Artist's concept of the Interplanetary Superhighway

The Interplanetary Superhighway has come to denote a set of transfer orbits between various planets and moons in the solar system. These transfers have particularly low delta-v requirements, and appear to be the lowest energy transfers, even lower than the common Hohmann transfer orbit that has dominated orbital dynamics in the past. Download high resolution version (1024x750, 428 KB)Artists concept of the Interplanetary Superhighway. ... Download high resolution version (1024x750, 428 KB)Artists concept of the Interplanetary Superhighway. ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ... A planet (from the Greek πλανήτης, planētēs which means wanderer or more forcefully vagrant, tramp) is an object in orbit around a star that is not a star in its own right. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... Presentation of the Solar system (not to scale). ... General In general physics delta-v is simply the change in velocity. ... In astronautics and aerospace engineering, the Hohmann transfer orbit is an orbital maneuver that moves a spacecraft from one orbit to another using a fairly low delta-v. ...

The Interplanetary Superhighway is based around a series of orbital paths predicted by chaos theory, leading to and from the unstable orbits around the Lagrange points — points in space where the gravity between various bodies balances out. There are a number of these around the Earth, created by the balance of forces between the Earth, Moon and Sun. For instance, the L1 point lies at the point between the Earth and Moon where forces between the two balance. Chaos theory, in mathematics and physics, deals with the behavior of certain nonlinear dynamical systems that (under certain conditions) exhibit the phenomenon known as chaos, most famously characterised by sensitivity to initial conditions (see butterfly effect). ... In celestial mechanics, the Lagrangian points, (also Lagrange point, L-point, or libration point) are the five stationary solutions of the circular restricted three-body problem. ... It has been suggested that Law of universal gravitation be merged into this article or section. ... Earth, also known as the Earth, Terra, and (mostly in the 19th century) Tellus, is the third planet outward from the Sun. ... Crust composition Oxygen 43% Silicon 21% Aluminium 10% Calcium 9% Iron 9% Magnesium 5% Titanium 2% Nickel 0. ... The Sun is the star at the centre of our Solar system. ...

Although the forces balance at these points, they are not stable equilibrium points. If a spacecraft placed at the L1 point is given even a slight nudge towards the Moon, for instance, the Moon's gravity will now be greater and the spacecraft will be pulled away from the L1 point. The entire system is in motion, so the spacecraft will not actually hit the Moon, but will travel in a winding path off into space. There is, however, a semi-stable orbit around each of these points. The orbits for two of the points, L4 and L5, are stable, but the orbits for L1 through L3 are stable only on the order of months. Ariane 5 lifts off with the Rosetta space probe on March 2, 2004. ...

The key to the Interplanetary Superhighway was investigating the exact nature of these winding paths near the points. They were first investigated by Jules-Henri Poincaré in the 1890s, and he noticed that the paths leading to and from any of these points would almost always settle, for a time, on the orbit around it. There are in fact an infinite number of paths taking you to the point and back away from it, and all of them require no energy to reach. When plotted, they form a tube with the orbit around the point at one end. Henri Poincaré, photograph from the frontispiece of the 1913 edition of Last Thoughts Jules Henri Poincaré (April 29, 1854 – July 17, 1912), generally known as Henri Poincaré, was one of Frances greatest mathematicians, theoretical scientists and a philosopher of science. ... The 1890s were sometimes referred to as the Mauve Decade, because William Henry Perkins aniline dye allowed the widespread use of that color in fashion, and also as the Gay Nineties, under the then-current usage of the word gay which referred simply to merriment and frivolity, with no... Infinity is a term with very distinct, separate meanings which arise in theology, philosophy, mathematics and everyday life. ...

As it turns out, it is very easy to transit from a path leading to the point to one leading back out. This makes sense, since the orbit is unstable which implies you'll eventually end up on one of the outbound paths after spending no energy at all. However, with careful calculation you can pick which outbound path you want. This turned out to be quite exciting, because many of these paths lead right by some interesting points in space, like Mars. That means that for the cost of getting to the Earth-Sun L2 point (Lagrange points exist for all bodies in orbit of each other, Earth-Moon, Earth-Sun, Mars-Sun etc.) which is rather low, one can travel to a huge number of very interesting points, almost for free. Mars, with polar ice caps visible. ...

The transfers are so low-energy that they make travel to almost any point in the solar system possible. On the downside, these transfers are very slow, and only useful for automated probes. Nevertheless, they have already been used to transfer spacecraft out of the Earth-Sun L1 point, a useful point for studying the Sun that was used in a number of recent missions, including the Genesis mission. The Solar and Heliospheric Observatory is here. The Interplanetary Superhighway is also relevant to understanding solar system dynamics; Comet Shoemaker-Levy 9 followed such a trajectory to collide with Jupiter. In its collecting configuration, the Genesis spacecraft exposed collecting wafers to the solar wind. ... The Solar and Heliospheric Observatory (SOHO) is a spacecraft launched in 1995 to study the sun. ... Comet Hale-Bopp, showing a white dust tail and blue gas tail (February 1997) A comet is a small body in the solar system that orbits the sun and (at least occasionally) exhibits a coma (or atmosphere) and/or a tail -- both due primarily to the effects of solar radiation... Hubble Space Telescope image of Comet Shoemaker-Levy 9, taken on May 17, 1994. ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ...

External links

• Shane Ross's Superhighway talk, papers, talks, movies, thesis, links, and description
• "Navigating Celestial Currents" Science News, April 18, 2005
• "Next Exit 0.5 Million Kilometers" Engineering and Science 2002
• Martin Lo's publications and communications
• "Connecting orbits and invariant manifolds in the spatial restricted three-body problem"
• "Transport in dynamical astronomy and multibody problems"
• "Transport of Mars-crossers from the quasi-Hilda region"
• "Asteroids lost in space (Physical Review Focus Article)"
• "Statistical theory of asteroid escape rates"
• "Statistical theory of interior-exterior transition and collision probabilities for minor bodies in the solar system"
• "Constructing a low energy transfer between Jovian moons"
• "Low-Energy Transfer from Near-Earth to Near-Moon Orbit"
• "The Lunar L1 Gateway: Portal to the Stars and Beyond"
• "The InterPlanetary Superhighway and the Origins Program"
• "Math Games: Manifolds in the Genesis mission"