Mind Map

  • History
    • Early Missions
    • Milestones
    • Notable Astronauts
  • Key Experiments
    • Material Exposure
    • Life Sciences
    • Technology Testing
  • Modern Applications
    • ISS Maintenance
    • Satellite Servicing
    • Lunar/Mars Preparations
  • Bacteria in Extreme Environments
    • Deep-Sea Vents
    • Radioactive Waste
    • Space Exposure
  • Controversies
    • Safety Risks
    • Cost-Benefit Debate
    • Biological Contamination
  • Education
    • Curriculum Integration
    • STEM Initiatives
  • Recent Research
    • Microbial Survival in Space

1. History of Spacewalks

Definition:
A spacewalk, or Extravehicular Activity (EVA), is any activity performed by an astronaut outside a spacecraft beyond the Earth’s appreciable atmosphere.

Early Missions:

  • First Spacewalk: Alexei Leonov (USSR, 1965, Voskhod 2) – 12 minutes outside the spacecraft.
  • First American Spacewalk: Ed White (Gemini 4, 1965) – 23 minutes.
  • Moonwalks: Apollo missions (1969–1972) – First human steps on another celestial body.

Milestones:

  • Longest Single Spacewalk: 8 hours, 56 minutes (Susan Helms & James Voss, 2001, ISS).
  • First All-Female Spacewalk: Christina Koch & Jessica Meir (2019, ISS).

Notable Astronauts:

  • Peggy Whitson: Record for most cumulative EVA time by a female astronaut.
  • Anatoly Solovyev: Most cumulative EVA time (82 hours, 22 minutes).

2. Key Experiments Conducted During Spacewalks

Material Exposure

  • Purpose: Test the durability of materials in the vacuum, temperature extremes, and radiation of space.
  • MISSE (Materials International Space Station Experiment): Exposed hundreds of material samples to space for up to four years.

Life Sciences

  • Biological Sample Exposure:
    • Microbes, fungi, and plant seeds placed outside the ISS to study survivability and mutation rates.
    • Findings: Some extremophiles survive prolonged exposure, indicating potential for panspermia (life transfer between planets).

Technology Testing

  • Spacesuit Improvements:
    • Testing new suit designs for mobility, durability, and life support.
  • Tool Prototyping:
    • Use of specialized tools for satellite repair and construction tasks.

3. Modern Applications of Spacewalks

International Space Station (ISS) Maintenance

  • Solar Array Installation/Repair:
    • Regular EVAs to maintain and upgrade solar panels.
  • Module Assembly:
    • Connecting new research modules and truss segments.

Satellite Servicing

  • Hubble Space Telescope Repairs:
    • Multiple missions to upgrade and repair optics and instruments, extending Hubble’s lifespan.

Lunar and Mars Mission Preparations

  • Surface Mobility Studies:
    • Testing suit and rover designs for future Moon and Mars exploration.
  • Habitat Construction Simulations:
    • Practicing assembly of habitats and scientific equipment in simulated microgravity.

4. Bacteria in Extreme Environments

Deep-Sea Vents

  • Thermophilic Bacteria:
    • Thrive at temperatures above 100°C, using chemosynthesis instead of photosynthesis.
  • Significance:
    • Demonstrates life’s adaptability; informs astrobiology and search for extraterrestrial life.

Radioactive Waste

  • Deinococcus radiodurans:
    • Survives high doses of ionizing radiation.
  • Applications:
    • Bioremediation of radioactive waste sites.

Space Exposure

  • ISS Experiments:
    • Bacteria like Bacillus and Tardigrades survive direct space exposure for over a year (Yamagishi et al., 2020, Frontiers in Microbiology).
  • Implications:
    • Supports theories of panspermia and planetary protection protocols.

5. Controversies

Safety Risks

  • Micrometeoroids:
    • High-velocity particles pose puncture risks to spacesuits.
  • Radiation Exposure:
    • Increased cancer risk due to cosmic rays and solar flares.

Cost-Benefit Debate

  • Expense:
    • Each EVA costs millions in training, equipment, and mission planning.
  • Alternatives:
    • Use of robotics versus human EVAs for routine maintenance.

Biological Contamination

  • Forward Contamination:
    • Risk of Earth microbes contaminating other planets during EVAs.
  • Backward Contamination:
    • Potential for extraterrestrial organisms to be brought to Earth.

6. How Spacewalks Are Taught in Schools

  • Curriculum Integration:
    • Covered in physics (forces, pressure, temperature), biology (human physiology in space), and technology (engineering design).
  • STEM Initiatives:
    • Hands-on activities: model spacesuit construction, simulated EVAs using VR, and robotics competitions.
  • Educational Outreach:
    • NASA and ESA provide lesson plans, video demonstrations, and live Q&A sessions with astronauts.

7. Recent Research

  • Microbial Survival in Space:

    • Yamagishi, A., et al. (2020). “Tanpopo Mission on the Exposure Facility of the ISS: Studies of the Radiation Resistance of Microbes.” Frontiers in Microbiology, 11:2050.
    • Findings: Certain bacteria can survive in space for extended periods, suggesting robust planetary protection measures are needed.

  • News Article:

    • “NASA Astronauts Complete Spacewalk to Upgrade ISS Power System” (NASA News, June 2021): Highlights ongoing reliance on human EVAs for critical station upgrades.

Summary

Spacewalks (EVAs) are essential for spacecraft maintenance, scientific research, and preparing for future exploration missions. Since the first EVA in 1965, astronauts have performed hundreds of spacewalks, leading to advancements in materials science, biology, and engineering. Key experiments have revealed the surprising resilience of life, even in the harsh environment of space. However, spacewalks present significant risks and raise debates about cost, safety, and planetary protection. Education systems increasingly integrate spacewalk-related topics into STEM curricula, inspiring the next generation of researchers. Recent studies confirm that some bacteria can survive in space, reinforcing the importance of strict contamination controls for interplanetary missions.