SPONSERED BY ROCKOMAX: The Mainsail Interplanetary Challenge

[RadHazard]

The Rockomax Conglomerate needs your help! With the rise of spaceplanes and C7 Aerospace in the space exploration market, Rockomax has seen the lowest stock prices in years! The board of directors had hoped the new R.A.P.I.E.R. engine designed in conjoint with C7 Aerospace would help boost their revenue. Unfortunately, due to it's less-than-stellar performance, Rockomax has found that many customers prefer the Turbojet/Aerospike combo - both C7 engines, of course. Rockomax needs something to boost their sales, and like everything else they do, they're thinking of something big.

This is where you come in. Rockomax has provided KSC with a massive amount of funding for one of the most ambitious missions yet attempted by kerbalkind -- land a kerbal on another planet. But there's a catch. Rockomax wants you to endorse their flagship product: The "Mainsail" Liquid Fuel engine. Specifically, they want you to land a kerbal on another planet and (hopefully) return using nothing but Mainsails!

Rules

• You are only allowed to use Mainsail engines. You cannot use any other thrust-generating parts, including SRBs. Separatrons and RCS are fine, but may only be used for separating stages and rendezvous maneuvers, respectively. Launch, circularization, transfer burns, and landing must all be done using only Mainsails (or parachutes).
  
• A landing is considered successful if the Kerbal lives long enough to plant a flag. You are only eligible for return points for that body if the kerbal that planted that flag is returned to Kerbin.
  
• This challenge is limited to stock parts only with one exception: Any information mod that requires a part is allowed (e.g. MechJeb, Kerbal Engineer, etc.)
  
• MechJeb and any other information mods are allowed -- this is primarily a design challenge.
  
• Part clipping is allowed, but infinite fuel and other debug menu options are not.
  
• Multiple launches and in-orbit assembly are allowed, but once your craft is complete and begins it's first transfer burn to leave Kerbin's SoI, you may not launch any more crafts.
  
• You may refuel your craft in at a station in Kerbin orbit at any point before you begin your first transfer burn. Once you leave you cannot use any fuel you did not bring on your craft.
  
• Pictures required: VAB or Launchpad Shot, intercept for each planetary SoI, approach for landing on each body, planted flag on each body, ascent for each body (if applicable), and one pic of the kerbals splashed down/landed if you returned to Kerbin.
  

Scoring

Scores are determined by which bodies you have landed and planted a flag on. Each body has two scores: One for landing and placing a flag on it, and one for returning the kerbal to Kerbin. You can only earn each of these once. Additionaly, for each planetary SoI you enter and then land on a body (either the planet or one of it's moons), your gain a multiplier. You can only gain this once per planetery SoI (i.e. Going Eve -> Duna -> Eve only gains you a 2x multiplier. Landing on both Duna and Ike will only net you a 1x multiplier)

Your score is equal to the sum of the landing scores, plus the sum of the return scores (if you successfully bring your Kerbalnauts back to Kerbin), times your multiplier.

Planet Scores:

Moho:     Landing - 650 points    Returning - 450 points
Eve:      Landing - 100 points    Returning - 1500 points
  Gilly:  Landing - 200 points    Returning - 200 points
Duna:     Landing - 100 points    Returning - 250 points
  Ike:    Landing - 150 points    Returning - 150 points
Dres:     Landing - 500 points    Returning - 200 points
Jool:     Landing* - 200 points   Returning** - Infinity points
  Laythe: Landing - 250 points    Returning - 600 points
  Vall:   Landing - 450 points    Returning - 400 points
  Tylo:   Landing - 650 points    Returning - 600 points
  Bop:    Landing - 400 points    Returning - 350 points
  Pol:    Landing - 350 points    Returning - 350 points
Eeloo:    Landing - 650 points    Returning - 200 points

*I think this might have been done before

**Good luck with that

(Scores are roughly based on the dV costs to intercept and land to the body, and then to take off and return to Kerbin)

High Score List

1. ThreeMartiniLaunch - 850 points (Eeloo, returned)
   
2. Jasonden - 300 points (Ike, returned)
   
3. RadHazard - 100 points (Duna, didn't return)
   

Good luck!

