Low Mass Duna Challenge

[JacobJHC]

The Low Mass Duna Challenge

Based off of the Low Mass Eeloo Challenge

The Challenge: Conduct a Duna return mission that has a mass less than 50 Kerbal tons.

The Rules:

- The craft must have a mass of less than 50 tons.

- No infinite fuel or hack gravity. (obviously)

- The Kerbal must return to Kerbin.

- Re-entry heating must be set to atleast 100% 

- No kraken drives

- Kerbal must be in a capsule/crew cabin during launch, interplanetary space and the return. A chair on the lander is ok but the Kerbal must have an actual capsule, a cargo bay and a chair does not count.

- Mass does not include launch clamps.

- No ISRU

- No part clipping for any parts other than structural parts. (No clipping of crew compartments, fuel tanks, engines, fuel cells, solar panels, generators, etc.)

Submission Rules

- Have a screenshot from inside the VAB showing the craft's mass or show it in a video if you are submitting by video.

- If you are submitting by screenshots be sure to screenshot every major burn and the landing on Duna and the return to Kerbin.

- If you are submitting by video remember to show the mass and all major burns.

Winners

- @Foxster Imgur album, some part clipping- wasn't disqualified because the no clipping rule hadn't been added yet. Very nicely done - 23.069 Tons

- @Aegolius13 Imgur Album, A nice and small nuclear vessel lifted to space mostly by a vector engine, looked a bit like a fish. Very nice - 38.498 Tons

          - Another submission in another Imgur Album, shaved off about 10 tons by  "putting decouplers on the right way."  Nice launch vehicle - 28.35 Tons

- @maccollo Video Submission, Made by the legend himself, this mission was launched with an interesting duel engined launch vehicle - 28.43 Tons

- @Nefrums Imgur Album, Rapier launched, spark engine assisted in orbit, ion-powered transfer stage, Duna lander made of cockpit of launch vehicle, Mun assist into Kerbin Orbit, glided down to KSC, powered landing on a spark engine. Very impressive, especially the powered Kerbin landing. - 7.5 Tons

- @Eidahlil Video Submission, Very awsome craft, rapier engine shot it out of the atmo, the lander and ion shuttle assisted each other in achieving orbit, lander has no parachutes, Kerbin and Duna captures both done manually by the ion engine. - 5.473 Tons

- @Der Anfang Imgur Album, and a very detailed one at that, staged jet engines in a multistage to orbit. Final nuclear stage flew out to Duna, flewby Ike on the return how to Kerbin. - 27.1 Tons

- @Martian Emigrant Submission in the thread itself, Jet-powered launch vehicle, used an ion shuttle and a very small lander. Val owns Duna now I guess. - 21.118 Tons

- @AeroGav Video Submission, Used a duel stage spaceplane to complete the mission, plane called the WhippyNerv-II. Muy bueno - 21.35 Tons

- @ManEatingApe Vimeo Submission Somehow achieved 1700+ meters per second using a rapier, used a tiny wheel like lander and a tiny ion shuttle, utilized aerobraking at both Duna and Kerbin saving fuel. - 4.992 Tons

- @tseitsei89 Imgur Album, Jet engine launch, spark booster to help speed up, ions to orbit. Tiny lander using a pair spider engines - 4.609 Tons

 

Edited October 26, 2016 by JacobJHC
Winner board additions

[AeroGav]

Aww, while the rest of the world looks forward to a weekend of gaming, my shift starts in the morning.  That's a pity because i dont have time to fly the mission (It takes me ages finding a launch window :-( )

But I have an under 20 ton spaceplane that'd likely do it 

https://kerbalx.com/AeroGav/WhippyNerv-II

I've landed it on Duna before (horizontally, it's got the field capability of a Fieseler Storch)  , but never flown the whole way there and back.

Looks to have enough fuel for such a mission though, surely ?

_{I'm sure this thing used to have a jet engine on the back of it....}

[Firemetal]

Hmmmmmm. I could probably make an SSTO to go to Duna...

Also I am very happy that I'm inspiring people!  

Fire

[Der Anfang]

20 minutes ago, Firemetal said:

Hmmmmmm. I could probably make an SSTO to go to Duna...

Also I am very happy that I'm inspiring people!  

Fire

Before this even became a thing on the forums. I was already attempting a lowmass challenge version of this.

[Violent Jeb]

Not sure that anything except a ssto-assisted round trip is even possible under 50t. so ofc it'll have to be done with ssto. no ISRU? put the nail in the coffin.

