Minmus with Ion engines (and now other moons!!)

[Captain Sierra]

Going to the Mun is like going to work for many of us. Going to Minmus isn't much harder. Unless you have to go electric.

After testing out a new 'green' hybrid car, the KSC are hooked on this whole 'conserve fuel' thing. They have asked you to build a manned Minmus lander that does not use nuclear or chemical engines, only electric (lander only, not launcher or transfer stage).

You may use mods to give yourself greater variety of ion engines. Some that I encourage are the ion hybrid electric pack (but you may not use the hybrid engines), KSPX, and RLA electric engines. Your lander must be manned and you must return the kerbal safely to kerbin.

You may NOT use the transfer stage to aid your descent in any way other than the de-orbit burn. ALL landing decelleration must be under ion power.

Scoring: based on points

Use of mods: separate leaderboard

Weight: 10 pts per ton

Engines: 10 pts per engine running AT FULL THROTTLE indefinitely.

No return stage: 75 pts

Landing lander on Kerbin: 25 pts

use of electric engines on transfer/capture stage: 25 pts

Use of electric engines on kerbin ejection stage: 100 pts

Kerbin SSTO launch: 50 pts

Has capsule (no lawn chairs): 25 pts

extra kerbals: +25 pts per kerbal landed and returned to kerbin alive

Starting at sea level (under 500m alt): 10 pts

Starting on ridge (over 4km alt): -5 pts

Fits inside fairing: pts per size (size chart below; based off KW Rocketry sizes)

3.75m expanded: 10 pts

3.75m: 15 pts

2.5m expanded: 25 pts

2.5m: 30 pts

1.25m expanded: 45 pts

1.25m: 50 pts

Wanna go elsewhere? Here are some other locations and the bonus pts you can earn from going there. All interplanetary missions are scored in a separate leaderboard.

Gilly: 150 pts

Bop: 200 pts

Pol: 175 pts

Eeloo: 225 pts

Pics or it didn't happen.

Local (kerbin system: Minmus)

Stock:

1: infatuatedPP - 310 pts

2: WafflesToo - 23 pts

3:

4:

5:

Mods:

1:

2:

3:

4:

5:

Interplanetary (other systems; moon landed on will be indicated on score)

Stock:

1:

2:

3:

4:

5:

Mods:

1:

2:

3:

4:

5:

This is very doable. I have a lander that can do it. I'll post pics when I actually finish the mission.

Edited September 3, 2013 by Captain Sierra
updated pts

[Tw1]

Sure about including the hybrid pack? As much as I like them, you can just about land on the Mun with them if your craft is super light, and you fly very well.

[Captain Sierra]

Well, I guess I may change that. I did notice it has changed a LOT since the version I am still using (XD). As aforementioned, only the larger ions are allowed, not the hybrids. I'll download the latest version and do some testing. I know RLA EE is quite balanced for this.

[DaveofDefeat]

The rules confuse me, can I only use electric from launch pad to minmus? if not when can I not use chemical? Can I use rcs? Can I use docking?

[Captain Sierra]

You can use any engines to get into orbit of Minmus, You must land and take off with electrics. As per scoring, you get more points for using electric engines for other areas of the challenge.

[Johnno]

Engines: 5 pts per engine running AT FULL THROTTLE indefinitely.

This implies that we're supposed to set infinite fuel, please confirm.

[Epthelyn]

This implies that we're supposed to set infinite fuel, please confirm.

Xenon tanks can last for thousands of dV, Minmus only requires a few hundred to land and take-off again. It's practically infinite for the purposes of this challenge, even without Alt-F12.

I think the idea is that you'll need enough solar panels to keep the engines running at full throttle.

Confirmation would be nice though

[Captain Sierra]

Xenon tanks can last for thousands of dV, Minmus only requires a few hundred to land and take-off again. It's practically infinite for the purposes of this challenge, even without Alt-F12.

I think the idea is that you'll need enough solar panels to keep the engines running at full throttle.

Confirmation would be nice though

You are correct. Xenon is not the limiting fuel factor. That scoring is meant for how many you can power at once WITHOUT your power depleting.

[Ninety-Three]

I'm not sure I like the idea of awarding more points per ton instead of the usual challenge style of rewarding efficiency, it's going to lead to the challenge winner being whoever's computer can handle the three thousand solar panels that it takes to power their hundred ton ship. Despite my reservations, I've had a lot of fun messing around with solar panels on Minmus, so I'll be signing up.

