The Stardust spacecraft located the comet in preparation for the encounter with Comet Wild 2 at the end of January, but already at the beginning of the month it will begin to feel its influence * The spacecraft will pass 300 kilometers from the nucleus of the comet and collect dust samples from the tail which it will return to Earth in 2006
Avi Blizovsky
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Flight through the comet's tail
A NASA spacecraft is about to fly through the tail of a comet and collect hundreds of dust particles ejected from the comet. The "Stardust" spacecraft is supposed to arrive tomorrow at a distance of less than 300 kilometers from the comet Wild 2, which is about 370 million kilometers from Earth. Scientists are eager to study the dust particles because it is the primordial material from which the solar system was formed. "Stardust" is expected to absorb a much smaller amount of particles than what fills a thimble.
Stardust
This coming Saturday, for the first time, man will be able to touch real stardust - using a robotic spacecraft
Dr. Noah Brosh
If all goes as planned, this coming Saturday, January 3, 2004, man will lay his hand on real stardust for the first time. It will come from the material from which a comet is made, a kind of "space glacier" made of ice, frozen gases and dust grains. This material will be brought from the depths of space by a robotic spacecraft straight to laboratory tests on Earth. The tests will begin within three years. A spacecraft called "Stardust", which was launched in 1999 and has so far traveled about 5 billion km, will approach on Saturday up to 150 km from the comet "Wild-2", and will try to capture grains from it in a sophisticated way. It has a huge spoon, lined with a very soft spongy material, a kind of porous gel, which is supposed to capture the grains of the comet thrown from its nucleus. When the spacecraft approaches 150 km from the comet, the grains will be trapped in the gel, and then it will immediately close in a special chamber in the spacecraft. It will also be the signal to start the journey back to Earth.
The spacecraft's storage compartment was designed to protect the cometary material from contamination or damage to its original composition.
The spacecraft itself was designed so as not to damage in any way the delicate texture of the comet grains. It is estimated that this material is very porous, as it was formed in space under conditions of significant weightlessness. Therefore, if there is an impact of such a grain of dust on the side of the spacecraft, while the relative speed between the two bodies is high - a tiny crater will form in the spacecraft, or the impact will completely evaporate the grain of dust.
The spacecraft's camera will transmit to Earth a series of close-up photographs of this dramatic and historic event, also of the comet's nucleus, starting 10 minutes from the moment of the meeting between the two bodies.
Stardust lands on Comet Wild-2
4/12/2003
49 days before the historic encounter with a comet, the Stardust spacecraft managed to photograph its target - the comet Wild 2 (spelled like WILD it is pronounced Wilt-2, after the name of the discoverer). She is still 25 million kilometers from him. The image, the first of many images that will be taken in the next four weeks, will help the spacecraft's navigators and scientists plan the change of trajectory planned for January 2, as well as the approach flight and the collection of samples from the comet's tail.
The project manager, Tom Duxbury, from NASA's Jet Propulsion Laboratory in Pasadena, California, says that the mission is to steer a 5-meter-long spacecraft to a comet that is 5.4 kilometers in diameter at a speed that is 6 times the speed of a rifle bullet. "We plan to miss the comet by about 300 kilometers, and every This takes place at a distance of 389 million kilometers from Earth. By finding the comet as early as possible, as we did, the complexity of the operation decreases drastically."
The comet, a ball of ice and dust only three times the size of the Brooklyn Bridge, was first spotted on November 3 by the spacecraft's optical navigation system on the first attempt. The series of images were stored on a computer on board the spacecraft and transmitted to Earth the next day when mission navigator Dr. Shyam Bhaskaran processed the images and noticed a ball of light, glowing like a bulb near the base of a triangle formed by three stars that Stardust used to navigate .
"When I first looked at the picture, I couldn't believe it," Baskaran says. "We didn't expect to see the comet for at least another two weeks. But here he is, very close to where I thought he would be."
Wild 2's location was confirmed on November 18 using a second set of navigation images downloaded from Stardust's computer. To confirm the discovery, the spacecraft's camera was aimed to view stars down to magnitude 11, stars 1,500 times fainter than the human eye can see on a clear night.
Wild 2's early discovery provides mission navigators with critical information about the comet's location and orbit around the Sun. Additional shots will be required to allow them to fine tune. After that, a series of maneuvers are planned, the first of which will be on December 2 or 3.
Unlike other bodies that orbit the Sun, it is impossible to predict exactly the orbit of comets because their orbit around the Sun is not dictated only by gravity. The escape of gas, dust and rocks from the comet creates a "missile effect" that causes them to deviate from the expected trajectory. It is also impossible to estimate their exact position from terrestrial telescopes because the comet is surrounded by a cloud of gas and dust that escapes from it. What is actually visible from Earth is not a 5.4 kilometer wide rocky body but a mixture of gas and debris surrounding it.
Using this image, we can reach a distance of 300 kilometers from the comet, plus or minus 16 kilometers, Baskaran says. "Without the images we would not have been able to get any closer to the comet than a few thousand kilometers."
Stardust will return to Earth in 2006 and make a soft landing at a large training and testing area in Utah. It will bring back microscopic dust samples from the comet and interstellar dust and these will be taken to a facility at the Johnson Space Center in Houston, where the samples will be carefully stored and examined.
to locate the spaceship
