Reentry guidance control unit (RGCU)

[Gameslinx]

The only reason I'm suggesting this is for newer players or those inexperienced with reentry. Although it may be more suitable as a mod, I feel like the main game lacks in the reentry and safety aspect of the game. The reason being because most reentries and done by computer with little input from the crew.

So what does the RGCU do? Well, it is like a second SAS module. You activate it either through staging or right clicking it. It prioritises the crew pod, then parachutes, then scientific experiments in the course of reentry. What it will try to do is if a part is heating up rapidly, it will then turn the craft accordingly to protect it.

If another part exceeds the temperature of the first, it will spin the craft to accommodate for both overheating parts. If one of them explodes, it will protect the part which isn't.

If nearly everything is overheating, it will force the craft into a prograde or radial outwards roll to distribute heat evenly whilst keeping a large surface area to slow down in the atmosphere.

This module can be toggled on and off, and uses electricity.

What are your thoughts?

Edited February 11, 2017 by Gamel0rd1

[John FX]

Sounds good, I think the functions could be built into the pod though, no need for an extra part which new players would probably not fit if they are that new.

[Snark]

Gotta say I'm not a big fan of the idea myself, for a few reasons.

Problem #1:  Suspension of disbelief.  I have trouble swallowing it, since I don't think that any real spaceship ever does anything like this, at all.  They're designed to enter at a certain orientation and maintain that orientation, and that's what they do.  They're designed so that when they're in that orientation, they're fine, which means that no such system is necessary.

Problem #2:  Not really necessary.  KSP already has a mechanism for this:  design the ship to be able to handle reentry.  Skilled players can get really fancy with it.  Newbie players can just do the simple thing, which is what every single IRL spaceship except the space shuttle does:  stick a heat shield on the front, and design the ship so that it's aerodynamically stable with the heat shield facing forward.  Problem solved.

Problem #3:  Difficult to even make it work.  A ship in reentry tends to be very strongly controlled by aerodynamic stability.  Chances are good that even if you had such a system, it won't actually have the physical ability to turn the ship in a way that does any good, because there's simply not enough control authority available.  Yes, it's possible for a skilled player to design a ship that has the ability to steer and orient itself even during reentry... but if they have that much skill, they also have enough skill that they don't need this thing anyway.

Problem #4:  I have trouble seeing how it would actually be all that helpful.  KSP does a pretty good job of warning "this thing is overheating!" well in advance of it going kaboom.  If you just watch the ship, and see something overheating, and steer that thing away from the blowtorch... how is that hard?

Maybe this might be an interesting idea for a mod or something, but it really seems like a stretch to me to have it in stock-- especially given the finite development resources at Squad.  Personally, I think their time would be better spent elsewhere.

[Gaarst]

Not needed.

New KSP players don't go out of the Kerbin system, and a quarter of a heatshield is more than enough to reenter from anywhere in the Kerbin system, except when building spaceplanes but new players don't build spaceplanes.
More experienced KSP players need more heat management but they are experienced, so they can deal with it.

[luizopiloto]

It's not hard to design heat resistant crafts... cargo bays, utility bays, heat shields, structural panels, radiators... there are plenty of parts that can be used if used the right way...

[paulprogart]

The process of figuring all that stuff out is supposed to be part of the fun!  That's why it's Kerbal Space Program and not Human Space Program:  so players can try stuff without feeling like it has to be perfect the first time, fail at it miserably, and try again.

Besides, If that's not someone's particular fancy or if it gets too frustrating, then they're probably gonna search for tutorials or mods or something anyhow.

Maybe it'd be a useful RO mod, but stock game?  Nah.

 

[monstah]

I can easily imagine a craft attempting to change its orientation mid-reentry and ending up flipping all over the place...  

[Jollyrodger22]

On ‎2‎/‎11‎/‎2017 at 5:00 AM, Gamel0rd1 said:

The only reason I'm suggesting this is for newer players or those inexperienced with reentry. Although it may be more suitable as a mod, I feel like the main game lacks in the reentry and safety aspect of the game. The reason being because most reentries and done by computer with little input from the crew.

