Some questions regarding orbits

[Martian Music]

Well my main question is the views from orbit. So I recently found out that the ISS is at a 400km orbit (lol) but when you look at pictures taken from the ISS and compare them to KSP, you need to be in a 70km orbit (in KSP) to get the same view. So what am I missing here? LEO apparently reaches out to 500km orbits, how is that a "low" orbit?

Thanks in advance. (ISS is visible in my sky in 5 mins, as @Sanic says.. gotta go fast!) 

[Shpaget]

Kerbin is a lot smaller than Earth.

Edited December 22, 2015 by Shpaget

[swjr-swis]

Kerbin is a lot smaller than Earth (check the radius in tracking center), so to see the same curvature you need to be in a much closer orbit.

[Martian Music]

Ohh I never looked at Kerbin's diameter lol. Thanks guys, makes sense now ;p

P.S: I missed the ISS -.- my android app is supposed to ring when there's a sighting. It rang at 6:10 PM while the ISS was visible from 6:00 PM to 6:02 PM. Gonna uninstall the app I guess ;p

Edited December 22, 2015 by Martian Music

[Red Iron Crown]

29 minutes ago, Shpaget said:

Kerbin is a lot smaller than Earth.

Odd for such a well constructed image to get Kerbin's radius wrong, it's actually 600km.

[Shpaget]

Good eye!

Let's all blame @Hayoo for it.

Edited December 22, 2015 by Shpaget

[Martian Music]

So Jool is smaller than Earth? Cool ;p

[Frida Space]

1 hour ago, Martian Music said:

Ohh I never looked at Kerbin's diameter lol.

That's why it only takes 3300 m/s of Delta V to get in LKO compared to the roughly 9500 m/s needed for LEO

[Martian Music]

And yet I still sometimes fail to orbit. Hahaha epic!

[swjr-swis]

That's because it's not the size of the boat that matters, it's the depth of the gravity well.

Or something.

[Bill Phil]

There's something called angular size. It's actually really cool how it works. It depends on the linear size of the object and the distance to the object. 

Let's compare 500 to 6000(rounded...) It's 1/12. Adding it make 6500 km. If those were concentric circles the outer one would be the orbit in question. It hugs the earth. Quite closely.

[Scotius]

400 km orbit IS low ISS needs regular boosts from visiting ships (or her own propulsion system) to stay in orbit, because it still experiences significant amount of atmospheric drag. For the same reason, during station's night solar panels are rotated to make the station more aerodynamic

[SuperFastJellyfish]

I always like visualizations.  Here's a graph from here:

Edited December 22, 2015 by SuperFastJellyfish

[KerbonautInTraining]

5 hours ago, Scotius said:

400 km orbit IS low ISS needs regular boosts from visiting ships (or her own propulsion system) to stay in orbit, because it still experiences significant amount of atmospheric drag. For the same reason, during station's night solar panels are rotated to make the station more aerodynamic

I read somewhere that what you're describing is called the "Night Glider" mode or something. It's only done when propulsion isn't going to be in abundance, as it puts extra wear on certain components,

[Martian Music]

Yeah I've heard of the boosts, that also made me wonder how a "high" 400km orbit would experience that much drag but yeah I was unaware of the size comparison ;p thanks everyone.

[tomf]

Also Kerbin's atmosphere dissapears abruptly at just below 70km whereas Earth's atmosphere just gets very gradually more tenuous.