History
The DARPA SBIR program received a proposal for a temperature gradient glider in 1988. DARPA was aware at that time of similar research projects underway in the USSR.
The concept of an underwater glider was first explored in the early 1960s with a prototype swimmer delivery vehicle named Concept Whisper. The sawtooth glide pattern, stealth properties and the idea of a buoyancy engine powered by the swimmer-passenger was described by Ewan Fallon in his Hydroglider patent submitted in 1960. In 1992, the University of Tokyo conducted tests on ALBAC, a drop weight glider with no buoyancy control and only one glide cycle. The idea of a glider with a buoyancy engine powered by a heat exchanger was introduced to the oceanographic community by Henry Stommel in a 1989 article in Oceanography, when he proposed a glider concept called Slocum, developed with research engineer Doug Webb. They named the glider after Joshua Slocum, who made the first solo circumnavigation of the globe by sailboat. They proposed harnessing energy from the thermal gradient between deep ocean water (2-4 °C) and surface water (near atmospheric temperature) to achieve globe-circling range, constrained only by battery power on board for communications, sensors, and navigational computers.
By 2005, not only had a working thermal-powered glider (Slocum Thermal) been demonstrated by Webb Research (founded by Doug Webb), but they and other institutions had introduced battery-powered gliders with impressive duration and efficiency, far exceeding that of traditional survey-class AUVs. The University of Washington Seaglider and Scripps Institution of Oceanography Spray vehicles have performed feats such as crossing the Gulf Stream from the mainland USA to Bermuda, and, together with the Webb Slocum, conducting sustained, multi-vehicle collaborative monitoring of oceanographic variables in Monterey Bay.
In 2011, the first wingless glider, SeaExplorer was released with a large payload capacity, dedicating the first third of the vehicle to interchangeable payloads, in addition to typical CTD sensors. The vehicle achieves 1 knot speeds, is equipped with externally-rechargeable Li-Ion batteries and its torpedo shape is able to glide relying on two pairs of small static rear fins for stability.
Originally conceived as testbed for the thermal-power gliders before developing into a platform of their own, the Webb Slocum electric gliders have been widely deployed since 2003. On December 4, 2009, one of these gliders, RU-27, became the first to complete a transatlantic journey, traveling from New Jersey to the coast of Spain in 221 days. The effort was led by a team from Rutgers University, which has become one of the largest glider operators.
Read more about this topic: Underwater Glider
Famous quotes containing the word history:
“Social history might be defined negatively as the history of a people with the politics left out.”
—G.M. (George Macaulay)
“Postmodernism is, almost by definition, a transitional cusp of social, cultural, economic and ideological history when modernism’s high-minded principles and preoccupations have ceased to function, but before they have been replaced with a totally new system of values. It represents a moment of suspension before the batteries are recharged for the new millennium, an acknowledgment that preceding the future is a strange and hybrid interregnum that might be called the last gasp of the past.”
—Gilbert Adair, British author, critic. Sunday Times: Books (London, April 21, 1991)
“I am ashamed to see what a shallow village tale our so-called History is. How many times must we say Rome, and Paris, and Constantinople! What does Rome know of rat and lizard? What are Olympiads and Consulates to these neighboring systems of being? Nay, what food or experience or succor have they for the Esquimaux seal-hunter, or the Kanaka in his canoe, for the fisherman, the stevedore, the porter?”
—Ralph Waldo Emerson (1803–1882)