Aggressive Aerobraking

[CFYL]

As we have made some rocket first stages land by, aggressive lithobraking, it's now time for us to adopt an aggressive aerobraking maneuver. 

In brief: land a craft on Eve, with no heat shields, radiators or TCS. That includes both ablative ones and inflatable one(s?). Stock parts only.

Rules:

Spoiler

1. General Rules: 

I. Purpose: Landing on Eve. From orbital speed.

II. Craft Building: No parts from the "thermal" category.

III. Orbital Flight: Any cheats or serious flying are allowed.

IV. Atmospheric Flight: No cheats. No autopilot. No Kraken Drive. Aerodynamic or heating exploits are, somehow fine here.

V. Settings: Default settings on, as of sandbox. Aside from that: Part G-force limits on. Part pressure limits on. Reentry heating at 100%(or higher if you like). Other settings are optional.

 

2. Mod Rules:

I. Purpose: Make it fair.

II. Craft Building: No mod parts.

III. Aerodynamic: FAR and stock aerodynamic model are accepted.

IV. Extra: DLCs, Graphics mods, Visual mods, Audio mods, Informative mods are not considered mods here.

Scoring:

Spoiler

#1. Velocity hitting atmosphere in km/s: Add points as this times 10. It’s hard to be accurate on this one, so a velocity taken between 90km and 100km ASL is fine. Faster is really harder. Beware of burning up.

#2. Lander mass in tons: Add points as this times 0.5. This is the mass that survived landing. Heavier is harder.

#3. No control: +20pts. This refers to no control input(with an exception), from entering atmosphere, to hitting the ground. Exception: staging with space bar. The intention is to award an aerodynamically-stable design.

#4. No chutes or wings: +20pts. Chutes are easy to understand. Wings refer to anything that is in "Aero" category, and generates lift in stock. Engines can be used but still getting this 20 points, as a powered landing on Eve is considered hard.

#5. Lose no parts during reentry: +20pts. This means that the entire craft that hits the atmosphere at 90km, finally lands intact.

Submission guide:

Spoiler

1. Preferably, include a KerbalX link for your vessel so we can see some details without your writing things. 

2. Provide some images or videos as proof, also with textual information to document your mission.

Leaderboards:

Spoiler

1. Stock parts, FAR

Spoiler

1. @AllenLi with an Entry that got: 65.3 points.

2. Pure stock

Spoiler

1. @ralanboyle with an Entry that got: 294.3 points, for a combination of craft from his previous entries. (Cargo plane carrying another massive glider).

2.  @king of nowhere with an Entry that got: 165.5 points,

3.  @ralanboyle with an Entry that got: 161.8 points. I am actually using pe speed calculated before, but a few m/s doesn’t matter anyways.

4.  @king of nowhere with an Entry that got: 74 points.

5.  @ralanboyle with an Entry that got: 70.8pts.

 

 

Feel free to submit your entries as always!

(This challenge is basically for creativity and craft building skill.)

 

Tips:

Spoiler

These are my own experience, and also some learned from participants. Some may not be correct, and you can always find better solutions.

General

1. Build really heat-resistant crafts. Cheat it to some sort of high orbit. Then (,with infinite fuel,)Burn radial in, prograde, radial in, prograde... After some time you can get insane speeds, and then boost points. WARNING: Excessive heating will be generated.

2. Sharp descent profile. Just make sure you don’t dive straight down... This reduces heat generation as you slows down faster, and the little increase of air density doesn’t matter compared to high speeds. Usually, even with exposed delicate probe cores, landing legs, or wheels, the craft is intact if you’re slower than 2000m/s, somewhere near 50km. WARNING: Sharp just mean pe at 20 or 10 for me. Or perhaps about 20 degrees down, when hitting the atmosphere.

FAR

1. Be draggy. Build things wide but short can have great drag and great stability.

2. Multiple layers of heat protection if needed. FAR would not calculate aero forces of anything inside a hollow shell that is closed up. No matter how you made it, fairing, cargo bay, or even home-made structural-panel fairing.

Stock Aerodynamics

1. Make a plane. A heavy glider that lands intact gains a significant sum of points. You just have to keep above 50km when over 2000m/s. Thanks to @ralanboyle for pointing out.

