The Incredible Double Mun Double Kerbin Landing Challenge

[Der Anfang]

On 8/19/2016 at 9:30 AM, Nefrums said:

this was a fun challenge!

not sure how this scores, but I think it is 1,8M points

 

 

Full album:

http://imgur.com/a/j1FzD

Okay, you came in at second place, points wise. However, your work is as equally impressive as ManEatingApe. You've certainly pushed the upper limits of this challenge. Thank you for your submission! (And sorry it took me so long to update the scoreboard.)

On 9/11/2016 at 4:04 PM, ManEatingApe said:

Jeb, Bill and Bob couldn't decide who should go on the mission. The debate was finally settled by breaking out a roll of duct tape and combining their crafts into one.

This resulted in a slightly unorthodox design just under the 50 ton threshold with an entire 133 kilos to spare for snacks!

Notes:

• The Communotrons protect the shock cones from exploding from heating past 1,300 m/s
• The double decoupler on the central rear stage takes advantage of the Rapier fuel flow rules so that all 3 Rapiers drain from this first and use the side stages next.

 

The lads made it to the Mun and back twice, and also threw in a trip to Minimus.

If I've read the OP correctly then that is 1000 base points + (3 * 50%) + (5 * 5%) + 20% + 30% = 3250 total

 

Flag planting snapshots:

    

 

Link to full Imgur album

You've hit first place. And indeed, your points calculation was correct. I'd have to say, I am speechless. 3 Kerbals is no easy feat for a lightweight entry. I'm extremely honoured to have you participate in my challenge!

[zolotiyeruki]

One clarification--when you say that all kerbals have to be in command pods to count, that excludes passenger compartments/crew cabins, right?

[Der Anfang]

34 minutes ago, zolotiyeruki said:

One clarification--when you say that all kerbals have to be in command pods to count, that excludes passenger compartments/crew cabins, right?

Hmm... that's a good question. I guess if they aren't in a command seat, that's all that matters. So a passenger compartment could count toward the "command pod" condition.

[zolotiyeruki]

On 9/11/2016 at 4:04 PM, ManEatingApe said:

 

• The Communotrons protect the shock cones from exploding from heating past 1,300 m/s
• The double decoupler on the central rear stage takes advantage of the Rapier fuel flow rules so that all 3 Rapiers drain from this first and use the side stages next.

 

This is the first I've heard of these two tricks (dare I call them exploits?).  Can you explain how they work?

[ManEatingApe]

1 hour ago, zolotiyeruki said:

This is the first I've heard of these two tricks (dare I call them exploits?).  Can you explain how they work?

Sure, but I can't claim any credit for either, as I shamelessly pinched them from other peoples designs 

 

The Communotron trick actually mimicks a real world effect https://en.wikipedia.org/wiki/Drag-reducing_aerospike although the intention is a little different.

The shock wave produced from the antenna disrupts the airflow around the tip of the shock cone and prevents it overheating. If you look carefully at a lot of spaceplane designs since 1.0.5 you'll see a cheeky antenna stuck on the most forward point (usually unextended as this reduces drag)

Since the aero-changes in 1.0.5 this allows you to hit decent (> 1500 m/s) speeds between 10,000 and 20,000 meters altitude without heat-sploding. Another option is to use a blunt body with good heat tolerance e.g heatshield, a blunt fairing or the shielded docking port.

 

The  double decoupler was simply reverse engineering how the Rapier fuel flow works. In the description for the Rapier it says "drains fuel evenly stage by stage".

The game seems not to calculate this from your staging sequence, but instead by counting the number of decouplers between the command pod and the fuel tanks. So in the case of my design adding an extra decoupler made the central tank have 2 decouplers between it and the command pods, versus 1 for the outer tanks. So the Rapier algorithm drained this first. You do need to right click on each decoupler and enable fuel flow. Hopefully the new visual fuel flow option coming in 1.2 will make this more obvious!

 

 

 

 

Edited September 14, 2016 by ManEatingApe

[zolotiyeruki]

2 hours ago, ManEatingApe said:

The Communotron trick actually mimicks a real world effect https://en.wikipedia.org/wiki/Drag-reducing_aerospike although the intention is a little different.

The shock wave produced from the antenna disrupts the airflow around the tip of the shock cone and prevents it overheating. If you look carefully at a lot of spaceplane designs since 1.0.5 you'll see a cheeky antenna stuck on the most forward point (usually unextended as this reduces drag)

Since the aero-changes in 1.0.5 this allows you to hit decent (> 1500 m/s) speeds between 10,000 and 20,000 meters altitude without heat-sploding. Another option is to use a blunt body with good heat tolerance e.g heatshield, a blunt fairing or the shielded docking port.

