The sun always rises. Twenty-four hours into their space adventure, the three Chinese taikonauts on board the Shenzhou-7 spaceship have witnessed sunrise and sunset for 16 times in their 680,000-kilometer journey.
When asked about what the astronaut will actually do outside the spacecraft, Qi said he once suggested retrieving the national flag that hangs outside the spaceship.
Extra-vehicular activity (EVA) is work done by an astronaut away from the Earth and outside of a spacecraft.
An EVA is dangerous for a number of different reasons. The primary one is collision with space debris. Orbital velocity at 300 km above the Earth (typical for a space shuttle mission) is 7.7 km/s.
Space debris or orbital debris, also called space junk and space waste, are the objects in orbit around Earth created by humans, that no longer serve any useful purpose.
A spacesuit is more than clothes astronauts wear in space. The suit is really a small spacecraft. It protects the astronaut from the dangers of being outside in space.
Spacesuits help astronauts in several ways. Spacewalking astronauts face a wide variety of temperatures.
Astronauts use white spacesuits when they go on spacewalks to do work outside the space shuttle or International Space Station.
On the back of the spacesuit is a backpack called the Primary Life Support Subsystem. This backpack contains the oxygen that astronauts breathe during a spacewalk.
The airlock module is a pressure chamber linking the main body of the spacecraft to the outside. It is a complex piece of equipment but was not required on the previous six Shenzhou space flights.
Spacewalkers must wear pressurized spacesuits in order to work in space. These suits have pressures significantly lower than ambient cabin pressure of a spacecraft.
Preparation varies with the food type. Some foods can be eaten in their natural form; others require adding water.
Since there is no washer or dryer in the space shuttle, astronauts bring a change of underwear for each day they are in space. They also have a few extra shirts, shorts and trousers.
Spacesuits are fitted with diapers so that astronauts can work outside for long hours(especially during spacewalks). Toilets have various restrains (foot loops, thigh restraints, etc.) so that astronauts will not float away when he/she is using it.
While on the International Space Station, astronauts communicate with each other by talking. There is air on the station, and air will support the transmission of sound waves. Just like it does here on earth.
Shuttle missions are short. Each day is devoted to achieving the mission objectives. However, shuttle astronauts do get time off for breakfast, lunch, dinner and personal relaxation time before going to sleep.
