Arthur Bertram Cuthbert Walker II, also known as Art Walker to close friends, was born on August 24, 1936, in Cleveland, the only child of Cuthbert and Hilda Walker. Walker had a lifelong interest in the sciences, which his parents encouraged.
Walker’s family relocated to New York City in 1941, and he attended the Bronx High School of Science. There, he encountered numerous challenges, including a teacher who attempted to discourage him from studying science. However, his mother intervened and informed the teacher that her son would learn whatever he pleased. She also encouraged him to apply to Case Institute of Technology in Cleveland, Ohio (now Case Western Reserve University). Walker received an honors bachelor’s degree in physics in 1957. At the University of Illinois, Urbana-Champaign, he earned his master’s (1958) and doctorate (1962) degrees.
Walker joined the United States Air Force as a first lieutenant after finishing his education. His first job was in the weapons laboratory, where he designed instrumentation for a rocket-launched satellite that would measure Van Allen belt radiation in the Earth’s magnetic field. This project piqued his interest in space research.
Walker completed his military service in 1965 and joined the Aerospace Corporation’s Space Physics laboratory in southern California. He began studying the Sun’s atmosphere using rocket-launched instruments, first at ultraviolet wavelengths and then X-rays.
Walker joined Stanford University’s Applied Physics department as a professor in 1974. Between 1977 and 1980, he was a Center for Space Science and Astrophysics member and chaired the Astronomy Program. He also left an indelible mark on Stanford’s academic life, as the majority of his 13 graduate students were from underrepresented groups in astronomy, specifically women and African Americans. Sally Ride, the first female astronaut in the United States, was his first doctoral student.
Walker became interested in technology for making mirrors that selectively reflect X-rays of a specific wavelength soon after arriving at Stanford. In 1987, Walker collaborated with Troy Barbee of Stanford’s Material Science Department, as well as graduate and undergraduate students, to build and launch a solar-observing rocket. This sounding rocket was the first to capture high-resolution images of the Sun’s corona at extreme ultraviolet and X-ray wavelengths. These ground-breaking images demonstrated the capabilities of new X-ray mirror technology, which is now used in solar telescopes such as the Solar and Heliospheric Observatory/Extreme ultraviolet Imaging Telescope (SOHO/EIT) and the Transition Region and Coronal Explorer (TRACE) (TRACE).
Walker continued to develop novel X-ray optics systems for astronomical observations throughout the 1990s. Walker was also launching an X-ray spectroscopy program to detect dark matter before his death in 2001.
Walker was the chair of the presidential commission that investigated the 1986 space shuttle Challenger disaster, in addition to his work with X-rays. NASA honored him with the Distinguished Public Service Medal in 2000 for “four decades of distinguished scholarship, achievements in experimental space sciences, and extensive service to NASA and the nation on innumerable advisory and review boards.” The Astronomical Society of the Pacific established the Arthur B.C. Walker II Award in 2016, recognizes exceptional achievement by an African American in astronomy as well as actively promoting diversity in science. Katherine Johnston, a NASA mathematician, was the first recipient.
Walker is remembered as being composed and composed, with a historical anecdote for every occasion. Nonetheless, he was a fierce protector of his domain, particularly when it came to teaching and his graduate students. He didn’t back down from taking on new tasks or accepting responsibilities. He and his wife Victoria had three children, and he enjoyed growing camellias and roses.