|
|||||||||||||||||||||||||||
| When things went terribly wrong at the worst possible time, the team worked against the clock to fix the problem. When the clock ticked away all but the last chance, and put even that in doubt, they went for it, and took... | |||||||||||||||||||||||||||
...The SHOTBy Fred Gorell |
|||||||||||||||||||||||||||
"Some likened putting the ROVs on target to being in a helicopter 30 stories high, lowering a yoyo on 30 stories of string, and putting the yoyo in a bucket, while the wind is blowing. "
|
The wreck of RMS Titanic lay on the ocean floor more than two miles below NOAA ship Ronald H. Brown. Scientist-explorers on the Ron Brown were on a science mission--to better understand how and why Titanic was deteriorating. Their research would have them studying colonies of bacteria that consumed iron from the ship's steel forming rusticles that looked very much like rusty icicles, giving the appearance of a ship melting away. They would also inspect ramp marks from previous submersible landings to help determine how much of the ship's deterioration was caused by nature, and how much by man. "Titanic is a great test bed for analyzing the deterioration of steel-hulled shipwrecks," said NOAA LT. Jeremy Weirich, a marine archaeologist and a navigator on board for the mission. There was one additional mission that caused a "buzz" on the Ron Brown and filled some of the ship's bunk space with filmmakers and television producers. It was to capture live images of Titanic for a special television presentation on National Geographic Channel, a show in which Dr. Robert Ballard returned to Titanic for the first time since he discovered the wreck in 1985 and visited it a year later, to obtain images of the legendary ship. The 2004 "Return to Titanic" mission was a partnership teaming NOAA with The National Geographic Society, Mystic Aquarium Institute for Exploration, The Jason Foundation for Education, a film crew from the National Geographic Channel, the Institute for Archaeological Oceanography of the Graduate School of Oceanography at the University of Rhode Island and scientists and archaeologists from industry and academia. The live television show was planned for a Monday night during the mission, and Ballard would be relying on a number of team members including Justin Manley, a Mitretek contract employee with NOAA's Office of Ocean Exploration. He was the mission navigator on the shift assigned to position the Brown, and the Remotely-Operated Vehicles (ROVs) Argus and Hercules, in the right places at the right time, to get the live shot necessary for the Monday night show.
The plan was to lower ROV Argus on a fiber optic umbilical, more than two miles deep to a position just above the ocean floor. From Argus, the ROV Hercules, or "Herc," would range out on a 90-foot tether that flexed each time Herc turned to investigate a new target. Both robots had bright lights and high-definition cameras, but Herc also had sophisticated tools and systems to search for, collect and retrieve specimens. No specimens would be collected from Titanic, as this was a "look-but-don't touch" mission, designed to obtain scientific data and high quality still and video images of the ship. It's normally a four-hour process to position the Ron Brown and lower the ROVs slowly while the Ron Brown moved toward the wreck. If the ROV landed 500 meters from the wreck, the Ron Brown would again move ahead, but for every 100 meters the ship moved, it would be a half hour for before the ROVs advanced that distance far below. Once positioned, the ROV's would feed a stream of images and other data to scientists. On Sunday night, the ROV control team practiced everything they would do for Monday night's live shot. Things went well and the team obtained video of Titanic as "back-up" images that could be used in the unlikely event of problems with Monday night's live shot. At the same time, Hercules's cameras captured images of diverse life in the deep sea. NOAA scientist Catalina Martinez observed the symbiotic pairing of an anemone, hitch-hiking a ride on the back of an orange crab. The anemone gets mobility and a better position to capture food particles from the water column, she explained, while the crab benefits from added protection in terms of camouflage and the anemone's stinging tentacles. "It was at once beautiful and sobering to see marine life on and around Titanic, itself a deep-sea grave for more than 1,500 souls," she said.
