“A space suit is a garment worn to keep a human alive in the harsh environment of outer space, vacuum and temperature extremes.” – Wikipedia 
UNTIL NOW we’ve created and used mainly 3 different types of spacesuits:
- EVA (extravehicular activity | outer spaceship activity)
- IEVA (intra/extravehicular activity | inner and outer spaceship activity)
- IVA (intravehicular activity | inner spaceship activity)
Picture 1. International Space Station (ISS) | Photo Credit: NASA
EVA suits are designed to be used in outer space. That makes them one of the most sophisticated piece of technology. Generally they serve many different functions like:
- Provide fixed inner pressure (about 1/3 atm meaning 1/3 of sea level pressure) so crew can survive and effectively perform work in dangerous environment of space .
airoxygen (due to low pressure) for breathing (eliminate carbon dioxide) sufficient enough for 6-8.5 hours of space activities .
Important note: The air can’t be used due to very low concentration of oxygen at 1/3 atm. Technically it could be done but only with at least 1 arm pressure inside the suit.
- Maintain temperature at life sustainable level. Not to forget that side exposed to Sun heats up to 121 C (250 F) and side in the shadow freezes down to -157 C (-250 F) .
- Protect against various types of radiation. EVA suits give astronauts protection from UV rays and limited protection from particle radiation.
- Shield against micrometeorites (which could travel with speed up to 7.5 km (4.7 mile) per second).
- Ensure mobility (an astronaut has to be able to perform different tasks) and have a communication with spaceship.
- Deal with wastes.
Picture 2. Gemini-Titan (GT)-8 Equipment & Suit | Photo Credit: NASA
IEVA suits are very much like EVA suits, designed for inner and outer spaceship activities. Most of functions are the same like for EVA (mentioned above) however some of them are limited due to functional compromises (done in early development stage). Nowadays most of space agencies moved out from IEVA design (there’s no more such a severe weight limitation like it used to be). IEVA suit was separated in two (EVA and IVA). IEVA design might be brought up in talks about first human Mars mission .
Picture 3. SpaceX Spacesuit | Photo Credit: SpaceX through NASA website
IVA suits are designed for intra vehicular activities (launch, re-entry and docking). Therefore list of functions is completely different. It includes (but not limited to) :
- Provide stable air pressure environment.
- Have a 10 minute backup oxygen supply.
- Have a parachute, Earth survival kit and flotation device.
IVA spacesuits are really good for its purpose. However, EVA suits are not that great. There’s a lot of problems with it.
Firstly, there was no major improvements since 1980th (in case of EMU). Secondly, majority of suits are not really custom made. If new astronaut joins the team, the parts needed an adjustment are replaced according to new crew member’s size and the rest is recycled. Thirdly, EVA suits are bulky and heavy. It’s really hard to move and easy to injure yourself while wearing one. Fourthly, before using the astronauts have to do some preparations due to pressure difference.
What can be done?
- Real custom suit is a must.
- Lightweight and mobile spacesuit design (which should improve performance and reduce risk for the astronauts’ health).
- Different approach to the pressurizing could potentially solve majority of issues (skintight suit or something completely new).
- The newest technologies and materials should be considered (AR screen in helmet, self-repairing materials, better cooling system, etc).
It’s just a few suggestions of my own. Obviously there can be done much more. Space agencies are aware of these problems and they’re working on ways to solve them. Over the years NASA have invested more than $200 million in different spacesuit projects. According to NASA’s Office of Inspector General audit report: Constellation Space Suit System ($135.6 million) (IEVA and EVA spacesuits), Advanced Space Suit Project ($51.6 million) (Z series EVA spacesuits) and Orion Crew Survival System ($12 million) (IVA spacesuit) .
In addition research and development is conducted in private and public sectors. Here a few projects you should keep in mind:
- Space-X suit by Space-X (IVA spacesuit)
- BioSuit by MIT (IEVA spacesuit)
- I-Suit and Mark III by ILC Dover (EVA spacesuits)
- Final Frontier Design suit by FFD (IVA spacesuit)
- Auoda.X by Austrian Space Forum (IEVA spacesuit)
- North Dakota suit by collaboration of five North Dakota colleges (EVA spacesuit)
 Thomas, Kenneth S.; McMann, Harold J. (23 November 2011). U.S. Spacesuits. Springer Science & Business Media