It was very unusual at the time to have a female engineer at all. “The designer of this sensor, Virginia Norwood, she’s still with us, in her 90s. “It was an instrument that used an oscillating mirror that went back and forth to scan a path at 7-14 Hz, underneath the orbital path of the sensor, to create a digital image. That was a big turning point,” recalled Irons. “After launch, the RBV had problems, and the data from the MSS became the preferred data. But the team clearly saw the writing on the wall, and good thing too. It hardly needs to be said that in 1972, digital anything was pretty innovative, let alone high-performance digital sensors in orbit.

“But Hughes convinced NASA to put another instrument on the payload that was more experimental: the Multi-Spectrum Scanner. “Landsat 1 launched in 1972 - it carried two instruments, one was the Return Beam Vidicon, and it was kind of like a TV camera, it took analog data,” Irons said.

It’s fitting that for a project that would redefine Earth imaging, its very first satellite was both innovative and historically significant. Irons told the story of Landsat from the beginning, both what he took part in himself and the lore he’s absorbed over the years. I talked with Jim Irons, who has worked at NASA since 1978 and on Landsat since 1992.

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