enow.com Web Search

  1. Ads

    related to: celestrak norad elements quartz cabinets colors available

Search results

  1. Results from the WOW.Com Content Network
  2. Simplified perturbations models - Wikipedia

    en.wikipedia.org/wiki/Simplified_perturbations...

    This set of models is often referred to collectively as SGP4 due to the frequency of use of that model particularly with two-line element sets produced by NORAD and NASA. These models predict the effect of perturbations caused by the Earth’s shape, drag, radiation, and gravitation effects from other bodies such as the sun and moon.

  3. Satellite Catalog Number - Wikipedia

    en.wikipedia.org/wiki/Satellite_Catalog_Number

    The Satellite Catalog Number (SATCAT), also known as NORAD Catalog Number, NORAD ID, USSPACECOM object number, is a sequential nine-digit number assigned by the United States Space Command (USSPACECOM), and previously the North American Aerospace Defense Command (NORAD), in the order of launch or discovery to all artificial objects in the orbits of Earth and those that left Earth's orbit. [1]

  4. Two-line element set - Wikipedia

    en.wikipedia.org/wiki/Two-line_element_set

    A two-line element set (TLE, or more rarely 2LE) or three-line element set (3LE) is a data format encoding a list of orbital elements of an Earth-orbiting object for a given point in time, the epoch. Using a suitable prediction formula, the state (position and velocity) at any point in the past or future can be estimated to some accuracy.

  5. Orbital elements - Wikipedia

    en.wikipedia.org/wiki/Orbital_elements

    Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are considered in two-body systems using a Kepler orbit . There are many different ways to mathematically describe the same orbit, but certain schemes, each consisting of a set of six parameters, are commonly used in ...

  6. Dumortierite - Wikipedia

    en.wikipedia.org/wiki/Dumortierite

    Substitution of iron and other tri-valent elements for aluminium result in the color variations. It has a Mohs hardness of 7 and a specific gravity of 3.3 to 3.4. Crystals show pleochroism from red to blue to violet. Dumortierite quartz is blue colored quartz containing abundant dumortierite inclusions.

  7. Semi-Automatic Ground Environment - Wikipedia

    en.wikipedia.org/wiki/Semi-Automatic_Ground...

    The Semi-Automatic Ground Environment (SAGE) was a system of large computers and associated networking equipment that coordinated data from many radar sites and processed it to produce a single unified image of the airspace over a wide area. [5]

  8. List of GPS satellites - Wikipedia

    en.wikipedia.org/wiki/List_of_GPS_satellites

    Samples of three GPS satellites' orbits over a five-year period (2013 to 2018) USA-242 · USA-239 · USA-151 · Earth As of 22 January 2025, 83 Global Positioning System navigation satellites have been built: 31 are launched and operational, 3 are in reserve or testing, 43 are retired, 2 were lost during launch, and 1 prototype was never launched. 3 Block III satellites have completed ...

  9. Hexagonal crystal family - Wikipedia

    en.wikipedia.org/wiki/Hexagonal_crystal_family

    In particular, there are crystals that have trigonal symmetry but belong to the hexagonal lattice (such as α-quartz). The hexagonal crystal family consists of the 12 point groups such that at least one of their space groups has the hexagonal lattice as underlying lattice, and is the union of the hexagonal crystal system and the trigonal ...

  1. Ads

    related to: celestrak norad elements quartz cabinets colors available