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Engine performance
Published in Mohammad H. Sadraey, Aircraft Performance, 2017
An example of an aerospace vehicle that is equipped with a rocket engine is the Space Shuttle (Figure 4.26). NASA’s Space Shuttle, officially called Space Transportation System (STS), had been the U.S. government’s crewed reusable spacecraft from 1981 to 2011. At launch, it consists of an external liquid fuel tank, two slender solid rocket boosters, and a winged orbiter. The orbiter has a delta wing and carries astronauts and payload-like satellites or space station parts into low earth orbit.
Industry analysis II
Published in Louis Brennan, Loizos Heracleous, Alessandra Vecchi, Above and Beyond, 2018
Louis Brennan, Loizos Heracleous, Alessandra Vecchi
Once the spacecraft is deployed for tourism, the flight will start early in the morning and will be conducted in two phases. At launch, the spacecraft will be attached to a carrier aircraft that will take it to an altitude of 15 km. Then, the shuttle will come off the plane and will start the rocket engine that will propel it to an altitude of 110 km. There, the passengers will experience a feeling of weightlessness for about five minutes and will enjoy a panorama of about 1,600 km in all directions. Thereafter, the vessel will enter earth’s atmosphere where it will be slowed down until it reaches an altitude of about 18 km. From here, it will land at the company’s spaceport. The whole trip will last for about two and a half hours, but the actual flight time is much shorter. There will be two pilots and six tourists on board the shuttle. Each tourist will be assigned a seat next to a window to be able to enjoy the view and have enough space to experience the five minutes of weightlessness (Papathanassis, 2011). The SpaceShipTwo cabin was designed to offer tourists a maximum of safety and comfort, being the only spacecraft ever created to optimize the passenger experience. There are twelve windows on the side and above the tourists, thus giving passengers a better view of the earth and the cosmic space. Before the actual flight, the tourists will be staying for three days at a location near the space terminal, where they will go through a series of short training procedures that include training in an acceleration simulator, several presentations related to safety and a basic medical examination. The price of these services was set at USD 200,000 per person with the price expected to decrease as operations expanded and with the expansion of providers of such services in the market. There were more than 65.000 applications for the 100 tickets available for the first flights. In December 2007, Virgin Galactic recorded 200 customers who had paid in advance and 95% of them successfully passed the physical tests. By 2011, the number of paying customers had reached 400 and by early 2013, 575. In April 2013, Virgin Galactic increased the suborbital trip price to USD 250,000, the motivation being related to inflation (Papathanassis, 2011). The estimated total cost of the SpaceShipTwo project in 2011 was somewhere around USD 400 million. Except for the rocket engine that has to be replenished with fuel and oxidant after each flight, SpaceShipTwo is a fully reusable spacecraft.
Health condition estimation of spacecraft key components using belief rule base
Published in Enterprise Information Systems, 2021
Xilang Tang, Xueqi Wang, Mingqing Xiao, Kai Leung Yung, Bin Hu
Nowadays, spacecraft becomes more and more complex, and it consists of various mechanical and electronic sub-systems (Rui et al. (2014)). Due to the influence of space environment and the degradation of components themselves (Liu et al. (2015)), the health condition of spacecraft components will gradually deteriorate over time. If the health condition of key components is not monitored, the spacecraft may fail unexpectedly, which will cause the spacecraft fail to complete its operational tasks even bring disastrous consequences (Wang and Xie (2010)). Therefore, the health condition estimation of key components has become increasingly important to spacecraft. With the results of health condition estimation, the maintenance strategy of spacecraft system is supported, which is of great significance to prevent major failures of spacecraft systems. (Mohammad and Hussein (2014); Johnson (2005)). The concept of Integrated Vehicle Health Management (IVHM) is proposed by National Aeronautics and Space Administration (NASA) to meet the requirement of reusable spacecraft, which contains health condition monitoring, estimation, fault diagnosis and fault treatment for key subsystems of spacecraft (Figueroa and Melcher (2013)). The health condition estimation method proposed by this paper is used on a CubeSat project, called ‘Kaituo-1B’, developed by a research team of Hong Kong Polytechnic University. Compared to the weight of traditional satellites ranging from a few hundred kilograms to several thousand kilograms, the ‘Kaituo-1B’ weighs only about 2 kg, which greatly reduces the cost of developing and producing micro-satellites for sending small payloads and instruments into space (POLYU (2018)). It is of great significance to monitor and estimate the health condition of ‘Kaituo-1B’ during its 3-month life cycle in real time (Xhafa and Andrew (2019)).