Just before 4 a.m. Monday morning, Manley arrived at ROV control van to stand his assigned watch. That's about when the screen went black. Hercules was no longer sending pictures from the deep. Worse, the ROV was no longer responding to commands. Images taken by Argus' cameras showed Hercules still attached, but lifeless. After a long and slow recovery, Hercules was lifted on deck later that morning and the problem was identified as a worn section of the cable from Argus where it connected with Hercules. "We had a problem with the inch-thick ROV cable - a wire with a fiber optic cable inside it where a huge volume of electricity that passes through it," said CAPT. Craig McLean, who was then director of NOAA's Office of Ocean Exploration. "The tether had been pushed back and forth during underwater operations so much that the cable weakened and shorted out." The ROV repair team was one that had been assembled by Ballard's Institute for Exploration or IFE, and they were the best in the business. Their team included electrical engineer Dave Wright, and his reputation for fixing anything. Wright and his skilled crew went to work. When they asked for help, the marine engineers of the Ron Brown's crew, normally assigned to operate the ship's engines and machinery, were up to the task. Ron Brown's engineers found a hose to arrest the tether's flexibility at its weak point and as they blended into the ROV team, the Institute for Exploration guys saw what skills they had to offer and said, 'don't leave.' The fix didn't look pretty -- sequential layers of hydraulic tubing to apply both strength and flexibility. It was a very basic fix applied to space age fiber optic system, but it a test showed the signal was good--it worked. By mid afternoon, just after the team lowered Hercules into the ocean, the signal from the ROV to the control van failed again. The crew quickly brought Hercules back onto the ship's deck, and when the ROV was powered-up again, there were "arcs and sparks and some smoke" according to a crewmember. The decision was made to replace Hercules's entire tether. With Monday night's live shot scheduled for 9:45 p.m., Manley reported to the ROV control van for his afternoon watch at 4 p.m. The navigator works closely with the bridge crew to maintain the ship's position, which, to a large extent, determines the position of the ROVs. The navigator must also work closely with the ROV pilots as they control the rate of ascent or descent of the vehicles and the position of the ROVs in the water column or on the seafloor. While the repair team continued to labor over Hercules on the after deck, Manley studied data logs of the mission thus far. As the clock ate up precious time, the final calculations would have to be spot on if there was any chance to put the ROVs on target in time for the live shot. Everyone knew they had back-up video from the day before, but the National Geographic Channel had promoted a live shot, and the entire team on the Ron Brown was working as one to make it happen. There was no instrument to measure currents across a range of depths and Manley knew that an understanding of currents, or as he called it. "the weather down there," was key to any chance of success. Other navigators joined him to review the data logs. Because the ROVs surveyed the bow of the Titanic the day before, the navigators had data to project and estimate both where to launch the ROVs, and then the direction and distance the Ron Brown should sail to swing the ROVs into position. Manley marked the two positions on the chart and the Ron Brown steamed toward ROV launch station. After the ROVs were in the water, Hercules sent back pictures of white bubbles near the surface. It was a good beginning, but it was a long way down, and everything, especially Manley's marks on the chart, had to be just right if Hercules was going to bring live images to a waiting audience. The ROVs were lowered as fast as the system would allow. Normally, a winch kept tension on the umbilical but this time the winch was almost freewheeling, sending the ROVs deeper, and deeper, racing against time. No one knew for sure if they would find their target, if the currents were indeed moving as the team calculated, or if the tether fix would hold.
In the shipboard ROV control van, the one-hour National Geographic show came up on one of their plasma screens. The ROVs were still streaming toward their position on the bottom, and the live shot was just 40 minutes away. When the Ron Brown reached its station, the ROVs, remarkably, swung into their target spot, 30 minutes ahead of the scheduled live shot. Even more remarkably, the scanning sonar on Hercules, which has a range of only 300 feet, showed that the ROV was just 170 feet from the bow of Titanic, in perfect position for the planned live shot that would begin with a view up and over the bow of the famed ship. When the team realized they were exactly on target, they remained quiet, focused on the job. There was no release of stress - no, "Yeah, we did it! There was nothing like that, because the live shot still loomed ahead of them, and it only took short-term memory to know that things can go wrong, and quickly. And then it was there - time for the live shot. An image of Titanic's bow anchor slowly emerged. Jim Newman, IFE's chief engineer and the man who designed and built the ROV systems, controlled Argus. Though he modestly calls himself a "marginal" pilot, he was selected to pilot Argus during the live program as he is clearly the most comfortable at the controls. Indeed, all the ROVs, Argus and Hercules (and Little Hercules), are his "babies." IFE pilot Todd Gregory is usually in the pilot's seat for all the 'Hollywood shots' acquired during Ballard expeditions, and he sat there now, powering Hercules' s thrusters to move the ROV and its cameras up Titanic's anchor chain and over the bow railing, then up and along the fallen mast toward the ship's bridge. The live shot cut out for a bit as cameras picked up Ballard describing what he saw. Then, back to the live shot, as Hercules came to the port side of the wheelhouse. The live shot began with Titanic emerging into focus, and now it ended, drifting back from the ship, first with a boat davit dissolving from view and then the wreck of Titanic filling the screen before slowly fading, then disappearing. Those in the ROV control van watched the screen go black as the National Geographic Channel special ended. They had done it. Later, there were "high fives" all around as the entire team celebrated, and in one of the ship's labs, Ballard shared what they all felt when asked Manley, "Doesn't it feel good to be good?" The shot was 12,500 feet deep and seen around the world. In a book following the mission, Ballard wrote, "Herc and Argus reached the ocean bottom in two and a half hours, their fastest descent yet. Even more miraculously, Justin navigated them so they arrived less than 170 feet from the bow." It was a great team effort and Manley is quick to share credit. "Some likened putting the ROVs on target to being in a helicopter 30 stories high, lowering a yoyo on 30 stories of string, and putting the yoyo in a bucket, while the wind is blowing. "A superb team of professionals made this happen," said Manley. "I was proud to be part of it."
|
||||||||||||||||||||||||||
[2/21/05] |
|||||||||||||||||||||||||||
|
CLIMATE · OCEANS, GREAT LAKES, and COASTS · WEATHER and AIR QUALITY |
|||||||||||||||||||||||||||