Glossary

A brief explanation of aerospace terms

Glossary

A:

  • Antenna: it is a normally conductive metallic device, designed with the aim of emitting and/or receiving electromagnetic waves into free space. A transmitting antenna transforms electrical energy into electromagnetic waves, and a receiving antenna performs the reverse function. There is a great diversity of types of antennas. In some cases they must expand the radiated power as much as possible, that is, they must not be directive (example: a commercial radio station or a mobile phone base station), other times they must be so to channel the power in one direction and not interfere to other services (antennas between radio link stations).

B:

  • ISM band (Industrial, Scientific and Medical): these are bands internationally reserved for non-commercial use of electromagnetic radio frequency in industrial, scientific and medical areas. Today these bands have been popularized for their use in WLAN (e.g. Wi-Fi) or WPAN (e.g. Bluetooth) communications. The ISM bands were defined by the ITU in article 5 of the Radio Regulations (RR), specifically points 5.138 and 5.150. The use of these frequency bands is open to everyone without the need for a license, respecting the regulations that limit the levels of transmitted power. This fact forces this type of communication to have a certain tolerance against errors and to use protection mechanisms against interference, such as spectrum spread techniques.

C:

  • Space rocket: it is a machine that, using a combustion engine, produces the kinetic energy necessary for the expansion of the gases, which are launched through a propellant tube (jet propulsion). By extension, the generally space vehicle having a propulsion engine of this type is called a rocket or missile. Typically its purpose is to send artifacts (especially artificial satellites and space probes) or spacecraft and humans into space. A rocket consists of a frame, a jet propulsion engine, and a payload. The structure serves to protect the fuel and oxidant tanks and payload. The propulsion engine itself is also called a rocket.
  • COTS components (Commercial Off-The-Shelf): technological components, in this case hardware, available for purchase by the general public.
  • Connectivity: it is the ability to establish a connection: a communication, a link. The concept usually refers to the availability of a device to be connected to another or to a network.
  • Satellite constellation: it is a group of artificial satellites that work together as a single system. Unlike an individual satellite, a constellation can provide permanent global or quasi-global coverage, since at any time, at any point on Earth, at least one satellite is visible. Typically, satellites are placed in sets of complementary orbital planes, and connected to globally distributed ground stations. They can also use intercommunication between satellites of the same constellation. They should not be confused with groups of satellites, which are satellites that move very close to each other in nearly identical orbits, satellite programs (such as Landsat), which are generations of satellites launched in succession, and fleets of satellites, which they are groups of satellites of the same manufacturer or operator that work independently (not as a system).

E:

  • EPS (Electrical Power System): is a network of electrical components installed to supply, transfer and use electrical energy. An example of a power system is the network that provides power to an extended area. The power system of the electrical network can be divided into the generators that supply the energy, the transmission system that transports the energy from the generation centers to the load centers and the distribution system that feeds the energy to homes and industries. . The smallest power systems are found in industry, hospitals, commercial buildings, and homes. Most of these systems rely on three-phase power, which is used for large-scale electrical power transmission and distribution throughout the modern world. Specialized power systems that do not always rely on three-phase systems are found in airplanes, electric rail systems, ocean liners, and automobiles.
  • Terrestrial station: it is a terrestrial radio station for telecommunications for the retransmission of different television, voice and data services via satellite. These complexes, which are named after the conceptual similarities that they present with port stations, are connection points between satellites and terrestrial communication networks, allowing the transmission and reception of communication signals and thus solving the lack of transmission networks. wired in remote or isolated areas. They are usually made up of a set of large antennas that transmit the signals already prepared (compressed, digitized and with built-in conditional access) to the satellite.

I:

  • IOD (In-Orbit Demonstration): tool / service to accelerate the development of new technologies, allowing the flight in space of a subsystem or critical technology that is not yet mature enough (TRL 9) for use in commercial missions.
  • IoT (Internet of Things): is a set of technologies that facilitates the deployment of sensors and actuators that inform us of the state of everyday elements, such as vehicles, tools or even living beings. It allows us to interact with them, enabling their connectivity with cloud platforms that receive and process the information so that, after analysis, we can make decisions.

L:

  • Linux: it is a free software operating system (it is not owned by any person or company), therefore, it is not necessary to buy a license to install and use it on a computer. It is a multi-tasking, multi-user system that provides a command interface and a graphical interface, which makes it a very attractive system.
  • LoRa:means “long range” (LOng RAnge) and it is the modulation technology of Lorawan networks, this is a type of LPWAN (Low power Wide Area Network) network. It enables connected IoT devices to exchange small amounts of data at low speed with a long range and low power consumption.
  • LEOP (Launch and Early Orbit Phase): it is the most critical phase within the operations carried out during the useful life of the satellite, in which the operators assume control of the satellite until the satellite reaches its nominal orbit, checking the status and correct operation of all subsystems, as well as the deployment of antennas and solar panels.

