The STARDUST Spacecraft will make three orbits around the Sun. At the end of the first orbit the Spacecraft will fly by Earth and receive a gravity assist that will boost its speed thus enabling it to fly further out for its second and third orbits. At the end of the second orbit the Spacecraft will be back again at the position where it received the gravity assist from Earth, but this time the Earth will not be nearby so there is no gravity assist.
On its third orbit, STARDUST will encounter comet Wild 2 which, due to its higher speed, will overtake STARDUST from behind and pass it. The Spacecraft Navigation camera will take pictures of the comet at close range and beam them back to Earth while at the same time capturing samples of comet dust with its Aerogel collector.
After the close encounter, the Spacecraft will continue on its third orbit toward a rendezvous with Earth at which point the Sample Return Capsule containing the comet dust captured from Wild 2 will be dropped by parachute onto the desert floor in Utah on the night of January 15th, 2006.
The view shown here is looking down on the North pole of the Sun. The scale is
in AU (Astronomical Units where 1 AU = 93 million miles, the average distance
from the Earth to the Sun). As can be seen from the plot, the STARDUST
Spacecraft will fly about twice as far from the Sun as the planet Mars in order
to encounter Wild 2. The comet itself has a highly elliptical orbit which
falls inside the orbit of Mars during its nearest approach to the Sun and
outside the orbit of Jupiter (see other movie) at its outer extreme.