Suitport

A suitport or suitlock is a proposed alternative to an airlock, designed for use in hazardous environments and in human spaceflight, especially planetary surface exploration.

Operation

In a suitport system, a rear-entry space suit is attached and sealed against the outside of a spacecraft, space habitat, or rover. To go on an extra-vehicular activity (EVA), an astronaut first enters the suit from inside the vehicle, and closes and seals the space suit backpack and the vehicle's hatch (which seals to the backpack for dust containment). The astronaut then unseals and separates the suit from the vehicle, and is ready to perform an EVA.cite web
last = Culbertson
first = Philip, Jr.
title = Suitlock docking mechanism — United States Patent 5697108
publisher = freepatentsonline.com
date = 09/30/1996
url = http://www.freepatentsonline.com/5697108.html
accessdate = 2006-06-15 ] cite web
last = Boettcher
first = Joerg
coauthors = Stephen Ransom, Frank Steinsiek
title = Apparatus and method for putting on a protective suit — United States Patent 6959456
publisher = freepatentsonline.com
date = 07/17/2003
url = http://www.freepatentsonline.com/6959456.html
accessdate = 2006-06-15 ] [cite web
title = Docking Fixture and Mechanism for a Protective Suit
work = NASA Tech Briefs
publisher = NASA
date = March 1, 2003
url = http://www.techbriefs.com/content/view/1242/34/
accessdate = 2006-06-15 ]

To re-enter the vehicle, the astronaut backs up to the suitport and seals the suit to the vehicle, before opening the hatch and backpack and transferring back into the vehicle. If the vehicle and suit do not operate at the same pressure, it will be necessary to equalize the two pressures before the hatch can be opened.

Advantages

Suitports carry two major advantages over traditional airlocks. First, the mass and volume required for a suitport would be significantly less than that required for an airlock. Launch mass is at a premium in modern chemical rocket-powered launch vehicles, at an estimated cost of US$60,000 per kilogram delivered to the lunar surface. [cite conference
title = Earth to Lunar CELSS Evolution
booktitle = Proceedings of the NASA/USRA Advanced Design Program 7th Summer Conference
pages = 123–132
publisher = University of Colorado
url = http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930020538_1993020538.pdf
accessdate = 2006-06-15 ]

Secondly, suitports can eliminate or minimize the problem of dust mitigation. During the Apollo program, it was discovered that the lunar soil is electrically charged, and adheres readily to any surface with which it comes into contact, a problem magnified by the sharp, barb-like shapes of the dust particles.cite web
last = David
first = Leonard
title = Lunar Explorers Face Moon Dust Dilemma
publisher = Space.com
date = November 7, 2006
url = http://www.space.com/scienceastronomy/061007_moon_dust.html
accessdate = 2008-06-15 ] Lunar dust may be harmful in several ways:

*The abrasive nature of the dust particles may rub and wear down surfaces through friction
*The dust may have a negative effect on coatings used on gaskets to seal equipment from space, optical lenses that include solar panels and windows as well as wiring
*The dust may cause damage to an astronaut's lungs, nervous, and cardiovascular systems [cite web |url=http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2193.pdf |title=Micro-Morphology And Toxicological Effects Of Lunar Dust |accessdate=2007-03-08 |last=Park |first=J.S. |authorlink= |coauthors= Y. Liu, K. D. Kihm, and L. A. Taylor |date= |year= |month= |format= |work= |publisher=Lunar and Planetary Science XXXVII (2006)- |pages= |language= |archiveurl= |archivedate= |quote=The particle size distribution of the lunar dust from Apollo 17 sample 77051 has been determined using SEM imaging analysis. The size-distribution data features an approximate Gaussian distribution with a single mode at around 300-nm. The reactivation surface area of highly porous “Swiss-cheese” particles is about 26% higher than a sphere. The morphologies of dust grains have been classified based upon their four types: 1) spherical; 2) angular blocks; 3) glass shards; and 4) irregular (ropey or Swiss-cheese). These data will assist the medical researchers in their studies of the toxicological effects of inhalation of lunar dust by humans.] [cite news |first=Kelly|last=Young |author= |coauthors= |title=Lint rollers may collect dangerous Moon dust |url=http://space.newscientist.com/article/dn11326-lint-rollers-may-collect-dangerous-moon-dust.html |format= |work= |publisher=New Scientist |id= |pages= |page= |date=06 March 2007 |accessdate=2008-02-17 |language= |quote=While hailed as a potential source of oxygen and metals, Moon dust is a concern because doctors fear the smallest grains could lodge in astronauts' lungs, possibly causing long-term health effects.]

During the Apollo missions, the astronauts donned their space suits inside the Apollo Lunar Module cabin, which was then depressurized to allow them to exit the vehicle. Upon the end of EVA, the astronauts would re-enter the cabin in their suits, bringing with them a great deal of dust which had adhered to the suits. Several astronauts reported a "gunpowder" smell and respiratory or eye irritation upon opening their helmets and being exposed to the dust.

With a suitport, dust or other environmental contaminants cannot enter the cabin of the vehicle. When the suit is attached to the vehicle, any dust which may have adhered to the backpack of the suit is sealed between the outside of the backpack and the vehicle-side hatch. Any dust on the suit that is not on the backpack remains sealed outside the vehicle. Likewise, the suitport prevents contamination of the external environment by microbes carried by the astronaut.

Development and future use

Patents for suitport designs were filed in 1996 by Philip Culbertson Jr. of NASA's Ames Research Center, and in 2003 by Joerg Boettcher, Stephen Ransom, and Frank Steinsiek.

Suitports may find use as part of future NASA projects aimed at achieving the Vision for Space Exploration, which calls for a return to the Moon and eventual manned exploration of Mars.

ee also

*Space exploration
*Project Constellation
**Lunar outpost (NASA)
**Altair (spacecraft)
*Lunar surface
*Colonization of the Moon
*Colonization of Mars

References