Severo Ochoa, born in Spain, was a co-winner of the 1959 Nobel Prize in Physiology or Medicine. Dr. Sarah Stewart, a Mexican-American Microbiologist, is credited with the discovery of the Polyomavirus and successfully demonstrating that cancer causing viruses could be transmitted from animal to animal. Mexican-American psychiatrist Dr. Nora Volkow, whose brain imaging studies helped characterize the mechanisms of drug addiction, is the current director of the National Institute on Drug Abuse. Dr. Helen Rodríguez Trías, an early advocate for women's reproductive rights, helped drive and draft U.S. federal sterilization guidelines in 1979. She was awarded the Presidential Citizens Medal by President Bill Clinton, and was the first Hispanic president of the American Public Health Association. Some Hispanics have made their names in astronautics, including several NASA astronauts: Franklin Chang-Diaz, the first Hispanic NASA astronaut, is co-recordholder for the most flights in outer space, and is the leading researcher on the plasma engine for rockets; France A. Córdova, former NASA chief scientist; Juan R. Cruz, NASA aerospace engineer; Lieutenant Carlos I. Noriega, NASA mission specialist and computer scientist; Dr. Orlando Figueroa, mechanical engineer and director of Mars exploration in NASA; Amri Hernández-Pellerano, engineer who designs, builds and tests the electronics that will regulate the solar array power in order to charge the spacecraft battery and distribute power to the different loads or users inside various spacecraft at NASA's Goddard Space Flight Center. Olga D. González-Sanabria won an R&D 100 Award for her role in the development of the "Long Cycle-Life Nickel-Hydrogen Batteries" which help enable the International Space Station power system. Mercedes Reaves, research engineer and scientist who is responsible for the design of a viable full-scale solar sail and the development and testing of a scale model solar sail at NASA Langley Research Center. Dr. Pedro Rodríguez, inventor and mechanical engineer who is the director of a test laboratory at NASA and of a portable, battery-operated lift seat for people suffering from knee arthritis. Dr. Felix Soto Toro, electrical engineer and astronaut applicant who developed the Advanced Payload Transfer Measurement System (ASPTMS) (Electronic 3D measuring system); Ellen Ochoa, a pioneer of spacecraft technology and astronaut; Joseph Acaba, Fernando Caldeiro, Sidney Gutierrez, José M. Hernández, Michael López-Alegría, John Olivas and George Zamka, who are current or former astronauts. Sports Football There have been far fewer football and basketball players, let alone star players, but Tom Flores was the first Hispanic