2. Exploit stock aerodynamics. Gently. Kraken drives are not supposed to used though.

 

Edited August 27, 2020 by AllenLi
OK. Comment on is a good option, but sometimes annoying if you’re on the other side of Eve. Rule changed to remove the “Require Signal For Control” rule.

[doggonemess]

This sounds pretty cool. I'm going to give it a shot.

I'm confused about one thing - scoring criteria 5:

5. Add points: Theoretical Orbital Speed at pe, before hitting the atmosphere: in km/s, add points as this times 100.

Wouldn't this number be incredibly high? As in, so high that the other scoring criteria are irrelevant? I'm probably misunderstand something here.

EDIT: I just looked again and I get it now. I was thinking meters per second - not km per second. Higher velocity at reentry would make your craft burn up a lot more easily, so it's worth way more points. Got it.

Thanks!

Edited August 19, 2020 by doggonemess

[EveMaster]

Is it allowed to use engines after entering the atmosphere?

[CFYL]

On 8/20/2020 at 2:06 AM, EveMaster said:

Is it allowed to use engines after entering the atmosphere?

Ah. Actually, No. I seemed to have forgotten that when writing rules... Thanks for pointing out.

Edited in the rules. 

Edited August 23, 2020 by AllenLi

[doggonemess]

One more question regarding criteria 4 - when you say 'turning on things' do you mean control surfaces, or any action at all? For instance, can I deploy airbrakes at some point during the descent? How about robotic parts?

[CFYL]

On 8/20/2020 at 4:06 AM, doggonemess said:

One more question regarding criteria 4 - when you say 'turning on things' do you mean control surfaces, or any action at all? For instance, can I deploy airbrakes at some point during the descent? How about robotic parts?

Just the space bar. Have then on in the editor, or... add the action group to “stage”(hazardous).

Edit: on second thoughts, I think it had better just be space bar staging. With no extra AG added.

Edited August 23, 2020 by AllenLi

[ralanboyle]

For rule 5, what if you have a negative pe when entering the atmosphere? 

[CFYL]

On 8/20/2020 at 11:08 PM, ralanboyle said:

For rule 5, what if you have a negative pe when entering the atmosphere? 

In orbital calculations, pe should be the distance to the planetary core. We will add Eve radius to that value.

Edited August 23, 2020 by AllenLi

[ralanboyle]

Okay, I don't understand your scoring so I'll let you figure out the numbers. Mine weighs 38tons. It has no parachutes and 7 experiments. My deorbit burn drops me from 100km to 80km. and it lands at 1537m. It doesn't lose any parts after entering the atmosphere. 

 

[CFYL]

On 8/21/2020 at 10:46 AM, ralanboyle said:

Okay, I don't understand your scoring so I'll let you figure out the numbers. Mine weighs 38tons. It has no parachutes and 7 experiments. My deorbit burn drops me from 100km to 80km. and it lands at 1537m. It doesn't lose any parts after entering the atmosphere. 

 

Congrats for finishing this mission!

Scores:

1, +100; 2, +200; 6, +153.7; 7, +21; 8, +3800(interesting); 

Criterion 5 calculation:

Spoiler

With your information, I assume you’re on a 100*80 km orbit above the ground. Which is actually 800*780. That is a 790km SMA. Orbital energy is -GMm/2r: Take GM/R^2 for the surface gravitational acceleration on Eve, which is 16.7m/s^2. R is 700,000m. r is 790,000m.Therefore, GM is 8.183e12. Hence -GMm/2r is -5,179,114m. Ep at pe is mgr, which equals m*(-GM/r^2)*780,000m, or -10,227,111m. Ek+Ep=E, so Ek is 5,047,997m. Ek=mv^2/2, so the velocity is 3177m/s.

Note: some of the “m” following numbers in this calculation resembles “meter”, while some others resemble the mass of your vessel, which doesn’t actually play a role in the calculation. I hope you could understand my badly-written calculations.

So we get 311.8 pts for that.

Take a sum of all points here, it’s an amazing 4570.5 pts. You didn’t give me your part count or KerbalX link, so I can’t do cut points for you. Please mention if you use FAR, or mod parts.

