Low energy transfer

A low energy transfer, or low energy trajectory, is a route in space which allows spacecraft to change orbits using very little fuel. [1][2] These routes work in the Earth-Moon system and also in other systems, such as traveling between the satellites of Jupiter. The drawback of such trajectories is that they take much longer to complete than higher energy (more fuel) transfers such as Hohmann transfer orbits.

Low energy transfer are also known as weak stability boundary trajectories, or ballistic capture trajectories.

Low energy transfers follow special pathways in space, sometimes referred to as the Interplanetary Transport Network. Following these pathways allows for long distances to be traversed for little expenditure of delta-v.

Missions that have used low energy transfers include:

Proposed missions using low energy transfers include:

Contents

History

Low energy transfers to the Moon were first demonstrated in 1991 by the Japanese spacecraft Hiten, which was designed to swing by the moon but not to enter orbit. The Hagoromo subsatellite was released by Hiten on its first swing-by and successfully entered lunar orbit, but suffered a communications failure.

Edward Belbruno and James Miller of the Jet Propulsion Laboratory had heard of the failure, and helped to salvage the mission by developing a ballistic capture trajectory that would enable the main Hiten probe to itself enter lunar orbit. The trajectory they developed for Hiten used Weak Stability Boundary Theory and required only a small perturbation to the elliptical swing-by orbit, sufficiently small to be achievable by the spacecraft's thrusters.[1] This course would result in the probe being captured into lunar orbit using zero delta-v, but required five months instead of the usual three days for a Hohmann transfer.[3]

Delta-v savings

From low-earth orbit to lunar orbit, the delta-v savings approach 25% and allow for a doubling of payload. [4]

For rendezvous with the Martian moons, the savings are 12% for Phobos and 20% for Deimos. Rendezvous is targeted because the stable pseudo-orbits around the Martian moons do not spend much time within 10 km of the surface. [5]

See also

References

  1. ^ a b Belbruno, Edward (2004). Capture Dynamics and Chaotic Motions in Celestial Mechanics: With Applications to the Construction of Low Energy Transfers. Princeton University Press. pp. 224. ISBN 978-0-691-09480-9. http://press.princeton.edu/titles/7687.html. 
  2. ^ Belbruno, Edward (2007). Fly Me to the Moon: An Insider's Guide to the New Science of Space Travel. Princeton University Press. pp. 176. ISBN 978-0-691-12822-1. http://press.princeton.edu/titles/8375.html. 
  3. ^ Frank, Adam (September 1994). "Gravity's Rim". Discover. http://discovermagazine.com/1994/sep/gravitysrim419/. 
  4. ^ Edward A. Belbruno and John P. Carrico (2000). "Calculation of Weak Stability Boundary Ballistic Lunar Transfer Trajectories". AIAA/AAS Astrodynamics Specialist Conferenc. http://astrogatorsguild.com/wp-content/papers/0800_wsb.pd. 
  5. ^ A. L. Genova, S. V. Weston, and L. J. Simurda (2011). ""Human & robotic mission applications of low-energy transffers to Phobos & Deimos". http://multimedia.seti.org/PhD2011/abstracts/PhD2-11-010.pdf. 

External links