What Are the Different Types of Environmental Specialist Jobs?

Spacecraft environmental engineering is the study of the environment experienced by the spacecraft during its manufacture, launch, operation and return, the impact of the environment on the spacecraft and its mechanism, environmental simulation methods and simulation techniques, environmental test methods, technologies and theories, and the environment A comprehensive discipline in the use and protection of human spaceflight and environmental simulation conditions and test methods. ^[1]

In the 20th century, with the development of aerospace technology, spacecraft environmental engineering received tremendous momentum for development. This is first manifested in the fact that all countries in the world, including China, that have developed aerospace technology have established environmental testing centers and test facilities with a large scale of test equipment, which is sufficient to meet the needs of the development of various types of spacecraft. In the long-term development process, a complete set of experimental theories and practices have been formed and summarized in the relevant spacecraft test standards. The development of aerospace environmental engineering is also manifested in the following aspects:

1. Clarify and highlight the importance of environmental verification in spacecraft development

Many years of spacecraft development work experience proves that in order to ensure that the spacecraft developed meets the predetermined performance requirements and service life, although careful design and manufacturing are key, comprehensive and rigorous verification work is absolutely essential. Attention was paid to the verification of spacecraft, and corresponding standards were formulated. In January 1999, the U.S. military issued MIL-STD-1540D "Carrier, Top-Level Aircraft and Spacecraft Product Validation Requirements." The European Space Agency (ESA) has long developed the standard ESA-PSS-01-80 "ESA Manned and Unmanned Spacecraft Validation Guide." On this basis, the European Space Standardization Cooperation Organization (ECSS), which was later established, has a standard ECSS-E-10-02A "Space Engineering: Verification" in the Engineering Series (E Series) standard that specifies how to perform aerospace product verification. (Promulgated in November 1998). The verification work is not only an important part of the spacecraft development unit, but also an important part of the orderer's supervision of the spacecraft development process and quality through various verification work in the development process. There are many forms of verification work, as pointed out by M IL-STD-1540D: Verification can be achieved by analysis, experiment, inspection, demonstration, similarity, etc., or a combination of them. From the above standards, it can be seen that the verification work is essentially an environmental verification work, that is, verifying whether the design and manufacturing quality of the spacecraft can withstand the test of various environments and meet the performance and life requirements stipulated in the contract. It is based on environmental engineering, and environmental testing is the main content and important means of environmental verification. ^[2]

As we all know, a spacecraft is a very complex product consisting of multiple sub-systems and tens of thousands of parts. Once a failure occurs during orbital operation, it is generally not directly repairable except for the space shuttle and the space station. Reliability; due to small production batches, it is difficult to realize automated processing, 'product quality and stability are difficult to guarantee, long development cycles and extensive collaboration have added difficulty to product quality control, and spacecraft development and launch are costly and generally cost In terms of billions or even billions of yuan, it is necessary to conduct sufficient environmental tests. Adequate ground environment simulation tests can also enable spacecraft to be reasonably designed, avoid excessively thick shields and structures, reduce backup fuel, reduce development costs, and save money. Therefore, the research and test of "spacecraft environmental engineering" is an important part of the spacecraft design and development process. ^[1]

Environmental engineering serves product reliability. Because the reliability of the product is closely related to the environment it is subjected to, in order to ensure the reliability of the product, a series of environmental issues need to be solved by environmental engineering. A large number of environmental tests are to verify product design and manufacturing quality, and to improve and ensure product reliability. Environmental engineering, just like many other engineering disciplines such as: quality assurance, ergonomics, system safety, component, material and process control, maintainability, etc., plays an important supporting role in reliability engineering, and at the same time There is an interface relationship between them. Neglecting environmental engineering will make the reliability of the product not well solved. ^[3]

Like the development of other advanced and complicated weapons and equipment, the development of spacecraft is also a huge system project. In the current era of fierce market competition, in order to improve work efficiency, make products developed with high quality and reliability, low development costs and short cycles, fully mobilize and make use of the relevant departments (design, manufacturing, testing and logistics support, etc.). Force coordination is necessary. It is a characteristic of current product development work to carry out total quality management during the product development process, and to apply the working method of concurrent engineering at the same time. Among them, environmental engineering is an indispensable and important part, and it will inevitably receive more and more attention.

