Neil Armstrong could have died during Apollo 11 mission if...

If the ascent stage of the lunar module had failed to lift off from the moon's surface, the situation could have been extremely dire for Neil Armstrong and Buzz Aldrin. The ascent stage was their only means of returning to lunar orbit and rendezvousing with the command module, where Michael Collins was waiting.

Here's a breakdown of the potential risks and scenarios:

Risk of Being Stranded

If the ascent stage's engine failed to ignite or malfunctioned, Armstrong and Aldrin would have been left stranded on the moon's surface. With no means of propulsion, life support, or communication, their chances of survival would have been minimal. They would have faced challenges like lack of breathable air, extreme temperatures, and limited resources.

Limited Resources

The lunar module's ascent stage was not designed to support long-term habitation. It had a limited amount of oxygen, water, and supplies for the journey back to lunar orbit. Without a functional ascent stage, the astronauts would have had no way to sustain themselves until a rescue mission could be organized, if even possible.

Communication Challenges

Communication between the stranded astronauts and mission control on Earth would have been problematic. The moon's terrain and the absence of a direct line of sight could have hindered radio signals, making it difficult for NASA to provide assistance or guidance to the astronauts.

Lack of Backup

During the Apollo missions, there were no backup spacecraft or rescue missions readily available to retrieve stranded astronauts from the moon. The Apollo program was meticulously planned, and each mission was executed step by step. There was no contingency plan in place for a scenario where the ascent stage failed to lift off.

In the event of such a failure, the potential outcomes were grim, and the chances of survival would have been very low. Fortunately, the rigorous training of the astronauts, meticulous planning by NASA, and the dedication of countless engineers and experts contributed to the successful execution of the Apollo 11 mission, ensuring that Armstrong and Aldrin could return safely from the moon's surface.