The Stardust Mission was unique because for the first time, a space probe has collected dust particles from a comet and brought these samples back to Earth. Previous missions to comets only took pictures, and therefore, scientists were really curious about these samples because comets consist of remnants from the beginning of our solar system and can answer many fundamental questions.
The Stardust probe, an American space probe developed by Lockheed Martin Astronautics, was launched on February 7, 1999, from Cape Canaveral aboard a Delta 2 rocket. Stardust was NASA’s first mission to return particles from beyond the Earth-Moon orbit (Apollo program) and is part of the Discovery program.
The target of the mission was Comet P/Wild 2, which was discovered in 1978 by Swiss astronomer Paul Wild. At the time of the space probe's launch, the comet was 820 million kilometers away. Wild 2 has a rotation period of 6.39 years.
Stardust flew by Wild 2 on January 2, 2004. During the flyby, it collected dust samples from the comet's coma—the envelope around the nucleus—and took detailed pictures of its icy nucleus. Already before this, the space probe had flown by asteroid 5535 Annefrank on November 2, 2002, and taken several photographs.
Comets
Comets, often known as "icy travelers," are cold bodies and are considered the best-preserved raw materials in our Solar System. They are visible only because the gases in their coma and tails fluoresce in sunlight and due to sunlight reflected from the solids. Gravitationally bound to the Sun, comets are of great interest to scientists studying the conditions of the early Solar System.
Relative to planets, comets are very small, typically 5-10 kilometers in diameter, and irregularly shaped, with the longest dimension often twice that of the shortest. They are believed to be fragile and are thought to have delivered water and a diverse array of carbon-based molecules to Earth during its late phase of evolution, possibly playing a crucial role in the origins of life. Through complex investigations, scientists hope to learn more about the nature of these cometary molecules and the detailed role of comets.
Spacecraft
The total weight of the spacecraft, including the propellant needed for deep-space maneuvers, was 380 kilograms. The spacecraft was approximately 1.7 meters long.
Sample Return Capsule (SRC)
The Sample Return Capsule was a compact system primarily consisting of a sample canister with an aeroshield/base cover, navigation recovery aids, an event sequencer, and a small parachute system. The SRC performed a direct entry to Earth. After entry, it continued to free-fall until approximately 3 km above ground, at which point the parachute deployment sequence was initiated. The landing site was in Utah, USA.
Mission Results:
Glycine discovery: Scientists discovered glycine, a fundamental building block of life, in samples of comet Wild 2 returned by NASA's Stardust spacecraft.
Comet dust samples: The spacecraft returned samples of comet dust, which were found to contain rocky materials that formed at extremely high temperatures.
Organic compounds: The mission found a new class of organics in comet dust captured from comet Wild 2 in 2004.
Interstellar dust: Scientists identified possible interstellar dust particles from the Stardust capsule returned to Earth in 2006.
Comet Tempel 1: The spacecraft flew by and imaged Comet Tempel 1, providing stereo images of the comet and its impact crater created by Deep Impact.
Asteroid Annefrank: The spacecraft flew by and imaged the asteroid Annefrank, revealing its binary nature.
Comet Wild 2: The spacecraft flew by and imaged Comet Wild 2, providing high-resolution images of the comet's coma and nucleus.
Mission Overview:
February 7, 1999 | Launch |
February - May 2000 | First interstellar dust collection |
January 15, 2001 | Earth gravity assist |
April 18, 2002 | Aphelion (spacecraft's furthest distance from the Sun) |
August - December 2002 | Second interstellar dust collection |
November 2, 2002 | Asteroid Annefrank flyby |
January 2, 2004 | Comet Wild 2 encounter |
January 15, 2006 | Sample return capsule parachutes to Earth |
February 15, 2011 | Encounter with Temple 1 at the Stardust NExT mission |
March 24, 2011 | Last transmission |