Since its launch on February 7, 1999, the Stardust spacecraft
has traveled over two billion kilometers completing one and
a half elliptical orbits around the Sun. On Thursday, April
18th, the mission will reach a major milestone when it arrives
at its furthest distance from the Sun, also known as its aphelion.

At this time the spacecraft will be 2.72 Astronomical Units
(407 million kilometers or 253 million miles) from the Sun, and
near the middle of the asteroid belt. This is the farthest
distance ever reached by a solar-powered spacecraft. Far beyond
the orbit of Mars, the sunlight intensity is only 13% of what
we see at Earth resulting in very cold temperatures and
diminished power generation by the spacecraft’s solar cells.
The spacecraft is performing excellently in this environment
and operations teams at the Jet Propulsion Laboratory, California
and Lockheed Martin Astronautics, Denver are eager to enter the
final phases of the mission.

After aphelion, Stardust will begin falling back towards the Sun
and by the end of the mission, in January 2006, it will have completed
another loop and a half around the Sun. On January 2, 2004, on its final
solar orbit, Stardust will fly past comet Wild 2 to collect samples and
return them to Earth in 2006. In January 2006, the samples will be
delivered by parachute inside the Stardust Sample Return Capsule to
the Utah Testing and Training Range.

The comet samples that Stardust will be collecting and returning to
Earth have been preserved since the early formation of the Solar System.
During the Solar System’s formation, they accumulated to form comets
beyond the orbit of Neptune and they are believed to be the initial
building blocks of planets and life as we know it. The returned
samples from Stardust will be distributed world wide to scientists
who will study them with the best microanalytical techniques available.
The mission will provide fundamental insights into the nature of
materials that aided in the formation of planets, both in the solar
system and around other stars.