An Analysis of Free-Flight Circumlunar Trajectories

Penzo, P. A.

doi:10.2514/6.1963-404

Cited by 10 publications

(5 citation statements)

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“…Penzo [27] impelled the patched conic method further in both theory and computing techniques. He also proposed a free-return orbit design scheme, and determined the effect of the perilune distance and outward/return inclinations to the Moon's plane on the flight time [28]. It is concluded that the possible launch conditions would be constrained when the perilune distance, flight path, and landing location are fixed.…”

Section: Patched Conic Modelmentioning

confidence: 99%

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Overview of Earth-Moon Transfer Trajectory Modeling and Design

Zhang¹,

Yu²,

Dai³

2023

Computer Modeling in Engineering &Amp; Sciences

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The Moon is the only celestial body that human beings have visited. The design of the Earth-Moon transfer orbits is a critical issue in lunar exploration missions. In the 21st century, new lunar missions including the construction of the lunar space station, the permanent lunar base, and the Earth-Moon transportation network have been proposed, requiring low-cost, expansive launch windows and a fixed arrival epoch for any launch date within the launch window. The low-energy and low-thrust transfers are promising strategies to satisfy the demands. This review provides a detailed landscape of Earth-Moon transfer trajectory design processes, from the traditional patched conic to the state-of-the-art low-energy and low-thrust methods. Essential mechanisms of the various utilized dynamic models and the characteristics of the different design methods are discussed in hopes of helping readers grasp the basic overview of the current Earth-Moon transfer orbit design methods and a deep academic background is unnecessary for the context understanding.

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Section: Patched Conic Modelmentioning

confidence: 99%

“…Fig. 5 shows a free-return orbit studied in [28]. It can be seen that the geocentric orbit is an ellipse orbit, and the selenocentric orbit is a hyperbolic one relative to the Moon.…”

Section: Patched Conic Modelmentioning

confidence: 99%

Overview of Earth-Moon Transfer Trajectory Modeling and Design

Zhang¹,

Yu²,

Dai³

2023

Computer Modeling in Engineering &Amp; Sciences

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“…Reich suggested that the size of orbital launch window is a function of three general factors: the geometrical relationship between parking and lunar orbit planes, the amount of extra propellant allowed for the window, and the launch technique employed. Penzo (1963) considered the launch windows for free return circumlunar trajectories also from orbital launch. After Apollo 11, Berry's (1970) discussion of the mission's lunar trajectory profile and control included the determination of its launch window, stressing the influence by operational constraints.…”

Section: Introductionmentioning

confidence: 99%

“…The patched conic model first described and used by Egorov (1958) in 1956 is an analytical two-body approximation, and was also used by Penzo (1963) to outline schemes of free return generation. Schwaniger (1963) applied a CRTBM to numerically study the characteristics of two symmetric kinds of cislunar and circumlunar free returns.…”

Section: Introductionmentioning

confidence: 99%

Generation of launch windows for high-accuracy lunar trajectories

Yim

Gong

Baoyin

2015

Advances in Space Research

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“…Historically, the design of free returns started with a patched conic or circular restricted three-body problem approximation. The patched conic model first described and used by Egorov (1958) is an analytical two-body approximation, and was also used by Penzo (1963) to outline schemes of free return generation. Schwaniger (1963) applied a circular restricted three-body model to numerically study the characteristics of two symmetric kinds of cislunar and circumlunar free returns, based on the theorem of image trajectories in the Earth-Moon space developed by Miele (1960).…”

Section: Introductionmentioning

confidence: 99%

High-latitude-landing circumlunar free return trajectory design

Yim

Baoyin

2015

Aircraft Eng & Aerospace Tech

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Purpose -The purpose of this paper is to design free return trajectories launching at lower-latitude launch site Wenchang and landing at relatively high-latitude landing site Siziwang Banner tailored to human lunar missions for China, and in general demonstrate the feasibility of high-latitude landings with acceptable entry range. Design/methodology/approach -Free return trajectories satisfying all basic constraints were generated directly by a high-fidelity model with multiple differential corrections. Suitable initial assumptions, control parameters, constraints and stopping conditions were set. Method was developed to automatically converge unlimited trajectories accurately to the same constraints, and their characteristics affected by the ephemeris were analyzed. Findings -Launching into lower Earth inclination plus high-latitude landing with acceptable entry range requires asymmetric trajectories with high inclination Earth entry only from the south. Periodic trends of parameters at launch, injection and entry were found and analyzed. Nominal trajectory covering phases from launch to landing for China human moon flight with minimum entry range were designed. Practical implications -Such trajectories can be used by China's future manned lunar missions. Spacecraft capability and ground station distribution shall adjust accordingly. Originality/value -Previous studies mainly concentrated on symmetric free returns using low-fidelity models first. This paper investigates asymmetric free returns skipping simplified gravity model approximation to simultaneously achieve high-latitude landing and acceptable entry range, and accurate automated generation of feasible trajectories daily across 19-year lunar nodal cycle within every monthly launch window without trial and error to reflect the actual effect by the ephemeris only. Others include landing accurately by controlling entry direction and range (and altitude), minimizing entry range and designing an effective scheme of differential correction for full convergence.

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An Analysis of Free-Flight Circumlunar Trajectories

Cited by 10 publications

References 0 publications

Overview of Earth-Moon Transfer Trajectory Modeling and Design

Overview of Earth-Moon Transfer Trajectory Modeling and Design

Generation of launch windows for high-accuracy lunar trajectories

High-latitude-landing circumlunar free return trajectory design

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