What is a Spacewalk?

A spacewalk, officially called an Extravehicular Activity (EVA), is when an astronaut leaves the confines of a spacecraft to work in the vacuum of space. Spacewalks are essential for spacecraft maintenance, scientific experiments, and construction tasks outside the International Space Station (ISS) and other orbital platforms.

Spacewalk Diagram

History of Spacewalks

Year Astronaut Country Mission Duration (min) Notable Achievement
1965 Alexei Leonov USSR Voskhod 2 12 First spacewalk
1965 Ed White USA Gemini IV 23 First US spacewalk
1984 Bruce McCandless II USA STS-41-B 320 First untethered EVA
2001 Susan Helms USA STS-102 513 Longest EVA
2019 Christina Koch & Jessica Meir USA ISS 420 First all-female EVA

Spacewalk Suit Technology

  • Spacesuit Layers: Modern suits (EMU) have up to 14 layers, including thermal, micrometeoroid, and pressure protection.
  • Life Support: Oxygen tanks, carbon dioxide scrubbers, and water cooling systems.
  • Communications: Integrated radio and telemetry systems.
  • Mobility: Joints and bearings for movement; gloves designed for dexterity.

How Spacewalks Work

  1. Preparation: Astronauts pre-breathe pure oxygen to purge nitrogen and avoid decompression sickness.
  2. Airlock: The airlock is depressurized before exit.
  3. Tasks: Repair, maintenance, installation, or scientific sampling.
  4. Safety: Tethers and SAFER (Simplified Aid for EVA Rescue) jetpacks prevent drifting away.
  5. Return: Astronauts re-enter the airlock, which is then repressurized.

Surprising Facts

  1. Human Adaptation: Astronauts can experience “space euphoria,” a psychological effect due to the view and isolation.
  2. Bacteria Survival: Some bacteria, such as Deinococcus radiodurans, have survived exposure to space vacuum and radiation during experiments on the ISS.
  3. Tool Loss: Over 20 tools have been accidentally lost during spacewalks, now orbiting as “space debris.”

Case Studies

1. ISS Cooling System Repair (2013)

  • Astronauts replaced a faulty ammonia pump.
  • Required two spacewalks, each over 5 hours.
  • Demonstrated the complexity of repairs in microgravity.

2. All-Female Spacewalk (2019)

  • Christina Koch and Jessica Meir conducted the first all-female EVA.
  • Task: Replace a power controller.
  • Highlighted the evolution of suit design for diverse body types.

3. Bacteria Exposure Experiments

  • Deinococcus radiodurans and other extremophiles were placed outside the ISS for over a year.
  • Some survived, suggesting possible panspermia (life transfer between planets).
  • Source: NASA “Microbes in Space” experiment (2020).

Data Table: Spacewalk Durations and Outcomes

Spacewalk Date Astronaut(s) Task Duration (min) Outcome
2020-07-01 Chris Cassidy, Bob Behnken Battery Replacement 360 Successful
2019-10-18 Christina Koch, Jessica Meir Power Controller Swap 420 Successful
2013-12-21 Rick Mastracchio, Mike Hopkins Ammonia Pump Repair 330 Successful
2008-09-05 Sergey Volkov, Oleg Kononenko Satellite Deployment 300 Partial Success
1965-03-18 Alexei Leonov First EVA 12 Successful

Scientific and Technological Connections

  • Robotics: Many spacewalk tasks are being replaced or assisted by robotic arms (e.g., Canadarm2).
  • Materials Science: Spacesuit development drives innovation in flexible, durable materials.
  • Biotechnology: Studying extremophile bacteria informs sterilization and planetary protection protocols.
  • Telemedicine: Real-time health monitoring during EVAs advances remote medical technology.
  • Artificial Intelligence: AI assists in planning, monitoring, and supporting EVAs.

Challenges of Spacewalks

  • Radiation Exposure: Outside the spacecraft, astronauts are vulnerable to cosmic rays and solar flares.
  • Temperature Extremes: Temperatures can swing from -157°C to +121°C.
  • Physical Fatigue: Suits are bulky, and tasks require significant strength and endurance.
  • Communication Delays: Real-time support is limited by transmission lag.

Recent Research

A 2021 study published in Frontiers in Microbiology found that Bacillus and Deinococcus bacteria survived 18 months outside the ISS, supporting theories that microbes could endure interplanetary travel (Frontiers in Microbiology, 2021).

Spacewalks and the Future

  • Mars Missions: EVA technology is being adapted for Mars’ thin atmosphere and dust storms.
  • Commercial Spaceflight: Private missions (SpaceX, Axiom) are training non-career astronauts for EVAs.
  • Planetary Protection: Understanding microbial survival shapes protocols for sample return missions.

Diagram: Spacewalk Safety System

Spacewalk Safety System

Summary Table: Spacewalk Technology Connections

Technology Spacewalk Application Broader Impact
Robotics Remote manipulation Surgery, manufacturing
AI EVA planning/support Autonomous vehicles
Materials Science Suit durability Sports, firefighting
Biotechnology Microbial research Medicine, ecology
Telemedicine Health monitoring Remote healthcare

References

  • Frontiers in Microbiology (2021): “Survival and Growth of Bacteria in Space”
  • NASA: Microbes in Space (2020)
  • ESA: Spacewalk Technology Updates (2022)