VIRGINIA NORWOOD

1. Context

2. Who was Virginia Norwood?

• Virginia Tower was born on Jan. 8, 1927, in Fort Totten, New York, to John Vogler and Eleanore (Monroe) Tower.
• Eleanore Tower was a homemaker and also a linguist who spoke nine languages. John Tower was a decorated Army colonel with a master’s degree in physics who eventually taught at Carnegie Tech (now Carnegie Mellon University).
• He encouraged Virginia to study math and physics and made her first slide rule with her when she was 9. As a military family, they moved frequently, living in Panama, Oklahoma, and Bermuda, among other places.
• Virginia attended five high different high schools before graduating as the salutatorian of Germantown High School in Philadelphia.
• A day after graduating in 1947, she married Lawrence Norwood, a graduate student who had been her calculus instructor during her third semester. They had three children.
• She and her husband were hired by the U.S. Army Signal Corps Laboratories in Fort Monmouth, New Jersey.
• She worked in the weather radar division, where she designed a radar reflector for weather balloons that could detect previously untraceable winds at 100,000 feet.
• She later moved to an antenna group, working on antennas that used microwaves, and designed one that remains classified.
• Norwood designed the transmitter and receiver for the world’s first communications satellite in her new role.
• A couple of years later, NASA sent a lander called Surveyor to the moon to scout possible landing locations for astronauts. Norwood’s team designed the equipment the lander used to communicate with ground control.

3. Virginia's Norwood 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". At the dawn of the era of space exploration in the 1950s and 60s, she was working at Hughes Aircraft Co., developing instruments.
• One of a small group of women in a male-dominated industry, she stood out more for her acumen.
• In the late 1960s, after NASA's lunar missions sent back spectacular pictures of Earth, the director of the Geological Survey thought that photographs of the planet from space could help the agency manage land resources.
• The agency would partner with NASA, which would send satellites into space to take the pictures.
• Norwood, who was part of an advanced design group in Hughes's space and communications division, canvasses 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.

4. 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.
• Norwood and Hughes were told that their multispectral scanner system, or MSS, could be included if it weighed no more than 100 pounds.
• Norwood had to scale, back her scanner to record just four bands of energy in the electromagnetic spectrum instead of seven, as she had planned.
• The scanner also had to be high precision. In her first design, each pixel represented 80 meters.

5. About Landsat Satellite

• 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; they were astounding.
• The RCA system was supposed to be the primary recording instrument aboard the satellite, and the MSS was a secondary experiment.
• The MSS proved not only better but also more reliable. Two weeks after liftoff, power surges in the RCA camera-based system endangered the satellite and the camera had to be shut down.
• Over the next 50 years, new Landsat satellites replaced earlier ones. Norwood oversaw the development of Landsat 2, 3, 4, and 5.
• Currently, Landsat 8 and 9 are orbiting the Earth, and NASA plans to launch Landsat 10 in 2030.
• Each generation of the satellite has added more imaging capabilities but is always based on Norwood’s original concept.
• The Landsat program has mapped changes in the planet brought on by climate change and by Human actions.
• They include the near disappearance of the Aral Sea between Kazakhstan and Uzbekistan, the shrinking of the Great Salt Lake in Utah, the evolving shape of the Mississippi Delta, and the deforestation and increasing agricultural use of land in Turkey and Brazil.

Image Source: NASA