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:
“If you look at history you’ll find that no state has been so plagued by its rulers as when power has fallen into the hands of some dabbler in philosophy or literary addict.”
—Desiderius Erasmus (c. 1466–1536)
“I believe that in the history of art and of thought there has always been at every living moment of culture a “will to renewal.” This is not the prerogative of the last decade only. All history is nothing but a succession of “crises”Mof rupture, repudiation and resistance.... When there is no “crisis,” there is stagnation, petrification and death. All thought, all art is aggressive.”
—Eugène Ionesco (b. 1912)
“The basic idea which runs right through modern history and modern liberalism is that the public has got to be marginalized. The general public are viewed as no more than ignorant and meddlesome outsiders, a bewildered herd.”
—Noam Chomsky (b. 1928)