Definitions list
Click one of the letters above to advance the page to terms beginning with that letter.
  • satelliser
    Mettre un véhicule spatial en orbite autour d’un astre.
  • satellite
    From the Latin satellitis, meaning escort or bodyguard. A celestial object that revolves periodically around another, larger object. It adopts a projectile trajectory as it is subjected to the pull of gravity. Satellites may be artificial or man-made, or natural.
    How satellites work
  • satellite imagemap
    Map generated from data collected by Earth-observation satellites, sometimes merged with data from other sources. The term also covers satellite-based mapping of other planets.
  • satellite positioning
    Set of manoeuvres required to place a man-made satellite into its final orbit.
    How orbital manoeuvres work
  • satellite à défilement
    Voir défilement
  • senseur
    Synonyme de capteur ou détecteur. Terme déconseillé.
  • sensor
    Measuring instrument that senses a physical phenomenon and usually converts it into an electrical signal. For example, a pressure, temperature, velocity or wind direction sensor.
  • simulator
    Full-scale model capable of simulating how a device operates under real-life conditions. Astronauts use simulators to acquire expertise and proficiency in mission operations. A simulator may also be hardware or software capable of reproducing certain environmental conditions for test purposes.
  • solar panel
    Device consisting of a large number of solar or photovoltaic cells mounted on a panel, usually making up a larger solar array. Solar panels are the main source of power for man-made satellites and orbital stations.
    How satellites work
  • solar system
    Planetary system consisting of the Sun and the planets, natural satellites, comets and asteroids orbiting around it.
  • solar wind
    Stream of charged particles, mostly protons and electrons, continuously flowing outward from the Sun, carrying plasma into the interplanetary medium. This outflow is controlled by the Sun’s magnetic field.
  • sounding radar
    Radar with a narrow, usually vertical, beam used to determine meteorological properties by analysing waves backscattered by the atmosphere.
  • sounding rocket
    Unmanned spacecraft used for short, non-orbital flights. Sounding rockets are designed to study the Earth’s atmosphere and for microgravity research.
  • Soyuz
    Russian manned spacecraft.
  • space
    Region of the Universe beyond the Earth’s atmosphere, where celestial bodies and spacecraft are.
    What is space?
  • space probe
    Unmanned spacecraft designed for Solar System exploration, capable of operating millions of kilometres from Earth. Some 100 probes have been launched into the Solar System in the last 40 years, half of them to the Moon.
  • space shuttle
    A partially recoverable and reusable spacecraft. Only the United States has so far built a space shuttle.
  • Space sickness
    Term encompassing the symptoms sometimes experienced by astronauts during the first days in weightless conditions (nausea, dizziness, vomiting, perspiration, etc.).
  • space station / orbital station
    Station designed to support long-duration missions in space. A space station may be manned or unmanned, and may be on the surface of a star or in orbit. So far, 10 space stations have been launched into Earth orbit: 1 by the United States, 8 by the former Soviet Union and then Russia, including Mir, and the International Space Station—the only station still in orbit—by 15 partner nations.
  • space technology
    Discipline encompassing all space sciences and technologies.
  • space transport
    Assets and resources used to send humans and experiments into space and bring them back to Earth.
  • space-based geodesy
    Science of the measurement of the Earth, its shape and gravity field using space-based techniques. Used to study the planet’s inner structure, rotational motion and gravity variations.
  • spacecraft / space vehicle
    Means of space transport. Applies equally to a launch vehicle carrying a payload and to a satellite.
  • spacecraft bus
    Structure designed to support a payload (for example, of a satellite) and equipped with the systems required to operate it. A bus may comprise measuring, control, onboard management and housekeeping systems.
    How satellites work
  • Spaceplane
    Reusable spacecraft that is lifted by a launch vehicle and lands on its own after gliding through the atmosphere. The U.S. space shuttle orbiter is the only spaceplane currently operating.
  • spaceport
    Synonymous with launch base.
  • spacesuit
    A gastight, pressurized suit worn by astronauts to withstand the hostile environment of space during an extravehicular activity or as an extra safety measure inside certain spacecraft.
  • spationaute
    Synonyme d’astronaute et cosmonaute. Mot apparu en 1982, à l’occasion du premier vol d’un français dans l’espace, pour désigner tout occupant d’un vaisseau spatial, quelle que soit sa nationalité. Voir cosmonaute, astronaute
  • spectrometer
    Instrument that measures the dispersion of radiation as a function of wavelength or frequency.
  • spectrum
    Arrangement of monochromatic radiation at different wavelengths into which light and more generally any kind of electromagnetic radiation is dispersed. Also, the radiation emitted, scattered or absorbed by an element under specific conditions.
  • sponsor proponent
    Organization that defines objectives and expresses high-level needs for the execution of a product it is funding.
  • stage
    Part of a launch vehicle that delivers thrust and performs automatic control functions for a certain phase of its flight. A stage usually separates from the vehicle once it has performed its intended function.
  • star
    Natural celestial body. Planets and their natural satellites, comets and asteroids are all stars.
  • star
    A celestial body that emits its own light. By comparison, a planet only reflects light.
  • Star City
    Town built by Russia starting in 1960, some 40 km north-west of Moscow, to house the cosmonaut preparation centre (TPK). It covers 310 hectares and has a population of 5,000.
  • stationkeeping
    Set of manoeuvres required to make adjustments in response to perturbing forces and maintain a satellite in a given orbit.
    How orbital manoeuvres work
  • stereoscopy
    Optical process used to view relief by combining two images of the same area acquired from different angles.
  • strap-on booster
    Booster usually strapped to the side of the main structure of a launch vehicle to deliver additional thrust at lift-off.
  • stratosphere
    Layer of the atmosphere, approximately 40 kilometres thick, above the troposphere. Temperature in the stratosphere increases with altitude, from –55°C to 0°C.
  • Submillimetre astronomy
    Branch of astronomy that studies radioelectric radiation in the submillimetre band, i.e., at wavelengths from 0.1 to 1 mm.
  • Sun
    Star at the centre of the Solar System, about which Earth and the other planets orbit.
  • Sun-synchronous
    Describes a satellite and orbit whose plane remains at a constant angle to the Earth-Sun line, resulting in relatively constant solar illumination.
    What is an orbit?
  • sun-synchronous orbit
    See Sun-synchronous
    What is an orbit?