HOME

TheInfoList



OR:

A low-energy transfer, or low-energy
trajectory A trajectory or flight path is the path that an object with mass in motion follows through space as a function of time. In classical mechanics, a trajectory is defined by Hamiltonian mechanics via canonical coordinates; hence, a complete tr ...
, is a route in
space Space is the boundless three-dimensional extent in which objects and events have relative position and direction. In classical physics, physical space is often conceived in three linear dimensions, although modern physicists usually consi ...
that allows
spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, ...
to change
orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as ...
s using significantly less fuel than traditional transfers. These routes work in the
Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...
Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
system and also in other systems, such as between the
moons of Jupiter There are 82 known moons of Jupiter, not counting a number of moonlets likely shed from the inner moons. All together, they form a satellite system which is called the Jovian system. The most massive of the moons are the four Galilean moons: ...
. The drawback of such trajectories is that they take longer to complete than higher-energy (more-fuel) transfers, such as
Hohmann transfer orbit In astronautics, the Hohmann transfer orbit () is an orbital maneuver used to transfer a spacecraft between two orbits of different altitudes around a central body. Examples would be used for travel between low Earth orbit and the Moon, or ...
s. Low-energy transfers are also known as
Weak Stability Boundary Weak stability boundary (WSB), including Low-energy transfer, is a concept introduced by Edward Belbruno in 1987. The concept explained how a spacecraft could change orbits using very little fuel. Weak stability boundary is defined for the thre ...
trajectories, and include ballistic capture trajectories. Low-energy transfers follow special pathways in space, sometimes referred to as the
Interplanetary Transport Network The Interplanetary Transport Network (ITN) is a collection of gravitationally determined pathways through the Solar System that require very little energy for an object to follow. The ITN makes particular use of Lagrange points as locations wh ...
. Following these pathways allows for long distances to be traversed for little change in velocity, or .


Example missions

Missions that have used low-energy transfers include: * '' Hiten'', from
JAXA The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into o ...
* '' SMART-1'', from ESA * ''
Genesis Genesis may refer to: Bible * Book of Genesis, the first book of the biblical scriptures of both Judaism and Christianity, describing the creation of the Earth and of mankind * Genesis creation narrative, the first several chapters of the Book of ...
'', from
NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...
.Interplanetary Superhighway Makes Space Travel Simpler
// NASA 07.17.02: "Lo conceived the theory of the Interplanetary Superhighway. Lo and his colleagues have turned the underlying mathematics of the Interplanetary Superhighway into a tool for mission design called "LTool," ... The new LTool was used by JPL engineers to redesign the flight path for the Genesis mission"
* ''
GRAIL The Gravity Recovery and Interior Laboratory (GRAIL) was an American lunar science mission in NASA's Discovery Program which used high-quality gravitational field mapping of the Moon to determine its interior structure. The two small spacecraf ...
'', from
NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...
. On-going missions planned to use low-energy transfers include: * BepiColombo, from ESA/
JAXA The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into o ...
* CAPSTONE from
NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedin ...
*
Danuri The Korea Pathfinder Lunar Orbiter (KPLO), officially Danuri, is South Korea's first lunar orbiter. The orbiter, its science payload and ground control infrastructure are technology demonstrators. The orbiter will also be tasked with surveying ...
from KARI Proposed missions using low-energy transfers include: *
European Student Moon Orbiter The European Student Moon Orbiter (ESMO) was a proposed European student mission to the Moon. Student teams from 19 universities throughout Europe worked on the program. ESMO was conceived by the Student Space Exploration & Technology Initiativ ...
(ESMO) *
Mars Direct Mars Direct is a proposal for a human mission to Mars which purports to be both cost-effective and possible with current technology. It was originally detailed in a research paper by Martin Marietta engineers Robert Zubrin and David Baker in 19 ...


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 may have successfully entered lunar orbit, but suffered a communications failure.
Edward Belbruno Edward Belbruno (born August 2, 1951, as a U.S. Citizen in Heidelberg, Germany) is an artist, mathematician and scientist whose interests are in celestial mechanics, dynamical systems, dynamical astronomy, and aerospace engineering. His artistic m ...
and James Miller of the
Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a Federally funded research and development centers, federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, La Cañada Flintridge, California ...
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. This course would result in the probe being captured into temporary lunar orbit using zero , but required five months instead of the usual three days for a Hohmann transfer.


Delta-v savings

From low Earth orbit to lunar orbit, the savings approach 25% on the burn applied after leaving low Earth orbit, compared to the retrograde burn applied near the Moon in the traditional , and allow for a doubling of payload. Robert Farquhar had described a 9-day route from low earth orbit to lunar capture that takes 3.5 km/s. Belbruno's routes from low Earth orbit require a 3.1 km/s burn for trans lunar injection, a delta-''v'' saving of not more than 0.4 km/s. However, the latter require no large delta-''v ''change after leaving low Earth orbit, which may have operational benefits if using an upper stage with limited restart or in-orbit endurance capability, which would require the spacecraft to have a separate main propulsion system for capture. 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.


See also

* Bi-elliptic transfer *
Gravity assist In orbital mechanics and aerospace engineering, a gravitational slingshot, gravity assist maneuver, or swing-by is the use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the p ...
*
Interplanetary Transport Network The Interplanetary Transport Network (ITN) is a collection of gravitationally determined pathways through the Solar System that require very little energy for an object to follow. The ITN makes particular use of Lagrange points as locations wh ...
*
Orbital mechanics Orbital mechanics or astrodynamics is the application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft. The motion of these objects is usually calculated from Newton's laws of ...


References


External links


Celestial Mechanics Theory Meets the Nitty-Gritty of Trajectory Design

Earth-to-Moon Low Energy Transfers Targeting L1 Hyperbolic Transit Orbit
June 2005
Low Energy Trajectories and Chaos: Applications to Astrodynamics and Dynamical Astronomy

Navigating Celestial Currents
{{DEFAULTSORT:Low Energy Transfers Astrodynamics