evidence: Sri Lanka’s Piyumi Wijesekera Joins NASA’s Simulated Mars Mission Crew Piyumi Wijesekera from Sri Lanka has been chosen as one of NASA’s four new volunteer crew members for a simulated mission to Mars, to be conducted at the Johnson Space Center in Houston. [...] This mission is the second of four planned simulated Mars missions in HERA this year. Piyumi Wijesekera, a postdoctoral research scientist at NASA Ames Research Center in California’s Silicon Valley, specializes in developing tissue models to study the effects of spaceflight stressors on the human respiratory system.