So what does the RGCU do? Well, it is like a second SAS module. You activate it either through staging or right clicking it. It prioritises the crew pod, then parachutes, then scientific experiments in the course of reentry. What it will try to do is if a part is heating up rapidly, it will then turn the craft accordingly to protect it.

If another part exceeds the temperature of the first, it will spin the craft to accommodate for both overheating parts. If one of them explodes, it will protect the part which isn't.

If nearly everything is overheating, it will force the craft into a prograde or radial outwards roll to distribute heat evenly whilst keeping a large surface area to slow down in the atmosphere.

This module can be toggled on and off, and uses electricity.

What are your thoughts?

Well this is already in the game just stick a heat shield o it and set the thing to retrograde bit nooby but I'm new

[eagle92lightning]

On 2/13/2017 at 5:51 PM, Gaarst said:

Not needed.

New KSP players don't go out of the Kerbin system, and a quarter of a heatshield is more than enough to reenter from anywhere in the Kerbin system, except when building spaceplanes but new players don't build spaceplanes.
More experienced KSP players need more heat management but they are experienced, so they can deal with it.

I am and I don't think I have even logged 100 hours.

[EnderKid2]

What it should really do is predict landing point.

[natsirt721]

1 minute ago, EnderKid2 said:

What it should really do is predict landing point.

There's a mod for that! I don't know which (FAR?) but I have seen surface landing predictions in some screenshots here.

 

[Yaivenov]

Snark's points 1 and 3 are wrong.

 

Edited February 19, 2017 by Yaivenov
Forgot a link.

[natsirt721]

13 minutes ago, Yaivenov said:

Snark's points 1 and 3 are wrong.

I believe Snark (and the OP) was referring to a shuttle-esque spacecraft, not an Apollo reentry capsule. Two totally different control problems.

[Yaivenov]

Does not matter if capsule or plane type. Both make maneuvers during reentry to control their landing points, something Snark stated very explicitly (and wrongly) can't/isn't done.

[Tex_NL]

55 minutes ago, Yaivenov said:

Snark's points 1 and 3 are wrong.

No, they are not. They are spot on!

Since you're referring to the Apollo I'll stick to that too. The capsule was designed to be aerodynamically stable in the shield-first position. Even if they would for some reason turn sideways it would revert back to the shield-first orientation. And that is exactly what @Snark is saying.
They ONLY control ability Apollo had on re-entry was a bit of roll. The asymmetric weight distribution and aerodynamic pressure then did the rest to make minor course corrections. It did NOT have the pysical ability to drastically change its orientation just as @Snark said.

Please explain in more detail why you think he's wrong.
Oh wait. You can't. Because he was 100% right.

Edited February 19, 2017 by Tex_NL

[Tex_NL]

37 minutes ago, Yaivenov said:

Does not matter if capsule or plane type. Both make maneuvers during reentry to control their landing points, something Snark stated very explicitly (and wrongly) can't/isn't done.

There is a huge difference between making tiny coarse corrections and drastically changing your orientation.

Take an airplane for example. Nobody will disagree it can change its course to make a pinpoint landing. But it does so by making tiny movements with flaps, ailerons and other control surfaces. What it CAN NOT do is turn sideways to 'reduce the load' on one of the wings. It is not 'physically capable' to make such a manoeuvre. And even if it did it would revert back to a nose-first orientation due to its aerodynamic design. As long as it did not enter a complete stall of course. But even then, given enough time, it will naturally try to find an aerodynamically 'stable' orientation.

Edited February 19, 2017 by Tex_NL

[Snark]

FWIW, it's also worth noting that talking about controlling your landing point and doing course correction is completely irrelevant to this discussion.

Go back and take another look at the OP. There's nothing there at all about guidance, or steering, or caring at all about where the ship ends up landing.

