> There needs to be a better technology to harvest the massive amounts of energy wasted when decelerating from 30k mph to 1 thousand mph during re-entry. Or, i

> There needs to be a better technology to harvest the massive amounts of energy wasted when decelerating from 30k mph to 1 thousand mph during re-entry. Or, in the case of of Mars, we can focus on in-situ resource utilization [1]. Zubrin's Mars Direct [2] is built around this, and there are some immense fuel savings to be had [3]. [1] https://en.wikipedia.org/wiki/In-situ_resource_utilization https://en.wikipedia.org/wiki/In-situ_resource_utilization [2] https://en.wikipedia.org/wiki/Mars_Direct https://en.wikipedia.org/wiki/Mars_Direct [3] Zubrin, Robert. The case for Mars. Free Press, 1996.