A clarification: The 75 points for "no return stage", am I right in reading that as "Single stage ion vehicle"?

[Captain Sierra]

I'm not sure I like the idea of awarding more points per ton instead of the usual challenge style of rewarding efficiency, it's going to lead to the challenge winner being whoever's computer can handle the three thousand solar panels that it takes to power their hundred ton ship. Despite my reservations, I've had a lot of fun messing around with solar panels on Minmus, so I'll be signing up.

A clarification: The 75 points for "no return stage", am I right in reading that as "Single stage ion vehicle"?

What that means is that the lander can take off from and achieve orbit around Minmus and then return to and deorbit at Kerbin without docking to a separate return vehicle, push stage, or without dropping the existing ion stage used to land. It means you use teh same engine to land, take off, return to Kerbin, and de-orbit.

[SunJumper]

It'll be interesting to see how much the smallest one weighs. Now that we can do it with the seats, this shouldn't require some behemoths...

[Captain Sierra]

I can do it with a mk 1 lander can with RLA electric engines 1.25m resistojet cluster and it weighs 3.21 tons.

[WafflesToo]

This actually sounds like a fun engineering challenge.

Let's see... Minmus gravity at sea-level is 0.491 m/s^2

The theoretical maximum acceleration for ion engines (assuming one can of fuel per engine) is right around 1 m/s^2

You are quite correct, very doable (though it will require a different piloting technique from what most of us are used to with landers I'm quite sure). Gonna start on my shot and see where I get.

@Ninety-Three - Normally I'd agree with you; however, given the PATHETIC thrust-to-weight ratio of ion engines and coupled with the engineering challenge of powering more than a handful at a time I think Captain Sierra is correct to give more points to delivering larger payload in this case. I'm actually terrified to consider some of the hermaphroditic monstrosities that will come out of this XD

[Captain Sierra]

This actually sounds like a fun engineering challenge.

Let's see... Minmus gravity at sea-level is 0.491 m/s^2

The theoretical maximum acceleration for ion engines (assuming one can of fuel per engine) is right around 1 m/s^2

You are quite correct, very doable (though it will require a different piloting technique from what most of us are used to with landers I'm quite sure). Gonna start on my shot and see where I get.

@Ninety-Three - Normally I'd agree with you; however, given the PATHETIC thrust-to-weight ratio of ion engines and coupled with the engineering challenge of powering more than a handful at a time I think Captain Sierra is correct to give more points to delivering larger payload in this case. I'm actually terrified to consider some of the hermaphroditic monstrosities that will come out of this XD

Glad to see another competitor. Stuff is getting in the way and KSP is blowing me up at every turn (it's literally hitting me with every glitch I know the game has) so my attempt is delayed. My lander is 3.21 tons and uses a single engine (though from the RLA EE pack with thrust of 8) I may change out the engine to make it more efficient or I might make it heavier. Suddenly I get the idea for a full 2 man lander >: D

I'm considering adding the following to the scoring:

plus a few points for starting from sea level and possibly minus a few less points for starting on one of the 5 km high plateaus. No points added or removed for starting at average Minmus height (2-3km according to the wiki).

Thoughts?

Edited September 2, 2013 by Captain Sierra

[Ninety-Three]

Ignoring the points, I built a maximum efficiency model that is theoretically sound, and weighs in at under 620 kg, manned. It's currently in orbit and awaiting me to be struck by the fit of patience required to set up a Minmus intercept that coincides with good solar power, I'll probably have photos in by the end of the day.

[thereaverofdarkness]

This is actually a very easy challennge. I think it could be neat to add more bodies into the challenge, and consider the TWR that ion engines have on their surface. I estimate that an ion engine can just barely pick itself off the Mün with very little thrust left over for any other weight, making it vaguely feasible to have an ion-powered Mün lander. That could perhaps be the ultimate challenge, while other bodies with less gravity than Mün but more than Minmus could have varying score values.

I have an ion craft I put on Minmus a while back. It's fully capable of taking off again but it has no parachute. Maybe if I'm not lazy later I'll post a pic of it.

[WafflesToo]

All stock 2 kerbal lander massing just over a ton. Made one attempt this morning that resulted in a new crater on minmus due to pilot error.