The only thing the OP is talking about is having a system to try to orient the craft to protect individual components in automatic fashion from overheating.

That's what the OP is asking for, and that's what I directed my comments at, and any discussion of steering or course correction is a completely different topic and irrelevant to that discussion.

That's not to say that steering and course correction are irrelevant or useless. Certainly KSP players care where they land, and certainly that's hard to predict, so that's a valid pain point that may be worth discussing.

All I'm saying is that that's not at all what the OP was asking; that's not what I was addressing in any of my previous posts in this thread. Apples and oranges.

8 hours ago, Yaivenov said:

Snark's points 1 and 3 are wrong.

Since Apollo didn't actually do anything even remotely like what the OP is asking for, my original comments still stand.  Again:  Note that this discussion isn't about "Have some kind of guidance in case you care about reentry trajectory for any reasons".  (Because Apollo did have to care about reentry trajectory and attitude.  A lot.)

Rather, this discussion is about what the OP asked for:  "have a system that monitors the temperature of individual bits of the spacecraft, detects when an individual piece is in danger of overheating, and rotates that piece away form the airstream to save it."  Not only didn't Apollo have a system like that, it's also the case that they absolutely wouldn't have put such a system on, because it would have killed them.

Lengthy rant in spoiler section.

Spoiler

The reentry procedure for Apollo capsules was far less forgiving than KSP.  KSP reentry is easy.  Apollo reentry was a nail-biter, for  a couple of reasons.

First, they were hitting atmosphere at a much higher speed than happens in KSP (since they weren't working with a toy planet at 1/10 Earth scale, with correspondingly higher orbital speeds), and dealing with real materials (which have many, many ways in which they can fail under thermal load, unlike KSP which vastly simplifies it-- as it should, since it's a game and needs to be playable).  That means that it would be really easy to catastrophically overheat the whole craft and explode if they don't maintain exactly the right attitude to the incoming airstream.

Furthermore, they had to care a lot about hitting exactly the right angle of descent.  On the one hand, going too steeply would have overwhelmed the heat shield and fried the ship.  On the other hand, I'm pretty sure they were going quite a bit faster than escape velocity when they hit atmosphere, which means if they were too shallow, they wouldn't aerobrake enough and would go flying off into interplanetary space, to their doom.  And the margin between "too steep" and "too shallow" was razor-thin.  KSP does model this quandary, somewhat-- it does have that game feature where, if you're going too fast and dive too steeply into atmosphere, you can explode even if you have a heat shield.  But KSP is so incredibly forgiving, with such a giant, wide, easily-targeted-and-hard-to-mess-up margin between "too steep" and "too shallow" (for heat-shielded craft), that it's basically a non-issue.  "Set Pe to approximately 30 km, give or take several kilometers; hold retrograde; stage parachutes; and get a cup of tea while you wait for it to successfully land" is about all a KSP player needs to worry about for such a reentry.

That means that Apollo had to care about precisely how the craft is oriented during reentry, in order to balance overall thermal load against overall atmospheric drag.  That attitude and descent profile was precisely calculated and worked out by the scientists and engineers who built the spacecraft, before it ever launched.

If Apollo had had a piece of equipment like the OP describes-- "Oh noes, there's a science instrument that's overheating, and that costs many thousands of dollars and we don't want to lose it!  Quick, rotate the capsule so the science instrument is protected!" -- it almost certainly would have messed up that razor's-edge descent profile and killed the whole crew.

 

[Yaivenov]

Thank you for clarifying, Snark. Your original points came across as stating that ballistic reentry was the only reentry as opposed to controlled flight.

As to the OP's rotisserie idea: while pointless for reentry a slow constant rotation was used to evenly warm the CSM in space. This game mechanic is already partially implemented via Persistent Rotation (mod, keeps craft spinning during time warp) and just needs a thermal mechanic to benefit from it.

Edited February 19, 2017 by Yaivenov
Typo