Skip Entry Trajectory Planning and Guidance

Skip entry guidance using numerical predictor–corrector and patched corridor

“…D'Souza and García-Llama extended the strategy of tracking a drag profile from the Space Shuttle to the reentry capsules, but certain coefficients that are used in the profile fitting depend on empirical analyses or a priori information (D'Souza, 2008;García-Llama, 2011). A numerical predictor-corrector guidance method has successfully demonstrated its performance in terms of enhancing the range capability of a low-lifting vehicle during lunar returns (Bairstow, 2006;Tigges et al, 2007;Rea and Putnam, 2007;Miller, 2007;Brunner and Lu, 2008).…”

“…The essence of the "predictor" is to parameterize the bank profile. One or two parameters were used to describe the bank angle magnitude in Powell and Braun (1993); Powell (1998); Zimmerman et al (2003); Brunner and Lu (2008); Bairstow (2006); Tigges et al (2007). A three-dimensional profile, including the magnitude and sign, was proposed in Fuhry (1999); Leavitt and Mease (2007); Lu (2008).…”

“…By comparing the predicted and prescribed ranges, a discrepancy that should be eliminated using the "corrector" was obtained. Two types of methods were introduced: a gradientbased algorithm (e.g., the Newton-Raphson method used in Powell and Braun (1993); Fuhry (1999); Bairstow (2006); Miller (2007); Lu (2008)) and an interval-searching algorithm (e.g., the bisection, secant, and false position methods used in Powell (1998); Leavitt and Mease (2007); Brunner and Lu (2008)). Although the interval-searching algorithm converges more slowly than does the gradient-based algorithm, it will not produce a no-solution situation.…”

“…As a result, the Earth's rotational effect plays a significant role in the crossrange excursion when observing from a fixed Earth frame (Brunner and Lu, 2008;Luo et al, 2014). A heading angle corridor that is defined in the inertial frame was used to manage the crossrange in the Apollo, PredGuid, and Numeric Skip-Entry Guidance (NSEG) algorithms, wherein the latter two algorithms were developed for the Orion program and almost inherited the Apollo lateral control logic (Bairstow, 2006;Tigges et al, 2007).…”

“…However, as stated in Rea and Putnam (2007), this lateral control logic provides limited robustness when involving negative interaction effects between the longitudinal and lateral channels. In Brunner and Lu (2008), a pseudo-site method was applied to compensate for the Earth's rotation, but the method's performance relies on empirical results.…”