As the Genesis
capsule descends through the atmosphere, it will be
"painted" by powerful radars located on the
Utah Test & Training Range. This will provide tracking
information allowing ground-based cameras to spot the
capsule. Backup tracking is provided by a Global Positioning
System (GPS) unit on the Genesis capsule that transmits
position data to a ground station, which in turn relays
the information to the mission control center. The radar,
visual and GPS data will provide an accurate plot in
three dimensions for the capsule's location. This plot
is generated at the mission control center located about
160 kilometers (100 miles) away from the range at Hill
Air Force Base. A ground control intercept officer based
at the Hill Air Force Base mission control will direct
helicopter flight crews towards the capsule.
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Artist rendering
of Vertigo helicopter
lining up to
snap parafoil |
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Descending at about 3.7 meters per
second (12 feet per second, or slightly over 8 miles
per hour), it will take about 10 minutes for the capsule
to descend after its parafoil deploys until it reaches
the 3,000-meter (10,000-foot) altitude inhabited by
the two chase helicopters. By this time, the two flight
crews will have been hovering for about 10 minutes when
they receive the information on the capsule's location.
Each helicopter has the capability of making a successful
intercept anywhere on the Utah Test & Training Range.
When the primary flight crew "tally-ho's"
(visually spots) the Genesis capsule, they will take
over the intercept, flying into position behind the
parafoil. The crew will lower the capture pole and its
hook to about a 50-degree angle as they fly in a trailing
formation and observe the parafoil's flight characteristics.
If all looks well, they will accelerate so as to overtake
the parafoil at a closing speed of about 7 to 10 meters
per second (15 to 20 miles per hour). The pilot will
skim the top of the capsule's parafoil with only about
2.5 meters (8 feet) separating the helicopter's landing
skids and the top of the parafoil.
As the parafoil strikes the boom,
its fabric will wrap around the pole and slide down
its length into the hook. When the hook encounters 200
pounds of force, the hook will separate from the boom
activating a piston that secures the parafoil to the
hook. The hook and its out-of-this-world catch will
remain connected to the helicopter via a 137-meter (450-foot)
Kevlar cable. The helicopter pilot will then pitch the
ship's nose up, quickly decelerating to prevent the
possibility that the parafoil will re-inflate and cause
mischief with the flight characteristics of the helicopter.
If the approach does not look satisfactory, the lead
flight crew can wave off. From the anticipated 2.75-kilometer
(9,000-foot) altitude for a first capture attempt, there
will be an estimated five additional opportunities to
perform a successful mid-air retrieval.
Mid-Air Retrieval Tests (.mpg)
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