| Much of Murphy's math and physics are wrong. For example to get delta V to go to Mars he adds earth's 11 km/s escape velocity to the 3.6 km/s Mars injection velocity. A freshman aerospace student could tell the speed of a Mars bound ship in a hyperbolic earth orbit is sqrt(11^2 + 3.6^2). I've done a number of posts calling out Murphy's bad arguments: https://hopsblog-hop.blogspot.com/2014/02/the-most-common-de... https://hopsblog-hop.blogspot.com/2014/03/murphys-reply.html and
https://hopsblog-hop.blogspot.com/2018/06/space-meow-boys_30... I generally agree with him that we live on a fragile, limited planet and need to learn to live within our means. However I don't see preserving our own planet and opening a new frontier as mutually exclusive. Musk is one of the most passionate space advocates and he's working for a sustainable future (solar panels, electric cars). Some technologies benefit both space development and sustainable comfort here on earth. For example CELSS (Closed Ecological Life Support Systems) technologies needed for space might be used here on earth. Murphy may be correct that opening a new space frontier is implausible. But he hasn't conclusively demonstrated that's the case. |