In addition, the characteristics of uncontrolled space objects including the ballistic coefficients are largely insufficient to model the reentry trajectory. This is because the exact physical parameters of the objects like mass, area of cross section, shape, and dimensions are not available.
For the analysis of the effects of the density model affecting the accuracy of the reentry prediction, four difference density models were used in the prediction of reentry trajectory. Specifically, NRLMSISE-00 , CIRA-72 , U.S.
Failure of the reentry vehicle to separate from the third stage changed the reentry trajectory
, reducing the angle of attack at the point of maximum heating.
In view of such fact that a lot of research has been done for reentry trajectory
optimization design of near-earth orbit returning spacecraft, only initial reentry of vehicle skip reentry is discussed in this paper.
Since the plan currently involves attaching a rocket to control HST's reentry trajectory
, why not use that rocket to boost it to a higher orbit instead, maybe a thousand kilometers high, where it would represent little danger to other satellites or manned missions and where it could wait in relative safety until the technology to bring it back to Earth in one piece becomes available?
The reference trajectory is one of the key components of reentry guidance design for hypersonic glide vehicle; therefore, reentry trajectory
optimization plays an important role in steering a safe and efficient flight of hypersonic glide vehicle in complex reentry environment, as well as meeting all of the mission requirements .
The European ferry undocked on 28 October at 08:55 GMT (09:55 CET) and manoeuvred itself into a safe reentry trajectory
about 100 km below the Station.
In order to steer an efficient and safety flight in the complex conditions, the reentry trajectory
optimization problem of HV has been widely of concern.
Compared with the motions of variables [[[alpha], [beta], [mu], p, q, r].sup.T] in reentry dynamics equation (1), only a slight effect on system dynamics is shown when sections of [[omega].sub.e] are considered; instead of that obvious effects will act on the motions of trajectory variables in reentry trajectory
equations for researches of trajectory optimization and guidance.
Previous researches in reentry trajectory
optimization are summarized as follows.
optimization usually needs to consider multiple performance indicators.
Abrahamson, Boost through Reentry Trajectory
Planning for Maneuvering Reentry Vehicles, Massachusetts Institute of Technology, 2007.