Visco-elastic memory foam was first created by NASA in the late 1970's. At the time,
the issue was that astronauts were subjected to a tremendous amount of g-forces during lift-off. So they needed flight seats that would be able to reduce pressure points, but at the same time still provide enough support.
The answer was visco-elastic memory foam due to its temperature sensitive characteristics. When it's exposed to warmer temperatures, it softens and conforms to the body. In cooler conditions, it becomes more firm. During lift-off, the astronauts would sink down into this foam so they would't feel pressure points.
Memory foam is the only material that reacts in this manner. If the seats were made out of your everyday foam, it would push back against the body instead of conform. This is how pressure points are created.
Because of the g-force felt during lift-off, being subjected to pressure points could be overwhelming and cause harm to the astronauts.
By conforming, the memory foam would act as a shock absorber by distributing the forces over a wider area.
However, NASA ultimately decided not to use memory foam because they were not able to perfect it enough for practical use. Since chemicals are used during the manufacturing process, the smell it emitted would be unhealthy in a small, congested space shuttle.
All memory foam mattresses give off a chemical smell that customers have to manage at least for a short period of time. After awhile, most people say that they barely notice it. However, they also have the luxury of airing out the mattress by opening windows and allowing fresh air to come it. Obviously, astronauts aren't able to get fresh air while up in space, so they would be inhaling these fumes the entire time.
The other issue is that the memory foam seemed to break down in a very short period of time. It would begin to flake and tear after limited use.
So, NASA decided that enough was enough. They sold the technology to Fagerdala World Foams of Sweden, which is one of the largest foam manufacturers in Europe.
They spent a great deal of time tweaking the memory foam so the general population could benefit from it. Early on, it was primarily used by those who were looking for pain relief while sleeping at night.
Fagerdala then created the Tempur-Pedic mattress that would be sold to the everyday customer. Soon, a number of other manufacturers began creating their own memory foam to sell.