Tips:

• Use tweakables to limit the thrust of the mainsail you use as your lander engine(s)
  
• Use the mainsails as you would LV-Ns, that is, put as few as possible on your transfer stages while retaining a tolerable TWR (it shouldn't be hard!)
  
• Mainsails are heavy! Dump useless mainsails as soon as possible, especially on your transfer stage. (Rockomax won't mind, since you'll just have to buy more )
  

Edited January 6, 2014 by RadHazard
D'oh, forgot to update high score list with new scores

[RadHazard]

My entry:

I managed to make it to Duna. I would have been able to return to Kerbin, but alas I didn't have quite enough fuel in my lander to rendezvous with the fuel tanks I left in orbit. Rockomax has honored the sacrifice of those brave souls by slashing their prices across the board -- This weekend only! Buy now!

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Score:

100pts * 1x SoIs = 100 points

[Jasonden]

Here's my entry: the Mainsailor ONE. I tried to see how far I could get using just a single Mainsail for EVERYTHING. Got to Ike and back (360pts by my count), with about 450m/s delta-V to spare. So I might have gotten further, but not THAT much further. Definitely a score for tweakables, needed them for downrating the Mainsail at the end and controlling which tanks were on and off.

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[gm537]

How do multiple landings work?

Let's say I land on Bop and then land on Eeloo and then return to Kerbin? How many points is that worth? My math would suggest: (500+600+650+200) x 2 = 3900. Is that correct? Also might I suggest I slight decrease to Pol's points and a slight increase for Moho? (Everyone always underestimates Moho; with it's inclination change and insertion burn that are more dV than the ejection.)

Edit: Okay I missed a bit of your initial explanation that clarifies my understanding as correct.

[RadHazard]

I used the launch window planner at http://alexmoon.github.io/ksp/ to predict roughly how much dV it would take to get to each planet. It suggests Moho needs a 3000 m/s ejection burn and a 2000 m/s insertion burn using a ballistic (i.e. no mid-course plane change) trajectory. The delta-V map on the wiki suggests it needs 1500 m/s to land on, giving a total of 6500 m/s. That's how I got the current score.

If I switch it to mid-course plane change, it gives me a 1800 m/s ejection, 1000 m/s plane change, and a 2500 m/s insertion burn for a total of 6800 m/s (including the landing). Does that sound about right, or would you think it'd be even more than that?

I was thinking of adjusting a few of the scores, including Ike, but I didn't want to step on Jasonden's toes and reduce his score, given he already landed there.

[Jasonden]

I was thinking of adjusting a few of the scores, including Ike, but I didn't want to step on Jasonden's toes and reduce his score, given he already landed there.

Thanks, but no need to worry about this on my account! I think that Duna return would be harder than Ike, for instance, and should be worth more. I'm probably going to try this again, so go ahead and update the scores if you think it appropriate, and I'll aim my next attempt based on the new values.

Given my self-imposed limit of just one Mainsail, I won't be competitive for long anyway.

Thanks for the challenge!

[700NitroXpress]

What about the use of SRB's?

[SirJodelstein]

how about an extra category or multiplier for not using the thrust limiter? Landing on Gilly or other low-grav moons might be a challenge because of too much thrust for controlled descents then? Wait, i gotta try that on Minmus now

[Highlad]

May I ask something?

Are we allowed to launch fuel tanks to the low orbit around the planets/moons we plan on visiting? Or do we only have the fuel we take with us?

I may give this a shot if I have the time

[700NitroXpress]

Also might I suggest I slight decrease to Pol's points and a slight increase for Moho? (Everyone always underestimates Moho; with it's inclination change and insertion burn that are more dV than the ejection.)

I have to fully agree with this. Moho should be worth more points than Laythe or Vall. Moho has a higher inclination burn and often much more DV to achieve orbit and land. Laythe has atmosphere so landing is easy and doesn't require powered landing. Vall requires powered landing, but using other planets and moons in the system makes achieving orbit very easy to do with much less delta V than is required for Moho since Moho is all alone. Pol, Bop, and Vall should all be within 100 points of each other. I would swap out the Moho points for the Vall points. Also, landing on every moon in the Jool system is worth more than Eeloo, so what's the point in going to Eeloo?

