February 7, 2000
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
Last updated
November 26, 2003 |
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