Wednesday, December 18, 2013

Space Suit for Asteroid Work

I recall when the first space suits for the Apollo program were shown of that I felt a sense of disappointment tempered by the knowledge that it was a starting point to evolve from.   Now here we are attempting to evolve.  It is still not too impressive.

The advent of graphene will provide and impervious outer shell in time, but we are not there yet.  Yet joint technology was improved hugely with the deep sea hard suit and should be adjusted into the space environment.

I would also like to see gloves with natural soft points that allow serious tactile feedback.   I suspect it can be done.  The back of a finger of thumb digit can be stiff to avoid compromising forward movement and squeezing.  Hinging can reflect natural bone hinging as well.

NASA testing lighter space suits for asteroid work

December 15, 2013

Sometimes you have to take a step back to take a step forward. NASA is carrying out initial tests on a new, lighter spacesuit for use by the crew of the Orion spacecraft that is currently under development. The tests are being carried out in the Neutral Buoyancy Laboratory near the Johnson Space Center in Houston, Texas on a modified version of the pumpkin orange suit normally worn by Space Shuttle crews during liftoff and re-entry and is a return to a space suit design of the 1960s.

The Orion program has posed something of a wardrobe problem for NASA. When the space agency started looking at developing a new spacesuit for the 21st century, it had the now-cancelled Constellation spacecraft in mind. The original plan was to go with either armor-like hard suits or something along the lines of the hard/soft hybrid Extravehicular Mobility Unit (EMU) suits deployed on the International Space Station (ISS) for extravehicular activities (EVA).

The hard and semi-hard suits, such as the Z-1 prototype, are bulky with lots of hard shells, bearings, hatches, and other components. This isn’t a problem on the station or in a large vehicle like the Space Shuttle or the Constellation, but when the Constellation program was cancelled in favor of the Orion, all that hardware had to go out the porthole. Orion is more of an upgraded Apollo Command Module and space will be at a premium. There isn’t room for a specialized EVA suit that looks like it was designed for jousting with laser beams.

That’s a stumbling block because NASA wants to use Orion to send a manned mission to collect samples from an asteroid relocated to an orbit near Earth. This means the Orion crew needs spacesuits for the EVAs, which means a different kind of space suit is required.

NASA’s solution is to take a step backwards. Instead of having one suit for launch and reentry operations, and another for EVAs, the space agency wants a multi-purpose spacesuit that can be worn for both flight operations and for working outside the spacecraft, as was the case up to the Apollo-Soyuz mission in 1975.

The new suit is a harkening back to and an evolution of the suit worn by Ed White during his historic spacewalk during the Gemini 4 mission in 1965. When the US space program started, the first “spacesuit” worn by the Mercury astronauts was a modified Mark IV high-altitude suit painted silver. For the Gemini missions, a new suit was developed that was an advanced version of the suit worn by SR-71 Blackbird pilots as they flew on the edge of space at supersonic speeds.

Both of these were suits designed mainly to protect the wearer in the event of a sudden loss of cabin pressure. Since the astronaut spent most of his time sitting down, and would certainly be doing so in an emergency, the suits didn’t allow much in the way of mobility when inflated.

The biggest advance came when the Gemini astronauts started doing spacewalks and the suits had to be modified with more flexible joints and gauntlets, so the astronauts wouldn’t be floating around looking like crouching balloons, and could get in and out of the spacecraft with a minimum of effort and cursing.

When Apollo came along, the designers had to make something that someone could actually walk in and get some work done in while inflated. That worked fine for the moonwalks, Skylab, the Space Shuttle program, and the ISS, as suits became bulkier and incorporated more hard components to provide more mobility and a one-size-fits-all design.

The new Orion suit is based on the Advanced Crew Escape System (ACES). Like the Gemini spacesuits, this too is a development on the flight suit for the SR-71 Blackbird. Notable for its distinct pumpkin orange color, it was worn by Shuttle crews from 1994 on. Its current purpose is to protect the astronaut in the event of an emergency, to provide life support for a very limited time, and to carry emergency gear, such as parachutes, flotation devices, radios, and survival kits.

According to NASA, the advantages of the ACES suit are that it has over 30 years of experience behind it, is low cost, the infrastructure for supporting it is already in place, and it’s designed to be easily upgraded. Though it will be modified for working in hard vacuum for extended periods, the new suit will look very similar to the current ACES, except that it will be white instead of orange.

The main modifications to the suit will be to make it more suitable for regular work instead of just emergencies. It will need to operate with a life support backpack and the systems on Orion, operate for hours instead of minutes, and it will need more flexibility in the elbows, wrists, and other high mobility joints. The trick will be to do so without introducing too many hard points that might injure the wearer on take off or hinder an escape in an emergency.

"The shell of them is very much the same, and to the casual user you may not even notice the difference, but internally we modified them to work with the plumbing inside Orion," says Dustin Gohmert, Crew Survival Systems Manager at Johnson.

The neutral buoyancy tests and others involving dangling from harnesses and crawling through Orion mockups are designed to assess the suitability of the ACES suit for EVAs and to find out what modifications need to be made. This is a bit tricky because its a constant tradeoff between efficiency in moving around, which favors shells and bearing rings, and as an emergency suit for walking to the launch pad and being worn during flight, which benefit from everything being soft. The tests will also help engineers to evaluate spacewalking techniques, such as getting through hatches, moving between spacecraft and asteroid, and handling tools.

"We're stepping back to our heritage to be able to use one suit for multiple tasks," says Gohmert.

The video below shows part of the water tank tests.

Source: NASA

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