M:

  • Magnetorque: or magnetic torque is a satellite system, for attitude control, disarming and stabilization, built from electromagnetic coils.
  • Microprocessor: or simply processor, it is the most complex central integrated circuit of a computer system; by way of illustration, it is often called by analogy the “brain” of a computer. It is in charge of executing all the programs, from the operating system to the user applications; It only executes instructions in binary language, performing simple arithmetic and logic operations, such as adding, subtracting, multiplying, dividing, binary logic and memory accesses.
  • Microsatellite: or microsat is a satellite with a mass between 10 kg and 100 kg.
  • MPPT (Maximum Power Point Tracker), sometimes referred to as Power Point Tracker (PPT), is a technique generally used to maximize power extraction under all conditions. The MPPT regulators allow to obtain the maximum power from the solar panels since they always work at that point.

N:

  • Nanosat (CubeSat): or nanosat is a satellite with a mass between 1 kg and 10 kg and that follows the CubeSat design standard (10x10x10cm).
  • NewSpace: is a term used to refer to a global commercial sector and relatively new aerospace companies with a clear vocation to facilitate access to space. Working independently of governments and their prime contractors, (Old Space), they develop faster and more economically technologies and space missions, all driven largely by commercial reasons.
  • Network node: is a connection point that can receive, collect, store or send data along distributed network paths. Each node in the network, whether it is an end point for data transmission or a point of redistribution, has a programmed or designed capacity to recognize, process and forward transmissions to other nodes in the network.

O:

  • Earth Observation (EO): they are missions of artificial satellites and scientific instruments in Earth orbit, designed for long-term observations of the Earth’s surface, biosphere, atmosphere, and oceans.
  • Orbit: it is the path that a physical object describes around another while it is under the influence of a central force, such as the gravitational force.
  • Orbit GEO (Geostationary Orbit): the geostationary orbit is an equatorial and circular orbit located 35,786 km from the Earth’s surface and has an orbital period of exactly 23.93446 hours (coinciding with the length of the sidereal day), which makes the Satellites placed in that orbit appear “immobile” in space, since they rotate with the same angular velocity as the earth.
  • Orbit HEO (High Eccentricity / Elliptic Orbit): they are orbits of ellipticals of high eccentricity. One of the clearest examples of this type of orbits is the Molniya, which are used in communications satellites to provide coverage at high latitudes (Russia). Molniya orbits have a period of 12 h, an eccentricity of approximately 0.75 (so that the satellite is most of the time over the area of ​​interest) and an inclination of 63.4º, which eliminates the disturbance in the perigee argument due to effect of J2. Another type of HEO orbits are Tundra orbits, unlike Molniya, Tundra orbits are geosynchronous and have an eccentricity between 0.24-0.4.
  • Orbit LEO (Low Earth Orbit): Commonly known as “low orbit”, it is a wide orbital strip that is located between 160 km high and 2000 km high. As the orbital speed is higher the lower the orbit, the objects located in this strip move at high speed with respect to the Earth’s surface, covering a complete orbit in minutes or a few hours. It is the kind of circular orbit where the International Space Station, the vast majority of meteorological or observation satellites, and many communications satellites are located.
  • Orbit MEO (Medium Earth Orbit): intermediate circular orbit, between 2,000 and 36,000 km away from the Earth’s surface, with an average orbital period of several hours (12 hours on average). Used by observation, defense and positioning satellites, such as GPS satellite networks, and the Russian Glonass or European Galileo satellites.
  • Orbit SSO (Sun-Syncrhonous Orbit): the heliosynchronous orbit is a quasi-polar orbit in which the satellite passes over a given point on the planet’s surface at the same local solar time. SSOs are widely used in remote sensing applications (Earth Observation, Meteorology or Reconnaissance) since the lighting conditions remain practically constant. Typically they are defined by two parameters, the altitude and the time of passage through the ascending node (LTAN, the satellite crosses from the southern hemisphere to the north) or descending (LTDN, the satellite crosses from the northern hemisphere to the south), since the inclination comes set by altitude.

P:

  • Picosatellite (PocketQube): a picosatellite (in English SmallSat) is any satellite whose mass is less than 1 kg and that follows the PocketQube design standard (5x5x5cm).

R:

  • Remote Sensing: remote sensing, or remote sensing, is the acquisition of information on a small or large scale of an object or phenomenon, either using recording instruments or real-time scanning instruments that are wireless or not in direct contact with the object (such as airplanes, satellites, spaceships, buoys, or ships). In practice, remote sensing consists of collecting information from a specific object or area through different devices. For example, ground observation or weather satellites, oceanic and atmospheric buoys, magnetic resonance imaging (MRI), positron emission tomography (PET), X-rays, and space probes are all examples of remote sensing. Currently, the term refers specifically to the use of sensor technologies for image acquisition, including: instruments on board satellites or airborne, uses in electrophysiology, and differs in other fields related to images such as medical imaging.

S:

  • Satellite: it is a technological device placed in orbit around the Earth for scientific, military or communication purposes.
  • Solar sensor: it is a navigation instrument used by spacecraft to detect the position of the sun.Solar sensors are used in attitude controls, solar panel steering, gyroscope update, and safe mode reset. In addition to spacecraft, solar sensors are used in weather stations, solar tracking systems, and in air vehicles including hot air balloons and UAVs.