Roads to Duna: No Moar Boosters (UPDATES!)

[Human Person]

@sevenperforce Sound all very reasonable.

Didn't think I would beat any high scores either way, but others may.

 

whoa, it rhymes.

Edited September 13, 2017 by Physics Student

[Laie]

Why I hate challenge rules: because it makes us put Lander Cans as the cockpit of a plane (and then complain all the way about how hard to control it is), or clad a lander in aerobrakes so we can claim to not have used parachutes. Or how I now try to somehow make a rocket landing on Kerbin where really, chutes or a glider would be the sane thing to do.

I like this challenge because it makes me dabble in the small stuff, something I haven't done in a long time ( and never as seriously as now). These past few days I tried to put together a neat, reusable LV that is on the proper scale for the Duna mission I'm planning. Mk2 spaceplanes can't hold the bulk, M3 becomes entirely too large and heavy for the task.

I don't think it's reasonable to scale this with # of Kerbals shipped. IMO, the task should still be to build something reasonably small and, well, credible -- not a huge mothership kind of thing. So maybe allow for another size class or two (like, 8 or 15 people) but not open-ended.

Edit to add:
while I'm complaining about rules, two gripes: a) I'd like if the "no fuel transfer" rule were separated from a specific mission plan. b) there should be enlarged crew capacity not only on the voyage, but also during the surface stay (which can last about as long as both trips taken together).

Sadly, the supposedly non-landable 2.5m part also is the heaviest container -- maybe make it a requirement that there should be both a surface and a space habitat? I'd like to encourage leaving pieces behind.

Edited September 13, 2017 by Laie

[mk1980]

a separate leaderboard for larger scale missions (maybe only one for all sizes, normalized/scaled by a "per kerbal" score) would probably make the most sense. so the entries that are already in the existing leaderboard aren't devalued by some new scaling rule.

[icantmakemodels]

On 9/6/2017 at 1:20 PM, sevenperforce said:

[Elon style conflicts with They see me rollin']

Not with that attitude, @sevenperforce. What if I bring the rover back?

Edited September 13, 2017 by icantmakemodels

[Laie]

Just now, icantmakemodels said:

What if I bring the rover back?

What for? Just to claim reusability? Seriously though, it's to prevent racking up a modifier in excess of 100%.

[sevenperforce]

2 minutes ago, icantmakemodels said:

Not with that attitude, @sevenperforce. What if I bring the rover back?

I was going to say that rovers only give the bonus if they stay on Duna; otherwise you run into >100% bonuses. But, on reflection, even if you combine Elon Style and Rollin', you can only get to a max of 96% (that's getting everything but Wing It, Brute Force, Justin Case, and A Solid Plan). So I'll allow it, I guess. Paging @Kergarin to let him know, since I said otherwise before.

34 minutes ago, Laie said:

Why I hate challenge rules: because it makes us put Lander Cans as the cockpit of a plane (and then complain all the way about how hard to control it is), or clad a lander in aerobrakes so we can claim to not have used parachutes. Or how I now try to somehow make a rocket landing on Kerbin where really, chutes or a glider would be the sane thing to do.

Propulsive landings on Kerbin are really just cool factor, but on Earth they do have some value. Splashdown recovery is inherently problematic, time-consuming, and not great for reuse. And chutes have to be prohibitively large to make a land touchdown gentle...and even then you have to deal with wind, which can flip your capsule if you're landing on chutes alone (hence the solid braking retrorockets on the Soyuz and New Shepard). The propulsive lander I'm going to use only has two aerobrakes and they double as (shaky) landing legs.

Making a lander can the cockpit of a plane IS pretty annoying...unfortunately there's not an easy way to avoid that.

34 minutes ago, Laie said:

I like this challenge because it makes me dabble in the small stuff, something I haven't done in a long time ( and never as seriously as now). These past few days I tried to put together a neat, reusable LV that is on the proper scale for the Duna mission I'm planning. Mk2 spaceplanes can't hold the bulk, M3 becomes entirely too large and heavy for the task.

I don't think it's reasonable to scale this with # of Kerbals shipped. IMO, the task should still be to build something reasonably small and, well, credible -- not a huge mothership kind of thing. So maybe allow for another size class or two (like, 8 or 15 people) but not open-ended.

Dividing by half the total number of Kerbals provides diminishing returns so it's not entirely open-ended.

 

[icantmakemodels]

@sevenperforce, Is it okay for Tounges of flame if I use a drogue, as long as I cut the chute before landing (i.e., curiosity landing)

Edited September 13, 2017 by icantmakemodels

[sevenperforce]

4 minutes ago, icantmakemodels said:

@sevenperforce, Is it okay for Tounges of flame if I use a drogue, as long as I cut the chute before landing (i.e., curiosity landing)

Nope!  

[icantmakemodels]

Can I get partial credit for Wing it if the crew launch and landing is with an SSTO?

[icantmakemodels]

Good news: We've landed on Duna.

Bad news: It was a crash landing.

