The universe is the most primitive basis of matter and space. It is infinite and full of infinite unknowns. It has brought a very dreamy imagination to mankind. Faced with the call of stars in the night sky, the temptation of extraterrestrial space makes mankind become more yearning for the universe. After doing a lot of theoretical calculations and practice, scientists discovered that we can launch small celestial bodies to orbit the earth, thus providing humans with various information about observing things on the earth from the perspective of extraterrestrial celestial bodies. Since the former Soviet Union launched the first man-made earth satellite, there are now many small man-made satellite partners above our heads. They are continuously transmitting data in the form of electromagnetic waves day and night, mainly for humans. Military reconnaissance, environmental monitoring, data communications, and deep earth observations are alternately transmitting information.

The molybdenum rhenium alloy coated with iridium particles is an important part of the power plant in the attitude and orbit control system of some low-orbit satellites. The iridium-coated molybdenum-rhenium alloy is based on the molybdenum-rhenium alloy, which is manufactured into a nozzle structure, and then the metal iridium is attached to the surface of the substrate by means of PVD or CVD coating.

The main purpose of spraying iridium particles is: the liquid fuel used on low-orbit satellites will form high temperature, high pressure and strong corrosive substances during the reaction process. The use of iridium as a surface coating effectively protects the molybdenum-rhenium alloy nozzle. Anti-oxidation and anti-corrosion performance. Because iridium is expensive and dense, it is not cost-effective to use iridium alone as a nozzle. The technology of using molybdenum-rhenium alloy as a substrate and iridium as a coating greatly saves production costs and launching and carrying costs. Compared with fixed attitude and invariable orbit satellites, the emergence of low-orbit attitude control and variable-orbit artificial satellites will greatly increase the use space and living space of satellites.