Orbit

In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a planet, moon, asteroid, or Lagrange point. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory. To a close approximation, planets and satellites follow elliptic orbits, with the center of mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion. For most situations, orbital motion is adequately approximated by Newtonian mechanics, which explains gravity as a force obeying an inverse-square law. However, Albert Einstein's general theory of relativity, which accounts for gravity as due to curvature of spacetime, with orbits following geodesics, provides a more accurate calculation and understanding of the exact mechanics of orbital motion.

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Classified Chinese satellite releases small object in orbit

SpaceX Prepping for First Full Test Fire of Its Mega Starship Rocket Next Week. The Super Heavy booster designed to get Starship to orbit has never before lit up all 33 of its engines at once.

Rocket operators can now apply to launch to orbit from Canadian soil

ESA's mission to Jupiter's icy moons ready for launch | It will conduct 35 fly-bys of Callisto, Ganymede and Europa before permanently settling into an orbit around Ganymede. It has an advanced package of instruments to investigate whether any of these moons are habitable.

We Asked a NASA Technologist: Does Anything Orbit the Moon?

CAPSTONE Becomes First Probe to Enter Unique Halo Orbit Around the Moon

China launches 14 commercial satellites into orbit atop Long March 2D rocket (video)

The Space Force wants to create temporary 'training ranges' in orbit

Orbit of Doom: The Surprising Connection Between Earth’s Orbital Patterns and an Ancient Warming Event

What the failure of Virgin Orbit means for Britain’s space ambitions

Starship's much-anticipated first orbital flight could be as soon as next month. All 33 engines on the Superheavy booster will burn for 170 seconds before separating for a water landing in the Gulf of Mexico. If Starship reaches orbit it will return for a water landing off the coast of Hawaii.

The first ShadowCam image from orbit reveals an area of the Moon that lies in total darkness — the permanently shadowed wall and floor of Shackleton Crater, in never-before-seen detail

China launches new commercial communications satellite to orbit

Virgin Orbit Offers More Details on Rocket Failure

In photos: Virgin Orbit's first UK launch from Spaceport Cornwall

7-year eclipse reveals 'exceptionally rare' binary system with 1000-year orbit

SpaceX had four rockets on four pads and two Dragons on orbit today—as CRS-26 Dragon departed the space station with Crew-5 Dragon still attached to the orbiting lab, Falcon Heavy rolled out of the hangar, two Falcon 9’s readied for launch, and Ship 24 was stacked onto Booster 7

Last year marked the end of an era in spaceflight—here’s what we’re watching next: Will Artemis happen? Can Starship actually work? Will humans destroy low-Earth orbit?

Failed Virgin Orbit launch leaves open opportunity for UK as a space 'underdog'

LauncherOne rocket from failed Virgin Orbit launch spotted crashing to Earth (video)