“…In this study, a vacuum air-intake device is reported; it is composed of a multi-hole plate (or collimator, composed of many small tubes), a turbo with a large inlet, a small turbomolecular pump and a miniature scroll vacuum pump in series. Given it is hard to get the molecular flow gas with a velocity of 7.8 km/s in a lab [2,4], in the study, the Monte Carlo method is chosen to investigate the performances of the multi-hole plate and the turbo at the altitudes of 150-240 km; and an experiment is implemented to analysis the compression performances and the needed powers of the small turbomolecular pump and the miniature scroll pump.…”