Thursday, July 05, 2007

The Mission


Now the journey begins. In building a spacesuit, it is best to learn from the experience of our astronaut crews. When dealing with people who have already been to Space, the customer is always right. Here are some spacesuit requirements from an agency that loves Powerpoint.

For this set of outcomes, a counter-pressure suit has inherent advantages. It minimises mass and volume while maximising mobility. Tests have shown that current "soft suits" can not provide adequate mobility when pressurised. Regarding quick-donning, preliminary tests verify that an astronaut can quickly dress herself, thank you. For future upgrades, design flexibility and modularity are built into the system.

"Return scenarios from the lunar surface could require up to 120 hours of unpressurized survival." The original Lunar Module was built of very fragile materiels and depressurisation was a real danger. 55 hours and 53 minutes hours into flight Apollo 13 suffered an explosion in an oxygen tank. All power and oxygen was lost in the Command Module. By improvising and using the LEM as a lifeboat, the crew barely survived until splashdown at 142:54 hours. If their suits had 120 hour duration they would have needed only to lower their visors.

Humans can't last 120 hours without drinking. You can survive 5 days without food, but we wouldn't want you at the controls of a spaceship. Current spacesuits have a plastic drink bag stuffed into the helmet. During Apollo 16's walks on the Moon, the bags of orange juice burst inside the astronauts' helmets. Yuck! It must have made them wonder about the rest of their suit. One bag of juice will not last 120 hours.

120-hour capability will be available as an option. Another hole can be built into the helmet for a feeding tube from the backpack. The tube is electrically heated to prevent freezing. A pinch valve allows the astronaut to drink at will. A nutritious smoothie-like drink provides liquid and food needs in an emergency. (This blogger prefers chocolate.) Canisters of the stuff can be stored in the spacecraft for easy replacement.

The other end poses a challenge. The infamous "astronaut diaper" can simply not cut it. Can you imagine sharing a sealed spacesuit with 5 days of waste? Without revealing any proprietary information, having a suit fit closely to the skin may be the only way to solve this problem. Only a counter-pressure suit can meet this important requirement.

"Suit system must be able to accommodate various functions (i.e. reconfiguration) without necessarily requiring doffing of entire system." Apollo 15, 16 and 17 missions included both lunar surface EVA's and zero-G EVA's on the return home. Especially on long missions, a crewmember will need both capabilities. In that 120-hour situation, she may need to change from EVA to Earth return configuration without without opening the suit. As Darnell of Colony Worlds so kindly notes, the suit can be customized to fit different needs, even inflight. A compact, flexible inner layer makes this possible.

"Minimize dust in crew habitable space...Maintaining suit system performance." That abrasive lunar regolith gets into everything. NASA wants to leave the dusty portions of the suit behind and still have a spacesuit to return home. This requires that the outer EVA layers be removable. Previous "hard suits" require that you bring back to Earth the heavy shell, dust, germs and that Alien attached to your suit.

For these reasons and others, this technology is the best way to meet NASA requirements. It may be the only way. We owe our crews the safest and best equipment possible. Many tests lie ahead. The spacesuit is beginning a long and challenging journey.

Other interesting Space news in the new Carnival Of Space!

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3 Comments:

Blogger Kea said...

This is all fascinating. Thanks for giving us such a good idea of what space engineering is about.

You can survive 5 days without food, but we wouldn't want you at the controls of a spaceship.

Ah, yes, I can certainly attest to that. And experience shows that food shortages are often accompanied by other environmental problems, but I guess in a spacecraft these are of a more drastic nature than we are used to thinking about, let alone planning for!

5:12 PM  
Blogger L. Riofrio said...

HI Kea. Your outdoor experience is very valuable. Much of the technology developed for climbing has applications in Space. It is very exciting working on an environmental system.

8:43 AM  
Anonymous Darnell Clayton said...

Hey Louise,

Keep us all posted how this new suit goes.

Note: I was just thinking, you may have potential customers abroad, as designing space suits is something many nations can't afford (although renting may be an option for them).

10:37 AM  

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