How does it work with the game mechanics, though? Does the game actually model the antenna having that effect, or is it a happy coincidence?

[ManEatingApe]

8 hours ago, zolotiyeruki said:

How does it work with the game mechanics, though? Does the game actually model the antenna having that effect, or is it a happy coincidence?

That's an interesting question, I don't have enough knowledge of the game engine internals to answer that with any authority - perhaps posting a query in "Gameplay Question and Tutorials" would provide a more definitive answer. 

EDIT: There's already a thread here:

And another discussion here https://www.reddit.com/r/KerbalAcademy/comments/47de5d/question_about_overheating_nosecones/

As to why the antenna doesn't simply explode from the heat instead of the shockcone - perhaps it's entirely made of asbestos? 

Edited September 14, 2016 by ManEatingApe

[zolotiyeruki]

Well, gee, that changes *everything!*  If thermal is that much smaller of an issue, that's a couple hundred m/s dV on each launch I can avoid!

[zolotiyeruki]

On 9/12/2016 at 10:12 AM, ManEatingApe said:

For example here's the dV planning for the mission:

What's the dV multiplier column for?

[ManEatingApe]

 

40 minutes ago, zolotiyeruki said:

What's the dV multiplier column for?

Oops, looking at it, that's the wrong name - it's really a v_e multiplier. (don't think that there's an official term for it)

The formula for the columns are just the Tsiolkovsky rocket equation broken out ( )  

• m₀ is initial mass (fuel + payload)
• m_f is final mass (payload)
• v_e is effective velocity (ISP in seconds multiplied by g₀)
• g₀ is the gravity at Kerbin's surface (9.81 m/s²)

So:

A to D entered by user

E = B / (B - C)

F = ln(E)

G = 9.81 * D * F

Columns E and F are actually redundant and you could combine the calculations into a single column, I only left them in because I found them mildly interesting

Edited September 14, 2016 by ManEatingApe

[Mesklin]

Here is my entry with ship "Munshot Twins": 49.214t on launchpad, 4 kerbonauts on board. 5 engines used: 3 RAPIERs, 1 LV-N and 1 ion engine for Minmus trip from Mun (as planned).

Imgur link: http://imgur.com/a/OvwDh

[Der Anfang]

3 hours ago, Mesklin said:

Here is my entry with ship "Munshot Twins": 49.214t on launchpad, 4 kerbonauts on board. 5 engines used: 3 RAPIERs, 1 LV-N and 1 ion engine for Minmus trip from Mun (as planned).

Imgur link: http://imgur.com/a/OvwDh

Colour me impressed: I believe you may have one-upped ManEatingApe. As if his/her entry wasn't impressive already. You leave me speechless. Well done.

 

Can I ask how it is that the final reentry didn't cause you to burn up?

Also, what are the mods I see with the sand timer and the thermometer?

[Mesklin]

3 hours ago, Der Anfang said:

Can I ask how it is that the final reentry didn't cause you to burn up?

Also, what are the mods I see with the sand timer and the thermometer?

1. In classical KSP Kerbin atmospheric reentry no so deadly (especially on Normal mode), you can land from low orbit almost in all capsules without heat shields. You need to make swallow descend: PE should be about 50-55 km and your craft should be as light as possible with bad aerodynamic for big drag.

2. Mods:

 

 

[boolybooly]

Well for a little historical entertainment I did this in 2012 in a very ancient version of KSP. The video is still up on YouTube so here it is. No idea how much it weighed though, quite a lot.

 

 

Edited September 17, 2016 by boolybooly

[Der Anfang]

1 hour ago, boolybooly said:

Well for a little historical entertainment I did this in 2012 in a very ancient version of KSP. The video is still up on YouTube so here it is. No idea how much it weighed though, quite a lot.

 

 

Oh wow, that's yours?? Hahah holy crap. What version is that? I've been playing since... 0.23? It looked nothing like that and the Mun is much whiter...

[purpleivan]

I saw this challenge a few days ago and it looked like it would be fun, so I set a select crew of Bill, Bob and Valentina about the task of making it a reality.

Bill was adamant that this would be an all rocket affair, with... and I quote... "none o' yer faaaancy jets an' yer faaaancy wings". So that meant it was not going to be lightweight. In fact it weighed in at a positively chunky 684 tons, but at least that means it gets more than an honourable mention.

