Rocket Booster Retrieval
dawn breaks over the western Atlantic Ocean, a dive team
arrives at the site of a floating SRB. See more SRB retrieval
photos in the Gallery.|
The space shuttle's
Solid Rocket Booster, or SRB, casings and associated flight hardware
are recovered at sea after each launch and recycled in order to
reduce the cost of launches.
boosters are disassembled, refurbished and reloaded with solid propellant
The two NASA
retrieval ships that perform the SRB recovery, named Liberty Star
and Freedom Star, were specifically designed and constructed for
this task. Built at Atlantic Marine Shipyard, Fort George Island,
near Jacksonville, Fla., in 1980 and 1981, the ships are 53.6 meters
(176 feet) in length, 14.3 meters (37 feet) in width and draw 3-4
meters (10-12 feet) of water.
Each ship is
designed to retrieve one booster. Each ship's complement includes
a crew of 10, a nine-person SRB retrieval team, a retrieval supervisor
and observers. The maximum complement is 24 persons.
challenge we face during retrieval is weather," said Joseph Chaput,
manager of United Space Alliance Marine Operations and captain of
the Liberty Star. "We might have to wait out there for days if the
weather is too rough. We can't retrieve the SRBs in 20-foot seas."
When the weather
cooperates, the team conducts a visual assessment of the flight
hardware upon arrival. The pilot parachutes and main parachutes
are the first items to be brought onboard. With the chutes and frustum
recovered, attention turns to the SRB. The dive team prepares for
Two small boats,
with nine retrieval divers aboard, are deployed. The job of the
first dive team is to install an Enhanced Diver-Operated Plug, or
EDOP, in the nozzle of the booster. The EDOP is launched from the
ship and towed to the booster by one of the small boats. Once dive
preparations are complete, the dive team enters the water for EDOP
insertion. The EDOP is 7 meters (22 feet) in length and weights
500 kilograms (1,100 pounds). It is slightly buoyant in water, meaning
it just floats and is easily guided to the aft skirt at a depth
of about 33 meters (110 feet) by the divers. A quick inspection
of the nozzle is conducted. The EDOP is then inserted into the booster
nozzle. Once the EDOP legs are locked in place and the nozzle sealed,
an air hose is attached, which is deployed from the ship.
SRB retrieval team attaches towlines to a spent booster.|
team double-checks the aft skirt and EDOP installation to ensure
there are no problems. After the second dive is completed, de-watering
operations begin. Air is pumped from the ship through the EDOP and
into the booster, displacing water within the casing.
As the process
continues, the booster rises in the water until it becomes top-heavy.
It falls horizontally, like a log in the water. Air pumping continues
until all water is expelled from the empty casing. The final step
in the ocean retrieval procedure is to connect the ship's tow line.
Once the tow connection is made, the divers return to the ship,
and the trip to NASA's Hangar AF on Cape Canaveral Air Station begins.
The ships enter
Port Canaveral, where the booster is changed from the stern tow
position to a position alongside the ship, the hip tow position,
to allow greater control. The ships then pass through a drawbridge,
Canaveral Locks, and transit the Banana River to Hangar AF. The
SRBs are lifted from the water with a straddle-lift style crane
and placed on rail cars to begin the disassembly and refurbishment
In 1998, the
Solid Rocket Booster recovery ships took on a new service for NASA.
Space Flight Operations contractor United Space Alliance, or USA,
streamlined efforts for the Space Shuttle program by taking over
the towing of the shuttle's External Tanks from Louisiana to Florida
using the Liberty Star and the Freedom Star.
for their role supporting space shuttle operations, the Liberty
Star and Freedom Star also have proven themselves in other operations.
Over the years, both vessels have seen service in side-scan sonar
operations, cable-laying, underwater search and salvage, drone aircraft
recovery, as platforms for robotic submarine operations and numerous
support roles for other government agencies.
vessels are one of the significant tools used to provide reuseable
hardware and controlled costs for manned space flight," said USA
SRB Operations Director Jim Carleton.
photos for this story were provided by Kennedy Space Center's Spaceport