Preliminary Planning For NEAR's Low-Altitude
On February 14, 2000, an orbit insertion burn will place NASA's Near Earth Asteroid Rendezvous (NEAR) spacecraft (S/C) into orbit around asteroid 433 Eros.
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Engineering topics
Dunham, D.
Publications and source records attributed to Dunham, D..
Preliminary Planning for Near's Low-Altitude Operations at 433 Eros
This paper will provide preliminary plans for mission design and navigation during the last two weeks of the orbit phase, where several close passes to the surface will be incorporated to enhance the science return.
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Near Earth Asteroid Rendezvous (NEAR) Revised Eros Orbit Phase Trajectory Design
Trajectory design of the orbit phase of the NEAR mission involves a new process that departs significantly from those procedures used in previous missions. In most cases, a precise spacecraft ephemeris is designed well in advance of arrival at the target body.
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Estimating the Mass of Asteroid 433 Eros During the NEAR Spacecraft Flyby
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mass rotation pole Eros Asteroid 433↗
Estimating the Mass of Asteroid 433 Eros During the Near Spacecraft Flyby
The terminal navigation of the Near-Earth Asteroid Rendezvous (NEAR) spacecraft during its flyby of asteroid 433 Eros on December 23, 1998 involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Eros and then to determine the relative trajectory of the spacecraft with respect ot Eros.
Asteroid Near-Earth Asteroid Rendezbous (NEAR) mas↗
Near Earth Asteroid Rendezous (Near) Orbit Phase Trajectory Design (Extended Abstract)
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Trajectory Design (Near) Orbit Phase Near Earth As↗
Preliminary Considerations for NEAR's Low-altitude Passes and Landing Operations at 433 Eros
NASA's Near Earth Asteroid Rendezous (NEAR) mission is currently on course for rendezous and orbit insertion about the asteroid 433 Eros in December 1998.
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Near Earth Asteroid Rendezvous Orbit Phase Trajectory Design
Trajectory design of the orbit phase of the Near Earth Asteroid Rendezvous (NEAR) mission involves procedures that depart significantly from those used for previous missions.
Missions↗
Trajectories for the Sakigake extended-mission phase
The trajectory profile that will be used by Japan's Sakigake spacecraft to accomplish its extended-mission objectives is described. Currently, Sakigake is following a heliocentric trajectory that will return to the earth's vicinity in January 1992. Four earth gravity-assist maneuvers are planned to redirect Sakigake to an encounter with Comet Honda-Mrkos-Pajdusakova (HMP) in February 1996. While carrying out the earth-swingby maneuvers, the spacecraft will make several passes through previously unexplored regions of the distant geomagnetic tail.
Farquhar, R.↗
Alternative gravity-assist sequences for the ISEE-3 escape trajectory
The International Sun-Earth Explorer-3 (ISEE-3) was moved from its mission halo orbit upstream of the earth's magnetosphere on June 10, 1982. Multiple lunar swingby maneuvers were then used to shape the trajectory for extensive exploration of the distant geomagnetic tail and finally to place the spacecraft on a course that will intercept the comet Giacobini-Zinner on September 11, 1985. With this new mission objective, the spacecraft was renamed the International Cometary Explorer (ICE). A double-lunar-swingby control technique involving five passes by the moon was eventually implemented to accomplish this, but in the process of finding this solution several feasible, though less optimal, alternative trajectory sequences implementing the same procedure were discovered. This paper provides a descriptive comparison of these very different orbital profiles and serves to illustrate the utility and great flexibility of this orbital control procedure. Targeting methodology for finding constrained solutions in this space is also presented.
Muhonen, D.↗
Doubly-periodic orbits in the Sun-Earth-Moon system
A series of periodic orbits in the Earth-Moon circular restricted problem of three bodies was found which is ideally suited for exploring the Earth's geomagnetic tail. The mean apsidal motion of the basic highly elliptical Earth orbit was maintained at about one degree per day by a sequence of lunar swingbys, keeping the apogees in the anti-Sun direction. The orbits were periodic in reference frames rotating at both lunar and solar rates. Apogee distances were alternately raised and lowered by the lunar swingby maneuvers. Several categories of these Sun-synchronous double lunar swingby orbits were identified. The strength and flexibility of this trajectory concept was demonstrated with real world simulations.
Farohar, R.↗