Air is lava!

[Altaïr]

Now that reentry is out, going, and above all returning from Mars or Venus is a new challenge, as the atmosphere can now burn your return ship to death.

While working on a design I am testing on Earth, I thought... Why not making a challenge of it? So here it is!

The challenge for you is to build a ship, send it in LEO, then make it reenter and land safely on Earth. From there, the ship must be able to fly again by itself.

Obviously, you'll have to find a way to allow your ship to survive reentry. It doesn't matter if you break things or let some parts burn, all that matters is that the ship has to fly again once it landed, even if it's just for a small hop. Of course, the further you can go, the better.

The ship can be a rocket, a shuttle, you can coat it entirely with heat shields... This is up to you, you are totally free to design it as you wish.

Good luck!

 

[Mars Pathfinder]

Go fly - fire it up - land

Then refly it, nice

 

[Altaïr]

As usual, I'll do my own challenge myself first. So here is my rocket:


Reaching LEO is a formality at that point.


I'll even go higher for a spicier reentry:


Then, time for some reassembly:

The ship is protected by the main shield, the... umbrella on top of the ship is to make the upper part more resistive to keep the ship stable during reentry. Otherwise the ship flips back during reentry, and then Burn baby, burn!

Now the reentry itself:

Hot!

Hopefully, the design works, and I can land it safely:


It's a bit dirty, but it's ready to fly:

Not very far, but it will reach space a last time!

Now reentry again.

Even at that speed the shield is necessary.

And finally, landing:

 

[Mars Pathfinder]

So we can do a hop in 2nd flight then

Btw nice spicy flight

 

[Altaïr]

So we can do a hop in 2nd flight then

Btw nice spicy flight

Thanks!

Yes of course you can start with a modest objective, the same as I did. Personally I just see it as a step before attempting something more ambitious.

 

[Altaïr]

Let's add some spices! Now I'll land a Moon rocket:


First step is to make orbit this thing:


Let's make it orbit higher...

Better.

Time to assemble the umbrella:


Now I'm ready. This is gonna be hot!

Even for the heat shields, the heat load was very important, they were not far from burning

Now it's time to land this thing:

Perfect. I can smell burnt metal just by seeing the pictures.

Now it's time for the Moon mission:


Moon landing is done, now back to Earth for a second and last reentry:


Mission accomplished

 

[[____Negative_Space____]]

if it's worth doing, it's worth overdoing:

it would appear i have something stuck in the sky:

back to the mater at hand:

as Launchpad McQuack always says, "any landing you can walk away from is a good landing." so i'm callin' it good enough:

uh, Houston? we have a problem:

it didn't get that hot anyway:

 

[Altaïr]

Well done, even if it's totally overkill indeed. At that stage the braking/stabilizing mechanism is not an umbrella, it's a tennis court

 

[[____Negative_Space____]]

felt like two tennis courts.

 

[Junipurr]

Experiments with Umbrella stabilisers.

The basic chassis I used for my tests, Ideal stages, with added heat shield under stage two, landing gear, parachutes, Titan engines and mounting point on stage three for different stabilisers.



With each test, I took off at 45°, emptied stage one, and attempted re-entry, aligning the rocket so at first the main heat shield took most of the damage. Then as things started getting really hot, I turned left slightly, to see if the rocket stabilised itself.

First test with no stabilisers, obviously it burnt up on re-entry because with no stability, the side of the rocket just burnt up immediately.



Second test, Normal umbrella stabilisers, they worked well, the rocket actually slowly straightened itself.



Third test, Vertical Stabalisers, fail, the structural part burnt first.



Next, Double Vertical Stabilisers, fail, same problem.



Next, Tripple Vertical Stabalisers, to try and protect the structural parts above, fail.



Next, shortening Horizontal Stabalisers, to show that mounting them Vertically provides no stability, success.



I really wanted to find a way of giving the re-entry rocket stability, without an umbrella style thing at the top. Turns out the umbrella doesn't need to be very wide, it just needs to be at the top, since the drag tilts the rocket straight again.

 

[Junipurr]

Challenge completed. Heavily modified Ideal stages with extra tanks and engines, for Earth - LEO - Earth - Moon - Earth.



Phase one: Earth - LEO - Earth



Phase two: Earth - Moon - Earth



Mission Logs

 

[Junipurr]

Re: Umbrella Stabilisers...

This arrangement is light and generates more stability, because it is further forwards, unfortunately it decreases the usable length of the rocket, unless your capsule is not needing to be at the very top. Maybe I can make a better Venus Lander now, with this feature.

 

[Altaïr]

Ah, well done!

I made another experiment myself, until now all my reentry vehicles had a capsule so they were assisted in stability. I wondered if a non-assisted vehicle would remain stable, so I made the test:


After reaching orbit, I assemble the umbrella as usual:


Then go for reentry. Just before entering the atmosphere I orient the vehicle as suited, and the probe is separated:


Now this vehicle is uncontrollable, if something goes wrong there's nothing I can do to save it!

But it behaves surprisingly well, the vehicle is very stable by itself.

Until obviously...


At least it shows that such a vehicle is intrinsically stable, which is a huge advantage to survive reentry.

 

[Junipurr]

I love your two stage Umbrella, how the bottom one protects the structure for the upper one. Unfortunately I rarely BP edit, too much effort, and my new device isn't root enabled yet. I also noticed flying my various rockets, that if the bottom tank is mostly empty, it makes the front heavier, reducing re-entry stability. I haven't tested it yet, but I suspect having a bigger main heat shield at the bottom makes things more unstable too.

 

[Altaïr]

I love your two stage Umbrella, how the bottom one protects the structure for the upper one. Unfortunately I rarely BP edit, too much effort, and my new device isn't root enabled yet.

Thanks
The purpose of those side protections are to protect the upper part of the launcher indeed: I had some trouble previously if the launcher wasn't oriented exactly opposite to the air flow. That was to give some margin.

In terms of bp edit that was quite simple, I just edited a shield and a fuselage, then I placed them as usual and the symmetry did the rest

I haven't tested it yet, but I suspect having a bigger main heat shield at the bottom makes things more unstable too.

That's quite logical actually. If the force is exerted below the center of mass it will destabilize the rocket, but if on the contrary it's applied above the center of mass it will stabilize it. That's why the umbrella works, and that's why Space X puts the grid fins on the upper part of the first stage too.

Even before the reentry update I toyed a lot with this, I always favored passive stability. I'm glad I made that choice today.

 

[Junipurr]

This may be a little off topic, but I used this new information to land on Venus easily. Tall four stage to boot.

 

[Junipurr]

That's quite logical actually. If the force is exerted below the center of mass it will destabilize the rocket, but if on the contrary it's applied above the center of mass it will stabilize it. That's why the umbrella works, and that's why Space X puts the grid fins on the upper part of the first stage too.

Even before the reentry update I toyed a lot with this, I always favored passive stability. I'm glad I made that choice today.

Big layered Heat Shield, very unstable, massive failure, pretty flames though.

 

[Altaïr]

This may be a little off topic, but I used this new information to land on Venus easily. Tall four stage to boot.

View attachment 76661

That was actually my goal. Well, you beat me to it.

 

[Deepspacegod]

Almost made a second reentry! But it flipped and my parachute broke

 

[Altaïr]

Almost made a second reentry! But it flipped and my parachute broke

Well tried
That's the reason why I deploy that sort of umbrella on my ships, it makes it stable during reentry.

 

[Deepspacegod]

Well tried
That's the reason why I deploy that sort of umbrella on my ships, it makes it stable during reentry.

Ya I designed my granny1 mar lander like that, I designed this one for max rocket efficiency after reentry