{I have no access to imgur so I can’t tell from pics if you included it. Pics can act as proof between you yourselves.}

BTW, I didn’t expect landing ships could be this heavy(mine was no more than a ton landed, but still under testing), so this seems to be overwhelming. I would keep it as of now, and here I ask opinions from the community, to tweak scoring to the majority’s needs.

The requirement of pe and eccentricity is actually because I wanted your SMA. eccentricity is because, that would be more convenient if you were on a escape orbit. pe is for calculating the exact velocity, and calculating your SMA with pe and eccentricity combined.

 

EDIT: Minus part count points, -31; deleted mass multiplier, -3800, so you actually get...

739.5 points. In full stock entry.

Edited August 23, 2020 by AllenLi

[ralanboyle]

6 hours ago, AllenLi said:

Congrats for finishing this mission!

Scores:

1, +100; 2, +200; 6, +153.7; 7, +21; 8, +3800(interesting); 

Okie dokie. Here is a kerbalx link.  It has 31 stock parts. I don't use part mods and I didn't change any physics. I have several graphics mods like EVE and Restock. I have several info mods like mechjeb and KER. Obviously I used Hyperedit to yeet over to Eve on this one. It does seem like you should lower the mass modifier on scoring since it makes the others obsolete. I don't think there is a real upper limit to the mass of a spaceplane that can be dropped on Eve as long as you can control the lift/drag and understand how. In a nut shell, one needs to stay above 50km until they are below 2000m/s. I may revisit this with a bigger plane... maybe. 

[CFYL]

31 minutes ago, ralanboyle said:

Okie dokie. Here is a kerbalx link.  It has 31 stock parts. I don't use part mods and I didn't change any physics. I have several graphics mods like EVE and Restock. I have several info mods like mechjeb and KER. Obviously I used Hyperedit to yeet over to Eve on this one. It does seem like you should lower the mass modifier on scoring since it makes the others obsolete. I don't think there is a real upper limit to the mass of a spaceplane that can be dropped on Eve as long as you can control the lift/drag and understand how. In a nut shell, one needs to stay above 50km until they are below 2000m/s. I may revisit this with a bigger plane... maybe. 

I understand this. Thank you for details, they will be updated. 

To be frank, I thought uploading a craft to KerbalX could be easier than manually writing things, like mods, parts, etc., but doing it “the old way” is always accepted. Thank you for taking part!

Maybe... if I deleted the mass for scoring...

Going to ask:

1. Delete mass multiplier(currently applied)

2. Make it no chutes and no planes.

Which would be better?

[ralanboyle]

Just now, AllenLi said:

Maybe... if I deleted the mass for scoring...

Going to ask:

1. Delete mass multiplier(currently applied)

2. Make it no chutes and no planes.

Which would be better?

Alright, it seems to me that deleting the mass component means the best place to make mad points is with orbital speed... This can be fun and different. You could keep the mass component and just make it about 1/10 of current (No doubt, heavier is harder when landing on Eve).

I don't personally like the idea of disallowing planes and chutes all together because it will limit the number of people who get involved (and so far its just me anyway). Instead, you could add an additional points qualifier for not being an space plane, but then you will have to define space plane...which might be hard. 

[CFYL]

On 8/21/2020 at 10:11 PM, ralanboyle said:

Okie dokie. Here is a kerbalx link.  It has 31 stock parts. I don't use part mods and I didn't change any physics. I have several graphics mods like EVE and Restock. I have several info mods like mechjeb and KER. Obviously I used Hyperedit to yeet over to Eve on this one. It does seem like you should lower the mass modifier on scoring since it makes the others obsolete. I don't think there is a real upper limit to the mass of a spaceplane that can be dropped on Eve as long as you can control the lift/drag and understand how. In a nut shell, one needs to stay above 50km until they are below 2000m/s. I may revisit this with a bigger plane... maybe. 

I re-calculated your points according to new rules:

31.8+19+20=70.8pts. 

I just wrote a new set of clearer, simpler rules and scoring. May we run this again! My own entry will come... soon...

[ralanboyle]

Alright, I did it again with a bigger ship. I did lose one part going down and didn't rerun it so i lost out on 20 points. I'll do it again if someone challenges my lead. 

