefix ''mega'' is a multiplier of (106) in the International System of Units (SI). Therefore, one megabyte is one million bytes o ...
s, 20% of which was occupied by the flight system software. The system software is a form of
VxWorks
VxWorks is a real-time operating system (or RTOS) developed as proprietary software by Wind River Systems, a wholly-owned subsidiary of Aptiv. First released in 1987, VxWorks is designed for use in embedded systems requiring real-time, determi ...
, an
embedded operating system
An embedded operating system is an operating system for embedded computer systems. Embedded operating systems are computer systems designed to increase functionality and reliability for achieving a specific task. Resource efficiency comes at the ...
developed by
Wind River Systems
Wind River Systems, also known as Wind River (trademarked as Wndrvr), is an Alameda, California–based company, subsidiary of Aptiv PLC. The company develops embedded system and cloud software consisting of real-time operating systems software, ...
.
Scientific instruments
Sample collection
Comet and interstellar particles are collected in ultra low density
aerogel. The
tennis racket
A racket, or racquet, is a sports implement used for striking a ball or shuttlecock in games such as squash, tennis, racquetball, badminton and padel. In the strictest sense a racket consists of a handled frame with an open hoop across which a ...
-sized collector tray contained ninety blocks of aerogel, providing more than 1,000 square centimeters of surface area to capture
cometary
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are ...
and
interstellar dust grains.
To collect the particles without damaging them, a
silicon
Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic tab ...
-based solid with a porous,
sponge
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...
-like structure is used in which 99.8 percent of the volume is empty space. Aerogel has the density of
glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of ...
, another silicon-based solid to which it may be compared. When a particle hits the aerogel, it becomes buried in the material, creating a long track, up to 200 times the length of the grain. The aerogel was packed in an aluminium grid and fitted into a Sample Return Capsule (SRC), which was to be released from the spacecraft as it passed Earth in 2006.
To analyze the aerogel for interstellar dust, one million photographs will be needed to image the entirety of the sampled grains. The images will be
distributed Distribution may refer to:
Mathematics
*Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations
*Probability distribution, the probability of a particular value or value range of a varia ...
to home computer users to aid in the study of the data using a program titled,
Stardust@home. In April 2014, NASA reported they had recovered seven particles of interstellar dust from the aerogel.
''Stardust'' microchip
''Stardust'' was launched carrying two sets of identical pairs of square silicon
wafers
A wafer is a crisp, often sweet, very thin, flat, light and dry biscuit, often used to decorate ice cream, and also used as a garnish on some sweet dishes. Wafers can also be made into cookies with cream flavoring sandwiched between them. They ...
. Each pair featured engravings of well over one million names of people who participated in the public outreach program by filling out internet forms available in late 1997 and mid-1998. One pair of the microchips was positioned on the spacecraft and the other was attached to the sample return capsule.
Mission profile
Launch and trajectory
![Animation of Stardust trajectory](https://upload.wikimedia.org/wikipedia/commons/5/5f/Animation_of_Stardust_trajectory.gif)
''Stardust'' was launched at 21:04:15 UTC on 7 February 1999, by the
National Aeronautics and Space Administration
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding th ...
from
Space Launch Complex 17A at the
Cape Canaveral Air Force Station
Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida.
Headquartered at the nearby Patrick Space Force Base, the statio ...
in Florida, aboard a
Delta II 7426 launch vehicle. The complete burn sequence lasted for 27 minutes bringing the spacecraft into a heliocentric orbit that would bring the spacecraft around the
Sun
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
and past
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
for a
gravity assist maneuver in 2001, to reach asteroid
5535 Annefrank in 2002 and
comet Wild 2 in 2004 at a low flyby velocity of 6.1 km/s. In 2004, the spacecraft performed a course correction that would allow it to pass by Earth a second time in 2006, to release the Sample Return Capsule for a landing in Utah in the
Bonneville Salt Flats
The Bonneville Salt Flats are a densely packed salt pan in Tooele County in northwestern Utah. A remnant of the Pleistocene Lake Bonneville, it is the largest of many salt flats west of the Great Salt Lake. It is public land managed by the Bur ...
.
During the second encounter with Earth, the Sample Return Capsule was released on Jan 15, 2006.
