Abstract
This paper entitled Stardust is about none other than the famous Stardust mission by NASA. This paper will go in depth about how the mission was conceived and who was the primary funder of the mission. After the introduction of the mission stardust we go in depth of how the spacecraft was designed. What material was used for the frame of the spacecraft and why that certain material was used instead of anything else. This paper will also go over how the spacecraft communicated back to earth when it was thousands of miles away. Another interesting thing that will be explained is how the spacecraft was powered. What was or were the technologies implemented on the spacecraft to make it active for so long. Like anything else that is unmanned and automated, there has to have been a computer on board and this paper will go through the details of what computer was on board and why that particular computer was chosen if possible. Since this was a spacecraft with a set trajectory, what else controlled it to make it stay in place? That’s when this paper talks about the attitude control and propulsion systems onboard the stardust spacecraft. The last thing that will talked about in the spacecraft design section of this paper is the scientific instruments the stardust spacecraft carried in order to fulfill its primary objective. Its primary objective was to do a fly by and collect samples from preset meteor targets. The next major body of this paper is the actual mission profile of the spacecraft. The mission’s primary objective was to fly by a meteor and collect samples from space and another meteor. This sections will go over where the spacecraft was launched and what its trajectory was. Also, what date it was actually launched successfully. Its first trajectory was aimed towards a meteor called Anne frank. Brief information about the meteor Anne Frank will be given and what the purpose of the meteor encounter was for during the stardust mission. The second trajectory of the spacecraft was a second meteor called Wild 2. Like the first meteor, brief information will be given about the meteor and also why it was a part of the spacecraft’s pre-designated trajectory. The next section of the paper will go over the discoveries that were found during the stardust mission. One part of the section will be about what was gathered from the fly by when the stardust spacecraft came in contact with the meteor Anne Frank. The other part of this section will be about what was discovered and recovered from the second meteor Wild 2. Another things that was part of the mission was to gather dust from space itself. This part of the paper will also go over how the samples were collected and stored while in space. Since the whole point of this mission was to collect samples from space and the meteor, in this section I will also go over how the samples were retrieved when the spacecraft was still in space and when the samples were successfully received. The last thing that will be mentioned about the stardust mission is that it had a mission extension. Soon after the primary mission was completed, the stardust mission was extended with new primary objectives. The last section will go over the new primary mission and when it was set and finished. Also, information will be given about its encounter with meteor Tempel 1. This paper uses information gathered from valid resources like NASA’s official website and others noted in the reference page.

Introduction:
Stardust was a spacecraft that NASA launched into space on February 7, 1999. The launch site was Cape Canaveral, United States. The vehicle used to launch the spacecraft was the Delta I I, which is an American launch system. The Stardust spacecraft weighed at about 300 kilograms and it was classified as a robotic space probe since its mission was to study comets. Studying comets had been an interest for scientists in the United States since the early 1980s. The earliest missions to study comets had been successful (Nasa). These missions were about studying comet Halley and scientist were thrilled to have succeeded and have close up data of a comet for the first time. After the earlier missions, Stardust was conceived to be the next spacecraft on a mission to retrieve information on a comet. Stardust was conceived during the fall of 1995 by one of NASA’s programs, NASA’s discovery program. Stardust was a low cost mission with very high scientific goals. It was low cost compared to other missions before it that unfortunately got canceled. Stardust had begun construction the year after in 1996. Since Stardust had big scientific goals it had been subjected to maximum contamination restriction. For this, NASA follows a strict guideline principle called planetary protection. Its main goal is to prevent any type of contamination to preserve the planetary record of information gathered outside earth by preventing human contact microbial introductions. Stardust was subjected to level 5 planetary protection, which is the maximum level. Since this was a United States mission, it was received its major funding from NASA office of Space Science (Nasa). The total mission cost of Stardust was approximately $199.6 million. Even though it’s nearly $200 million, it was still considered low cost considering its main goal. Out of the $199.6 million dollars roughly $128.4 million was how much it cost to develop Stardust and construct the spacecraft. The rest of the cost which was another rough estimate of about $40 million was for mission operations. When it came to the actual construction of the Stardust spacecraft, Lockheed Martin was the major contractor that NASA had appointed to construct it. This was how Stardust was conceived, by brilliant scientist at NASA and funded by NASA as well (Nasa).
