The Dilemma of Dropping Something in Space: What Happens When an Astronaut Accidentally Drops an Object Outside the ISS?

Imagine the scenario where an astronaut accidentally drops something from their glove while performing a spacewalk outside the International Space Station (ISS). What would happen to that object? Would it suddenly fall to Earth, escape into space, or float nearby indefinitely?

Understanding Orbital Mechanics

In the realm of orbital mechanics, objects in space behave uniquely. The object you drop will not fall to Earth or exit Earth's orbit; instead, it will simply float nearby. This is due to the laws of orbital motion, where objects in orbit tend to follow the same trajectory unless acted upon by an external force.

However, even the slightest disturbance, such as a change in momentum, can gradually alter its path over time. Let's delve deeper into what happens to that dropped object.

The Object's Path

The object dropped by an astronaut outside the ISS would drift very slowly away from both the astronaut and the station. All three are in almost the same orbit around Earth, meaning they share the same speed and trajectory. Therefore, the astronaut would need to manually adjust their position to retrieve the object.

Depending on the relative velocity and the direction in which the tool is released, it will continue to orbit the Earth but in a different elliptical orbit. Over time, the object may encounter atmospheric drag, causing it to gradually lower its orbit and ultimately burn up in the atmosphere.

Clarifying the Mental Experiment

For a clearer understanding, let's consider a thought experiment. If you were stationary in orbit and threw a tool, say a hammer, towards Earth with a velocity less than 28,000 kilometers per hour (the typical re-entry speed from low Earth orbit), it would simply bounce back into space rather than entering Earth's atmosphere.

This demonstrates that even with a very low relative velocity, an object cannot re-enter Earth's atmosphere. The ISS and the tool are already traveling at a sufficient speed to maintain their orbit. Therefore, any object dropped from the ISS will have the same orbital speed as the station and will not fall to Earth.

Conclusion

In summary, when an astronaut accidentally drops something from the ISS, the object will not fall to Earth or escape into space. Instead, it will simply float gradually away from the astronaut and the station. With proper maneuvering, the astronaut can retrieve the object. However, over time, factors like atmospheric drag can cause the object to re-enter Earth's atmosphere and burn up.