near-circular orbit
51Solar sail — Solar sails (also called light sails or photon sails, especially when they use light sources other than the Sun) are a proposed form of spacecraft propulsion using large membrane mirrors. Radiation pressure is about 10 5 Pa at Earth s distance… …
52List of orbits — The following is a list of types of orbits:Centric classifications* Galactocentric orbit: An orbit about the center of a galaxy. Earth s sun follows this type of orbit about the galactic center of the Milky Way. * Heliocentric orbit: An orbit… …
53Non-rocket spacelaunch — Non rocket space launch (NRS) is a launch into space where some or all needed speed and altitude is provided by non rocket means, rather than simply using conventional chemical rockets from the ground. A number of alternatives to rockets have… …
54Magellan (spacecraft) — Magellan Artist s depiction of Magellan at Venus Operator NASA / JPL Major contractors Martin Marietta / Hughes Aircraft …
55Formation and evolution of the Solar System — Artist s conception of a protoplanetary disk The formation and evolution of the Solar System is estimated to have begun 4.568 billion years ago with the gravitational collapse of a small part of a giant molecular cloud …
56Orbital resonance — For the science fiction novel by John Barnes, see Orbital Resonance (novel). In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their… …
57spaceflight — /spays fluyt /, n. the flying of manned or unmanned spacecraft into or in outer space. Also, space flight. [1945 50; SPACE + FLIGHT1] * * * Introduction flight beyond Earth s atmosphere. This article deals with the basic concepts associated with …
58Science and mathematics from the Renaissance to Descartes — George Molland Early in the nineteenth century John Playfair wrote for the Encyclopaedia Britannica a long article entitled ‘Dissertation; exhibiting a General View of the Progress of Mathematics and Physical Science, since the Revival of Letters …
59Delta-v budget — (or velocity change budget) is an astrogation term used in astrodynamics and aerospace industry for total delta v (or total velocity change) requirements for the various propulsive tasks and orbital maneuvers over phases of a space mission.… …
60Specific orbital energy — In the gravitational two body problem, the specific orbital energy (or vis viva energy) of two orbiting bodies is the constant sum of their mutual potential energy ( ) and their total kinetic energy ( ), divided by the reduced mass. According to… …
