The concept of launching a satellite into space using a cannon was first conceived by Isaac Newton in 1678. Since then, various superguns have been built, including the infamous Big Bertha. In 2007, Ballistic Flight Group LLC was founded with the goal of building the first cannon capable of launching a projectile into orbit, which […]
The US Space Surveillance Network has tracked every object in orbit over 10 cm since 1957. There are approximately 3,000 satellites in orbit, with the largest being the International Space Station. The operational lifetime of satellites is 5-20 years, and many countries and international companies have launched them for military and commercial purposes. The SSN […]
Earth has two other co-orbital satellites besides the Moon: asteroids 3753 Cruithne and 2002 AA29. Cruithne is 3 miles wide and orbits in synchrony with Earth, while AA29 is smaller and orbits in a horseshoe shape. The Earth is not a perfect sphere and may have had a second moon in the past. Earth’s best-known […]
Solar-powered satellites could provide abundant free energy by placing large solar arrays in high Earth orbit to collect sunlight and beam it onto a rectenna on Earth. They would need actuators to stay pointed at the sun and autonomous robotics for maintenance. Launch costs are currently too high, but reduced launch costs or space manufacturing […]
Reconnaissance satellites use high resolution CCD cameras and large lenses to take pictures of the ground. They return images via encrypted radio transmissions. The Rayleigh criterion is used to calculate the resolution of an optical image. Commercially available high-resolution color images of the world are available, but military reconnaissance satellites update their images every 45 […]