My most recent payload which was capable of getting from LKO to dunas surface, biome hop and return with seating for 2 in a rocket format came in at 58t. The launcher however was an additional 600t for a grand total of 658t. I'd be happy to crack 4-500t with a manned mission in a non-ssto format, which is 10x the requirement stipulated.

my point is, ssto-only challenge because conventional rockets just can't hit those margins (AFAIK).

ssto master race

[AeroGav]

My entry is not an SSTO because the jet engine is jettisoned, as people keep pointing out. So it is a Spaceplane.  It's crude as I 'd set the thing up for  a live build video.  No vernier engines, service bays, could really use some repositioning of fuel tanks.  But it's got me to the surface.  I imaging coming back to kerbin in a mk1 cockpit requires a lot of shallow aerobraking passes.

[Foxster]

2 hours ago, Violent Jeb said:

Not sure that anything except a ssto-assisted round trip is even possible under 50t. so ofc it'll have to be done with ssto. no ISRU? put the nail in the coffin.

My most recent payload which was capable of getting from LKO to dunas surface, biome hop and return with seating for 2 in a rocket format came in at 58t. The launcher however was an additional 600t for a grand total of 658t. I'd be happy to crack 4-500t with a manned mission in a non-ssto format, which is 10x the requirement stipulated.

my point is, ssto-only challenge because conventional rockets just can't hit those margins (AFAIK).

ssto master race

Really? My manned Duna return rocket weighs about 23t. 

Here are some pictures: http://imgur.com/a/lKqyw

Turned out to be rather over-engineered as I had 2449 dV left when I got back to Kerbin orbit.

If I was doing it again I'd put a probe core on the mothership I left in Duna orbit. I had to rendezvous using the lander and dV was OK in the end but I was chewing my nails for a few minutes. 

Edited October 14, 2016 by Foxster

[Aegolius13]

EDIT: I have a new lighter entry below, so disregard this one.

Just did it (I think) with an all-rocket approach, weighing a bit over 38 tons.  I used a Vector for the launch stage, a nuke for the rest, drop tanks for both, and a silly looking Ant final stage I did not end up needing.  Had a fair amount of extra fuel at the end, so could have lost a little more weight by removing a little LF and/or the Ant stage.  I also might add a heat shield to the capsule so I can come in hot to Kerbin, which would help save some LF.  

 

Album at:

http://imgur.com/a/1gkyM

 

 

Edited October 15, 2016 by Aegolius13

[maccollo]

Did the challenge with an all chemical rocket with a mass of 28.43 tons. Like @Aegolius13 I also didn't use a heatshield for Kerbin EDL, and instead opted for multiple aerobrake passes.

 

[Aegolius13]

1 hour ago, maccollo said:

Did the challenge with an all chemical rocket with a mass of 28.43 tons. Like @Aegolius13 I also didn't use a heatshield for Kerbin EDL, and instead opted for multiple aerobrake passes.

Dang, you beat me by 10 tons?  Impressive.  Likely the Terrier is a better choice than my nukes, due to the very low payload weight.  Also makes landing legs a lot easier. Are those Reliants or Swivels on the bottom?  

[maccollo]

14 minutes ago, Aegolius13 said:

Dang, you beat me by 10 tons?  Impressive.  Likely the Terrier is a better choice than my nukes, due to the very low payload weight.  Also makes landing legs a lot easier. Are those Reliants or Swivels on the bottom?  

They are Reliants, which is why I had to add those fins. There were some balance changes in 1.2 which appears to widen the performance gap between the two when used as booster engines.

Also, the spark got a 11% increase in thrust, and also a very significant 20 second increase in vacuum ISP.

[Aegolius13]

I've been compelled to try again, including such design innovations as "putting decouplers on the right way."  I was able to shave about 10 tons off, getting mass down to 28.35 tons.  Still had a few hundred delta-v left in the tank (might go back to toroidal tank on the top stage), but I'm satisfied for now.  

New album:

http://imgur.com/a/PiIwS

 

35 minutes ago, maccollo said:

They are Reliants, which is why I had to add those fins. There were some balance changes in 1.2 which appears to widen the performance gap between the two when used as booster engines

Yeah, I am not a fan of the new Swivel - seems like it's not really a good choice for much of anything anymore.  I'll put up with it for very small satellite launchers and the like, but that's about it.  May even have to start using the Thud...

[Der Anfang]

5 hours ago, maccollo said:

Did the challenge with an all chemical rocket with a mass of 28.43 tons. Like @Aegolius13 I also didn't use a heatshield for Kerbin EDL, and instead opted for multiple aerobrake passes.

 

How did you get KER to work in 1.2??

The KER wasn't updated yet... was it?

[maccollo]

1 minute ago, Der Anfang said:

How did you get KER to work in 1.2??

The KER wasn't updated yet... was it?

You need the version that's in the master zip file on github. There's a folder in it called output, and in there you will have a version that works with 1.2.

[Der Anfang]

http://imgur.com/a/z7gbm 27 tonne nuke ship. Hope you like it. Had to play in 1.1.3 because I wanted to use the KER mod, and was too lazy to muck around with the file stuff for 1.2.

Are resubmissions accepted?

