Could the Lunar Rover Jump-Start the Lunar Module in an Emergency?

Many ideas have been floated over the years regarding potential emergencies on the Moon, one of which involves the use of a lunar rover to jump-start the lunar module (LM) in a situation where it fails to ignite. However, this idea, as it is often proposed, is not only impractical but also lacks the necessary technical and logistical feasibility. Let's explore why this concept doesn't work and what alternatives were considered.

Practical Challenges with the Lunar Rover

First, it's important to understand the layout of the Moon's surface during operations. The lunar rover, an essential tool for exploration and resource gathering, was typically parked far from the lunar module to enable a clear view of the launch and landing operations. This distance alone makes it a significant challenge to approach the LM in an emergency situation where time is crucial.

Moreover, astronauts who faced an emergency when the ascent stage of the LM failed would have already taken substantial action to ensure their safety. For instance, they would have discarded the PLSS (Portable Life Support System) backpacks, which would have been essential for lunar surface operations outside the LM. They would have used the OPS (Open Pod System) oxygen bottles to provide emergency breathing support for up to an hour. Accessing and reactivating the LM, even if just one person were sent, would be a daunting task, utilizing a considerable amount of that critical time.

Furthermore, the rover's batteries might not be accessible for such purposes, especially in the event of an emergency. The design and practical limitations of the equipment used on the lunar missions meant that certain components were optimized for specific tasks, limiting the extent to which they could be adapted to new or unexpected needs.

Utilizing the Descent Stage as a Jump

A more practical alternative involves the use of the descent stage as a means of reignition. This idea, mentioned in the Apollo 14 and 17 Lunar Surface Journals, suggests using a wire connected to a circuit breaker within the descent stage to ignite the ascent stage. While this method sounds feasible, it also presents its own set of challenges.

The key issue lies in the procedure. The wire would need to be directed into the entry/exit hatch of the descent stage and connected to the appropriate circuit breaker to initiate the ascent. This process would need to be executed quickly and with precision. Additionally, the exit of the wire from the ascent stage to the descent stage would pose a risk of causing damage.

It's crucial to note that this process had not been extensively practiced and the success of such an operation would be highly dependent on the efficiency and timing of the astronauts' actions.

Other Considerations

Another potential danger is the separation of the descent and ascent stages. Once these stages are detached, they are atop each other with limited oxygen reserves. Therefore, any emergency procedure would need to factor in the preservation of the ascent stage's oxygen supply, which is critical for the astronauts' survival.

The complexity of the situation and the limited resources available mean that the astronauts would be in a very precarious position, relying on their training, quick thinking, and the highest degree of fortuitous circumstances to survive such an event.

Conclusion

In summary, the idea of using a lunar rover to jump-start the lunar module is not practical due to the lack of accessible and usable power systems and the physical distance between the rover and the LM. Additionally, the proposals involving the descent stage as a means of jump-starting the ascent stage were not extensively tested and pose significant risks. The astronauts faced immense challenges in any emergency situation, underscoring the importance of robust planning and redundancy in their equipment and procedures.