Looks like mostly gravity losses [1], which I understand to be essentially "how long does it take to reach orbit". [1] https://forum.nasaspaceflight.com/index.

Looks like mostly gravity losses [1], which I understand to be essentially "how long does it take to reach orbit". [1] https://forum.nasaspaceflight.com/index.php?topic=9959.msg189860#msg189860 https://forum.nasaspaceflight.com/index.php?topic=9959.msg18...