Re-entry velocity

[[email protected]]

I've been playing Kerbal for about a week now. I've been taking tourists up to orbits to collect easy cash. When I retro burn to re -enter, I've noticed that even though I have a low orbit to return (50,000-60,000K), if I have a high velocity, say above 2000 m/s, my ship just skips off the atmosphere and doesn't re-enter and just keeps on staying in orbit. What is the maximum velocity to accomplish a proper re -entry?

[Snark]

3 hours ago, [email protected] said:

When I retro burn to re -enter, I've noticed that even though I have a low orbit to return (50,000-60,000K), if I have a high velocity, say above 2000 m/s, my ship just skips off the atmosphere and doesn't re-enter and just keeps on staying in orbit. What is the maximum velocity to accomplish a proper re -entry?

The problem is your altitude, not your speed.  At 50-60 km altitude, there's practically no drag at all.  It's not zero, so if you keep orbiting and orbiting it'll eventually decay.  But you're not going to slow down and head groundwards on one pass.

You need to get your ship on a trajectory where your projected Pe (periapsis) is a lot lower than 50 km.  Exactly how low depends on various things such as how "dense" your ship is, how heat-resistant, etc., but in general 30 km is a pretty good target:  low enough that drag will bring you down, but not so low that you burn up before shedding speed, or faceplant at faster-than-parachutes-can-deploy velocity.

If you aim to put your Pe at around 30 km, then you'll re-enter just fine-- even if you hit atmosphere at 5000 m/s or more.

So, when you want to re-enter:  don't worry about your velocity, since that's not what matters.  You need to get down to where the air is thick.

So just point , switch to map view, and burn until your Pe marker drops to an altitude of 30 km or so.  Then you're all set.