The importance and complexity of spacecraft environmental problems should be fully recognized. Even if they are carefully designed and manufactured, and a large number of environmental tests are performed on the ground, it is still difficult to ensure that no problems will occur after the spacecraft is launched. As far as the United States is concerned, this is true despite the vast experience accumulated in spacecraft development. The satellites launched by NASA's Goddard Space Center in recent years still have many problems in orbital operation, called "anormaly", which include abnormal work and failures, and have varying degrees of impact on mission completion.

Fortunately, most of these anomalies were not serious and did not cause serious damage to the mission of the satellite. The emergence of these problems explains to a certain extent that people do not know enough about the complexity of the space environment in which the spacecraft is located and its comprehensive long-term impact, and the design is not comprehensive enough. Another reason is that ground tests, especially the environment, The test was not adequately performed or the results were problematic, failing to expose the potential defects of the product that should be exposed. Because the spacecraft has a precise and complex structure, the environment it is subjected to is very complex and it is difficult to fully grasp it. After entering orbit, problems such as these occur in the long-term operation process. The more new models, the more problems may occur. Therefore, environmental issues must not be taken lightly. More investment in environmental engineering and environmental testing, and efforts to improve the level of environmental engineering and environmental testing, is much less than the cost of spacecraft development costs or problems after launch. ^[3]

Make environmental engineering better serve the development of spacecraft, further improve the technical level of environmental tests, make the test conditions more reasonable, more realistically simulate the actual aerospace environment, and work hard to improve test time and cost The validity of the test will continue to be the direction of development of spacecraft environmental engineering in this century. China attaches great importance to the environmental reliability of spacecraft and environmental tests from the beginning. So far, China has established basic supporting experimental centers and laboratories for environmental test equipment, including computerization of test control and data collection. Its scale and level are world-class, and it has basically met the requirements of various spacecraft development. need. After many years of practice, a lot of experience has been accumulated in the application of environmental testing methods in the development of spacecraft, with its own set of practices and corresponding standards. Practice has proved that through environmental tests, many defects in design and manufacturing quality have been exposed and detected, which have played an important role in ensuring the normal operation and reliability of the satellite. ^[2]

The importance and complexity of spacecraft environmental problems should be fully recognized. Even if they are carefully designed and manufactured, and a large number of environmental tests are performed on the ground, it is still difficult to ensure that no problems will occur after the spacecraft is launched. The emergence of these problems shows that on the one hand, people do not know enough about the complexity of the environment experienced by the spacecraft and their comprehensive long-term effects, and they have not considered the design comprehensively; Failure to expose potential defects in products that should be exposed is also an important reason. Because the spacecraft has a sophisticated structure, the environment and its long-term comprehensive effects are very complex and difficult to fully grasp. After entering orbit, problems such as these and other problems will occur during the long-term operation. Therefore, we must not take environmental issues lightly. ^[2]

The cost of environmental testing is considerable. It is estimated abroad that for the high-reliability aerospace model plan, the test cost can account for 35% of the entire spacecraft cost, and this does not include special investment in laboratory construction and environmental effects and simulation research. It now appears that more investment is needed in spacecraft environmental engineering, including space environmental effects and their simulation, test method research, and improvement of test technology, to increase the depth and breadth of research work, and to strive to improve environmental engineering and environmental testing. Level, which has a long-term impact on the development of China's space technology. ^[2]

The entire environmental engineering and environmental testing work needs people to complete, and it involves all aspects of product development.Therefore, on the one hand, it is necessary to train more environmental engineering experts to participate in the development of aerospace models, manage, coordinate and solve the environmental aspects of model development Work; on the other hand, professional departments and units engaged in environmental engineering and environmental testing should strive to improve their technical level. In addition to completing various experimental tasks well, we must also work hard to carry out the necessary pre-research work. The test department shall cooperate with the design department to make use of its own test methods and experience, participate in the development of environmental predictions and test conditions, and participate in the evaluation of environmental verification results, and give full play to its role in the environmental verification of products. ^[2]