Unfolding, some say, like a huge hidden flower emerging in bloom, a radar antenna with a 39-foot, or 12-metre diameter has been unfurled aboard a satellite in low Earth orbit, following its launch in late July from India.

The mission is known as NISAR, an acronym reflecting the partnership between NASA and the Indian Space Research Organisation, ISRO.

NISAR will be capturing detailed data about forest and wetland ecosystems undergoing change, about the impact of earthquakes on the Earth's crust and the motion of glaciers and sheets of ice over time.

The mission is designed to help communities around the world plan ahead for natural disasters and implement recovery from them more efficiently. Karen St. Germain, director of NASA's Earth Science Division in Washington, DC, said this project will go a long way toward using science to assist in decision-making under these difficult circumstances -- from responding to disasters to formulating agricultural policy.

The antenna reflector, made of gold-plated wire mesh, has been compared to the "eye," of the system and it operates on both the L-band and the S-band. According to NASA, the system that operates on the L-band is particularly suited to penetrate forest canopy and clouds. The S-band system has particular sensitivity to light vegetation and moisture in snow.

The unprecedented joint satellite project will collect an estimated 80 terabytes of data daily.