The Biostack Experiments I and II aboard Apollo 16 and 17

Area of Science:

• Space biology
• Astrobiology
• Radiation biology

Background:

• Spaceflight exposes astronauts to unique radiation environments, including high-energy heavy cosmic particles (HZE).
• Understanding the biological impact of HZE particles is crucial for ensuring astronaut safety during extended missions.
• Previous studies lacked the capability to correlate individual particle impacts with specific biological damage.

Purpose of the Study:

• To investigate the biological effects of individual HZE particles in space.
• To assess the influence of combined spaceflight factors on biological systems.
• To determine the mechanisms of HZE particle-induced biological damage and estimate radiation hazards for humans in space.

Main Methods:

• The Biostack experiment utilized a variety of biological specimens (bacterial spores, protozoa cysts, plant and insect eggs) and physical radiation detectors.
• Special arrangements allowed for the precise correlation of individual particle tracks with biological effects.
• Analysis included evaluating biological responses across different organisms and radiobiological endpoints.

Main Results:

• Different biological objects exhibited varying degrees of response to HZE particle bombardment, likely due to cellular repair capabilities.
• The experiment successfully characterized the charge and energy spectrum of cosmic ions encountered.
• Data provided insights into the potential biological damage caused by individual HZE particles.

Conclusions:

• The Biostack experiment provided critical data on HZE particle radiobiology relevant to space exploration.
• Findings contribute to estimating radiation risks for astronauts on long-duration space missions.
• The study highlights the importance of organism-specific responses in assessing space radiation hazards.