By Ken Atkins
STARDUST Project Manager
The Stardust spacecraft blasted into space a year ago on February
7, 1999. Its destination – Comet Wild 2 (pronounced “Vilt 2”). Its
mission — to capture interstellar and comet particles before
returning to Earth in 2006. Over the past year, the ship and its
“sailors” have learned to voyage on the ocean of deep space. It is
just now passing its farthest point from the sun (aphelion) on
this leg of the journey. It takes radio signals, travelling at the
speed of light, almost a half-hour to reach Earth after they leave
the spacecraft.
There have been “storms” to sail through. The first attempt to
move from gyro-stabilized control of the celestial attitude to
pure star-referencing, found a software “bug” that caused the
spacecraft to invoke its automatic fault protection. This placed
Stardust in a “safe” mode to allow the controllers to troubleshoot
and fix the problem. When the ship invokes the safing routine, it
shuts down all unnecessary activities, including its
telecommunication with Earth, and turns to the sun to ensure the
lifeblood of solar energy floods its batteries and electronics
with electricity. When it deems all is well, it sets up a plan to
contact us on Earth, tell us what happened, and let us tell it
what to do next. This routine, while carefully designed to protect
the spacecraft, is still an “anxiety event” for the crew back on
Earth. It’s a bit like the feeling when your teenager is late
coming home, and you get no phone call. The anxiety builds fear
until the dutiful signal comes through. “I’m here!” “I’m O.K.!”
Stardust and its crew have navigated three more safing events, all
involving data handling by on-board software.
During this first year in space, Stardust has operated the
Cometary and Interstellar Dust Analyzer (CIDA) and the Dust Flux
Monitoring Instrument (DFMI). Both have worked well, but DFMI has
a power supply with an oscillation. That means the crew has had to
develop a way of compensating for this. Currently, the plan
involves limiting its operating time and cycling it off and on.
Testing of this technique will come late in the year. DFMI is
currently “off.” CIDA has collected data of some interest to the
science team. Analysis is underway to determine if interstellar
dust impacts occurred as the ship navigated “upwind” in the
interstellar dust stream. With Stardust rounding the “mark” to
sail back downwind toward Earth, the science team has turned the
CIDA off.
As Stardust turned toward home, the crew commanded Stardust to
fire on-board rockets to achieve the precise course for the
Earth-swingby next January. The ship performed flawlessly in
completing the three required rocket burns. In addition, the
sample-return capsule (SRC) housing the Aerogel collector has been
unlatched. This is in preparation for deployment of the collector
in late February. Deployment will mark the beginning of the
attempt to “catch” interstellar particles to bring home.
So, the adventure continues. It is bittersweet in that while
Stardust sails on, its sister ships at Mars were lost. The trauma
underscores the risks of voyaging into the unknown, attempting
audaciously to know it. To know the unknown most often requires
the birth pangs of failure. Earth’s oceans are littered with the
bones of the ships and sailors who brought us to the understanding
of our planet we now enjoy. We sail its sky with the safety
provided by the sacrifices of the Wrights, Lindberg, Doolittle,
Yeager, Earhart, and many others. And we plunge into deep space on
the shoulders of Newton, Kepler, Tsiolkovsky, Goddard, and Von
Braun, with the physics of space and the fire of rockets.
Stardust has yet to meet its destiny. The unknown “landfall” of
Wild 2 waits for the dawn of 2004. Nevertheless, the ship is
“spaceworthy.” The design is robust. A year of flight has made
crew and ship a team. We know each other better in the arena of
spaceflight. While we mourn our lost ships at Mars, we increase
our vigilance and resolve. We have sailed the year from Cape
Canaveral to First Aphelion.
I celebrate the spacecraft. I congratulate the crew.
Sail on, Stardust! May the “wind” be at your back! Happy birthday!
Dr. Kenneth L. Atkins
Project Manager,
STARDUST
