low earth orbit
51Non-inclined orbit — A non inclined orbit is an orbit which is contained in the plane of reference. The inclination is 0 for prograde orbits, and π (180°) for retrograde orbits. If the plane of reference is the equator, these orbits are called equatorial; if the… …
52Near Earth Object Surveillance Satellite — The Near Earth Object Surveillance Satellite (NEOSSat)[1] is a Canadian microsatellite using a 15 cm aperture f/5.88 Maksutov telescope similar to that on the MOST spacecraft, 3 axis stabilized with pointing stability of 2 arcseconds in a 100… …
53Rare Earth hypothesis — In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the emergence of complex multicellular life (metazoa) on Earth required an improbable combination of astrophysical and geological events and circumstances. The term… …
54Single-stage-to-orbit — The VentureStar was a proposed SSTO spaceplane. A single stage to orbit (or SSTO) vehicle reaches orbit from the surface of a body without jettisoning hardware, expending only propellants and fluids. The term usually, but not exclusively, refers… …
55History of the Earth — For the history of modern humans, see History of the world. Geological time put in a diagram called a geological clock, showing the relative lengths of the eons of the Earth s history The history of the Earth describes the most important events… …
56Kepler orbit — Gravitational attraction is the force that makes the Solar system stick together with the planets orbiting the Sun and the Moon orbiting the Earth. Isaac Newton formulated the physical law for this gravitational attraction which explained Kepler… …
57Risks to civilization, humans and planet Earth — This article is about the near and very far future. For past civilizations, see Societal collapse. Contents 1 Types of risks 2 Future scenarios 2.1 …
58Snowball Earth — The Snowball Earth hypothesis as it was originally proposedcite book author = Kirschvink, J.L. year = 1992 chapter = Late Proterozoic low latitude global glaciation: The snowball Earth title = The Proterozoic Biosphere: A Multidisciplinary Study… …
59Halo orbit — A halo orbit is a periodic, three dimensional orbit near the L1, L2, or L3 Lagrange points in the three body problem of orbital mechanics. A spacecraft in a halo orbit does not technically orbit the Lagrange point itself (which is just an… …
60History of Earth — The history of Earth covers approximately 4.6 billion years (4,567,000,000 years), from Earth’s formation out of the solar nebula to the present. This article presents a broad overview, summarizing the leading, most current scientific… …