Immediately afterwards, ''Stardust'' was put into a "divert maneuver" to avoid entering the atmosphere alongside the capsule. Under twenty kilograms of propellant remained onboard after the maneuver.
On 29 January 2006, the spacecraft was put in hibernation mode with only the solar panels and receiver active, in a 3-year
heliocentric
Heliocentrism (also known as the Heliocentric model) is the astronomical model in which the Earth and planets revolve around the Sun at the center of the universe. Historically, heliocentrism was opposed to geocentrism, which placed the Earth at ...
orbit that would return it to Earth vicinity on 14 January 2009.
A subsequent mission extension was approved on 3 July 2007, to bring the spacecraft back to full operation for a flyby of
comet Tempel 1 in 2011. The mission extension was the first to revisit a
small Solar System body
A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, ...
and used the remaining propellant, signaling the end of the useful life for the spacecraft.
Encounter with Annefrank
At 04:50:20 UTC on 2 November 2002, ''Stardust'' encountered asteroid 5535 Annefrank from a distance of .
The solar phase angle ranged from 130 degrees to 47 degrees during the period of observations. This encounter was used primarily as an engineering test of the spacecraft and ground operations in preparation for the encounter with comet Wild 2 in 2003.
Encounter with Wild 2
At 19:21:28 UTC, on 2 January 2004, ''Stardust'' encountered
Comet Wild 2
on the sunward side with a relative velocity of 6.1 km/s at a distance of .
The original encounter distance was planned to be , but this was changed after a safety review board increased the closest approach distance to minimize the potential for catastrophic dust collisions.
The relative velocity between the comet and the spacecraft was such that the comet actually overtook the spacecraft from behind as they traveled around the Sun. During the encounter, the spacecraft was on the Sunlit side of the nucleus, approaching at a solar phase angle of 70 degrees, reaching a minimum angle of 3 degrees near closest approach and departing at a phase angle of 110 degrees.
The
AutoNav software was used during the flyby.
During the flyby the spacecraft deployed the Sample Collection plate to collect
dust grain samples from the
coma
A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to respond normally to painful stimuli, light, or sound, lacks a normal wake-sleep cycle and does not initiate voluntary actions. Coma patients exhi ...
, and took detailed pictures of the icy
nucleus
Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to:
*Atomic nucleus, the very dense central region of an atom
* Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA
Nucl ...
.
New Exploration of Tempel 1 (NExT)
![Stardust20110323-full](https://upload.wikimedia.org/wikipedia/commons/8/8b/Stardust20110323-full.jpg)
On 19 March 2006, ''Stardust'' scientists announced that they were considering the possibility of redirecting the spacecraft on a secondary mission to image
Comet Tempel 1. The comet was previously the target of the
''Deep Impact'' mission in 2005, sending an impactor into the surface. The possibility of this extension could be vital for gathering images of the impact crater which ''Deep Impact'' was unsuccessful in capturing due to dust from the impact obscuring the surface.
On 3 July 2007 the mission extension was approved and renamed ''New Exploration of Tempel 1'' (NExT). This investigation would provide the first look at the changes to a comet nucleus produced after a close approach to the Sun. NExT also would extend the mapping of Tempel 1, making it the most mapped comet nucleus to date. This mapping would help address the major questions of comet nucleus geology. The flyby mission was expected to consume almost all of the remaining fuel, signaling the end of the operability of the spacecraft.
The
AutoNav software (for autonomous navigation) would control the spacecraft for the 30 minutes prior to encounter.
The mission objectives included the following:
Primary objectives
*Extend the current understanding of the processes that affect the surfaces of comet nuclei by documenting the changes that have occurred on comet Tempel 1 between two successive perihelion passages, or orbits around the Sun.
*Extend the geologic mapping of the nucleus of Tempel 1 to elucidate the extent and nature of layering, and help refine models of the formation and structure of comet nuclei.
*Extend the study of smooth flow deposits, active areas and known exposure of water ice.
''Secondary objectives''
*Potentially image and characterize the crater produced by Deep Impact in July 2005, to better understand the structure and mechanical properties of cometary nuclei and elucidate crater formation processes on them.
*Measure the density and mass distribution of dust particles within the coma using the Dust Flux Monitor Instrument.