Spacecraft design: The Stardust spacecraft was designed by NASA. The spacecraft bus was designed to be 1.7 meters in length, which is about 5.6 feet, and .66 meters in width, which is roughly 2.2 feet. Stardust’s design was adapted from a different space bus that was originally developed by Lockheed Martin Astronautics, the SpaceProbe seep space bus (JPL). The spacecraft bus was primarily constructed with graphite fiber and an aluminum honeycomb support structure underneath to provide greater structural integrity. To provide even further structural integrity, the entire Stardust spacecraft was covered with polycyanate and other material known as Kapton sheeting for even more protection. Since this was a low cost mission Stardust incorporated a lot of older designs and technologies that were meant for other spacecraft’s that were previously developed for other future missions by Small Spacecraft Technologies Initiative. These older designs and technologies were also from past successful missions. Stardust also featured several scientific instruments to collect data, this instruments will be elaborated on even more later on. The Stardust spacecraft was powered by two solar arrays that were capable of providing an average of 330 watts of power (JPL). The solar arrays also included whipple shields to protect the delicate surfaces of the spacecraft from the potentially damaging cometary dust while the spacecraft was in the course of its mission. A whipple shield is a type of hypervelocity impact shield used to protect manned and unmanned spacecraft from collisions with micrometeoroids and orbital debris whose velocities generally range between 3 and 18 kilometers per second (Nasa). The solar arrays that were incorporated on Stardust were designed primarily from the Small Spacecraft Technology Initiative spacecraft development guidelines. The solar arrays provided a unique method of switching from series to parallel depending on the distance the spacecraft was from the sun. As for power, the last thing Stardust included was a single nickel hydrogen (NiH2) battery, this battery was included to provide the spacecraft with power when the solar arrays didn’t receive enough sunlight. For communicating back to earth with the Deep Space Network, Stardust had to transmit data across the x-band using a parabolic high gain antenna that measured .6 meters. It also used two other antennas, the medium gain antenna and the low gain antennas. It also featured a 15 watt transponder that was originally designed for the Cassini spacecraft. The Stardust spacecraft also sported a computer (Admin). The computer that other spacecraft operated on was a radiation hardened RAD6000 32-bit processor card. The processor card was also able to store about 128 megabytes of data when the spacecraft was unable to communicate to earth. 20% of the storage was already taken up by the flight system software. VxWorks was a form of sytem software on Stardust, it was an embedded operating system that was developed by Wind River Systems. When it came to designing the Stardust spacecraft, a good attitude control and propulsion system. The spacecraft was three-axis stabilized with eight 4.41 N hydrazine monopropellant thrusters, and eight 1-N thrusters to maintain attitude control (Nasa). Many necessary minor propulsion maneuvers were performed by these thrusters as well throughout its course. 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. Stardust also included several scientific instruments. One of the scientific instruments was the navigation camera it was intended for targeting its primary objective during the flyby which will be mentioned later. It also captures black and white images through a filter wheel. This makes it possible to assemble color images and detect certain gas and dust emissions in the coma. The navigation camera also captures images at various phase angles, this makes it possible for scientists to create a three dimensional model of a target to better understand the origin, morphology, and mineralogical inhomogeneities on the surface of the nucleus (Nasa). The navigation camera also utilizes the optical assembly from previous spacecraft, Voyager Wide Angle Camera. In addition to that, it was fitted with a scanning mirror to vary the viewing angle. This was intended to avoid potentially damaging particles. For environmental testing and verification of the navigation camera, the only remaining Voyager spare camera assembly was used as a collimator for testing of the primary imaging optics. The second scientific instrument was the Cometary and Interstellar Dust Analyzer. The dust analyzer is a mass spectrometer able to provide real-time detection and analysis of certain compounds and elements. The way it works is that particles enter the instrument after colliding with a silver impact plate and traveling down a tube to the detector (JPL). The detector is then able to detect the mass of separate ions by measuring the time taken for each ion to enter and travel through the instrument. The third instrument was the Dust Flux Monitor Instrument. This instrument was located at the site of the whipple shield, this sensor provides data regarding the flux and size distribution of particles in the environment around Stardust primary objective. This sensor records data by generating electric pulses as a special polarized plastic sensor is struck by high energy particles as small as a few micrometers. The second to last instrument was the Stardust Sample Collector. This collector uses a material called aerogel. Aerogel is a low-density, inert, microporous, silica-based substance, to capture dust grains as the spacecraft passes through the coma of its primary objective. When this collector completed its goal, it receded into the Sample Return Capsule for entering the Earth's atmosphere. The return capsule with encased stardust samples would then be retrieved from Earth's surface and studied (Nasa). The last scientific instrument was the Dynamic Science Experiment. It was an experiment using the X-band to conduct radio science on the primary objective. It was used to determine the mass of objects it came across by. This radio science experiments were also use to estimate the impact of large particle collisions on the spacecraft. This was all that was needed to know about the spacecraft design.
Mission Profile: As mention briefly in the beginning, its primary objective was to collect data from comets. Also mentioned earlier, Stardust was launched February 7, 1999, by NASA from Space Launch Complex 17A at the Cape Canaveral Air Force Station in Florida, aboard a Delta II 7426 launch vehicle. Stardusts complete burn sequence lasted 27 minutes and this brought it into a heliocentric orbit that would bring the spacecraft around the Sun and past Earth for a gravity assist maneuver in 2001. It also used the gravity assist maneuver to reach asteroid AnneFrank in 2002 and its primary objective, Wild 2 comet in 2004 at a low flyby velocity of 6.1 kilometers per second (Admin). It was that same year that Stardust performed a deep space maneuver that would allow it to pass by Earth a second time in 2006, to release the Sample Return Capsule for a landing in Utah. On November 2, 2002, Stardust encountered asteroid 5535 Annefrank from a distance of 3,079 kilometers. 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 its primary objective, comet Wild 2 in 2003. On January 2, 2004, which was later than expected, Stardust encountered its primary objective, Comet Wild 2 on the sunward side with a relative velocity of 6.1 kilometers per second at a distance of 237 kilometers. The original encounter distance was planned to be 150 kilometers, but this was changed after a safety review board increased the closest approach distance (Nasa). This was intended to minimize the potential for catastrophic dust collisions from the comet. 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 sun-lit side of the comet’s 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. During the flyby the spacecraft deployed the Sample Collection plate to collect dust grain samples from the coma, and took detailed pictures of the icy nucleus. At this point is where Stardust completed its objective and returned what it received to earth.