[sevenperforce]

14 minutes ago, icantmakemodels said:

Can I get partial credit for Wing it if the crew launch and landing is with an SSTO?

SSTOs can be VTOL, you know.

But no, not unless your winged crew vehicle is part of your Duna stack. The Kerbin crew lander must be part of what you send to Duna. Otherwise people could just leave the "launch vehicle" in Kerbin Orbit, rendezvous with it when they come back from Duna, transfer crew back to it, and skip the entire Kerbin lander.

I mean, if you want to send up your Duna lander and a few refueling missions, assemble everything, send up a crewed SSTO with empty fuel tanks, ditch the old tanks, and take all that to Duna, then come back and land in your SSTO, that's certainly okay.

 

[Laie]

Adventures in launch vehicle design:

The first one was way over the top. Granted, there's an LES but considering that I only need to take 6t to orbit... Four Aerospikes should suffice for that task. However, cargo bay already comes to 3t and is a bit tight for my pieces. Finally, verniers and legs cause insane drag: they way to launch aerospikes is to go very flat despite the low initial TWR and soon pull 4g at 25km -- much like you do with a spaceplane, but a whole lot faster. You can learn a lot about drag that way.

(not shown:  simple stack with a fairing on top would work, but be entirely too boring)

The last one is promising, though it still has issues and a tight dV budget. The fairing makes up the core of the vessel, and all of the draggy bits are hidden in there. It's surprisingly sleek despite it's looks. In oder to have enough fuel left for a powered landing one needs to get the ascent just right, though. I only manage once every five attempts and neither MJ nor Gravity Turn can really handle it. Besides, zero cross-range makes the return a lot more exciting than it needs to be.

Spoiler

Dressing it up with jets was a fine idea if I may say so myself. They´re to allow a powered landing on very little fuel. The budget is there: these things are lightweight and if I don't need to have any dV left after de-orbit... well, it works out. What doesn't work is cross-range, though -- the vessels bobs around like a cork on the water and refuses to go in any particular direction. I'll have to redesign it with fewer bigger (gimballing) jets. It probably won't look as 60s-neat as this one, though.

 

Edited September 13, 2017 by Laie

[sevenperforce]

4 minutes ago, Laie said:

Adventures in launch vehicle design:

The first one was way over the top. Granted, there's an LES but considering that I only need to take 6t to orbit... Four Aerospikes should suffice for that task. However, cargo bay already comes to 3t and is a bit tight for my pieces. Finally, verniers and legs cause insane drag: they way to launch aerospikes is to go very flat despite the low initial TWR and soon pull 4g at 25km -- much like you do with a spaceplane, but a whole lot faster. You can learn a lot about drag that way.

(not shown:  simple stack with a fairing on top would work, but be entirely too boring)

The last one is promising, though it still has issues and a tight dV budget. The fairing makes up the core of the vessel, and all of the draggy bits are hidden in there. It's surprisingly sleek despite it's looks. In oder to have enough fuel left for a powered landing one needs to get the ascent just right, though. I only manage once every five attempts and neither MJ nor Gravity Turn can really handle it. Besides, zero cross-range makes the return a lot more exciting than it needs to be.

  Hide contents

Dressing it up with jets was a fine idea if I may say so myself. They´re to allow a powered landing on very little fuel. The budget is there: these things are lightweight and if I don't need to have any dV left after de-orbit... well, it works out. What doesn't work is cross-range, though -- the vessels bobs around like a cork on the water and refuses to go in any particular direction. I'll have to redesign it with fewer bigger (gimballing) jets. It probably won't look as 60s-neat as this one, though.

 

Damn! Love the SERV-inspired LV on the far right. Very very nice.

[DAL59]

For "Tongues of flame" are air brakes allowed?  What about blimps?  

[mk1980]

38 minutes ago, DAL59 said:

What about blimps?  

there are no blimps in the stock game

[sevenperforce]

2 hours ago, DAL59 said:

For "Tongues of flame" are air brakes allowed?  What about blimps?  

Air brakes are fine for tongues of flame; in fact, they're recommended. No part mods, so no blimps. 

[Human Person]

My take on the Interplanetary spaceship. It holds 108 Kerbals. This SpaceX-Style ITS Mission is not the best for this challenge, because I will only need 4 launches (the highest payload mass will be the 117 t of dry mass this spaceship has).

However, the spare launch might prove useful for an extra bit of fuel after returning from Duna, as I just discovered how much fuel I need to land this thing.

 

 

It uses 6 Poodle and 3 Vector engines and has (in theory) enough delta v to get to Duna and back once fully fueled in LKO.

 

 

 

Edited September 14, 2017 by Physics Student

[Laie]

Shouldn't ISRU be quite worthwhile on that scale?

[sevenperforce]

2 hours ago, Physics Student said:

My take on the Interplanetary spaceship. It holds 108 Kerbals. This SpaceX-Style ITS Mission is not the best for this challenge, because I will only need 4 launches (the highest payload mass will be the 117 t of dry mass this spaceship has).

However, the spare launch might prove useful for an extra bit of fuel after returning from Duna, as I just discovered how much fuel I need to land this thing.

