tag:blogger.com,1999:blog-8809438035746342262.post5317858824988199877..comments2023-10-27T19:34:05.946-07:00Comments on NEW PAPYRUS: SLS Derived Artificial Gravity Habitats for Space Stations and Interplanetary VehiclesMarcel F. Williamshttp://www.blogger.com/profile/16245086958213100840noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-8809438035746342262.post-45302388547167687292016-04-11T20:27:44.461-07:002016-04-11T20:27:44.461-07:00Thanks for your comments!
Aerobraking, of course...Thanks for your comments! <br /><br />Aerobraking, of course, would be a much more dangerous maneuver than simply going into high Mars orbit or returning from Mars orbit to a Lagrange point within cis-lunar space. Departing from low Mars orbit back to Earth instead of from high Mars orbit would also add an additional delta-v requirement of 1.4 km/s. <br /><br />A deceleration shield would also add additional launch mass and return mass to the vehicle both leaving for Mars and returning from Mars. <br /><br />As far as water shielding is concerned, you need at least 20 centimeters of water mass in order to stop the penetration of potentially-- brain damaging-- heavy nuclei. That amount of water might also be-- just enough-- to protect astronauts from a major solar event. But I'd add an additional 10 centimeters of water shielding in order to reduce annual cosmic radiation exposure aboard ship to about 25 Rem per year during solar minimum conditions. That should lower radiation exposure enough during a round trip journey to prevent a single mission from being a career ender for the youngest female astronauts. <br /><br />Cosmic Radiation and the New Frontier<br /><br />http://newpapyrusmagazine.blogspot.com/2014/03/cosmic-radiation-and-new-frontier.html<br /><br />Marcel <br /><br />Marcel F. Williamshttps://www.blogger.com/profile/16245086958213100840noreply@blogger.comtag:blogger.com,1999:blog-8809438035746342262.post-41024234995962356802016-04-11T19:13:49.690-07:002016-04-11T19:13:49.690-07:00Seems to be a huge waste to throw away 100 tons or...Seems to be a huge waste to throw away 100 tons or more of water when you've got an atmosphere which can aerobrake a tank-full of it just fine. So long as you cut it to less than escape velocity on the first pass you can take your time getting it into an orbit where you can re-use it.<br /><br />However, my understanding is that the radiation threat from all but solar storms is overblown. There are no signs of elevated cancer rates in places on earth with naturally high radiation levels on the order of half a Sievert per year. You'd need to block solar X-rays and keep the abundant but lower-energy protons from solar flares at bay, and that's probably it.Engineer-Poethttps://www.blogger.com/profile/06420685176098522332noreply@blogger.com