*Analyze the composition of dust particles within the coma using the Comet and Interstellar Dust Analyzer instrument.
Encounter with Tempel 1
At 04:39:10 UTC on 15 February 2011, ''Stardust-NExT'' encountered Tempel 1 from a distance of .
An estimated 72 images were acquired during the encounter. These showed changes in the terrain and revealed portions of the comet never seen by ''Deep Impact''.
The impact site from ''Deep Impact'' was also observed, though it was barely visible due to material settling back into the crater.
End of extended mission
On 24 March 2011 at approximately 23:00 UTC, ''Stardust'' conducted a burn to consume its remaining fuel.
The spacecraft had little fuel left and scientists hoped the data collected would help in the development of a more accurate system for estimating fuel levels on spacecraft. After the data had been collected, no further antenna aiming was possible and the transmitter was switched off. The spacecraft sent an acknowledgement from approximately away in space.
Sample return
![Stardust Capsule on Ground](https://upload.wikimedia.org/wikipedia/commons/c/c9/Stardust_Capsule_on_Ground.jpg)
On 15 January 2006, at 05:57 UTC, the Sample Return Capsule successfully separated from ''Stardust''. The SRC re-entered the Earth's atmosphere at 09:57 UTC,
with a velocity of , the fastest reentry speed into Earth's atmosphere ever achieved by a human-made object.
The capsule followed a drastic reentry profile, going from a velocity of Mach 36 to subsonic speed within 110 seconds.
[ Data in the simulation agrees with readings by the airborne observation team monitoring the reentry, available at Archived a]
Ghostarchive
and th
Wayback Machine
Peak
deceleration
In mechanics, acceleration is the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities (in that they have magnitude and direction). The orientation of an object's acceleration is given by t ...
was 34 ''
g'', encountered 40 seconds into the reentry at an altitude of 55 km over
Spring Creek, Nevada
Spring Creek is a census-designated place (CDP) in central Elko County, in northeastern Nevada in the western United States. It mainly serves as a bedroom community for the businesses and industries in and around the nearby city of Elko. It is pa ...
.
The
phenolic-impregnated carbon ablator (PICA)
heat shield, produced by Fiber Materials Inc., reached a temperature of more than 2,900 °C during this steep reentry.
The capsule then parachuted to the ground, finally landing at 10:12 UTC at the
Utah Test and Training Range
The Utah Test and Training Range (UTTR) is a Department of Defense military testing and training area located in Utah's West Desert, approximately west of Salt Lake City, Utah. UTTR is currently the largest contiguous block of over-land superson ...
, near the U.S. Army
Dugway Proving Ground
Dugway Proving Ground (DPG) is a U.S. Army facility established in 1942 to test biological and chemical weapons, located about southwest of Salt Lake City, Utah, United States, and south of the Utah Test and Training Range.
Location
Dugway P ...
.
The capsule was then transported by military aircraft from Utah to
Ellington Air Force Base
Ellington Field Joint Reserve Base is a joint installation shared by various active component and reserve component military units, as well as aircraft flight operations of the National Aeronautics and Space Administration (NASA) under the aegis ...
in
Houston
Houston (; ) is the most populous city in Texas, the most populous city in the Southern United States, the fourth-most populous city in the United States, and the sixth-most populous city in North America, with a population of 2,304,580 in ...
,
Texas
Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...
, then transferred by road in an unannounced convoy to the Planetary Materials Curatorial facility at
Johnson Space Center
The Lyndon B. Johnson Space Center (JSC) is NASA's center for human spaceflight (originally named the Manned Spacecraft Center), where human spaceflight training, research, and flight control are conducted. It was renamed in honor of the late U ...
in Houston to begin analysis.
Sample processing
![Aerogel labtest](https://upload.wikimedia.org/wikipedia/commons/9/90/Aerogel_labtest.jpg)
The sample container was taken to a
clean room
A cleanroom or clean room is an engineered space, which maintains a very low concentration of airborne particulates. It is well isolated, well-controlled from contamination, and actively cleansed. Such rooms are commonly needed for scientif ...
with a cleanliness factor 100 times that of a hospital operating room to ensure the interstellar and comet dust was not contaminated.
