Over the next few months, astronauts Joe Acaba and Ricky Arnold will conduct four of McAuliffe's six planned lessons, focusing on liquids, effervescence, chromatography and Newton's laws. They will be filmed and then posted online by The Challenger Center, which focuses on outreach to students about STEM topics in memory of the Shuttle and her crew. Acaba is a part of Expedition 53/54, which launched in September 2017 and is currently aboard the ISS. Arnold's mission to the space station will launch in March.
Both Acaba and Arnold have teaching backgrounds and were chosen as educator-astronauts. "As former teachers, Ricky and Joe wanted to honor Christa McAuliffe," Challenger Center spokeswoman Lisa Vernal told the Associated Press. NASA's first educator-astronaut, Barbara Morgan, was originally McAuliffe's backup on the Challenger mission. She assumed the Teacher in Space duties after McAuliffe's death, and was officially selected as an astronaut in 1998.