Comments on: ISDC 2011 Keynote Speech - Jeff Greason - A Settlement Strategy for NASA http://blog.nss.org/?p=2619 Blogging for the creation of a spacefaring civilization Tue, 21 May 2013 19:49:16 +0000 http://wordpress.org/?v=2.7 hourly 1 By: John Strickland http://blog.nss.org/?p=2619&cpage=1#comment-12490 John Strickland Sat, 04 Jun 2011 02:44:00 +0000 http://blog.nss.org/?p=2619#comment-12490 One of the main points that Jeff made in his talk can be expressed in another way. Prioritizing the production of propellants at each new base site means accepting the principle of using integrated base-vehicle systems with each base supporting the vehicle's operation and the vehicles supporting the base's operation, the same way the components of a car or animal work together. The car or the animal will not work without all of its components. The synergy of this concept is critical to enhanced access to both the Moon and Mars and could reduce costs allowing access to both destinations within a short period of time. I agree very much with almost all of Jeff's other points. About the only one I might disagree with is on a purely technical and pragmatic basis. He proposes to use Phobos as an initial source of fuel for access to the Mars system. With the recent discovery of probable water ice deposits within 25 degrees of Mars equator, it is now possible to migrate directly from methane-oxygen to using hydrogen-oxygen propellants, made from the Mars ice. This provides a 3-fold increase in payload to Mars orbit from the surface of Mars, and opens up the rest of the Mars system to exploration. With a 38% gravity, most or all of the fuel production equipment can be modified for use on Mars from existing Mars equipment, without needing to develop a microgravity fuel production infrastructure. This would allow a much more rapid advance to Mars than is currently envisioned, which assumes we have to create the microgravity systems first. John One of the main points that Jeff made in his talk can be expressed in another way. Prioritizing the production of propellants at each new base site means accepting the principle of using integrated base-vehicle systems with each base supporting the vehicle’s operation and the vehicles supporting the base’s operation, the same way the components of a car or animal work together. The car or the animal will not work without all of its components. The synergy of this concept is critical to enhanced access to both the Moon and Mars and could reduce costs allowing access to both destinations within a short period of time.

I agree very much with almost all of Jeff’s other points. About the only one I might disagree with is on a purely technical and pragmatic basis. He proposes to use Phobos as an initial source of fuel for access to the Mars system. With the recent discovery of probable water ice deposits within 25 degrees of Mars equator, it is now possible to migrate directly from methane-oxygen to using hydrogen-oxygen propellants, made from the Mars ice. This provides a 3-fold increase in payload to Mars orbit from the surface of Mars, and opens up the rest of the Mars system to exploration. With a 38% gravity, most or all of the fuel production equipment can be modified for use on Mars from existing Mars equipment, without needing to develop a microgravity fuel production infrastructure. This would allow a much more rapid advance to Mars than is currently envisioned, which assumes we have to create the microgravity systems first.
John

]]> By: Dave Fischer http://blog.nss.org/?p=2619&cpage=1#comment-12465 Dave Fischer Fri, 03 Jun 2011 04:48:00 +0000 http://blog.nss.org/?p=2619#comment-12465 The preceding post on this blog deals with two possible ways of creating the "settlement" infrastructure that Jeff Greason calls for herein. Dr. Spudis makes a cogent argument for the first step being the mining of lunar ice to create water, oxygen, LOX and H2 for fuel and selling these products commercially in the cis-lunar territory. The preceding post on this blog deals with two possible ways of creating the “settlement” infrastructure that Jeff Greason calls for herein. Dr. Spudis makes a cogent argument for the first step being the mining of lunar ice to create water, oxygen, LOX and H2 for fuel and selling these products commercially in the cis-lunar territory.

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