[Aegolius13]

1 hour ago, maccollo said:

You need the version that's in the master zip file on github. There's a folder in it called output, and in there you will have a version that works with 1.2.

What... huh... how... oh well, off to GitHub with me.

[Nefrums]

I made a small ship with a MCT inspired lander. Turn out that it works quite well to use a glider/powered lander. A bit harder then using chutes but more fun.

Full report: http://imgur.com/a/xnB3O

 

 

Edited October 16, 2016 by Nefrums

[JacobJHC]

I will update the score board later, my wifi is crap at the moment and I cannot open the imgur albums. @Nefrums, 7.5 tons on the runway? Wasn't your Jool 5 plane less than that? lol.

[Eidahlil]

Managed to do it in 5.5 tons, after a few redesigns. Jeb made it to Duna and back in, what is, essentially, a rapier launch capsule with a tiny ion spacecraft and a lander inspired by Foxster's mission (no clipping though).

1.2 stock craft, used MechJeb and Precise Node for help with the flying.

 

[Martian Emigrant]

Hi.

Here is my submission.

Learned a lot from it and used previously earned Eeloo challenge experience.

http://imgur.com/a/5yNZ7

21.118t in the SPH

Aeroengine, chemical engines, ION, Small lander.

Darn it....Imgur lost a few pics. I will load them now....Grrr.

Ready to go.

Shedding on the way up

Braking to make orbit followed by some manoeuver to lower my orbit. 60Km was desired.

Valentina EVAed to the Lander

The tank (Oscar-B) can take I believe 5 m/s my testing showed that 10 m/s was expected and slower cost more. The tank was designated as a crush zone. In case it should survive there was a decoupler.

The SAS was more than powerful enough to move the ship around.

Valentina "Totally own Duna".

Tilting at the lists

Plenty of fuel for the climb manoeuvring but the ship had a tendency to vibrate off heading. Couldn't figure it out. This is 1.1.3.

EVA-ing Valentina was better than flying the ship around. By far.

Valentina: "Tanks for the ride but I'll walk from here".

Raised the orbit to 1000km before departure for a better warp to the window and to be further away from the planet due to the long burns. The oculting of the panels and atmosphere entry they cause.

I had to redo the return. This one though was letter perfect. I have to learn from that.

 

Jump for joy.

I enjoyed the build and the challenge.

Thank you.

 

ME

Edited October 19, 2016 by Martian Emigrant

[n.b.z.]

Question for @JacobJHC about the rules:

Is it required to provide a proper crew module / lander can / capsule for the Kerbal?

There seems to be no rule about that, so someone could fly his Kerbal around using only a command chair. In fact, I would be tempted to do so.

While some participants have used command chairs for their landers — as far as I can tell, every submission to this challenge has provided the Kerbal with a proper accomodation for at least the long interplanetary journey and the Kerbin reentry.

May I kindly suggest to add a rule that requires a proper cabin? This would be only fair to everyone who has already participated (as they all followed this rule already, without it being explicitly stated) while keeping the playing field level for everyone who plans to take part in this challenge.

You see... for the first time, I'm thinking that I could beat Nefrums in a low mass challenge. However, this just cannot be true. Ridiculous. It would be an unsettling disturbance of the very fabric of the universe. And it would only be possible if I use only a command chair for the entire flight, while he was carrying a proper capsule all the way to the surface of Duna and back. It would feel like cheating.

[tseitsei89]

I just did 5.444t craft.

Don't have pics about the flight so it'll not be officially accepted but I will post some pics about the craft tomorrow.

I believe that is currently the lightest craft beating Eidahlil's craft by a whopping 0.029t

[JacobJHC]

15 hours ago, n.b.z. said:

Is it required to provide a proper crew module / lander can / capsule for the Kerbal?

Nope, you can have them in a chair if you want.

15 hours ago, n.b.z. said:

May I kindly suggest to add a rule that requires a proper cabin? This would be only fair to everyone who has already participated (as they all followed this rule already, without it being explicitly stated) while keeping the playing field level for everyone who plans to take part in this challenge.

Goof point I will add it.

15 hours ago, n.b.z. said:

May I kindly suggest to add a rule that requires a proper cabin? This would be only fair to everyone who has already participated (as they all followed this rule already, without it being explicitly stated) while keeping the playing field level for everyone who plans to take part in this challenge.

Good point I will add the rule.

[Der Anfang]

@

JacobJHC

Don't forget about my submission, mate. ;)

[Regiampiero]

On 10/17/2016 at 8:45 PM, Eidahlil said:

Managed to do it in 5.5 tons, after a few redesigns. Jeb made it to Duna and back in, what is, essentially, a rapier launch capsule with a tiny ion spacecraft and a lander inspired by Foxster's mission (no clipping though).

1.2 stock craft, used MechJeb and Precise Node for help with the flying.

Impressive, but there shouldn't be any way that can survived Kerbin re-entry. 

Edited October 19, 2016 by Regiampiero