The term "web propulsion" is not a standard or widely recognized term in the context of space travel or propulsion systems. It's possible that it's a made-up term or a specialized term within a specific community or field.

To understand what you mean, it would be helpful if you could provide more context:

* Where did you encounter this term? Was it in a book, a website, a conversation, or something else?

* What is the overall topic being discussed? For example, are you talking about space travel, futuristic technology, or something else entirely?

With more information, I can try to understand what "web propulsion" might refer to and give you a more accurate answer.