The Modern World Runs on Satellites
The modern world runs on technology in orbit around the Earth. Satellites contribute to business, energy production and distribution, education, governing, health, disaster recovery safety, security, transportation, the internet, scientific research, the battle to limit climate change and much more.
How It All Started
Sputnik, which means “satellite” in Russian, was launched into low Earth orbit by the Soviet Union in October 1957. It orbited the Earth for 3 weeks before running out of power, transmitting beeping audio signals by radio to receivers below. Sputnik dropped from orbit and burned up in the atmosphere after 4 months. But it sparked a competition for “the high ground of space” that was quickly termed the Space Race and that led to creation of the fundamental technologies of spaceflight and satellite services.
Where Do We Operate in Space?
There are more than 3,400 active satellites in orbit today - and thousands more are coming in the future. They orbit the Earth in:
- Geosynchronous orbit (GEO), in which satellites circle the Earth at the equator at the same speed the Earth itself is turning. This makes them appear to hover over a single point on the equator, which has been ideal for communications and TV services, because antennas on the ground point at a fixed place in the sky. GEO orbit is nearly 36,000 km or 22,000 miles high.
- Middle Earth orbit (MEO), in which they circle the earth at in a range of 10,000 to 20,000 km altitude (6,300-12,500 miles). This causes them to move across the sky from our perspective on Earth. Used for communications, MEO provides higher power and less delay (latency) because of its closer range.
- Low Earth orbit (LEO), circling the earth typically in orbits that move at high speed over most of the globe at an altitude between 160 and 1,600 km (100-1,000 miles) to provide weather, earth observation and communications.
What Do We Do in Space?
- Television and Radio - It was the first major satellite market, delivering sports, news and entertainment to over-the-air broadcast stations, then to cable television and direct to homes.
- Internet and Data - Beginning in the mid-1990s, satellites began connecting internet service providers to global networks and delivering internet service directly to consumers and businesses.
- Voice - The first trans-oceanic telephone calls were carried on both satellites and copper cables, but the introduction of fiber-optic cables beginning in the 1990s made satellite uneconomic. Satellites continue to connect wired networks, mobile base stations and satellite phones operating in remote locations.
- Business and Government Networks - From retail stores, ships and oil platforms to military operations and emergency first-responders, satellites offer private networks that keep facilities and people connected by voice, data and video.
- Navigation - Fully operational since 1993, the US GPS system gave rise to multiple national programs from Russia, China and the European Union, used for everything from digital maps to keeping data networks synchronized.
- Weather - Satellites gather data on all the factors that drive weather from visual, radar and other sensors in orbit to inform your daily forecast.
- Earth Observation and Remote Sensing - Going beyond weather, imaging and radar satellites measure changes in land and sea, evaluate the health of crops and track human activity.
- Defense and Security - Reconnaissance and signals interception satellites keep watch on adversaries and monitor border activities.
How Do We Get to Space?
Getting into space is the job of the launch industry. Space has become more accessible because businesses have driven the cost of launching rockets sharply downward:
- From 1970 to 2000, it cost an average of $18,500 to launch one kilogram (2.2 pounds) into low Earth orbit.
- Intensive innovation in launch technology has pushed that cost below $1,000 – a decline of 95% – and NASA expects costs to fall to a few tens of dollars per kilogram by 2040, 2/10ths of one percent of its 1970-2000 cost.
Lower launch costs have led to an explosion in the number and types of satellites in orbit, ranging in size from nearly 8 tons (7,000 kg) to less than 2 pounds (6 kg):
- Large satellites launch from Earth on rockets and raise themselves to GEO orbit using additional rocket motors or electric propulsion.
- Midsize satellites launch from Earth aboard “rideshare” missions and are ejected in batches from the rocket into MEO or LEO orbit.
- Smallsats and cubesats are launched to LEO through rideshare rocket missions and also from the International Space Station, using a special ejector.
In addition to satellites, companies are developing new robotic spacecraft to operate in orbit. A Mission Extension Vehicle developed by Northrop Grumman maneuvers to an existing satellite, captures it and acts as its maneuvering engine.
What Does the Future Hold?
- Orbital Operations - Our future in space may include multiple governmental and private-sector space stations, robotic “space tugs” moving satellites into new positions and extending their life with additional fuel, and the manufacturing of orbital structures in space.
- Thousands of Satellites - Plans and financing are in place for adding thousands of satellites to deliver broadband, data services, cloud computing and earth observation. Companies including SpaceX (Starlink), OneWeb, Amazon Kuiper (pronounced “KIGH-ber”) and Telesat Lightspeed will be launching thousands of small and midsize satellites in the next decade alone, and companies including Maxar Technologies, Spire Global, Planet, BlackSky Technology and HawkEye 360 have ringed the Earth with cameras and radar that show us our planet in amazing detail.
- Space Junk – For decades, satellite launches and human exploration have been leaving debris in orbit, ranging from rocket motors and “dead” satellites to nuts, bolts and flakes of paint. They circle the Earth at enormous speed and create the risk of collision with active spacecraft. Each such collision creates yet more debris and the risk of a chain reaction of collisions, as was shown in the 2013 movie Gravity, that would make spaceflight impossible. Governments and businesses are working to stop the creation of more space junk and finding ways to capture it and drop it into the atmosphere, where it will burn up on reentry.