Preliminary estimations suggested at least a million
microscopic
The microscopic scale () is the scale of objects and events smaller than those that can easily be seen by the naked eye, requiring a lens (optics), lens or microscope to see them clearly. In physics, the microscopic scale is sometimes regarded a ...
specks of dust were embedded in the
aerogel collector. Ten particles were found to be at least 100
micrometer Micrometer can mean:
* Micrometer (device), used for accurate measurements by means of a calibrated screw
* American spelling of micrometre
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; ...
s (0.1 mm) and the largest approximately 1,000 micrometers (1 mm). An estimated 45
interstellar dust
Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are c ...
impacts were also found on the sample collector, which resided on the back side of the cometary dust collector. Dust grains are being observed and analyzed by a volunteer team through the
citizen science project,
Stardust@Home.
The combined mass of the harvested sample was approximately 1 mg.
In December 2006, seven papers were published in the scientific journal ''
Science
Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earliest archeological evidence for ...
'', discussing initial details of the sample analysis. Among the findings are: a wide range of
organic compounds
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The s ...
, including two that contain biologically usable
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
; indigenous
aliphatic hydrocarbons
In organic chemistry, hydrocarbons ( compounds composed solely of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (; G. ''aleiphar'', fat, oil). Aliphatic compounds can be saturated, like hexane, o ...
with longer chain lengths than those observed in the diffuse
interstellar medium
In astronomy, the interstellar medium is the matter and radiation that exist in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, as well as dust and cosmic rays. It fills interstella ...
; abundant amorphous
silicate
In chemistry, a silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is al ...
s in addition to crystalline silicates such as
olivine
The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...
and
pyroxene
The pyroxenes (commonly abbreviated to ''Px'') are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents calcium (Ca), sodium (Na), iron (Fe II) ...
, proving consistency with the mixing of
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...
and interstellar matter, previously deduced
spectroscopic
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...
ally from ground observations;
hydrous silicates and carbonate minerals were found to be absent, suggesting a lack of aqueous processing of the cometary dust; limited pure carbon (
CHON
CHON is a mnemonic acronym for the four most common elements in living organisms: carbon, hydrogen, oxygen, and nitrogen.
The acronym CHNOPS, which stands for ''c''arbon, ''h''ydrogen, ''n''itrogen, ''o''xygen, ''p''hosphorus, ''s''ulfur, r ...
) was also found in the samples returned;
methylamine
Methylamine is an organic compound with a formula of . This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine.
Methylamine is sold as a solution in methanol, ...
and
ethylamine was found in the aerogel but was not associated with specific particles.
In 2010, Dr. Andrew Westphal announced that
Stardust@home volunteer Bruce Hudson found a track (labeled "I1043,1,30") among the many images of the aerogel that may contain an interstellar dust grain.
The program allows for any volunteer discoveries to be recognized and named by the volunteer. Hudson named his discovery "Orion".
![Stardust certisfication](https://upload.wikimedia.org/wikipedia/commons/b/b1/Stardust_certisfication.png)
In April 2011, scientists from the
University of Arizona
The University of Arizona (Arizona, U of A, UArizona, or UA) is a public land-grant research university in Tucson, Arizona. Founded in 1885 by the 13th Arizona Territorial Legislature, it was the first university in the Arizona Territory.
T ...
discovered evidence for the presence of liquid water in comet
Wild 2
Comet 81P/Wild, also known as Wild 2 (pronounced "vilt two") ( ), is a comet named after Swiss astronomer Paul Wild, who discovered it on January 6, 1978, using a 40-cm Schmidt telescope at Zimmerwald, Switzerland.
For most of its 4.5 billion ...
. They have found iron and
copper sulfide
Copper sulfides describe a family of chemical compounds and minerals with the formula CuxSy. Both minerals and synthetic materials comprise these compounds. Some copper sulfides are economically important ores.
Prominent copper sulfide mineral ...
minerals that must have formed in the presence of water. The discovery shatters the existing paradigm that comets never get warm enough to melt their icy bulk.
In the spring of 2014, the recovery of particles of interstellar dust from the Discovery program's Stardust mission was announced.
The Stardust samples are currently available for everyone to identify after completing the training at Berkeley webpage.
Spacecraft location
The return capsule is currently located at the
National Air and Space Museum
The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C., in the United States.
