July 30, 2012
Spacesuit Redesign In Store For NASA Astronauts
Lee Rannals for redOrbit.com - Your Universe Online
After about 20 years, NASA has decided it´s about time to change out the astronaut wardrobe by developing a new spacesuit.
NASA has its eyes set on some deep space missions in the coming years, including trips to a near-Earth object or Mars. Developing a new spacesuit for its astronauts is just another step to get it closer to its goal.
The Z-1 prototype spacecraft and Portable Life Support System (PLSS) 2.0 test article is undergoing tests right now.
NASA said that the Z-1 is a rear-entry prototype spacesuit which represents a soft exploration extravehicular activity (EVA) suit configuration.
“The suit actually contains several hard mobility elements," Spacesuit Engineer Kate Mitchell said in a NASA update about the new suits. "The term ℠soft´ is intended to convey the idea that the primary structures of the suit are pliable fabrics when unpressurized.”
The prototype is the first in a series being developed under the AES suit project by the space agency.
“The goal is by the 2014/2015 timeframe to have a new vacuum- compatible exploration-type suit,” Mitchell said in the update. “The Z-1 was developed as a test bed to go and test various technologies and mobility joints so we can further define our architecture going forward.”
The Z-1 prototype spacesuit is helping to prepare the way for the next-generation prototype, which will be called the Z-2.
“The data we´re gathering now will feed tools that will help us build better suits in the future,” Amy Ross, lead of the Space Suit Assembly Technology Development team, said in the update.
She said the last major spacesuit prototype was developed in 1992, and the last new flight system was the Extravehicular Mobility Unit (EMU).
A major milestone for the researchers is getting the suit ready to be tested in the human-rated thermal vacuum chamber. Ross said this is a step that hasn't been done since the shuttle suits.
One of the technologies that is being implemented in the new spacesuit is to add a suitport, so the astronauts would be able to attach themselves to the back of a rover.
“To enable suitport operations, the suit has to be able to equalize with the cabin pressure,” Mitchell said in the NASA update. “If the cabin pressure of the rover is 8.3 psi, we´d have to have a suit that would be able to operate at that pressure in order to get out the door.”
The technology required for suitport operations also benefits the astronauts by having less prep time, giving astronauts more time to explore other worlds.
Also being developed is the PLSS, which is a backpack on the suit that helps to carry out all life-support functions.
These functions include providing oxygen, removing carbon dioxide and trance contaminants, providing ventilation flow and cooling the crew member and onboard electronics, according to NASA.
“Our group is developing a new advanced technology PLSS that aims to be more robust, less sensitive to contamination, use less consumables and provide increased capabilities as compared with the current EMU PLSS,” PLSS Engineer Carly Watts said in the update.
The backpack prototype is the group's first attempt to package the backpack with components in a flight-like configuration. The predecessor to the current prototype, PLSS 1.0, was used to help the team tie up all development components with commercial off-the-shelf hardware to simulate the functionality of the PLSS design.
“We have been operating the EMU PLSS on orbit for 30 years now, and because it was developed prior to that, the technology is 40 years old,” Watts said.
The EMU PLSS uses a sublimator for its cooling function, which Watts said is extremely sensitive to contamination and can only be used in a hard vacuum environment.
In order to keep the Red Planet as its future destination, the team is developing a new tool called the Spacesuit Water Membrane Evaporator.
“It´s a completely different technology that we fostered and developed in house,” Watts said in the update. “The design gets the same performance as the sublimator, but it can be used in a Martian environment. It can be frozen without damaging the unit, and it´s not particularly sensitive to contamination.”
The researchers are also switching out the components currently used to help remove carbon dioxide. EMU's current system requires lithium hydroxide and metal oxide (MetOx) canisters that remove CO2 to be "baked" out in an oven on the space station for about 14 hours in order to be reused again.
“We´re looking to replace those capabilities with a Rapid Cycle Amine swingbed,” Watts said in the update. “Every few minutes it will cycle and regenerate itself to remove CO2 real time during a spacewalk ... so CO2 removal capability will no longer be a consumable.”
NASA said the Z-1 and PLSS 2.0 are not at a stage where they can be used together yet, but future iterations of the suit and backpack will see the two come together in the human-rated thermal vacuum chamber.
“The AES program has given us the tools to develop advanced EVA systems in a lean environment with low programmatic overhead,” Ben Greene, project manager for Advanced EVA Systems Development, said in a press release. “We intend to take full advantage of that opportunity to push EVA technology farther than it has been in decades.”