Talk:Bringing up Phobos

I can calculate the cable cross section reduction over a length of a thousand kilometers from Phobos, but my computer programing facility is temporarily unavailable by unfortunate circumstance. --Farred 06:27, 1 May 2009 (UTC)

"Phobos stuff dropped by this means would be ground up ..."

Would not be the atmosphere too thin to evaporate the dropped material? -- Rfc 20:01, 22 May 2009 (UTC)

• The atmosphere of Mars at the surface is about 1% as dense as that of Earth at sea level. This is about the same as the density of Earth's atmosphere at 22.6 miles altitude. Meteors begin to burn up in Earth's atmosphere at an altitude of about 60 miles. So the density of Mars' atmosphere is not insufficient to burn meteors. The problem would be that Mars' escape velocity is only 45% of Earth's. Small particles entering the atmosphere at a low enough speed would reach terminal velocity before completely burning up. However small particles travling at terminal velocity in Mars' atmosphere would not cause great damage. No one will be exposing bare skin to the Martian sky in any case.--Farred 16:04, 23 May 2009 (UTC)

Terminal velocity on Mars is much higher compared with Earth. I would not dare to unnecessarily expose a regular space suit to such particles larger than a few micrometers. Moreover, I would not want to expose square kilometers of photovoltaic cells to such kind of rain. Therefore, I think the dropped material does cause unacceptable damage to Mars installations. -- Rfc 20:08, 24 May 2009 (UTC)

• The conditions on the surface of Mars already include dust born aloft in occasional high velocity winds. These dust particles could be traveling at terminal velocity when they strike Mars installations. Mars suits and solar panel farms would need to be designed to deal with this sort of damage. The increase in damage from having ground up Phobos fall on them is only change in degree not a change in kind of the damage they will be exposed to. Mars suits must be tough. Solar cells and greenhouse roofs should be covered with replaceable glass panes that are level with the surrounding ground and set between the tracks used by a robotic cleaning machine. When a pane becomes excessively scratched and pitted due to the unavoidable wind carried dust or due to bits of Phobos falling on it, that pane is recycled at a glass factory. It is a process similar to changing light bulbs in that both are periodic maintenance.
• There is little that is free on Mars. If one wants to move Phobos, one must accept a cost. Is there a cheaper alternative?--Farred 22:37, 24 May 2009 (UTC)

The comparison with natural dust in the wind is convincing, at least as long as the dropped particles are small enough. Should we make that clear in the article? -- Rfc 19:11, 25 May 2009 (UTC)

• Done.--Farred 19:25, 25 May 2009 (UTC)