From the deck of Liberty Star, one of two KSC solid rocket booster recovery ships, a crane lowers a one-man submarine into the ocean near Cape Canaveral, Fla. Called DeepWorker 2000, the sub is being tested on its ability to duplicate the sometimes hazardous job United Space Alliance (USA) divers perform to recover the expended boosters in the ocean after a launch. Photo: NASA/KSC

A demonstration to evaluate the use of a one-man submarine during Space Shuttle solid rocket booster retrieval operations will be conducted at sea by United Space Alliance post flight operations during the upcoming STS-101 mission.

The demonstration is part of a continuing program by NASA and United Space Alliance (USA) to augment safety in all phases of Space Shuttle operations.

USA, prime contractor to NASA for the Space Shuttle program, is responsible for retrieving the two expended solid rocket boosters (SRB) after they separate from the Space Shuttle about two minutes into powered flight. The boosters splash down in an impact area about 140 miles east of Jacksonville, FL, and are towed back to Cape Canaveral Air Force Station for refurbishment by two specially rigged recovery ships, Liberty Star and Freedom Star.

For STS-101, a chartered one-man submarine, designated DeepWorker 2000, will be deployed from Liberty Star once the right hand booster splashes down. The submarine will be evaluated on its ability to duplicate the job USA divers presently do at the recovery site. Using a manipulator arm, the submarine pilot will demonstrate capabilities to cut tangled parachute riser lines, if necessary, and attach a Diver Operator Plug (DOP) used to extract water and provide flotation for the SRB. A team of USA divers currently performs these operations at depths of as much as 120 feet, sometimes under hazardous conditions.

At left, a manipulator arm on a one-man submarine demonstrates its ability to cut tangled parachute riser lines and place a Diver Operator Plug (top right) inside a mock solid rocket booster nozzle (center). Photo: NASA/KSC

The test also will include evaluation of a new Enhanced Diver Operator Plug (EDOP) that features a motor powered locking mechanism that replaces the present manual system to enhance diver safety and reduce work load at depth. It also has been streamlined for easier handling underwater.

Under the test plan, the submersible will attach the EDOP to the SRB nozzle on launch day with two divers in the water documenting the event. A third diver is present as a safety observer. Since the EDOP is not yet certified, it will be removed and taken onboard Library Star after the test.

On the morning after launch, the submarine pilot will install the conventional DOP to the SRB nozzle with five divers available to provide documentation and complete the installation as necessary. The SRB will then be towed back to Port Canaveral.

The newly designed DeepWorker 2000, built by Nuytco Research Ltd., North Vancouver, British Columbia, is 8.25 feet long, 5.75 feet high and weighs 3,800 pounds. It can explore to depths of 2,000 feet and is equipped with a package of eight high-powered thrusters, double the number used during preliminary testing at Port Canaveral last August.

Space Shuttle program management will evaluate the results of the demonstration.