ISS and Space Biology and Astronauts

Astrobiology Overview

  • Course Code: ES1006 Astrobiology ISS and Space Biology

Analogues in Astrobiology

  • Assumption: Extraterrestrial life is similar to life on Earth.

  • Problems:

    • Life on Earth evolved under 1g of gravity.

    • All life has been protected from radiation for most of its history.

  • Impact of Gravity and Radiation:

    • Significant effects on biological material, including molecules, cells, and behavior.

  • Remarkable Analogue: Life itself serves as the ultimate analogue for astrobiology.

Understanding Life's Behavior under Varying Conditions

  • Importance of studying evolution under low gravity and high radiation.

  • Objectives:

    • Understand how physical processes (gravity and radiation) impact biology.

    • Recognize limits of Earth biochemistry and physiology.

    • Explore how gravity and radiation influence evolutionary processes.

    • Identify important factors for future human space exploration.

    • Make discoveries that contribute to biotechnology and medicine.

Planetary Conditions

  • Mars as a Case Study:

    • Lacks a magnetic field, exposing surfaces to radiation.

    • Consequences for evolution of photosynthetic life:

      • Photosynthesis might not evolve.

      • Lack of photosynthetic pigments affects biosignature detection.

Gravity in Space

  • International Space Station (ISS):

    • Gravity at ISS: ~90% of Earth's gravity.

    • Objects in orbit experience continuous freefall—perceived weightlessness.

Astrobotany on the ISS

  • Need for Food:

    • Essential for long-duration space missions.

    • Photosynthesis provides oxygen and has positive psychological effects on astronauts.

  • Challenges:

    • Absence of gravity affects control over plant growth:

      • Stems exhibit phototropism to grow towards light.

      • Roots exhibit gravitropism to grow downwards.

    • Both processes controlled by auxins—plant hormones that respond to light/gravity.

Plant Growth Solutions

  • Phototropism:

    • Can be managed by providing optimal light wavelengths.

    • Auxin causes elongation on the shaded side of stems, redirecting growth toward light.

  • Gravitropism:

    • Influenced by auxin; roots' orientation managed similarly, though more complex.

Innovations in Plant Growth

  • Long-Duration Missions:

    • Key limitation: heavy soil and water.

    • Aeroponics: Technology for growing plants in air/mist.

  • Educational Engagement:

    • Students observed space-grown rocket seeds post-return, learning from growth effects.

Research Findings

  • ISS experiments show:

    • Vibration, temperature changes, and cosmic radiation do not hinder seed germination.

    • Positive indicator for future planetary missions.

Microbiology in Astrobiology

  • Importance of microorganisms:

    • Contribute to soil conditioning but may also introduce diseases.

    • Investigate extremophiles for insights into early Earth colonization.

  • EXPOSE Facility:

    • Located on ISS, allows exposure of biological samples to space conditions.

Exposure Experiments

  • Investigated effects of:

    • Desiccation.

    • High UV radiation and extreme temperature fluctuations.

  • Comparison with early Earth conditions lacking UV-protecting ozone.

Research on Microorganisms

  • Cyanobacteria:

    • Studied for resilience in space conditions, withstand various stressors.

Research on Ant Strategies in Microgravity

  • Ant-stronauts Studies:

    • Investigated collective searching behavior in zero-g conditions.

    • Ants showed challenges in surface adherence affecting their search efficiency.

Tardigrades Research

  • Tardigrades: Highly resilient organisms that survive extreme conditions, including space.

  • Survive through cryptobiosis—losing most water content to enter stasis.

Summary of Astronaut Research

  • Experiments on ISS involve diverse life forms (plants, fungi, insects, bacteria, humans).

  • Aims to understand adaptability and responses to space environments.

  • Insights into early Earth's colonization and future space exploration.

Human Space Exploration Preparation

  • Focus areas:

    • Stress response and teamwork in isolated environments.

    • Psychological impacts of long-duration spaceflight.

  • Researching cognitive performance in simulated conditions.

Major Mission Simulations since 2000

  • Include projects like MARS, HI-SEAS, MDRS, NEEMO, and ESA CAVES.

  • Investigate the psychological and teamwork aspects of long missions, with engaging civilian scientists and engineers.

Specific Missions

  • Mars Desert Research Station (MDRS):

    • Established in 2001 for field-based research simulating Mars.

  • Mars500 Experiment:

    • Lasted from 2007-2011 simulating long-term space isolation and communications delay.

Conclusion

  • Research on ISS encompasses various life forms and their adaptability to space.

  • Findings are vital for understanding life’s potential in extraterrestrial environments and implications for human colonization of other planets.