Close-up, slow-motion shots of Apollo missiles pop up when normally in contact with a spacecraft or missile, launching Saturn V while launching debris. The one who guesses that what we see is snow is right.
The Saturn rocket was powered by kerosene, liquid oxygen and hydrogen. Oxygen and hydrogen are gases at normal temperatures on the planet’s surface, and they need to be cooled to a liquid state. With respect to oxygen, the cold fuel is separated from the air by a steel plate so that the vapor condenses on its surface, even in a cold beer mug, where it condenses densely. The energies, sounds and vibrations emitted during a rocket launch cause the condensed ice to fall.
Liquid hydrogen is another case, which requires a much cooler temperature, as not only steam but also nitrogen and oxygen in the air freeze on the surface of the tank. If this ice escapes, it will cause the hydrogen to boil and explode. So this part of the rocket was protected by insulation. It was initially built of glass wool and then polyurethane was used, which was simply inflated in the form of foam. In both cases, the water-repellent seal layer is surrounded by insulation; If it is damaged, the liquid oxygen absorbed in the polyurethane may ignite under physical action, causing it to explode slightly near the hydrogen-filled container.
The ice that fell on the launch pad alone did not pose a threat until the space shuttle project. However, at that time, with the heat shield initially attached to the missile, it was no longer desirable for ice to fall to the bottom of the spacecraft. So the launcher was covered with polyurethane foam from top to bottom. Initially yellow, the sun-aged material is still used in Delta IV, SLS, Atlas V and Vulcan Centaur missiles.
However, polyurethane does not always protect the spacecraft because the wind resistance at supersonic speeds peels off large pieces from the launcher. In one case, it was almost dangerous. Later, the Columbia Space Shuttle Tragedy also led to:
The split foam collapsed at high speed and broke the thermal shield of one of the wings.
The Columbia spacecraft crashed on February 1, 2003 when it returned to space due to injury. All of the crew were killed Monday in the crash.
The space shuttle project was completed in May 2009 with the repair of the Hubble Space Telescope, and the lesson learned is that insulation may be more optimal at the beginning of the launch.
It can also be found on Chinese Long March missiles and European Ariane missiles, from which the backup is pulled by wires attached to the launch pad. What turned out to be the story is that none of the said rockets required fuel for cooling, but operated at room temperature with liquid hyperglycemic, self-igniting nitrous oxide. Since hypercholesteric fuel is also sensitive to temperature, insulation is required, for example, as it freezes. So, in China, rockets are shielded against the cold, while the European Space Agency is shielding them from the equatorial heat of the Grove space station in Guyana.
Backup, even the initial dismissal, was a problem for the Chinese. On one occasion, one of the pieces detached from the Long March got caught in one of the wings, which eventually led to the failure of the whole mission.
One of the most interesting events is the Minotaur Rocket. Minutemen carrying nuclear weapons have been developed from intercontinental ballistic missiles and have been used in the United States since the 1990s to launch low-cost military and reconnaissance satellites. These are solid propulsion rockets, the performance of which varies with temperature. For minotors, the backup is one ThrowingThe age is peeled off with the help of beautiful yellow layered rods, which makes the launch so spectacular that it looks like it is rising from a banana peal at the start of the first stage of a rocket.