Al Gore proposed the satellite in 1998, at the National Innovation Summit at the Massachusetts Institute of Technology. Gazing skyward from the podium, the vice president described a spacecraft that would travel a full million miles from Earth to a gravity-neutral spot known as the Li Lagrangian point, where it would remain fixed in place, facing the sunlit half of our planet. It would stream back to NASA video of our spherical home, and the footage would be broadcast continuously over the Web. Not only would the satellite provide "a clearer view of our world," Gore promised, but it would also offer "tremendous scientific value" by carrying into space two instruments built to study climate change: EPIC, a polychromatic imaging camera made to measure cloud reflectivity and atmospheric levels of aerosols, ozone and water vapor; and NISTAR, a radiometer. NISTAR was especially important: Out in deep space, it would do something that scientists are still unable to do today-directly and continuously monitor the Earth's albedo, or the amount of solar energy that our planet reflects into space versus the amount it absorbs.
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