Suggested Searches

Space Radiation

The Space Radiation Element (SRE) of NASA’s Human Research Program (HRP) seeks to characterize human health outcomes associated with space radiation exposure, helping the space agency build strategies that protect astronaut health and ensure safe human spaceflight.

Meet the SRE Team

Element leaders integrate and coordinate science, as well as handle project costs, schedules, technical work, and resources. Across HRP, all leadership teams work hand-in-hand to ensure that research proposed by the other HRP elements is implemented using the best method possible while maintaining the health of crew members.

Meet the leadership team for HRP’s SRE. To contact them, email the group at jsc-hrp-space-radiation-element at

SRE Leadership

Jason Weeks portrait

Jason Weeks, Element Manager

Jason Weeks has more than 20 years of experience at NASA, including as a budget analyst for NASA’s chief financial officer.

Janice Zawaski, Element Scientist

Janice Zawaski has 15 years of radiation research experience. During graduate school, she studied the combined effects of radiotherapy and brain tumor presence on surrounding tissue. 

Ryan Norman portrait

Ryan Norman, Deputy Element Manager

Ryan Norman first joined NASA at Langley Research Center in 2013 as a research physicist investigating the physics of space radiation to understand how it affects human health

Brock Sishc

Brock Sishc, Cancer Discipline Lead

Brock Sishc’s scientific background is in radiation biology, translational radiation oncology, the response of biological systems to charged particle exposure, charged particle radiotherapy, and radiation carcinogenesis.

Janapriya “JP” Saha

Janapriya “JP” Saha, Degenerative Disease Discipline Lead

Janapriya “JP” Saha's research focuses on ionizing radiation-induced DNA damage signaling, repair, and carcinogenesis, with a strong emphasis on the characterization of space radiation-induced biological effects and charged particle radiotherapy.

Gregory Nelson

Gregory Nelson, Central Nervous System Discipline Lead

Greg Nelson  joined SRE on a part-time basis in his current role in 2014. His laboratory investigates dose rate effects on central nervous system responses to charged particles.