09.02.04
Is the sample safe to bring to Earth?
The Genesis
sample, consisting of protons, ions and atoms from the
Sun, does not pose any risk to the Earth. The National
Research Council's Space Studies Board determined
that the sample has no potential for containing life or
other material of concern. The samples are handled in
clean rooms to protect them from contamination by
Earth material -- not the other way around. They will
be housed for study at the Advanced Curation
Laboratory at NASA's Johnson Space Center in
Houston.
What if it doesn't land on target?
The return of the
sample capsule is planned to occur at the Utah Test and
Training Range (UTTR), a vast and unoccupied salt flat
controlled by the U.S. Army and Air Force. The site
was chosen because it provides an ample area to allow
for aerodynamic uncertainties and winds that might
affect the direction the capsule travels in the
atmosphere. The area of the landing zone and its
surrounding safety margin measures thousands of
square miles. Based upon the nearly flawless
performance of the spacecraft so far, combined with a
history throughout the flight of being able to navigate
the spacecraft extremely accurately, it is fully expected
that the Genesis team will be able to deliver the capsule
well inside this zone.
How does the sample come back to Earth?
The
sample return capsule, still attached to the main
Genesis spacecraft, will be aligned to its proper entry
orientation about six hours before entry. At that time it
will be spun to 15 revolutions per minute, adding
stability for its descent into Earth's atmosphere. The
capsule will be released two hours later. After the
capsule is released, the main spacecraft will be diverted
so it cannot collide with the sample return capsule.
Having completed its mission of carrying the return
capsule and its scientific cargo, the spacecraft will fire
its large thrusters one last time in a "divert maneuver"
that will deliver it into an orbit around the Sun, just
ahead of the Earth.
What if something goes wrong before the capsule is released?
In the unlikely event of a problem
preventing accurate targeting for entry, an option exists
to delay the release of the capsule and make a course
change that would place the entire spacecraft into orbit
around the Earth. Another sample return attempt would
follow approximately six months later.
How do you catch the sample before it hits the ground?
Nearly 19 miles above the ground over
UTTR, the capsule begins to decelerate by releasing a
small "drogue" parachute, which helps to slow down
and stabilize the 500-pound capsule. Moments later,
when the capsule is about 20,000 feet above ground,
a larger rectangular-shaped parafoil like a skydiver's
chute allows the capsule to gently spiral downward at
just 10 miles per hour. Meanwhile, two chase
helicopters (one lead and one backup) outfitted with
specially designed retrieval equipment, maneuver for
a mid-air capture. The lead helicopter follows the
parafoil's glide path, hooks and collapses the chute,
and gently lowers the capsule into a sealed container.
This is all done in an effort to safely transport the
capsule to contamination-controlled laboratory tents,
without disturbing the solar samples inside.
What if you miss catching it and it parachutes to the ground?
If the sample return capsule lands on its
own, some of the delicate collector materials will
likely break, making the sample more difficult to
identify and categorize. The sample would still be
valuable, but it would take longer for scientists to sort
through the broken pieces.
Are there any dangerous substances that could be released from the capsule?
Batteries in the capsule
contain sulfur dioxide, which, as with any battery,
will be treated with caution in the capsule recovery.
What if it lands and you can't find it?
Spacecraft
tracking data would be used to determine the vicinity
of the capsule, and a radio beacon would help
pinpoint its location for pickup.
Will it make any strange noises or be visible as it comes in from space?
Probably not, but it's
possible a sonic boom may be heard somewhere
along the descent path from Oregon to Utah. The
capsule probably will not make any visible streaks in
the sky as it descends through the atmosphere but it
might. The capsule itself is less than five feet in
diameter, probably too small to be seen, though its
parachute will be visible to the retrieval helicopter
pilots and possibly to nearby viewers at the test
range.
For more information, see
http://genesismission.jpl.nasa.gov, or contact Aimee
Whalen at 818-354-3245 or aimee.l.whalen@jpl.nasa.gov