EP wrote this nonsense: Given that Mars' atmosphere is closer to a vacuum than to the atmopshere or the Earth, something approaching an Apollo lunar suit would have to be used by any men there.

Chris writes: You're clueless and unwilling to learn. Look up Dr. Paul Webb and "Space Activity Suit" aka SAS aka MCP Suit aka Skinsuit or Skin Suit.

EP wrote: Next, given that that Apollo moon suit was made as light as possible, at Mars' gravity , double that of the Moon, it would simply be too heavy to wear.

Chris writes: Nope, they were not made as light as possible. The A7L were not the lightest suits made then...safety was a higher priority than weight.

The D-Suit is currently the lightest suit that could be used on Mars. NASA prefers the slightly heavier, but more mobile I-Suit which is far superior to those crappie leaky old A7Ls and A7LBs! Still the problem with pressure suits aren't the rubber suit itself but the weight of the PLSS, which could be reduced or spread over the users body making the center of gravity more akin to a nude human. BTW, I can tell you're hunting around for that "ideal suit weight" on Mars number...Im not going to give it to you...

A Skinsuit has major advantages over the pressure suits current or past. Higher mobility, less weight, and an unreachable puncture is not fatal in them (any puncture is a problem with bleeding but repairable)! The problem is convincing the powers that be that an astronaut is safer in them. In NASA there is a strong tendency to go with what "works" now.

Here is some more on Skinsuits (note: I give you active links where I can. Ask yourselves why doesn't Ed or Barry?)...

The Mechanical Counter Pressure (MCP) Suit

The Mechanical Counter Pressure Suit (MCP) is an alternative space suit technology which has many superior qualities to the gas-pressurisation technique that has been used unanimously on all space flights to date.

An MCP suit would differs by exerting pressure on the body using form-fitting elastic garments. Webb and Annis published the concept and early experiments of a MCP suit in 1967, and in 1971 described the first demonstration that highlighted the many advantages of the MCP approach. MCP garments were found to offer dramatic improvements to gas pressurised suits in reach, dexterity and tactility due to the replacement of stiff joints and bearings with light, flexible elastics. Further advantages included safety (because a tear or hole would remain a local defect rather than cause a catastrophic puncture), lower suit costs and vastly reduced weight and volume. MIT conducted flexibility tests with basic MCP elastics during the mid 1980’s and found MCP gloves to be measurably superior to gas-pressurised gloves.

http://www.marssociety.org.au/marsskin.shtml

The work by Paul Webb, M.D., in 1968 tested the suit with a volunteer subject. The tests included the volunteer wearing the suit into an altitude chamber with the pressure reduced to 155mm mercury, and an arm inserted into a chamber with the pressure reduce to near vacuum: 5mm mercury. That 5mm mercury is the same atmospheric pressure as Mars. The orginal NASA document is available here.

http://chapters.marssociety.org/winnipeg/sas.html

Thanks,
--Chris Vancil