The Soviet Union duplicated its dual-launch feat with Vostok 5 and Vostok 6 (June 16, 1963). This time they launched the first woman (also the first civilian), Valentina Tereshkova, into space on Vostok 6. Launching a woman was reportedly Korolev's idea, and it was accomplished purely for propaganda value.
Lumen: A luminous term referring to the channel within a tube such as a blood vessel or to the cavity within a hollow organ such as the intestine. Lumen is a luminous term because it is Latin for light, including the light that comes through a window. When a hollow organ is cut across, you can see light through the space that has been opened. So the word lumen came to mean this space.
The skin is the largest organ of the human body and of all mammals. In the average adult it weighs around six pounds, which is nearly twice the weight of the human brain or liver. The largest internal organ is the liver. It is also the heaviest organ, with an average of 1.6 kilograms (3.5 pounds). The largest external organ, which is also the largest organ in general, is the skin. The skin is the largest organ in the human body. The largest organ of the human body is the skin, because it stretches throughout ll the body parts. Although it feels lightweight, if you were to measure the weight of your skin alone, it could be several pounds.