August 2019 AJP coverAugust 2019 Issue,

Volume 87, No. 8


The delicate dance of orbital rendezvous

The meeting of two spacecraft in orbit around a planet or moon involves a delicate dance that must carefully balance the gravitational, Coriolis, and centrifugal forces acting on the spacecraft. The intricacy of the relative motion between the two spacecraft caused problems for the Gemini missions in the mid-1960s. Although now mastered, the problem of how to bring two orbiting objects together continues to be misrepresented in popular movies and books. In this article, I will consider the case when the two spacecraft are in close proximity (compared with the radii of their orbits), and examine the counter-intuitive trajectories that are needed to bring them together. I will examine how a stranded astronaut might use an impulsive force to return to her ship in Earth orbit, how and when line-of-sight targeting may be used for a rendezvous, and how the Apollo 11 lunar module executed a Terminal Phase Initiation maneuver to rendezvous with the command/service module as they both circled the Moon.



Resource Letter: GP-1: Gender and Physics by Jennifer Blue, Adrienne Traxler, and Geraldine Cochran. DOI: 10.1119/1.5114628

The delicate dance of orbital rendezvous by  Bradley W. Carroll. DOI: 10.1119/1.5115341

Maximal angular correlation in ? – ? coincidences: A quantitative study by Filipe Moura. DOI:  10.1119/1.5099891

Note on the history effect in fluid mechanics by Humphrey J. Maris. DOI: 10.1119/1.5100939

Free fall through the rotating and inhomogeneous Earth by Stefan Isermann. DOI: 10.1119/1.5100942

Data-driven decision making in an introductory physics lab by John R. Walkup, Roger A. Key, Patrick R. M. Talbot, and Michael A. Walkup. DOI:  10.1119/1.5100946

Electric field lines: The implications of students' interpretation on their understanding of the concept of electric field and of the superposition principle Esmeralda Campos, Genaro Zavala, Kristina Zuza, and Jenaro Guisasola. DOI:  10.1119/1.5100588

Why physical understanding should precede the mathematical formalism—Conditional quantum probabilities as a case-study byYakir Aharonov, Eliahu Cohen, and David H. Oaknin. DOI: 10.1119/1.5115980

Three-line derivation of the Thomas precession by Pawel Lewulis, and Andrzej Dragan. DOI:  10.1119/1.5115471

Back of the  Envelope

Low-entropy expressions by Sanjoy Mahajan. DOI:  10.1119/1.5111838

Notes and Discussions

Alternative statements of the Rayleigh monotonicity law for linear time-invariant resistor networks driven by only voltages or only currents by Seppo J. Karrila, and Alex Karrila. DOI:  10.1119/1.5111962

Comment on “Peculiarities in the gravitational field of a filamentary ring” [Am. J. Phys. 87, 384–394 (2019)] by J. West. DOI:  10.1119/1.5115584

Entropy and unavailable energy by P.-M. Binder, Dallas K. Tada, and Cooper B. Howlett. DOI: 10.1119/1.5115145

Computational Physics

The hardwall method of solving the radial Schrödinger equation and unmasking hidden symmetries by Siu A. Chin, and John Massey. DOI:  10.1119/1.5111839

Book Reviews

BOOK REVIEWS by Robert Socolow American Journal of Physics 87, 606 (2019);

The Simple Physics of Energy Use by Michael A. DuVernois. DOI: 10.1119/1.5098457


American Journal of Physics 87, 607 (2019);

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