The global economy, well-being of civil society, communication and security are increasingly dependent on space. The strategic and military importance of space has grown rapidly. Space activities are also increasingly important for the functioning of our society and everyday life. The most important services provided from space include navigation and timing data, telecommunications and remote mapping. The first telecommunications satellite to transmit television pictures, Telstar 1, was launched from the Cape Canaveral Space Center in Florida on 10 July 1962, making modern television broadcasting possible.

Statistics provided by the European Space Agency (ESA):

• 7,010 launches since 1957,
• 23,030 satellites have been put into orbit,
• 15,280 of them are still in space, with about 12,500 still operational,
• 42,930 pieces of space debris are large enough to be trackable,
• smaller pieces number over 141 million,
• The total weight of objects orbiting the Earth over 14,700 tonnes.

Most satellites are telecommunications satellites. Satellites in geostationary orbit (approx. 35,786 kilometres from Earth) orbit the Earth once a day. Large telecommunications satellite constellations have been formed to connect small ground stations to the Internet. For example, SpaceX’s Starlink system already has more than 7,600 active satellites, with 12,000 satellites planned, and the total potentially increasing to 34,400 in the future.

Using remote mapping, the Earth and objects on its surface are imaged, measured and observed in various ways for different purposes. Visible light and other wavelengths of electromagnetic radiation are used and provide information on humidity, temperature, objects below the Earth’s surface, the state of the sea and of the Earth’s vegetation, for example. Radar satellites can also be used to make observations at night and through cloud cover.

There are two types of weather satellites:

• Satellites in geostationary orbit constantly study the same area on the Earth’s surface
• Satellites in polar orbit can make more accurate observations.

In addition to detecting weather phenomena, weather satellites can also detect forest fires, oil spills and the spread of pollution, for example. The most important for Europe are the Meteosat and MetOp polar satellites operated by EUMETSAT.

The purpose of reconnaissance satellites is to monitor activities on the territory of other states (e.g. troop deployments and movements, or the construction of missile bases and industrial facilities). Reconnaissance satellites can take high-resolution photographs (at different wavelengths), or they can intercept communications. Thus, they can enforce a nuclear test ban or detect missile launches. It is estimated that the latest reconnaissance satellites can distinguish and identify objects as small as 4 to 10 cm in size. Signals intelligence gathered from space is also an essential part of intelligence gathering.

Satellite positioning refers to global positioning that relies on a local or globally comprehensive satellite system. A Global Navigation Satellite System (abbreviated as GNSS) refers to any satellite constellation that provides global positioning, navigation and timing services. The United States has GPS, Russia has Glonass, Europe has Galileo and China has BeiDou.

Satellite maintenance can extend the life of satellites. Some satellites have had to be taken out of service because they have run out of fuel to adjust their positions. In the future, satellite maintenance will be able to supply additional fuel and even make simple repairs. There are also plans for satellites to move satellites from one orbit to another. Such plans could involve the collecting of space debris and dispatching it for destruction in the Earth’s atmosphere.

Research satellites are used to study space and the objects therein. On the other hand, Earth exploration satellites are specialised remote mapping satellites that are used to measure the Earth’s magnetic field, changes in gravity and electromagnetic phenomena in near space, for example. Finland has four satellites on such research missions: Aalto-1, Suomi 100, Sunstorm and Foresail-1.

Small satellites are used to test technologies that will later be used in larger satellites.

There are also telescopes in space. As the Earth’s atmosphere interferes with astronomical observations and prevents many wavelengths of electromagnetic radiation from reaching the Earth’s surface, there are dozens of different space telescopes located in space that can observe everything from long radio waves to ultra-shortwave gamma radiation. Some of them focus on the search for exoplanets or the accurate mapping of stars, for example.

The United States, Russia and China are increasing their investments in space activities as part of the great power competition. About half of the satellites in orbit are American, and the United States’ ability to wage war is highly dependent on the use of space. The US space strategy focuses primarily on deterrence, but at the same time highlights the defence of its satellites. Several countries are developing capabilities to act against satellites (anti-satellite weapons, ASAT).

The military use of space includes the development of military technology for space activities and the placement of this technology in space. The conquest of space enabled the United States and the Soviet Union to develop ballistic missiles and other technology suitable for military use. Thus, outer space has come to be used as an operating environment for military spacecraft, such as imaging and communications satellites. The trajectory of intercontinental ballistic missiles partly also passes through space.

The Soviet Union and the United States began the military exploitation of space as far back as the beginning of the Cold War. Reconnaissance satellites provided accurate photographs of the opposing side’s military equipment. With the development of accuracy of the reconnaissance satellites the development of anti-satellite systems began. Reconnaissance satellites have also been used to verify compliance with arms control agreements.

The basic agreement governing the use of space is the Outer Space Treaty of 1967, which prohibits the contracting countries (including the United States, Russia, and China) from placing nuclear weapons in space. But the treaty does not apply to conventional weapons.

Russia, and newcomers such as China, Japan and India, have launched their own space programmes. The European Union is also working to create satellite systems that will ensure both the peaceful exploitation of space and the security of societies.

Over the past 20 years, in particular, the use of space for peaceful and commercial activities has increased. A growing number of countries and commercial actors are involved, which increases innovation and benefits, but also intensifies competition and congestion in space. More countries want to take advantage of space to improve their military capabilities and security.

At the same time, the threat posed by space debris to satellites, spacecraft and space stations is increasing. The larger debris includes, for example, broken satellites and launcher rocket parts. The smaller debris can include paint scraps, waste left behind by manned spacecraft, tools lost by astronauts and the remnants of collisions. Even objects such as paint particles can cause significant damage, as the collision speed of the objects can reach up to 35,000 km/h.

Launchers are needed not only for ballistic missile warheads, but also to transport spacecraft and those satellites that are used for other purposes. The know-how and technologies needed to launch rockets and transport satellites into space have only been released to commercial operators during the last 20 years.