Established in 1946 as the National Air Museum, it opened its main building on the Nat ...
in
Washington, D.C.
)
, image_skyline =
, image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...
It began exhibition there on 1 October 2008, the 50th anniversary of the establishment of NASA. The return capsule is displayed in sample collection mode, alongside a sample of the aerogel used to collect samples.
Results
The comet samples show that the outer regions of the early
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...
were not isolated and were not a refuge where interstellar materials could commonly survive.
The data suggest that high-temperature inner Solar System material formed and was subsequently transferred to the
Kuiper belt
The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...
.
;Glycine
In 2009 it was announced by
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
that scientists had identified one of the fundamental chemical building blocks of life in a comet for the first time:
glycine
Glycine (symbol Gly or G; ) is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid (carbamic acid is unstable), with the chemical formula NH2‐ CH2‐ COOH. Glycine is one of the proteinogeni ...
, an amino acid, was detected in the material ejected from comet Wild 2 in 2004 and captured by the ''Stardust'' probe. Glycine has been detected in meteorites before and there are also observations in interstellar gas clouds, but the ''Stardust'' find is described as a first in cometary material. Isotope analysis indicates that the
Late Heavy Bombardment
The Late Heavy Bombardment (LHB), or lunar cataclysm, is a hypothesized event thought to have occurred approximately 4.1 to 3.8 billion years (Ga) ago, at a time corresponding to the Neohadean and Eoarchean eras on Earth. According to the hypoth ...
included cometary impacts after the Earth coalesced but before life evolved.
Carl Pilcher, who leads NASA's Astrobiology Institute commented that "The discovery of glycine in a comet supports the idea that the fundamental building blocks of life are prevalent in space, and strengthens the argument that life in the universe may be common rather than rare."
See also
*
List of missions to comets
*
''Genesis'', sample return from the
solar wind
The solar wind is a stream of charged particles released from the upper atmosphere of the Sun, called the corona. This plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the sol ...
*''
Hayabusa
was a robotic spacecraft developed by the Japan Aerospace Exploration Agency (JAXA) to return a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis.
''Hayabusa'', formerly known as MUSES-C fo ...
'', sample return from an asteroid
*
List of uncrewed spacecraft by program
Here is an incomplete list of all uncrewed spacecraft categorized by program.
See also
* Timeline of Solar System exploration
* Lists of spacecraft
This is a list of lists of spacecraft.
* List of active Solar System probes
* List of crewed ...
*
Robotic spacecraft
*
Space exploration
Space exploration is the use of astronomy and space technology to explore outer space. While the exploration of space is carried out mainly by astronomers with telescopes, its physical exploration though is conducted both by robotic spacec ...
*
Space probe
A space probe is an artificial satellite that travels through space to collect scientific data. A space probe may orbit Earth; approach the Moon; travel through interplanetary space; flyby, orbit, or land or fly on other planetary bodies; or ent ...
*
Timeline of artificial satellites and space probes
This Timeline of artificial satellites and Space probe
A space probe is an artificial satellite that travels through space to collect scientific data. A space probe may orbit Earth; approach the Moon; travel through interplanetary space; fl ...
*
Timeline of first orbital launches by country
This is a timeline of first orbital launches by country. While a number of countries have built satellites, as of 2022, eleven countries have had the capability to send objects into orbit using their own launch vehicles. Russia and Ukraine inher ...
*
Timeline of Solar System exploration
This is a timeline of Solar System exploration ordered by date of spacecraft launch. It includes:
*All spacecraft that have left Earth orbit for the purposes of Solar System exploration (or were launched with that intention but failed), includ ...
References
External links
''Stardust'' websiteat NASA.gov
''Stardust'' websiteby NASA's Jet Propulsion Laboratory
''Stardust-NExT'' websiteby NASA's Jet Propulsion Laboratory
''Stardust'' Mission Archiveat the NASA Planetary Data System, Small Bodies Node
''Stardust-NExT'' Mission Archiveat the NASA Planetary Data System, Small Bodies Node
{{Use dmy dates, date=January 2018
NASA space probes
Missions to comets
Discovery Program
Derelict satellites in heliocentric orbit
Sample return missions
Spacecraft launched in 1999
Spacecraft launched by Delta II rockets
Missions to main-belt asteroids
Derelict space probes