Is it possible to complete 1 orbit within the atmosphere?

[Camacha]

There have been a couple of nonstop aircraft flights and balloon trips that some may argue as technically orbits too.

Sure, why not? Even throwing a ball is a very tiny orbit.

[Aghanim]

Well, the orbit intersects Earth's surface, with an apoapsis of 1m and periapis of 500ish km...

[rkman]

Maybe if you had wings that are ginormous and still applied thrust.

It's already by definition not an orbit if it is inside the atmosphere, it is even less an orbit if thrust is applied.

[Starman4308]

It's already by definition not an orbit if it is inside the atmosphere, it is even less an orbit if thrust is applied.

As far as I can tell, there is no requirement for orbits to be outside the atmosphere. An orbit simply describes a curved, repeating path around an object caused by a combination of inertia and gravity. Part of the reason for that is obvious: cutoffs for "what is atmosphere vs. space" are arbitrary. It's not like KSP where atmosphere cuts off at exactly 69,077.553m: atmosphere simply tails off into space. The customary demarcation is the Karman line, the point where a typical aircraft would have to fly at greater than orbital velocity to achieve sufficient aerodynamic lift to fight gravity. That is still a fairly significant amount of atmosphere for orbital vessels.

An orbit inside thick atmosphere is bound to decay and stop being an orbit, but it is still an orbit.

[Dodgey]

Well it depends if you are talking about achieving orbit or completing an orbit. For the former I guess you could stretch the defination do simply mean reaching orbital velocity with no constraints on maintaining your speed. For the latter there isn't as much leeway for interpretation. Of course it goes without saying that the more broard your definitions become the less useful they are.

[peadar1987]

I choose to declare that the first "orbit" was in fact completed by Magellan with the lowest altitude of roughly 10 feet above sea level (depends on where he was on his ship at any point). Check mate.

Pff, my head completes a roughly geosynchronous orbit once every 24 hours with a maximum altitude of about 50 metres and a minimum altitude of about sea level. Don't even need a ship!

[YNM]

Orbit litterally means to go around a thing; so if you are circling a roundabout you're orbiting the center of the roundabout. Electron orbits the nucleus. A coaster in a loop, for a brief period, orbits the center of the loop.

Now, what's your definition of an orbit ? (Because basically anyone on the equator would orbit the center of the Earth)

[worir4]

I managed to build a small station at an altitude of 55km up. It was stable enough for me to build it but i had to dock it quickly because drag doesn't affect it when it is on rails. It survived about 20 mins real time off rails.

[Mazon Del]

I managed to build a small station at an altitude of 55km up. It was stable enough for me to build it but i had to dock it quickly because drag doesn't affect it when it is on rails. It survived about 20 mins real time off rails.

Hah! I imagine it goes in the following way.

Bill: Alright guys, remember, we have to dock as quickly as possible, but SAFELY JEB! And while we are there we cannot think about how we are orbiting or else we'll fall out of the sky.

*docking connecion made*

Jeb: I still don't understand it! How are we keeping in the air?

Bill: NOOOO! *station falls out of the sky as it is no longer on rails*

[NASAFanboy]

If you fly around the entire equator of the Earth with some supplies and a solar-powered plan with a ridiculous range, that could be counted as a orbit. After all, it is one revolution.

So yes, it's possible. Use a plane, not a spacecraft.

[Kryten]

If you fly around the entire equator of the Earth with some supplies and a solar-powered plan with a ridiculous range, that could be counted as a orbit. After all, it is one revolution.

So yes, it's possible. Use a plane, not a spacecraft.

Already been done with extremely efficient jet (Globalflyer), albeit not at the equator.