This presentation, given at ISDC2024 in Los Angeles on May 23rd, 2024, helps to explain why orbital mechanics, engineering, and economics require us to invest in launch infrastructure if we wish to travel to destinations within our solar system beyond low Earth orbit.
The Ascend Paper mentioned in the Q&A section can be found here:
https://arc.aiaa.org/doi/10.2514/6.2023-4604