At 260T, and a drop from 100KM AP to 80KM PE I figure its about 150 points. You tell me. 

 

[CFYL]

15 minutes ago, ralanboyle said:

Alright, I did it again with a bigger ship. I did lose one part going down and didn't rerun it so i lost out on 20 points. I'll do it again if someone challenges my lead. 

At 260T, and a drop from 100KM AP to 80KM PE I figure its about 150 points. You tell me. 

 

Your new scores have been put up, with actually 161.8 points.

Another great vessel you made!

[CFYL]

Going to post my own entry,

This craft goes down from low speed but high altitude. The orbit is like from the edge of Eve SOI, to a pe of 20km.

So I get 45 points for going down at 4500+ m/s, and the fairing almost overheated to explosion. I got to nervous looking at the red overheating bar at the left side that I forgot to take a screenshot. But I have a substitute for that:

That is the image I tested it the first time, from a 100*10 orbit. It slows down fast with FAR, and I had to physics warp 4* through the last 30,000m descent.

And here it lands with three chutes(which might be unnecessary), but without control. Only staged three times.

Lander weighs 0.775 tons, so I actually get no bonus for that. Just 0.3.

Points are: 45+0.3+20=65.3 points.

[king of nowhere]

this abomination managed it.

orbital speed 3.1 km/s, mass 5.5 tons, no chutes or wings (you said no parts under aerodinamics, those are all structural panels), lost no parts. if i counted correctly, that's 74 points.

i may want to improve on this design later.

[CFYL]

1 hour ago, king of nowhere said:

this abomination managed it.

orbital speed 3.1 km/s, mass 5.5 tons, no chutes or wings (you said no parts under aerodinamics, those are all structural panels), lost no parts. if i counted correctly, that's 74 points.

i may want to improve on this design later.

Congratulations for a successful craft! 

I suppose your craft is a plane based on FAR Behavior, then. (I can’t see imgur pics though)

Edited August 24, 2020 by AllenLi

[king of nowhere]

ok, i improved on the design

https://kerbalx.com/king_of_nowhere/cake-tray-no-parachute-lander

 

with this thing i took advantage of those structural tubes having higher thermal resistance than most other parts. i put them like a cake so that no single part would be fully exposed to the air blast.

i put it (with cheats) into a highly elliptical orbit to get more speed.

around 150 km of altitude i accelerated prograde to get even more speed. then a little antiradial burn to correct periapsis around 70 km, and then there's just time to jettison the engine before entering atmosphere at 5.1 km/s

finally the cake tray has slowed down enough. not it must be on land, as it will crash on water. if it's not on land, i must reload before the reentry and change slightly the periapsis until i can find land. in this case, it was a close thing

i retract all those cumbersome cooling and solar panels and i point the wheels downward.

i use the flat tray as an improvised wing to adjust a bit my trajectory and make sure i don't end up on water

i impact the ground at 27 m/s, the wheels survive.

51 points for speed

20 points for 40-ton lander

40 for no parachutes or aerodinamic parts and lost nothing (the engine was jettisoned before rentry)

111 points

 

I could certainly keep the design and make this thing bigger to score more points, and i could try to go a little bit faster, but i don't see the need to try.

 

P.S. I should win a prize for originality of design and name. perhaps a cake...

Edited August 24, 2020 by king of nowhere

[ralanboyle]

2 hours ago, king of nowhere said:

51 points for speed

20 points for 40-ton lander

40 for no parachutes or aerodinamic parts and lost nothing (the engine was jettisoned before rentry)

111 points

 

I could certainly keep the design and make this thing bigger to score more points, and i could try to go a little bit faster, but i don't see the need to try.

 

P.S. I should win a prize for originality of design and name. perhaps a cake...

You used thermo parts on descent.  

[king of nowhere]

52 minutes ago, ralanboyle said:

You used thermo parts on descent.  

...

i never stopped to think that the radiators are also thermal parts.

and they are not even needed; they don't help cooling down during reentry, i discovered. they don't even get warm.

do i have to make a new entry?

[CFYL]

5 hours ago, king of nowhere said:

...

i never stopped to think that the radiators are also thermal parts.

and they are not even needed; they don't help cooling down during reentry, i discovered. they don't even get warm.

do i have to make a new entry?