The mission report is a tale of excessive complexity, docking... some more docking and the occasional fuel transfer to spice things up a bit.

As for the score, you're going to need a magnifying glass to see it, as it's a lowly 20280.(base score: 7800, 3 kerbals on board: 11700  and 2 flags planted: 780)

 

As a taster,here's a pic of the Kerbin lander with the Mun lander tucked inside, about to descend to Kerbin before blasting back into orbit again.

 

 

Edited September 18, 2016 by purpleivan

[ManEatingApe]

Hurray for the 1st rocket based entry!

Great level of effort, particularly the Kerbin lander. Landing something that large (intact and upright) is no easy feat.

Edited September 18, 2016 by ManEatingApe

[purpleivan]

19 minutes ago, ManEatingApe said:

Hurray for the 1st rocket based entry!

Great level of effort, particularly the Kerbin lander. Landing something that large (intact and upright) is no easy feat.

What made it harder was that about 2/3 of the chutes failed to open, I think due to some kind of "blocked by" rule, that I'd not encountered before, probably because I'd usually put them on the outside of the vehicle.

Fortunately I had the base stage engine available to soften the landing in the last few seconds.

[Der Anfang]

1 hour ago, purpleivan said:

I saw this challenge a few days ago and it looked like it would be fun, so I set a select crew of Bill, Bob and Valentina about the task of making it a reality.

Bill was adamant that this would be an all rocket affair, with... and I quote... "none o' yer faaaancy jets an' yer faaaancy wings". So that meant it was not going to be lightweight. In fact it weighed in at a positively chunky 684 tons, but at least that means it gets more than an honourable mention.

The mission report is a tale of excessive complexity, docking... some more docking and the occasional fuel transfer to spice things up a bit.

As for the score, you're going to need a magnifying glass to see it, as it's a lowly 20280.(base score: 7800, 3 kerbals on board: 11700  and 2 flags planted: 780)

 

As a taster,here's a pic of the Kerbin lander with the Mun lander tucked inside, about to descend to Kerbin before blasting back into orbit again.

 

 

Well, my entry was quite clunky and heavy too. It was mostly rocket, but I did use some jet engines. I plan on reentering with a much lighter vehicle, but I have no idea how it is that these other talented engineers can make such lightweight craft. Always amazes me. But your craft is equally amazing. I love rockets: they're heavy, dirty, inefficient, but boy are they tonnes of fun! I just have to say that it is very impressive how you managed to land that heavy thing upright, even with some failures. Also, really well done on the docking strategy. I think it was very well utilized and you are the first entry in this challenge to use that approach! Sure, the score may be on the lower end, but it was very fun to look at your mission and you've done things in this challenge other people have not done.

Btw, how much delta-v did that thing have? Also, you could have planted three flags. The third being on your final landing and recollection.  

Edited September 18, 2016 by Der Anfang

[purpleivan]

3 minutes ago, Der Anfang said:

Well, my entry was quite clunky and heavy too. It was mostly rocket, but I did use some jet engines. I plan on reentering with a much lighter vehicle, but I have no idea how it is that these other talented engineers can make such lightweight craft. Always amazes me. But your craft is equally amazing. I love rockets: they're heavy, dirty, inefficient, but boy are they tonnes of fun! I just have to say that it is very impressive how you managed to land that heavy thing upright, even with some failures. Also, really well done on the docking strategy. I think it was very well utilized and you are the first entry in this challenge to use that approach! Sure, the score may be on the lower end, but it was very fun to look at your mission and you've done things in this challenge other people have not done.

Btw, how much delta-v did that thing have?

Very difficult to say how much delta-v the thing had as I was moving fuel around between vehicles.

I have an idea to fairly significantly reduce the weight of the vehicle  while still remaining all rocket. Essentially the Mun package of the transfer vehicle and lander was hauling dead fuel around between Kerbin and the Mun and I should have dropped a tank of in Kerbin orbit before departing for the Mun and another when I got there, so that I could refuel at either end, and so significantly reduce the mass of the transfer Mun package when en-route between the two bodies.

Of course that would all me to save mass on the launcher as well and I'd probably remove the cargo bay on the Kerbin lander and just dock the Mun lander to it to save more mass.

A finger in the air guess would be that I could reduce the mass of the total vehicle by about 1/4.

[JSideris]

Does this count? 

