A brief summary isgiven in this paper on the research status and new developments ofnear space flying vehicles. Some key technical problems in bothlow speed and high speed cases are discussed, followed by a briefdescription of future development trends.

A brief introductionof the hypersonic airbreathing propulsion system is first given,followed by a descriptions of working principles and compositionof typical hypersonic airbreathing engines, including scramjet,detonation engine and combined cycle engines. In the third part,the key difficulties encountered in developing these engines arepresented together with relevant key technologies, such as conceptdesign, inlet, combustor, nozzle, heat protection, light structureand fuel fedding/controlling. The main projects of hypersonicairbreathing propulsion system and the advancement achieved arereviewed in the fourth part, as well as lesson learned anddeveloping trends. The fifth part is focused on the combustionprocess and the mechanisms in these engines, where a survey onrelated research works is given.

The study on thecontrol of hypersonic flight vehicles (HFV) includes mainly theproblems of the cruising control of the air-breathing HFV and thereentry control of the non-power HFV. The studies on air-breathingHFV are mainly focused on two configurations: the winged-coneaccelerator configuration and the X-30 one; while the studies onnon-power HFV are concentrated on the X-33 and the X-38configurations. The dynamics and the control of the winged-coneaccelerator configuration, the X-30 configuration, and the reentrymode are respectively reviewed, and the hot issues in the researchon the control of HFV are highlighted.