How to re-enter at KSC

[TheCanadianVendingMachine]

As the title says, I need to know how to re-enter so I land roughly at the KSC runway

- Where should I aim?

- When should I burn?

Thanks!

[lajoswinkler]

That depends on so many factors it's impossible to say when and where.

[TheCanadianVendingMachine]

Alright, I shall add something. How to re enter from 70 - 75 km

[ThinkOutsideTheHangar]

Burn retrograde as you come up behind the KSC in orbit. It depends when you should do it, but trust your gut. It will get you somewhere near it.

[DeMatt]

Conveniently, there is a thread on precision Kerbin reentry landings, located right in the Tutorials section of this forum.

[Guest]

Put something on the launch pad to give you something to aim at. Then it's trial and error.

[mcirish3]

Here are some things to think about when re-entering Kerbin Atmosphere. Altitude, Orbital angle from the equatorial, Kerbin's Rotation, Ship mass. All of these things are factors in returning from orbit. ship mass only matters in an atmosphere deorbit. I find that about 500 km orbit is easier to gauge than a 70-75 km orbit. Perhaps practice from that height first. If you go too high the rotation become too strong of a factor, and if you have a low orbit the angle into the Atmosphere gets harder to judge. Just my thought any way.

[Tank Buddy]

Lower your Pe to ~30 Km over the large peninsula to the east of KSC. That does the trick from LKO.

[Tada]

I use that when you are on the opposite side of Kerbin. Or you can burn for that small island close to KSC when flying over the desert.

[Padishar]

I assume you mean for a conventional rocket/lander type of vessel. A plane (unless it is a glider or out of fuel) can be quite sloppy as it should be able to fly a considerable distance once in the atmosphere.

If you use Kerbal Engineer (or something else that gives a deltaV readout) then you can set up a de-orbit burn node using an appropriate amount of deltaV and then move it on the orbit until it comes down a bit past your target. You have to account for both the slow down in the atmosphere making you drop short and the rotation of the planet (also making you drop short for the usual eastward orbit but making you go long for an opposite orbit). You can (if your ship design allows and you don't mind exploiting the lack of re-entry simulation) also keep a reasonable amount of deltaV in reserve so that you can kill off your residual horizontal speed if you overshoot the target (after the atmosphere has done most of the braking for you) or compensate if it looks like you are falling short. Just have a quicksave ready and if you miss by further than you can compensate for then reload and move your deorbit burn a bit and try again. After a number of goes you should be able to judge how far you need to overshoot to only require minimal correction. If you don't have KER then you have to be more approximate with your deorbit burn but the principle is the same, aim to overshoot by enough to compensate for the drag slowing you down and the rotation of the planet. The rotation of the planet should be the same as it should always take (very nearly) the same time to cover the vertical distance to the ground but the drag will depend on how steep your re-entry is. A steep entry will be affected less than a shallow one so the more you burn the less you need to overshoot.

Edit: Doh! Multi-ninja'd. That'll teach me to go make a cuppa in the middle of writing a post.

[RSwordsman]

The things that get me are estimating the rotation of Kerbin while my ship de-orbits, and the amount of horizontal distance lost due to atmospheric drag. But I usually make a maneuver node placing me somewhere a few klicks off the coast of KSC, then do correction burns as needed if it looks like I'm over- or undershooting.

**The distance/dV of your maneuver node make a big difference when it comes to accounting for both of the above factors, but especially planetary rotation. The farther out and lower the dV requirement of the burn, the farther west you'll have to aim as the planet spins under your ship.

Edited February 7, 2014 by RSwordsman