Outer space, also known as space, is the expanse existing beyond Earth and other celestial bodies. Space is a hard vacuum containing various particles of low density, primarily consisting of plasma of hydrogen and helium. Other things existing in space are:
- Electromagnetic radiation
- Cosmic rays
- Magnetic fields
The average temperature of space is extremely cold and unfit for human survival, and is a result of background radiation caused by the 'Big Bang.' Space at baseline sits at 2.7 kelvins, or −270.45 °C; −454.81 °F.
Human exploration of space began in the 20th century, after the invention of high-altitude balloon flight. Later, crewed rocket flights were launched and the first successful crewed space mission took place in 1961. The mission was completed by a Soviet Union astronaut Yuri Gagarin. In 1969, Neil Armstrong was the first person to set foot on the moon, during NASA's Apollo 11 mission. Due to the high costs of human space travel, human space exploration has been limited to low Earth orbit and the moon; however, uncrewed spacecraft have landed on all known planets in the solar system.
Various technologies and sub-industries exist in space or are being developed by a multitude of companies to further contribute to space exploration. Some of these technologies and sub-industries are:
- Spacecraft propulsion
- Satelite control
- Weather tracking
- Satellite imagery
- Space vehicles
Spacecraft propulsion is a common component of all space-related travel, not just for human crews but also for satellites, rovers, and crewless spacecraft. There are two types of propulsion: spacecraft propulsion, which broadly refers to any acceleration of satellites and spacecraft; and in-space propulsion, which relates exclusively to propulsion systems that can operate within a hard vacuum and should not be confused with space launch or atmospheric entry.
Launchers, also known as launch vehicles or carrier rockets, are rocket-propelled vehicles used to carry payloads from the surface of Earth into orbit or outer space. A launcher is actually a full launch system comprised of various parts, including:
- Launch vehicles
- Launch pads
- Vehicle assembly and fueling
- Range safety
- Other infrastructure components
Cislunar travel and exploration references travel or explorations occurring in the spaces between Earth and the moon. Cislunar travel is becoming more popularized by the private and public sectors due to the rising demand to commercialize space travel. The commercialization of space travel is aimed at making low-orbit space a premier destination for vacationing, cargo transport, and expansion in space-capable technologies.
Satellite control and data ingestion is a function of AWS Ground Control, an arm of Amazon that allows satellite communication, control, and collection of satellite data from a fully staffed station on Earth. The service is provided to allow companies to scale operations without having to manually manage systems themselves.
Weather tracking is the action of predicting weather based on various technologies like satellites, radiosondes, weather radar, and other ground-based technology. Satellite weather tracking is based in space and provides weather reporting services, like the National Weather Service (NWS), with a global picture of potential incoming weather patterns. The ground-based methods provide NWS with more localized weather information.
Space communications is made up of six different parts:
- Ground networks
- Space relays
- Data rates
At the core of space communications, a transmitter and receiver are needed to successfully communicate. Transmitters encode messages onto electromagnetic waves through modulation. The electromagnetic waves travel through space to the receiver where the message is then demodulated to decode the sender's message.
The concept is similar to wireless internet, in which the router will send information from the internet and transmit the message on the user's computer, providing the data the user was looking for. Space communications are performed on a maximized scale, in comparison.
Satellite imagery, also known as spaceborne photography, Earth observation, and satellite photography, is images of Earth collected by imaging satellites. Imaging satellites are often operated by government entities and private businesses around the world for the purpose of resale to governments or other private businesses, like Apple Maps or Google Maps.
Space vehicles with habitats provide living spaces for manned space crafts. Habitats include sleeping quarters, bathrooms, and other living comforts. Space habitats are also being built to have humans inhabit outer space. Space settlements would have more advanced living spaces than space stations or spacecraft as they are intended for more permanent living scenarios.
Space vehicles for transportation can include ships transporting humans or payloads. Payloads are often times shipped into space in unmanned spacecraft. Other space vehicles transport humans to various locations like the international space station, or to the moon for lunar exploration.