Add heatshield requirement for early uncrewed orbital and sub-orbital reentry contracts

[ezsnackeur]

No more cheesing the reentry using a large fairing with high stringer mass

[ezsnackeur]

the part check doesnt work for the mercury heatshield but it works fine for the adjustable one, any pointers?
the mercury shield check could also be removed i guess.

[ec429]

Would this also break using lifting RVs (i.e. unmanned spaceplanes)? I feel like if you can make one of those work it should be allowed.

[ezsnackeur]

It would break them but if a check for b9 spaceplane wings is implemented it opens the possibility to just add a minuscule one to pass it, defeating the point of the PR of forcing heatshield tech.
Tbf the other way around is true as well, an umanned spaceplane can have a small heatsink just to pass the check, so maybe the PR is fine as is.

[Clayell]

Perhaps a more robust way to do this could be to detect if the part has the ablator resource. (although obv that wouldn't detect heat sinks, but you could keep the part check for procedural heat shields)

[Capkirk123]

I agree that this is too restrictive, there's various probably valid ways to complete this program without heat shields

[ezsnackeur]

Do you mean that its intended for the contract to be completed with a retro burn or that it should include spaceplanes in the requirements? if so then i guess i can just add the requirement for b9 spaceplane wings as an alternative to a heatshield.
While still cheesable at least the contract would be hard locked between one of these 2 costly nodes

[Clayell]

I should note that test_account specifically pointed this problem out in the "Lessons learned" thread for RIS 2024.

2. Two first orbital return contracts in Crewed Orbit program can be completed before researching EDL and/or not using heatshields on the vessel. That is not right, not because it's physically impossible, but because the space program does these contracts specifically to test the new heatshield technology. There should be a contract requirement to have a heatshield on the vessel.

Additional discussion:
https://discord.com/channels/319857228905447436/1295137142762242139/1313441866628468746
https://discord.com/channels/319857228905447436/1295137142762242139/1313389131979689994

I agree with his point that the program is meant specifically for these heatshields and therefore these contracts should require them.

[Capkirk123]

Fair enough I suppose. Does this work with Vostok? It doesn't appear to check

[ezsnackeur]

No? this is an uncrewed contract, its required that theres no crew on board, i dont think you should expect anyone to try to complete this with an empty Vostok, if anything it could have an alternative check for B9 spaceplane wings to allow completion with a drone spaceplane.
Maybe someone would like to use the camera version of Vostok tho, so there could be a check for that one.

also this:

the part check doesnt work for the mercury heatshield but it works fine for the adjustable one, any pointers?
the mercury shield check could also be removed i guess.

[uriyuzhui]

The heatshield requirement was kinda explicitly removed by NK in 15fdf4d between v3.0.0.2 and v3.1.1.0
I would suggest we settle down as-is and stop imagining "these contracts are for heatshield testing" which came from nowhere.

[ezsnackeur]

That got removed because it wouldn't show up in the contract list with those requirements unless you had researched the tech.

[TwistedGiraffe]

I assume we can gate the return contracts after a dummy contract that asks for the heat shield tech node, so the player knows what's going on and avoid the fairing exploit.

We can also gate early lunar contracts after a dummy contract that asks for mission control and tracking center upgrades to avoid Principia bypassing maneuver nodes if necessary.

[ezsnackeur]

then you have the same problem where you cant see the contract unless you satisfy the requirements

[TwistedGiraffe]

Here is what I meant:

• Dummy contract: Unlock heat shield technology:
  • Unlock requirement (to have the contract show up in mission control): Nothing except having the relevant program activated. So it is always visible.
  • Contract goal (to complete the contract): Unlock the early EDL tech node.
• Real contract: Sub-orbital / Orbital return:
  • Unlock requirement: Unlock the early EDL tech node
  • Contract goal: have a heat shield on the craft AND return from 6500+ m/s or 200 km orbit

[uriyuzhui]

Lets ask ChatGPT and see what it says :P

1. Spacecraft recovery wasn’t always about ablative heatshields

Historically, not every spacecraft recovery used a dedicated “heatshield” part.
Vostok (1961): The capsule had a spherical design with distributed heating resistance. Yuri Gagarin actually ejected before landing; the craft itself wasn’t fully dependent on ablative shields in the way Mercury was.

Voskhod and later Soyuz had robust but integrated heat protection — not separate bolt-on “shields.”
Some experimental vehicles (like the U.S. ASSET lifting-body tests in the 1960s) relied on heat-resistant materials (reinforced carbon, refractory metals) rather than ablative shields.

👉 Requiring only a "heatshield part" ignores the fact that many different design philosophies existed historically. Using “thick metal shells” or heat-resistant fairings is actually in line with some real-world experiments.

2. Ablative shields are not the only valid engineering solution

A key part of player creativity is finding ways to survive reentry.

The Space Shuttle (1981–2011) used reusable silica tiles and reinforced carbon-carbon, not ablatives.
X-37B and modern spaceplanes follow the same path.
Even early Soviet R&D explored metallic thermal protection systems.

👉 If your forces heatshields as the only solution, it erases valid alternate pathways that are both fun and historically accurate.

3. Contracts should test outcomes, not parts

A real space program didn’t say “you must use a heatshield part.” They said: “Survive reentry with crew/science intact.”

In gameplay terms, it’s better to test the result (safe recovery) rather than a specific part.

If players can find a clever but mass-inefficient way (like thick fairings), that’s an engineering tradeoff — heavier rockets, less payload. That’s self-balancing without needing artificial restrictions.

4. Heatshield use was often discovered by necessity, not mandate

The U.S. learned through research that ablation was effective — but it wasn’t an obvious predetermined step. There were competing concepts (metallic radiative shields, inflatable shields, skip reentry, etc.).

By mandating a heatshield part, you’re saying “this was the only way history could have gone,” when in reality spaceflight history is full of competing concepts.

5. Player freedom mirrors real engineering creativity

If a player wants to strap 20 tons of tungsten to survive reentry, that’s a “valid but impractical” approach. Real engineers often tried wild things before settling on standards.

Removing that freedom makes the game feel less like a sandbox and more like a checklist.

Good design lets players discover why ablatives are superior (lighter, efficient), not forces them to use them.

I particularly agree to this line Removing that freedom makes the game feel less like a sandbox and more like a checklist tbh

[Capkirk123]

Lets ask ChatGPT and see what it says

Let's not. Most of that is nonsense or just plain wrong.

I agree that this contract (and RP-1 as a whole) should allow player freedom in finding a solution. I'll look into seeing if decreasing fairing temperature limits is viable instead od mandating heat shields, although that does still leave very aggressive retro-braking I suppose.

[NovemberOrWhatever]

I'll add that the point is to test the viability of heatshields for reentry of a crewed spacecraft (or, IRL, a nuclear warhead). Putting a heavy fairing around it is a perfectly viable option for returning a small payload and seems fairly realistic, but it's not exactly something that'd be practical for returning a crew capsule from orbit, and so doing that wouldn't actually be accomplishing the point of the contract. Also, yeah, an LLM-style noise generator is, as usual, not useful

[uriyuzhui]

Putting a heavy fairing around it is a perfectly viable option for returning a small payload and seems fairly realistic, but it's not exactly something that'd be practical for returning a crew capsule from orbit

The reach orbit velocity and return is also in EOS program and for film pod recovery, but yeah if it's the volume/mass of recovery makes the difference could we add a sounding payload requirement to the contract? 2000 sounding payload weights 1.32t, nicely simulating a crewed capsule.

[ezsnackeur]

1.32t needs 700kg of heatsink, to be lifted with 56-57 tech, are you out lf your mind?