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  2. Kármán line - Wikipedia

    en.wikipedia.org/wiki/Kármán_line

    Earth's atmosphere photographed from the International Space Station.The orange and green line of airglow is at roughly the altitude of the Kármán line. [1]The Kármán line (or von Kármán line / v ɒ n ˈ k ɑːr m ɑː n /) [2] is a conventional definition of the edge of space; it is widely but not universally accepted.

  3. Orders of magnitude (length) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude_(length)

    The millimetre (SI symbol: mm) is a unit of length in the metric system equal to 10 −3 metres (⁠ 1 / 1 000 ⁠ m = 0.001 m). To help compare different orders of magnitude , this section lists lengths between 10 −3 m and 10 −2 m (1 mm and 1 cm).

  4. Sub-orbital spaceflight - Wikipedia

    en.wikipedia.org/wiki/Sub-orbital_spaceflight

    An intercontinental ballistic missile is defined as a missile that can hit a target at least 5500 km away, and according to the above formula this requires an initial speed of 6.1 km/s. Increasing the speed to 7.9 km/s to attain any point on Earth requires a considerably larger missile because the amount of fuel needed goes up exponentially ...

  5. Scale height - Wikipedia

    en.wikipedia.org/wiki/Scale_height

    The earth atmosphere's ... with the equation for H given above to ... level value of ρ 0 roughly equal to 1.2 kg⋅m −3. At an altitude over 100 km, the atmosphere ...

  6. List of orbits - Wikipedia

    en.wikipedia.org/wiki/List_of_orbits

    In practice, only 1:1 ratio (geosynchronous) and 1:2 ratios (semi-synchronous) are common. Geosynchronous orbit (GSO): An orbit around the Earth with a period equal to one sidereal day, which is Earth's average rotational period of 23 hours, 56 minutes, 4.091 seconds. For a nearly circular orbit, this implies an altitude of approximately 35,786 ...

  7. Geographical distance - Wikipedia

    en.wikipedia.org/wiki/Geographical_distance

    Finding the geodesic between two points on the Earth, the so-called inverse geodetic problem, was the focus of many mathematicians and geodesists over the course of the 18th and 19th centuries with major contributions by Clairaut, [5] Legendre, [6] Bessel, [7] and Helmert English translation of Astron. Nachr. 4, 241–254 (1825).

  8. Earth radius - Wikipedia

    en.wikipedia.org/wiki/Earth_radius

    Earth radius (denoted as R 🜨 or R E) is the distance from the center of Earth to a point on or near its surface. Approximating the figure of Earth by an Earth spheroid (an oblate ellipsoid), the radius ranges from a maximum (equatorial radius, denoted a) of nearly 6,378 km (3,963 mi) to a minimum (polar radius, denoted b) of nearly 6,357 km (3,950 mi).

  9. Canonical units - Wikipedia

    en.wikipedia.org/wiki/Canonical_units

    In astrodynamics, canonical units are defined in terms of some important object’s orbit that serves as a reference. In this system, a reference mass, for example the Sun’s, is designated as 1 “canonical mass unit” and the mean distance from the orbiting object to the reference object is considered the “canonical distance unit”.