1,868 articles
Dish Network
Dish Network, formally DISH Network Corporation, is an American satellite television service that began operating in 1996 as a rival to DirecTV and is now part of EchoStar.
Dish TV
Dish TV, also known as Dish TV India, is a direct-to-home satellite television service in India, launched in 2003 as the country's first DTH platform.
Distant retrograde orbit
A distant retrograde orbit, also known as a quasi-satellite orbit (QSO), is a stable orbit around a body like the Moon, first studied by John Jackson in 1913.
DMSP
The Defense Meteorological Satellite Program (DMSP) is a US Defense Department program of polar-orbiting weather satellites that has supported military operations since 1962, declassified in 1972, with its final satellite launched in 2014.
Dnepr
The Dnepr was a Russian-Ukrainian space launch vehicle converted from surplus Soviet SS-18 intercontinental ballistic missiles, flown commercially by ISC Kosmotras from 1999 to 2015.
Docking and berthing of spacecraft
Docking and berthing, also called space docking, are the two ways spacecraft connect in orbit: docking under a spacecraft's own power, berthing by robotic arm, first achieved in 1966.
Dombarovskiy
Dombarovskiy, also written Dombarovsky and known as the Yasny launch site, is a Russian strategic missile base and space launch site in Orenburg Oblast, near the Kazakhstan border.
Donald A. Thomas
Donald A. Thomas, born Donald Alan Thomas in 1955, is an American engineer and former NASA astronaut who flew four Space Shuttle missions between 1994 and 1997.
Donald C. Fraser
Donald C. Fraser, born 1941, is an American engineer who led Apollo flight-control design at MIT's Instrumentation Laboratory and later founded the Boston University Photonics Center.
Donald P. Hearth
Donald Payne Hearth (1928–2013) was an American aerospace engineer who directed NASA's Langley Research Center from 1975 to 1984, managed its planetary exploration programs, and was elected to the National Academy of Engineering in 1989.
Dongfanghong (东方红) (satellite)
Dongfanghong (东方红, "The East Is Red") is China's first artificial satellite, launched on 24 April 1970, and the name of the DFH communications satellite bus family that grew from it.
Doppler orbitography
Doppler orbitography is a satellite tracking technique that uses the Doppler shift of radio signals between satellite and ground stations to find orbits or ground positions with centimeter accuracy.
Double Asteroid Redirection Test
The Double Asteroid Redirection Test (DART) was a NASA planetary defense mission that crashed a spacecraft into the asteroid Dimorphos in September 2022, shortening its orbit around Didymos.
Double Star (satellite)
Double Star (Tan Ce, "Explorer") was a joint China-ESA mission of two satellites, TC-1 and TC-2, launched in 2003 and 2004 to study Earth's magnetosphere with Cluster.
Dragon 2
Dragon 2 is a reusable SpaceX spacecraft carrying astronauts and pressurized cargo to the International Space Station, flying in Crew Dragon and cargo Dragon variants.
Dream Chaser
Dream Chaser is a reusable lifting-body cargo spaceplane built by Sierra Space, derived from NASA's HL-20 concept and selected under NASA's Commercial Resupply Services 2 contracts.
DS (satellite bus)
The DS (Dnepropetrovsk Sputnik) was a family of small standardized Soviet satellite buses developed from 1961 by OKB-586 in Dnepropetrovsk for scientific and military missions flown largely under the Kosmos and Interkosmos programs.
DS-2000
DS-2000 is a geostationary satellite bus developed by Mitsubishi Electric as Japan's first standard satellite platform, derived from JAXA satellite buses and flown on missions like Himawari 8 and Michibiki since 2006.
DS-U2
DS-U2 (ДС-У2) is a non-orienting, solar-powered Soviet small satellite bus developed in the mid-1960s at OKB-586 in Dnepropetrovsk, first flown as Kosmos 93 in 1965.
DSCS III
DSCS III, or Defense Satellite Communications System III, is the third generation of US military geostationary communications satellites, providing secure, jam-resistant links from 1982 until replacement by WGS.
DStv
DStv (Digital Satellite Television) is a satellite pay-TV platform run by South Africa's MultiChoice. Launched in 1995, it serves 14.5 million subscribers across sub-Saharan Africa.
Dual deployment
Dual deployment, also called dual-event recovery, is a rocket recovery method that deploys a small drogue parachute at apogee and a full-size main parachute shortly before landing.
DVB-RCS
DVB-RCS (Return Channel via Satellite) is a Digital Video Broadcasting standard that adds a two-way return channel to one-way satellite broadcasts, enabling IP traffic over VSAT.
DVB-S
DVB-S (Digital Video Broadcasting - Satellite) is the 1994 standard for transmitting digital television by satellite, and the first transmission standard of the DVB Project.
DVB-S2X
DVB-S2X (Digital Video Broadcasting, Satellite, Second Generation eXtensions) is a 2014 set of optional extensions to DVB-S2, adding higher-order modulation, channel bonding, and very-low signal-to-noise operation.
DVB-SH
DVB-SH (Digital Video Broadcasting – Satellite services to Handhelds) is a mobile broadcast standard, published by ETSI in 2008, for delivering video to handheld devices over hybrid satellite and terrestrial networks.
Early ballistic-missile rocket stages
Early ballistic-missile rocket stages were military missile boosters, like the R-7, Redstone, Atlas, and Titan, converted into the first space-launch vehicles of the late 1950s and 1960s.
Earth observation satellite
An Earth observation satellite is an uncrewed spacecraft that images Earth's surface or atmosphere from orbit, using passive optical sensors and active radar and lidar.
Earth Observing-1
Earth Observing-1 (EO-1) was a NASA satellite launched in 2000 to flight-test new technologies under the New Millennium Program; planned for one year, it operated for 16 years until 2017.
Earth Radiation Budget Satellite
The Earth Radiation Budget Satellite was a NASA Earth observation satellite launched in 1984 to measure Earth's energy balance and ozone, reentering in 2023 after 38 years.