Discoveries:
During the flyby of AnneFrank Stardust captured images and these images show the asteroid to be 6.6 × 5.0 × 3.4 kilometers, twice as big as previously thought, shaped like a triangular prism, with several visible impact craters. After Stardust sent back samples of AnneFrank it was then that ground based light curve data was used in an attempt to measure Annefrank's rotational period (LeBlanc). The data that was collected resulted in possible rotational periods of 0.5, 0.63 or 0.95 days, with 0.63 days fitting the data best. The light curve data also suggests that the asteroid is not Lambertian, meaning that surface features, such as shadows from boulders and craters, play a role in the object's perceived brightness and not just the asteroid's relative size when seen from that orientation. When Stardust collected data from comet Wild 2 and sent it back to earth, many discoveries were found. One of which being that a wide range of organic compounds were found. With two organic compounds that contain biologically usable nitrogen and indigenous aliphatic hydrocarbons (LeBlanc). These discoveries were published in December 2006 in seven papers that were published in the scientific journal. Another interesting finding was pure carbon. As of 2011 it has been discovered that there is evidence of liquid water in comet Wild 2. They also found copper sulfide minerals in the water. All of these were extraordinary finding that Stardust help retrieve (LeBlanc). New Mission:
After Stardust completed its mission, it received a mission extension. Its mission extension was named NExT and its goal was to explore another comet named Tempel 1. Stardusts new primary objective was to 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. Another primary objective was to extend the geologic mapping of Tempel 1’s nucleus (Stardust/NExT). Stardust also had a final primary objective which was to extend the study of smooth flow deposits, active areas and known exposure of water ice. In addition to the primary objectives, Stardust also had three secondary objectives. The first secondary objective was to image and characterize the crater that was produced by Deep Impact in July 2005. This was a secondary objective to better understand the structure and mechanical properties of the comet Tempel 1. The second secondary objective was to measure the density and mass distribution of the dust particles within the coma using the scientific instrument Dust Flux Monitor. The last secondary objective was to analyze the composition of dust particles within the coma using the Comet and Interstellar Dust Analyzer instrument. Stardust officially encountered Tempel 1 on February 15, 2011. It encountered Tempel 1 from a distance of 181 kilometers. During this encounter, an estimated 72 images were captured of Temple 1 (Stardust/NExT). These images were a great find because it showed that the terrain had changed and also revealed portions of the comet never seen by Deep Impact. Another thing that was observed was the impact site from Deep Impact, although it was barely visible due to the material settling back into the crater. After this mission was completed, Stardust was officially ended (Stardust/NExT).
Conclusion:
In conclusion, the Stardust Spacecraft was an interesting mission. Stardust was conceived in 1995, built in 1996 and launched in 1999. The spacecraft was also well designed considering it was low cost of nearly $200 million. It was well built to sustain power with dual 330 watt power solar arrays. It communicated back to earth efficiently using X-band. It also had an efficient processor, efficient enough to send back valuable data to earth. It also had well-made thrusters to control attitude and propulsion. Above all its design, it included very useful scientific instruments to collect samples and data for further studying and observation. All of its design and instruments were meant to complete its objective, which was to gather data from comet Wild 2. On that course Stardust was able to flyby AnneFrank asteroid to send back useful test data. With this information scientists were able to determine the period of rotation of AnneFrank amongst other things. Also, as a result of this mission, scientists and discovered and organic compounds to exist outside earth and can be usable. They have also found proof of water on the comet and minerals in it. After this mission was complete, Stardust was set off on a new mission to explore Tempel 1 were it made even more discoveries and retrieve more data to better understand what currently know. This was an interesting journey to look back at our history and explore what NASA has done in the name of science with Stardust.

References
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LeBlanc, Cecile. "Evidence for liquid water on the surface of Comet Wild-2." 10 april 2007: 1. Web. 10 Apr. 2013. .
NASA, . "Flight System Description." 26 nov 2003: 1. Web. 10 Apr. 2013. .
JPL, . "Cometary and Interstellar Dust Analyzer (CIDA)." 26 nov 2003: 1. Web. 10 Apr. 2013. .
Admin, . "StarDust." 20 Mar 2009: 1. web. 10 Apr. 2013. .
"Stardust/NExT." n.d. 1. Web. 11 Apr. 2013. .