It uses 6 Poodle and 3 Vector engines and has (in theory) enough delta v to get to Duna and back once fully fueled in LKO.

I like it! Great part use.

One thing to consider might be using the refueling tanker for the Duna Injection Burn. After the go vehicle is fully fueled, dock them nose to nose, use the tanker for the 950 m/s departure burn to send it right to the edge of Kerbin's SOI, then undock and use the transfer vehicle for the remaining 130 m/s to complete the transfer injection. Aerobrake the tanker in successive passes and bring it back to KSC. The transfer vehicle aerocaptures at Duna, lands, and returns.

19 minutes ago, Laie said:

Shouldn't ISRU be quite worthwhile on that scale?

I daresay it would be. Especially if you pack the liquid fuel you need and only carry a Convert-O-Tron 125 for cracking Duna's atmosphere into liquid oxidizer using Infinite Fuel in place of ore tanks and a drill.

Edited September 15, 2017 by sevenperforce

[Mesklin]

Here is my entry: Odin ship - Apollo scheme of expedition, fully reusable launcher, 3 crew members (all landed to Dune), crew has additional living space.

Maximum payload mass (five launches) - 4.600t (main ship has 4.577t, lander at launch time - 4.6t and 3 similar tanks with mass of 4.6t each).

Bonuses:  On Tongues of Fire (10%) + Old School (3%) + Slow Climb (4%) + Elon Style (25%) + Stayin' Alive (18%) + Loop The Loop (15%) + Consistency, Good Sir (6%) + They See Me Rollin' (15%) = 96%

Total Score: 4.6 * 0.96 = 0.18428

Imgur album: https://imgur.com/a/Osp1y

 

[mk1980]

i must have missed the rule change about rovers and full reusability. don't understand why you reverted that rule.

that rule change renders the "separate ascent vehicle" mission profile pointless.

the extra mass of the rover is trivial compared to the mass of a separate ascent vehicle that also has to be solid powered to (almost) break even with the bonus you'd get for full reusability.

[sevenperforce]

7 hours ago, Mesklin said:

Here is my entry: Odin ship - Apollo scheme of expedition, fully reusable launcher, 3 crew members (all landed to Dune), crew has additional living space.

Maximum payload mass (five launches) - 4.600t (main ship has 4.577t, lander at launch time - 4.6t and 3 similar tanks with mass of 4.6t each).

Bonuses:  On Tongues of Fire (10%) + Old School (3%) + Slow Climb (4%) + Elon Style (25%) + Stayin' Alive (18%) + Loop The Loop (15%) + Consistency, Good Sir (6%) + They See Me Rollin' (15%) = 96%

Total Score: 4.6 * 0.96 = 0.18428

Imgur album: https://imgur.com/a/Osp1y

 

Wow! Ridiculously, ridiculously impressive. I'll put you on the leaderboard right away. Nice job with the rover -- I wouldn't have believed it unless I saw it.

2 hours ago, mk1980 said:

i must have missed the rule change about rovers and full reusability. don't understand why you reverted that rule.

that rule change renders the "separate ascent vehicle" mission profile pointless.

the extra mass of the rover is trivial compared to the mass of a separate ascent vehicle that also has to be solid powered to (almost) break even with the bonus you'd get for full reusability.

The rover was originally intended to exclude Elon Style, but since bringing it back wouldn't actually put someone over 100%, I figured it could be allowed.

[mk1980]

35 minutes ago, sevenperforce said:

The rover was originally intended to exclude Elon Style, but since bringing it back wouldn't actually put someone over 100%, I figured it could be allowed.

ok fair enough. but the problem is now that you can't get elon style when you use a separate ascent vehicle, and even if you make that MAV solid rocket powered, you only get 24% bonus for it. elon style is (arguably) easier to do and defintiely requires less mass in total.

anyway, i guess it's too late to re-revoke it now

i suppose you could increase the score bonus for the solid rockets from 6% to 8 or 9. so a fully stacked mission with a solid powered MAV gets 97% (or even 98%). which doesn't sound sound like much, but actually allows you to make it 1/3rd (?) heavier (or twice as heavy at 98%) and still break even with a 96% bonus.

[sevenperforce]

25 minutes ago, mk1980 said:

ok fair enough. but the problem is now that you can't get elon style when you use a separate ascent vehicle, and even if you make that MAV solid rocket powered, you only get 24% bonus for it. elon style is (arguably) easier to do and defintiely requires less mass in total.

anyway, i guess it's too late to re-revoke it now

i suppose you could increase the score bonus for the solid rockets from 6% to 8 or 9. so a fully stacked mission with a solid powered MAV gets 97% (or even 98%). which doesn't sound sound like much, but actually allows you to make it 1/3rd (?) heavier (or twice as heavy at 98%) and still break even with a 96% bonus.

Yeah, bumping up the solid ascent vehicle bonus won't change any current scores but it will make that more competitive. I'll do it.

[sevenperforce]

@Mesklin You're now at the top of the leaderboard!