Satellite in orbit earth blue

Artificial satellites in Earth orbit perform critical functions such as communication, climate observation and navigation, with over 8,000 launched since 1957.

About this subject

Since the launch of Sputnik 1 by the Soviet Union on October 4, 1957, over 8,000 artificial satellites have been placed into Earth orbit. Currently, about 5,000 are still operational, distributed across various altitudes and inclinations. Most of these devices occupy low Earth orbit (LEO), between 160 and 2,000 kilometers in altitude, where remote sensing satellites such as the Landsat series and internet constellations like Starlink are concentrated. Geostationary orbit (GEO), at approximately 35,786 km, hosts telecommunications and weather satellites such as the GOES series, which remain fixed over one point on the surface. The Molniya elliptical orbit is used by Russian satellites to cover high latitudes. Satellites play essential roles in monitoring climate change, weather forecasting, GPS, television broadcasting, and broadband internet. Brazil has its own satellites, such as SCD-1 (launched in 1993) and CBERS-4A, developed in partnership with China, which provide images for agriculture and deforestation monitoring. Space debris is a growing concern: an estimated 34,000 fragments larger than 10 cm are in orbit, posing collision risks. To mitigate this, new international guidelines recommend that satellites be deorbited within 25 years after the end of their operational lives.

Frequently Asked Questions

How many satellites are currently in orbit?

Approximately 5,000 satellites are operational, but over 8,000 have been launched in total. Most are in low Earth orbit (LEO).

What is the difference between low Earth orbit and geostationary orbit?

Low Earth orbit (LEO) ranges from 160 to 2,000 km altitude, used for observation and internet. Geostationary orbit (GEO) is at 35,786 km, where satellites match Earth's rotation, ideal for communications and weather.

Does Brazil have its own satellites?

Yes, Brazil operates satellites like SCD-1 (launched in 1993) and CBERS-4A, in partnership with China, used for environmental and agricultural monitoring.