Why in news? Virginia Norwood, an aerospace pioneer who invented the scanner that has been used to map and study the earth from space for more than 50 years, has passed away.

What was her contribution to satellite imaging?

• The Landsat satellites, speeding 438 miles above the surface, orbit the earth every 99 minutes and have captured a complete image of the planet every 16 days since 1972. These images have provided powerful visual evidence of climate change, deforestation and other shifts affecting the planet’s well-being.
• Norwood, a physicist, was the person primarily responsible for designing and championing the scanner that made the program possible.
• NASA has called her “the mother of Landsat.”
• Norwood, was part of an advanced design group in the space and communications division at Hughes, canvassed scientists who specialized in agriculture, meteorology, pollution and geology. She concluded that a scanner that recorded multiple spectra of light and energy, like one that had been used for local agricultural observations, could be modified for the planetary project that the Geological Survey and NASA had in mind.

How were these techniques used by NASA?

• The Geological Survey and NASA planned to use a giant three-camera system designed by RCA, based on television tube technology, that had been used to map the moon. The bulk of the 4,000-pound payload on NASA’s first Landsat satellite was reserved for the RCA equipment.
• The first Landsat blasted into space on July 23, 1972. Two days later, the scanner sent back the first images, of the Ouachita Mountains in Oklahoma.
• Norwood’s invention was crucial to the Landsat program’s success. Her scanner recorded multiple spectra of light and energy, which could be modified for the planetary project. The images recorded by the scanner enabled scientists to monitor changes in the earth’s surface over time. Her invention revolutionized the field of remote sensing and her work has had a lasting impact on the scientific community.