[RadHazard]

What about the use of SRB's?

Nope, sorry. Separations are allowed, but only for separating stages, not for propulsion. Rockomax really wants to push their Mainsales (okay, you can shoot me for that one )

how about an extra category or multiplier for not using the thrust limiter? Landing on Gilly or other low-grav moons might be a challenge because of too much thrust for controlled descents then? Wait, i gotta try that on Minmus now

I could make a note by anyone's entry that doesn't use the thrust limiter. I'm not sure how to easily it would be to verify this, though.

May I ask something?

Are we allowed to launch fuel tanks to the low orbit around the planets/moons we plan on visiting? Or do we only have the fuel we take with us?

I may give this a shot if I have the time

You have to bring all the fuel with you in a single craft. You can assemble that craft in LKO using multiple launches and docking, but once you leave Kerbin's SoI you are only allowed to use what you bring on that craft.

I have to fully agree with this. Moho should be worth more points than Laythe or Vall. Moho has a higher inclination burn and often much more DV to achieve orbit and land. Laythe has atmosphere so landing is easy and doesn't require powered landing. Vall requires powered landing, but using other planets and moons in the system makes achieving orbit very easy to do with much less delta V than is required for Moho since Moho is all alone. Pol, Bop, and Vall should all be within 100 points of each other. I would swap out the Moho points for the Vall points. Also, landing on every moon in the Jool system is worth more than Eeloo, so what's the point in going to Eeloo?

Laythe's score, along with all the other moons of Jool, come from the fact that it takes ~2000 m/s to intercept Jool, plus some dV to intercept them once you hit Joolean orbit. I may have overestimated the amount of dV it will take to intercept them, however. As for Moho's score, it's already higher than Laythe and Vall's score for landing. Returning is a bit different. Laythe is much tougher to take off from due to the atmosphere and the gravity, but looking at it again, Vall definitely shouldn't have such a high return value. I'll look into adjusting the point values.

As for Eeloo, if I'm not mistaken it takes more dV to intercept and land on all the moons of Jool than it does to get to Eeloo, making it a more difficult challenge.

EDIT:

Okay, I looked at and adjusted the scores of the planets. The biggest change is that Jool's moons are mostly worth a lot less now. I seem to have tacked on an extra 250 points (~2500 m/s) to most of the return scores for the moons for reason I cannot even fathom. I assume a ~3000m/s return burn + however much it costs to liftoff the planet. Some of the other scores are also adjusted. Full list:

- Moho return increased by 100 points (underestimated liftoff dV)

- Duna return increased by 50 points (underestimated liftoff dV)

- Ike landing decreased by 50 points (overestimated intercept dV), return decreased by 10 points (rounded to nearest 50 like the other scores)

- All Jool's moons landing decreased by 100 points (overestimated intercept dV).

- Laythe return decreased by 50 points (overestimated liftoff dV)

- Vall return decreased by 150 points (vastly overestimated liftoff dV)

- Tylo return decreased by 250 points (I don't even know)

- Bop return cost decreased by 250 points (again, I don't even know)

- Pol landing decreased by additional 50 points (overestimated landing costs), return decreased by 250 points (My brain was broken when I made these scores up, apparently)

Edited December 22, 2013 by RadHazard
Adjusted scores

[obi_juan]

I have a question... the score table in the first post is the updated version?

I have a interplanetary ship orbiting at 450km above Kerbin and I wanted to see what planet/moon will give more points for the delta-V of that ship.

I hate MainSails for interplanetary ships the Isp is very low.

[RadHazard]

Yes, the scoring table is updated.

I hate MainSails for interplanetary ships the Isp is very low.

Yup, and that's half of the challenge! (the other is building and piloting a lander with a giant six ton engine)

[gamerpuppy]

im working on an eve lander right now. will report back

[ThreeMartiniLaunch]

Mainsails to Eeloo and back.

I believe that's 850pts.

TML