OK, remove the 8 foldingRadMeds from the craft, to get shown on the leaderboard. If it works without them, I guess we can download the craft, remove the radiators, and enter the atmosphere with similar conditions as you did. I don’t want to touch KSP for now though. 

Give that you said they “didn’t get warm”, I suppose they aren’t cooling down any parts. So I’ll put you in the list now, but it would be better if you could remove these parts and do it again.

10 hours ago, king of nowhere said:

ok, i improved on the design

https://kerbalx.com/king_of_nowhere/cake-tray-no-parachute-lander

 

with this thing i took advantage of those structural tubes having higher thermal resistance than most other parts. i put them like a cake so that no single part would be fully exposed to the air blast.

i put it (with cheats) into a highly elliptical orbit to get more speed.

around 150 km of altitude i accelerated prograde to get even more speed. then a little antiradial burn to correct periapsis around 70 km, and then there's just time to jettison the engine before entering atmosphere at 5.1 km/s

finally the cake tray has slowed down enough. not it must be on land, as it will crash on water. if it's not on land, i must reload before the reentry and change slightly the periapsis until i can find land. in this case, it was a close thing

i retract all those cumbersome cooling and solar panels and i point the wheels downward.

i use the flat tray as an improvised wing to adjust a bit my trajectory and make sure i don't end up on water

i impact the ground at 27 m/s, the wheels survive.

51 points for speed

20 points for 40-ton lander

40 for no parachutes or aerodinamic parts and lost nothing (the engine was jettisoned before rentry)

111 points

 

I could certainly keep the design and make this thing bigger to score more points, and i could try to go a little bit faster, but i don't see the need to try.

 

P.S. I should win a prize for originality of design and name. perhaps a cake...

Congrats for completing it with structural tubes! You get 111 points for now.

Oh yeah I guess I’ll get your first entry into the stock list then.

Spoiler

When I considered about using structural tubes, I found out that there was a problem... about what to put on top and bottom to seal it, so FAR don’t burn up my lander. Stock aerodynamics seems to work well now...

 

[king of nowhere]

well, since i had to rework, i decided to make a bigger version. i said the model could be scaled up at will, but there is one limit i overlooked, my CPU. i wanted to expand the original from 5x5 panels to 15x15 panels, but when i got to 11x11 and 790 parts the game already lags really badly, that's the most i can do without a bigger computer.

https://kerbalx.com/king_of_nowhere/bigger-cake-tray-no-parachute-lander

this time landing was a bit more complex because the craft exploded on freefall (except the first time i did it, when i tested if it had enough wheels to survive. that time it did not crash. it did crash all the times i tried in an actual reentry. probably i should have added a few more landing wheels). so i had to angle the surface a bit to use it as a wing and slow it down. those 5 m/s are enough to make the difference.

lander mass is now 149 tons, all else unchanged, i get 74.5 points for mass, total 165.5. looks like @ralanboyle will have to rerun his model.

Edited August 26, 2020 by king of nowhere

[CFYL]

1 hour ago, king of nowhere said:

well, since i had to rework, i decided to make a bigger version. i said the model could be scaled up at will, but there is one limit i overlooked, my CPU. i wanted to expand the original from 5x5 panels to 15x15 panels, but when i got to 11x11 and 790 parts the game already lags really badly, that's the most i can do without a bigger computer.

https://kerbalx.com/king_of_nowhere/bigger-cake-tray-no-parachute-lander

this time landing was a bit more complex because the craft exploded on freefall (except the first time i did it, when i tested if it had enough wheels to survive. that time it did not crash. it did crash all the times i tried in an actual reentry. probably i should have added a few more landing wheels). so i had to angle the surface a bit to use it as a wing and slow it down. those 5 m/s are enough to make the difference.

lander mass is now 149 tons, all else unchanged, i get 74.5 points for mass, total 165.5. looks like @ralanboyle will have to rerun his model.

Oh yeah! I replaced your old 111-point entry with this one. Looking great!

 

I am working on a design to... enter Eve atmosphere at insane speeds. Perhaps a bit over 20km/s I suppose. Meet you there on Eve surface.

Edited August 26, 2020 by AllenLi