 

So obviously I didn't finish it yet, but you get the picture... My thoughts on the challenge: I wanted to stay away from space planes. I designed a rocket (but didn't fly it) to complete the Minmus challenge but it's 3x heavier than if I was to just go to the mun 2 times and back (not to mention way harder to fly). Not worth it for a 50% bonus, even though that takes away some of the fun. I used my KSP calculator to help me with the rockets. I actually created a new (currently unreleased) version of the tool to help with this challenge, so this was a good exercise. But I guess using space planes are just a lot more clever and I haven't quite figured them out yet. 

On a serious note if you want to see the big rocket in action you'll have to adjust the scoring system to be more inclusive to staged-blastoff-class spacecrafts.

[Der Anfang]

3 hours ago, JSideris said:

Does this count? 

 

So obviously I didn't finish it yet, but you get the picture... My thoughts on the challenge: I wanted to stay away from space planes. I designed a rocket (but didn't fly it) to complete the Minmus challenge but it's 3x heavier than if I was to just go to the mun 2 times and back (not to mention way harder to fly). Not worth it for a 50% bonus, even though that takes away some of the fun. I used my KSP calculator to help me with the rockets. I actually created a new (currently unreleased) version of the tool to help with this challenge, so this was a good exercise. But I guess using space planes are just a lot more clever and I haven't quite figured them out yet. 

On a serious note if you want to see the big rocket in action you'll have to adjust the scoring system to be more inclusive to staged-blastoff-class spacecrafts.

That video made me giggle. I love that ladder glitch. But for obvious reasons, I think we both know that something like that probably wouldn't be scored. I suppose I didn't explicitly state "no cheats or exploits", but it gets old and redundant and I am pretty sure most people wouldn't bother with that (lest it defeats the point of the challenge). Still, I had a good laugh with that one. As for much larger rockets: I didn't really want to score anything above 700 tonnes simply because most rockets in KSP don't necessarily need to be that heavy. That, and if I wanted to look at a .craft and it's over a thousand tonnes or over 600 parts, it would start to lag my computer. I wouldn't really have the time and patience to look at that. Not only that, but also with the way I've scored the challenge based on weight, anything over 700 tones would have menial points, really, and seems kind of pointless to try to score for that.

That doesn't go without saying that I respect those who take the time and patience with really large rockets in the game, and it's not something I would really do myself.  It looks like an impressive build.

[JSideris]

1 hour ago, Der Anfang said:

That video made me giggle. I love that ladder glitch. But for obvious reasons, I think we both know that something like that probably wouldn't be scored. I suppose I didn't explicitly state "no cheats or exploits", but it gets old and redundant and I am pretty sure most people wouldn't bother with that (lest it defeats the point of the challenge). Still, I had a good laugh with that one. As for much larger rockets: I didn't really want to score anything above 700 tonnes simply because most rockets in KSP don't necessarily need to be that heavy. That, and if I wanted to look at a .craft and it's over a thousand tonnes or over 600 parts, it would start to lag my computer. I wouldn't really have the time and patience to look at that. Not only that, but also with the way I've scored the challenge based on weight, anything over 700 tones would have menial points, really, and seems kind of pointless to try to score for that.

That doesn't go without saying that I respect those who take the time and patience with really large rockets in the game, and it's not something I would really do myself.  It looks like an impressive build.

Yep it was just a joke post. I guess that exploit is well-known around here so sorry if it was spammy. In all honestly the big rocket at the beginning didn't make it to Minmus. Must have miscalculated something but it didn't have enough fuel to land. :(. I might try again in the future.

[purpleivan]

As my previous entry was a bit inefficient in various ways, I decided to take another crack at the challenge, but this time with Jeb going solo in a much smaller vehicle.

So I give you the Double Trouble

Weighing in at a doubletastic 222 tons I went for a slightly more complex mission then my first attempt, with tanks of fuel (with docking facilities of course) being dropped off for refueling purposes in both Kerbin and Mun orbit, to reduce the cost of hauling all that fuel around. In the end I only used the one left in Mun orbit to fuel the final trip home.

As for scoring it's still not going to trouble the winged vehicles, but it did improve on my prior entry by being much lighter as well as getting a full set of flags planted this time.

Base score (under 250 tons): 187500
Kerbals onboard x1 (50%): 93750
Flags x4 (20%): 37500

Total = 318750

 

 

Edited September 25, 2016 by purpleivan

[EvermoreAlpaca]

Would you consider a separate leaderboard for a passenger mission rendition of this?

Edited September 26, 2016 by EvermoreAlpaca