Is Feather/Carefree Re-entry Possible in KSP?

[sp1989]

Burt Rutan's design of space ship one is truly genius. It allows the ship to float through the atmosphere like a feather without any thermal protection. In fact it is a composite craft which basically means its fabric and glue and it has proven it self as an effective suborbital ship ready to take passengers. As most of you might know Virgin Galactic has teamed up with Burts company and is using his design for the Virgin Galactic flights. Now my question is, using deadly reentry in specific, and whatever realism mods you like is it possible to recreate this in KSP? I am not asking for a mod (that would of course be wonderful) but is it possible to create a ship that can easily take off with limited drag, but have so much drag during reentry that no thermal protection is necessary? Now obviously KSP doesn't have reentry effects yet. However Using DR, is this possible? Im not talking about powered descent either, I am talking about sending a ship up on a sub orbital path and coming down safely without burning up and with no heat shield like Space Ship Once? Also I am not talking about getting lucky I am talking about slow reentry with very low temperatures. Remember the windows on SS1 are plastic and the ship is made almost entirely out of composite materials if it gets too hot it will melt. Thoughts?

[Superluminaut]

Space ship one is sub orbital. A KSP analogue wouldn't even reach 70km, just high enough to see stars. 35km ish? So its not that hard.

[Guest]

If I'm reading that right, that's basically how I do reentry with a spaceplane under FAR/DRE. Come into the atmosphere and continually dive/climb to slow down. It's a much easier method when flying by keyboard than doing S-turns, but it is highly inaccurate and can take you most of the way around the planet.

[sp1989]

If I'm reading that right, that's basically how I do reentry with a spaceplane under FAR/DRE. Come into the atmosphere and continually dive/climb to slow down. It's a much easier method when flying by keyboard than doing S-turns, but it is highly inaccurate and can take you most of the way around the planet.

Actually I am talking about going straight up and coming straight down. Space Ship One goes straight up and straight down. But because of the "feather" wings there is so much drag the ship can't go fast enough to create anywhere near the amount of heat generated during a typical reentry. The fastest the ship goes during reentry is a little more than mach 3. So a ship that goes basically just as high as the mercury redstone experiences very little to no heating allowing it to have no need for shielding.

[Superluminaut]

Actually I am talking about going straight up and coming straight down. Space Ship One goes straight up and straight down. But because of the "feather" wings there is so much drag the ship can't go fast enough to create anywhere near the amount of heat generated during a typical reentry. The fastest the ship goes during reentry is a little more than mach 3. So a ship that goes basically just as high as the mercury redstone experiences very little to no heating allowing it to have no need for shielding.

Actually mercury went about twice as high and twice as fast.

[sp1989]

Actually mercury went about twice as high and twice as fast.

Crap one site is in feet and on is in KM. Space ship one 380k/ft feet and Mercury 487KM. So now I feel dumb lol. However Im still not sure how to describe what I am looking for. Lets just say we could leave on a suborbital flight with a ksp version of Space Ship One. Would the reentry procedure work/would it be more than just an aesthetic movement of the wings. Would the ship create so much drag it wouldn't heat up.

[Superluminaut]

Crap one site is in feet and on is in KM. Space ship one 380k/ft feet and Mercury 487KM. So now I feel dumb lol. However Im still not sure how to describe what I am looking for. Lets just say we could leave on a suborbital flight with a ksp version of Space Ship One. Would the reentry procedure work/would it be more than just an aesthetic movement of the wings. Would the ship create so much drag it wouldn't heat up.

I'm not sure, I have never played with FAR or deadly reentry. You would also need some kind of moving parts mod.

It should work. If you build a space ship one replica the center of gravity is at the front, center of pressure is at the back, and you have that huge tail thing to help with supersonic flight. Scaling the numbers to match a KSP flight may be tricky.

You could start a challenge, max survivable velocity/altitude with a SS1 lookalike and SS1 functionality.

[Wanderfound]

Crap one site is in feet and on is in KM. Space ship one 380k/ft feet and Mercury 487KM. So now I feel dumb lol. However Im still not sure how to describe what I am looking for. Lets just say we could leave on a suborbital flight with a ksp version of Space Ship One. Would the reentry procedure work/would it be more than just an aesthetic movement of the wings. Would the ship create so much drag it wouldn't heat up.

Build some and find out, then let us see how it went.

[StrandedonEarth]

Actually, SS1 and SS2 have thermal protection, but the thermal loads are low enough that it mostly amounts to a special paint/coating. The feathering part is the movable wing assembly that moves into a configuration similar to a (badminton) shuttlecock, which aerodynamically keeps the ship in the ideal attitude for re-entry. This allows for a hands-free re-entry because all ship systems could be dead and it would still stay in the proper attitude, although the rest of the descent could be problematic in that case.

