Uttu-Textiles.com // Issam Yousef // 16th December 2013
Mary Humphries wrote in her book, Fabric Reference, a very interesting statement about the vast use of textiles. To sum it, she said that some of textiles are really far out, as far as the space program has taken them. Textiles and human technology had reached beyond the solar system when Voyager 1 had passed to the deep space in September 2013.
I always wanted to explore the interesting field of space textiles, maybe because space and all related technology are very interesting and exciting topics by themselves. So What kind of textiles is used in space? and what makes them so special?
Textiles are used in space exploration since the beginning. Their use can vary from technical fabrics and composites used in the in building spacecraft to astronauts clothing or spacesuits to other applications such as the IAD fabrics.
One example of using textiles in the space constructions is the freeway landing method, which is used to deliver vehicles to the surface of Mars. The vehicle will be inside the lander, which is a strong light weight structure that protect the vehicle along with the air bags. The lander is made of sheets and beams. The sheets are composite material, fibre glass or fabric strengthened and stiffened with glue, while the beams are carbon based layers of graphite fibres woven into fabric creating a material lighter than aluminum and stronger than steel. On the outer side of the lander these are envelopes for airbags, figure (1).
Figure (1): The lander
After the shield and the parachute allow the lander to travel through the martian atmosphere for a certain distance, the airbags are inflated to allow the lander to bounce on the surface of Mars after landing, figure (2).
Figure (2): Lander’s airbags inflated
Before the lander reach the surface its speed is reduced to zero by rockets, then and just 3 seconds before landing, the ropes are cut off and the lander fall free and bounce on the surface of Mars, figure (3).
Figure (3): The free fall of the lander
Figure (4): The lander on the surface
The lander can bounce up to 4 stories high and for about one kilometer. When the lander stop, figure (4), the air bags will deflate and detract, the lander then will open allowing the vehicle to move to the surface of Mars, figure (5).
Figure (5): Lander opening
You can see the landing and airbags deployment in this video below.
The airbags are used from Vectran fibres, which is stronger than Kevlar and perform better in cold weather. There are two parts in the airbags, the outer layers, which consist of six 100 denier layers of woven Vectran making the outer layers soft and work as a protector of the inside layer or the bladders, which are made of 200 denier of Vectran threads.
Each lander has 4 to six airbags each with six lobes, figure (6), that are connected with each others. The air bags are tested thoroughly by dropping them at different angles and different surfaces from smooth to sharp. Any faults, figure (7), can be analyzed and fixed in order to avoid any problems in the real landing.
Figure (6): Airbags
Figure (7): Airbag puncture
This method of Mars landing was used for a very long time before it was replaced with the new technology, the sky crane touchdown system, in which a crane will be deployed to place the vehicle on the ground. The new system allows more accurate delivery to the surface and can take heavier weights.
IAD Fabrics, Inflatable Aerodynamic Decelerator, are used to improve the delivery of high mass missions to Mars. IAD fabrics deploy pressurized sections constructed from light weight fabrics to protect the vehicle upon entry.
Figure (8): IAD shield concept
Having an inflatable structure is very important to save space and weight when launching on rockets. This structure will be packed in small bag and only get stiff when gas is pumped into it. It should be soft like fabric to be packed and strong to withstand the forces of entering the atmosphere at high speed. The material used is braided Kevlar made into inflated rings lined with silicon from the inside to keep the compressed gas. Kevlar straps keeps the rings attached to each others and to the hardware. A thermal blanket will protect the structure form the heat generated during the reentry.
The structure will be packed in bags then before entering the atmosphere the gas will be pumped to it to give volume, saving more space and weight on the spaceships than the ones that use the rigid materials.
The importance of IADs comes from their ability to save weight and space on the spacecrafts, which is inessential to space travel.
You can see more about the IADs in these videos
There are other types of textiles that are used on the construction of the spacecrafts, such as the composites parts form carbon fiber and glass fibres that produce strong but very light parts. On the future we will cover composites on a different article.
It is known that 20 km above the surface the atmosphere become thin with low pressure, both the water and the human blood will boil. A protection is needed, spacesuits are inessential to enable us to work in the space providing pressure, oxygen and protection from the hazardous environment up there. There are different kind of spacesuit, they differ in shape and purpose. For example, astronauts will wear a flight suit inside the international space station, while this is not enough for the work in the outer space, i.e. the spacewalk.
The first spacesuit was worn by the first man in space, Yuri Gagarin in 1961, the SK1, figure (9).
Figure (9): SK1 suit
The SK1 provided the basic protection for astronauts during launching and reentry but not for space walk. On the American side, Mercury suit was designed, aluminum coated nylon to provide thermal control with air supply and the ability to be pressurized but it was never used for spacewalks. The first suit designed for spacewalk was the Berkut, figure (10) worn by the first man to do a spacewalk, Alexey Leonov in 1965 for 12 minutes.
Figure (10): Berkut suit
The Berkut suit used only once due to its bulkiness, it had oxygen supply. And just behind the Soviets, the American designed the Gemini suits to allow the spacewalk, layers of nylon with removable boots. This suit was significant for the Apollo suit used on the moon landing.
These first suits were difficult, they caused exhaustion and a lot of sweat for astronauts. The American then designed the Apollo A7L for landing on the moon. This suit provided more comfort, protection and maneuverability.
The suit worn by Neil Armstrong and Buzz Aldrin had 21 layers, Neoprene coated Nylon was used as bladder materials, polyester fibers were used as spacer between the layers of aluminized polyester to provide thermal protection. Additional protection was provided using aluminized Kapton polyimide film, which has working region from ( – 169 degree Celsius to + 400 degree Celsius). The outer layer of the moo suit was made of fibre glass coated with Teflon TFE fluorocarbon to provide protection against micrometeoroids. The surface layre was cover up to 50% with Teflon yarn for abrasion resistance. For inner protection Nomex fibres were used
Figure (11): DuPont on the moon
Z-1, figure (12) is the new suit to be used after 2015. The suit will be suitable for spacewalks and for landing on alien planets.
Figure (12): Z-1 suit
To sum it up it is noticeable that technology and textiles are always a successful mix when its come creating something new and highly functional, as the case of spacesuits and other space textiles. More and more tech fabric or clothing will emerge giving solution to various problem and situation providing wither more comfort and protection pushing the synthetics fibres to their maximum limits and maybe pushing towards new fibres as in the case of producing spider silk. However it is worth mentioning that protection and comfort are still a significant areas to research for traditional, technical and functional fabrics used in our daily activities here on Earth.
- -Humphries, M. ( 2003). Fabric Reference. USA, Prentice Hall.
- -Scott M. Murman and S. A. Suresh (2011). “Modeling Effective Stiffness Properties of IAD Fabrics.” American Institute of Aeronautics and Astronautics: 17.
- -The History of Spacesuits, 2013, All About Space, No. 11, 17 – 25.
- -What on Earth Do You Wear on the Moon, DuPont SpaceSuit Fact Sheet, www.dupont.com
- -DuPont on the Moon, October, 4, 2012. www.dupont.com