The first part of constructing the surface suit will be development through analogue testing in relevant environments.
We are making our decisions based on certain design concerns
We are working under the thought that the suit seeds to be as light as possible, but be completely self-sufficient. Consumables will need to be swappable while wearing the suit. (Remember, the first four will spend two weeks in it, and the follow on missions may need to spend 3-4 days in them.) We do not intend to significantly change the suits unless a dramatic change is made to the state of the art.
This suit is expected be of a MCP/HUT hybrid; although a HUT/soft suit in the style of the University of North Dakota NDX-2 is also being considered. The wearer will wear a coverall over the suit body for armour, heating, or dust mitigation. in future versions, these coveralls will be interchangeable. The helmet will be fixed to the HUT, with several flat planes for view plates. The rational behind flat plates is in ease of spares storage, ease of repair, and ease of polishing/maintenance. The PLSS, HUT, and helmet will also be integrated. The HUT will be entered from the front. Since the view plate is not hemispherical, the view plates will contain electronically polarizing elements for sun mitigation. There will be two water delivery nipples as described above, as well as two food delivery nipples, one for a savory food, one for a sweet food. Local communications will be handled via a routable VoIP protocol over WiFi, via a computer as described above. This entire system will be redundant. Long distance communication over amateur radio. The suit will be constructed from firm elastic cloth and laced to tension using a speed lace. The helmet will also have redundant lights and cameras.
Boots are expected to be near off the shelf Canadian Pack Boots.
The suit described above will be skin tight with laced seams on the sides. there will be small metal or plastic clips on the lace points. The color should be pleasing. the laces will be stainless or spectra. The HUT will basically cover the ribcage, like a short vest. The helmet is attached to the top, the PLSS and helmet are integral. The PLSS will extend down halfway to the waist and will be about 2 cm thick, as wide as the back, and up to the top of the shoulders. There will be a heavy solid connection between the back of the helmet and the PLSS. Note the faceplate panes from above. The armour coveralls will be looser, but not very over the suit, and will have several straps and clips to keep the knee, elbow, shin, forearm and thigh pads in place. The colour will be a combination of lime Hi-Vis green and some other artistic, attractive design.
Think a combination of "Red Planet" surface suits for the body, Cary-Ann Moss's helmet (but flat planes, not curved.) and the color and style of "Iron Man". 1/3/09 On first hearing this it seems insane, but consider: The human body requires pressure and oxygen. Oxygen must be supplied to the lungs at a specific pressure to sustain lung inflation and gas transfer. However, the REST of the human body is quite tolerant of very low pressure exposure for brief intervals. I'm suggesting a means where crewmwmbers can literally change out of contaminated suits into new suits even under lunar vacuum conditions. Maximum vac exposure for any specific part of the body would be a very few seconds. This can be safely tolerated provided it is properly facilitated. What this means is you have an unpressurized changing station that stores modular suit components at the ready. The astronaut would be positioned so that each component could be removed in sequence and changed out in mere seconds. Since the helmet would be the only component that is not 'skin tight', it remains. The contaminated elements are cleaned and recharged for the next change. Of course, this is only part of the problem. Clean suit components will help to maintain comfort and morale, but what about the astronaut himself? After about 36 hours a human being has perspired and eminated so much accumulation of skin cells, body oils, salts, microbial growth and urea-containing acids that he will begin to experience a mild allergic reaction. That is why we itch when we haven't showered. After four days, even the most enduring individual would be overwhelmed by the itching. Solution? A pressurized module about the size of an air lock allowing each astronmaut to clean himself periodically. Ideally he would also clean his suit. Such a unit would be the size of a phone booth and couls be designed to accomodate 'relief' measures of all types.