NASA has a free ebook on the U-2's development: https://www.nasa.gov/connect/ebooks/unlimited_horizons_detail.html https://www.nasa.gov/connect/ebooks/unlimited

NASA has a free ebook on the U-2's development: https://www.nasa.gov/connect/ebooks/unlimited_horizons_detail.html https://www.nasa.gov/connect/ebooks/unlimited_horizons_detai... It's good reading.