gravity assist


Also found in: Dictionary, Acronyms, Wikipedia.

gravity assist

An astronautical technique whereby a spacecraft takes up a tiny fraction of the orbital energy of a planet that it is flying past, allowing it to change direction and speed. It has been used, for example, in the Voyager and Ulysses missions.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
References in periodicals archive ?
A mathematical formulation (MGA-1DSM), which parameterizes a generic interplanetary trajectory as a sequence of legs containing a gravity assist and one deep-space maneuver, is outlined, leading to the purposeful definition of a global optimization problem.
The Earth flyby gravity assist increases the spacecraft's speed relative to the Sun from 78,000 miles (126,000 kilometers) per hour to 87,000 miles (140,000 kilometers) per hour.
In performing its first deep-space maneuver, the spacecraft initiated the first of two planned firings of its main engine to refine the spacecraft's trajectory, setting the stage for a gravity assist from a flyby of Earth Oct 9, 2013, that will send it on its way for arrival at Jupiter July 4, 2016, NASA Jet Propulsion Laboratory in Pasadena, Calif., was quoted as saying by the United Press International (UPI).
In an audacious venture using gravity assist at Earth and libration orbiting for two years near L1, the Genesis mission, launched by a Delta II in 2001, in 2004 returned a capsule to Earth bearing actual samples of the solar wind and interplanetary medium embedded in ultraclean collector plates.
The gravitational fields of these planets will pull on the spacecraft as it passes them, causing it to increase its speed, a phenomenon called gravity assist. NASA engineers liken gravity assist to a person running next to a merry-go-round.
The spacecraft passed about 8,000 kilometers from the Moon on Thursday, which provided a gravity assist that helped TESS sail toward its final working orbit, the US space agency said on Friday.
That data collection, which included study of the moon as well, began four hours after the gravity assist.
[3] discuss the planning of trajectories to Neptune using a variety of gravity assist maneuver schemes, highlighting the difficulty in finding an optimized solution with so many combinations of the planets considered.
Caption: Juno snapped this photo of Earth when it came close for a gravity assist on October 9, 2013.
After the Mars gravity assist, Rosetta's perihelion will drop until it reaches the orbit of Venus, but before the probe comes that close to the Sun, another Earth flyby will send it out of the ecliptic plane.