Microgravity, Latest News

Q: What is microgravity?

Microgravity refers to a condition of very weak gravity, typically experienced in orbiting spacecraft, where objects appear to be weightless and fall at the same rate as the spacecraft.

Q: How is microgravity different from zero gravity?

Microgravity is a near-zero gravity condition, while zero gravity is an idealised, absolute absence of gravity, which does not exist in practical terms.

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Microgravity Latest News

Researchers at the Indian Institute of Space Science and Technology (IIST) have developed a 3D computational model that shows microgravity consistently increases human core body temperature, which is crucial for long-duration space missions.

What is Microgravity?

Microgravity is a condition of apparent weightlessness experienced in space when objects are in free-fall orbit around Earth.
Microgravity does not mean the absence of gravity. At orbital altitudes (~250 miles above Earth), gravity is ~89% as strong as on Earth.
Objects appear to float because they are in continuous free fall around the Earth, a state first explained by Isaac Newton’s orbiting cannonball thought experiment.
Weightlessness ≠ no gravity; rather, it results from free-fall motion, where objects, spacecraft, and astronauts all fall simultaneously.
In such an environment, physiological changes occur, affecting bones, muscles, blood circulation, metabolism, and thermoregulation.
Thermoregulation is the process by which the human body maintains a stable core temperature. It is crucial during long-duration space travel, where the microgravity environment significantly alters normal physiological responses.

Thermoregulation Model

IIST’s Thermoregulation Model: Developed a 3D computational model to simulate how heat moves through the human body under microgravity.
Incorporates sweating, shivering, clothing effects, organ heat, and blood redistribution to simulate real conditions.
Key findings of the model include:
- Hands and feet become cooler in space over time.
- Head, abdomen, and core body regions become warmer.
- During exercise in space, the body temperature rises faster than it does on Earth.
- Core body temperature can rise from 36.3°C to 37.8°C in 2.5 months of microgravity exposure.
- With exercise, the temperature may rise to nearly 40°C, a potentially dangerous level.
The model’s accuracy was validated using past data from astronauts onboard the Mir Space Station and the International Space Station (ISS). The predicted results matched historical observations.
The model also estimates the Universal Thermal Climate Index (UTCI), which reflects how hot or cold it feels outside by factoring in wind, humidity, and solar radiation.