[sp1989]

I'm not sure, I have never played with FAR or deadly reentry. You would also need some kind of moving parts mod.

It should work. If you build a space ship one replica the center of gravity is at the front, center of pressure is at the back, and you have that huge tail thing to help with supersonic flight. Scaling the numbers to match a KSP flight may be tricky.

You could start a challenge, max survivable velocity/altitude with a SS1 lookalike and SS1 functionality.

Hahahaha like a Kprize?

[Kaa253]

I do my FAR/DRE reentry in much the same way as Regex describes above. If you keep the repetitive diving and climbing process going for long enough it is possible to reenter slowly and without generating any of the red atmospheric heating effects at all. My guess is that with FAR/DRE installed it should be possible to successfully fly a SpaceShipOne (or Two or Three) type flight profile with little or no heat shielding. I find that airbrakes (in B9 and Firespitter) are also useful.

[Wanderfound]

Each to their own, but I tend to the opposite approach: dive to 25,000m (adjust height for reentry speed), get level, aim for KSC and start doing S-turns when it's at 200km. It works once you get the hang of it. You only need a tiny amount of pitch; use trim or precision controls and ride the g-meter, not the navball.

[KerikBalm]

Why is it so hard to understand that as a suborbital craft, its going much much slower, and thus generates much less heat?

If you boosted Sace ship 1 to orbit, it would not survive reentry.

[merendel]

With standard DR setings you can prety much fly strait up to an 80km AP and then drop strait back down and be perfectly fine (baring unplaned lithobreaking) KSP might show some reentry flames but your not likely to have any parts even get close to overheating. The ship just wont have anywhere near the same amount of kenetic energy as something at orbital velocity.

[Hannu]

Many writers mentioned already, that orbital velocity is the key factor. I add some details. Kinetic energy is much more significant factor than potential energy, so we can neglect heights. Maximum speed of Space Ship one was 3,09 mach, which is about 1200 m/s. Re-entry speed of orbital spacecraft is at least about 7900 m/s. Kinetic energy per mass unit is proportional of velocity squared. Space ship one's kinetic energy per mass is 1/40 part of orbital spacecraft's energy. Therefore re-entry effects are very different and SpaceShipOne had very much easier conditions.

Proportions of aerodynamic effects and orbital velocity are different in KSP than in real world, but some kind of analogy is suborbital craft, which maximum velocity is 12/79 of low orbital velocity. That is about 500 m/s. There are not any significant re-entry effects in upper atmosphere on that speed even if you use Deadly Re-entry.

Virgin Galaxy uses technologies, which will not be suitable to orbital flights (in foreseeable future). If they would change their destination to that direction, they should make everything from beginning. Planes should be totally different (which means heavier). The performance of their special rocket engine technology is inadequate to orbital operations etc. It is suborbital tourism company, not satellite launch company.

[monophonic]

Virgin Galaxy uses technologies, which will not be suitable to orbital flights (in foreseeable future). If they would change their destination to that direction, they should make everything from beginning. Planes should be totally different (which means heavier). The performance of their special rocket engine technology is inadequate to orbital operations etc. It is suborbital tourism company, not satellite launch company.

Looks like they are changing their direction, or at least diversifying. Of course that includes some new, actually more like old technology as the LauncherOne SLV will have an RP-1/LOX engine.

[Red Iron Crown]

I don't think a ship can be made to feather its tails in stock KSP, you would need some sort of robotics mod to permit the moving parts.

Reading some of the replies, I'm not sure everyone is familiar with SS1's feathering system, it adjusts the angle of the tails for aerodynamic control while using the underside of the body for aerobraking. Presumably this spreads reentry heat over a larger area. Below is a picture of SS1 with the tails in reentry position:

Once it slows to an appropriate speed, the tails are moved back to the normal position for regular atmospheric flight and landing.

[StainX]

I had some hard time with FAR/DRE constantly overshooting/undershooting by far to much, so i started to experiment with huge airbrakes, which is working out pretty well.

So what i did is... put on some extra "Standard Control Surface" on top and bottom of my wings used as spoilers with positive value on top and negative on bottom, tadaaaaa... awesome airbrake.

Back to Topic, i never got a "Space Shuttle" like reentry with 40°AoA in KSP too , the maximum stable AoA i get out of my planes in mid/lower atmosphere is about 10°, maybe i just suck at spaceplanes anyway^^

[sp1989]

Lets revive this discussion. With the new 1.0 update will a virgin galactic type reentry be possible?

[Alshain]

You can definitely go straight up and straight down with little to no re-entry heat. It doesn't take as much speed to get suborbital as it does orbit. Therefore, there is less heat on a suborbital jaunt than coming in from orbit.

It's also possible to kill off your speed with engines before the heat gets too strong, but that is expensive fuel-wise.