Skip reentry is very well possile wihout FAR!

[Kasuha]

That corresponds to what I found in the FAA material. Lift is used for control. Yes, definitely.

But it does not say skip reentry only counts if lift is involved. Because it is not true. Skip reentry is defined as descent into the atmosphere followed by ascent out of thick atmospheric layers, followed by another descent. Lift may, but does not have to be involved.

Edit: okay, one point for you:

A skip reentry is characterized by a vehicle whose L/D is greater than

zero. Sufficient lift is produced to dominate the gravitational and centrifugal forces. If

this lift is combined with a large enough initial angle of descent, a reentry trajectory with

one or more skips may be produced. As the vehicle begins to reenter, it reaches a

minimum altitude where it begins to "pull-up" due to the lift force dominating over

gravity. Eventually, the vehicle will exit the atmosphere at a reduced velocity. If the

exit ielocity and flight path angle are correctly controlled, the vehicle will achieve a brief

orbital phase followed by a second reentry d***range from the first.

Edited April 1, 2014 by Kasuha

[Corw]

All that I'm finding about skip reentry indicates active guidance and lift control. Skips are controlled and planned. So it seams to indicate distinction between skip reentry and multiple aerobreakings.

Another reference here:

Managing energy and mode transitions in skip entry guidance for lunar return trajectories

Page 62

Once the drag reaches 0.05 g's Initaial Roll performs a test to determine if the current velocity and flight path angle indicate a shallow entry. If the entry is too shallow, full lift down is commanded to steepen the rntry. Otherwise, guidance commands full lift up.

[Corw]

Again, the slight hint is in the first wiki reference, the picture clearly shows pull up manoeuvre. What else but lift can make you pull up on command?

Edit: if there is no pull up, it is not a skip but a graze. So multiple aerobrake is clearly not same as skip reentry

Edited April 1, 2014 by Corw

[Corw]

Now thank you very much for needed distraction. The update is out and I have some asteroids to catch. Oh yeeeah.

[Rakaydos]

I thought the difference between a skip and an aerobreak was whether your skip's apoapsis was over the atmosphere on not. If it goes out, it's an aerobreak, if you start coming back up, but stop within the atmpsphere it's a skip.

[Kasuha]

Okay, for what I have found:

Skip trajectory, or "skipping off the atmosphere" does not have to involve lift. Too shalow entry (relative to speed) is sufficient.

When skip is planned as part of the reentry, it always involves control using lift. Uncontrolled skip reentry is too unpredictable in final landing site to be of any use. So probes and spaceships unable of controlled reentry always use ballistic reentry.

[Corw]

Okay, for what I have found:

Skip trajectory, or "skipping off the atmosphere" does not have to involve lift. Too shalow entry (relative to speed) is sufficient.

When skip is planned as part of the reentry, it always involves control using lift. Uncontrolled skip reentry is too unpredictable in final landing site to be of any use. So probes and spaceships unable of controlled reentry always use ballistic reentry.

OK, that sounds reasonable.

[Thogapotomus]

Okay, for what I have found:

Skip trajectory, or "skipping off the atmosphere" does not have to involve lift. Too shalow entry (relative to speed) is sufficient.

When skip is planned as part of the reentry, it always involves control using lift. Uncontrolled skip reentry is too unpredictable in final landing site to be of any use. So probes and spaceships unable of controlled reentry always use ballistic reentry.

While technically what the OP did can be considered a skip, I personally wouldn't call it that. I'd consider a skip as the atmosphere pushing or deflecting the object back into space. What the OP did was the equivalent of just giving the atmosphere the finger and plowing right through it. He/she was slowed down enough that the orbit was suborbital , but I'm guessing the trajectory wasn't altered much by deflection, but just drag itself.

Just my opinion/preference though, obviously. It's kind of like at what point does a pond become a lake? There's technically a set point, but what you'd call the body of water without knowing would come down to preference.

[MedwedianPresident]

Sorry i meant Periapsis not Apoapsis.

Periapsis in atmo after maneuver = Skip reentry

Periapsis out of atmo after maneuver = Aerobraking

Anyways, why should we be here right now? We are supposed to be playing around with ARM right now!

[BlazeFallow]

Somehow I visualize a skip maneuver to be such:

Say you have an Ap of 80km, you dip your Pe to 30km and are gliding towards it. As you approach you craft begins to aerobrake, causing your Ap to dip down tot he point where your Ap and Pe swap places on your orbital track. Generally in aerobraking such as this, your new AP stays behind you as you continue in a suborbital/ballistic trajectory down to the surface. In a Skip maneauver however, do to aerodynamic forces or inertia or whatever really, your Ap moves from behind your craft to in front of it again so that you are indeed flying back in an upward direction, but still on a parabolic flight path down to the surface. That last part is the important one to me at least. Because if you just pass through the upper atmosphere and reduce your Ap, but your Ap and Pe never swap places, then that (again to me) just means it's an aerobrake, and not skipping along the atmosphere.

Maybe what I say makes sense to the others here as well?

[karolus10]

Controlled reentry is not possible at the moment as blunt bodies (hull, heat shield, and so on) doesn't generate lift, without this it's only uncontrolled areobreaking.

[Kasuha]

Controlled reentry is not possible at the moment as blunt bodies (hull, heat shield, and so on) doesn't generate lift, without this it's only uncontrolled areobreaking.

Controlled reentry is possible with spaceplanes even using stock aerodynamics. I had hands-on experience with that during my mission to Laythe which in fact ended in what even the greatest purists here cannot deny was a skip reentry. In the end I did set my periapsis to a reasonable value and then steered it using pitch. Without pitching upwards, it would dip and fall to the ocean.

Regarding skip reentry in KSP, though, I think there is no reason to be such purist. KSP does not share many restrictions of real world. If you pass through the atmosphere and then either continue towards some other body, or raise the periapsis to keep the ship in orbit, it is aerobraking. If you continue hitting the atmosphere till the ship lands, we can pretty well call it skip reentry in my opinion because the purpose here is to slow the ship down gradually or to deliver it to a different place which are the two purposes of skip reentry in real world as well.