Why Real Space Travel is More Difficult Than On TV: The Challenges of Turning Around in Space

When it comes to space travel, movies and TV shows often portray a much simpler and more flexible scenario than the harsh realities of real-life space exploration. One common misconception is that a spaceship can simply turn around and go back if it misses its designated destination. However, the truth is far more complex and energy-intensive.

The Physics of Space Travel

Space travel is not like driving on Earth. There is no atmosphere to act as a gravitational or aerodynamic brake, eliminating the possibility of simply reversing the direction of a spacecraft. The key to navigating through space lies in a concept known as delta-v, which is the change in velocity a spacecraft must achieve to make a course correction or move from one orbit to another.

No such thing as a bootlegger reverse in space

Attempting to turn around and go back would require the spacecraft to reverse its momentum, a task that requires an immense amount of energy. To land back on Earth, the Apollo astronauts used the Moon's gravity to aid in their return. However, even with this assistance, they still needed to make meticulous course corrections to ensure a precise reentry angle. This demonstration underscores the importance of planning and the complexities involved in controlling a spacecraft's trajectory.

Fuel Constraints and Maneuvering Thrusters

Spacecraft are designed to carry only enough fuel to complete their planned mission and a small reserve. After the main engines are jettisoned to save weight, what remains are maneuvering thrusters. These thrusters provide much less power than the main engines, making course corrections and maneuvering in space an extremely challenging and energy-intensive operation.

Fueling the Journey

To put a spacecraft into motion, tens of millions of pounds of fuel are required for lift-off, and only a small fraction of that fuel is the actual spacecraft. The rest is needed to carry the significant weight of the launch vehicle. Once in space, the spacecraft continues to move due to the conservation of momentum, and changing direction or stopping involves applying power to a much smaller mass.

The High Cost of Turning Around

Reversing course and returning to Earth would require not only stopping but also heading back to the original starting point. This would necessitate several millions of pounds of additional fuel for the return journey. Generally, spacecraft are not equipped to carry the vast amounts of fuel necessary to make such a reversal.

Limitations and Refunds

The laws of physics dictate that an object in motion will continue in motion unless acted upon by a force. In space, this means that turning around and going back is not an easy feat. While high schools may not be able to refund tuition for the oversights in their science and physics curricula, the scientific community has long understood these limitations.

Conclusion

Real space travel is much more difficult and energy-intensive than portrayed in movies and TV shows. The complexities of controlling a spacecraft's trajectory, the limitations of fuel, and the laws of physics mean that turning around and going back requires a significant amount of planning and resources. The sacrifices of energy and fuel highlight the true challenges of space exploration.