Oh well, recruit more Kerbals and try again

[infatuatedPP]

I have completed the challenge. The lander is all stock and weighs in at 4.5 tons fully fueled, can run 8 engines at max throttle indefinitely (this leads to a slight thrust imbalance, so running 9 at ~90% is better) and has enough fuel to leave low Kerbin orbit, land on Minmus, and return.

http://imgur.com/a/nCrgB

Points:

Weight: 4.5*10 = 45

Engines: 8*5 = 40

No return stage: 75 pts

Landing lander on Kerbin: 25 pts* I am not sure what qualifies as landing, a number of peices exploded but the command pod survived

use of electric engines on transfer/capture stage: 25 pts

Use of electric engines on kerbin ejection stage: 100 pts

45+40+75+25+25+100 = 310

As a confession I did use Kerbal Engineer during the flight for data. I hope this doesn't disqualify me from being a stock entry.

[Captain Sierra]

I'll let it slide as a stock entry. I will also let the landing slide since a KSP landing is any landing you can walk away from. Updating leaderboards now.

I may also shut this challenge down in a week or so and then re-open it as where can you land with ion engines.

[WafflesToo]

I'll let it slide as a stock entry. I will also let the landing slide since a KSP landing is any landing you can walk away from. Updating leaderboards now.

I may also shut this challenge down in a week or so and then re-open it as where can you land with ion engines.

In that case my last attempt was flawless since both pilots survived (although the ship was in no shape to get them back into orbit XD)

[WafflesToo]

Just landed back on Kerbin. Sure enough, third time was the charm

Flying a lander with such a poor TWR was a bigger challenge than I thought it'd be (mostly having to relearn/rethink the relationship between vertical velocity and altitude, actually had to solve the problem using maths!)

Still haven't edited the video yet (about an hour-and-a-half uncut) but I did manage to get some screenshots.

http://imgur.com/a/JktBw

Lander mass 1.385 tons = 10 pts

2 engines at full power = 10 pts

Giving my attempt a whopping 20 points XD

I was wondering, is KOR (Kerbin Orbital Rendezvous) allowed? Meaning, if I left a kerbin lander in orbit around Kerbin, flew the ion lander to Minmus, performed the mission, then flew it back to Kerbin, rendezvoused in orbit with the Kerbin lander and rode it back to the surface would it count for No return stage, use of electric engines on transfer/capture stage, and Use of electric engines on kerbin ejection stage?

[Starwaster]

Question, if the Minmus landing party has to be rescued, does the rescue craft have to be an ion powered lander too? I only ask because it seems that half of my missions are rescue missions.

I'm getting rather good at it too! (hmmm maybe the rescue pilots should be the ones flying the main missions...)

[Captain Sierra]

Just landed back on Kerbin. Sure enough, third time was the charm

Flying a lander with such a poor TWR was a bigger challenge than I thought it'd be (mostly having to relearn/rethink the relationship between vertical velocity and altitude, actually had to solve the problem using maths!)

Still haven't edited the video yet (about an hour-and-a-half uncut) but I did manage to get some screenshots.

http://imgur.com/a/JktBw

Lander mass 1.385 tons = 10 pts

2 engines at full power = 10 pts

Giving my attempt a whopping 20 points XD

I was wondering, is KOR (Kerbin Orbital Rendezvous) allowed? Meaning, if I left a kerbin lander in orbit around Kerbin, flew the ion lander to Minmus, performed the mission, then flew it back to Kerbin, rendezvoused in orbit with the Kerbin lander and rode it back to the surface would it count for No return stage, use of electric engines on transfer/capture stage, and Use of electric engines on kerbin ejection stage?

Upon review, your score:

1.3 tons = 13 pts

2 engines full power = 10 pts

total score = 23 pts

And yes, the landing counts XD

[Captain Sierra]

Question, if the Minmus landing party has to be rescued, does the rescue craft have to be an ion powered lander too? I only ask because it seems that half of my missions are rescue missions.

I'm getting rather good at it too! (hmmm maybe the rescue pilots should be the ones flying the main missions...)

If they land and survive on Kerbin, no. If they are stranded on Minmus, yes, rescue them. BUT crash landing on Minmus and then rescuing does not count. If you want to do an ion powered rescue mission, you could enter that but crashing kinda DQ's your previous attempt.

[WafflesToo]

*snip*

I'm considering adding the following to the scoring:

plus a few points for starting from sea level and possibly minus a few less points for starting on one of the 5 km high plateaus. No points added or removed for starting at average Minmus height (2-3km according to the wiki).

Thoughts?

I don't think the altitude thing matters for Minmus so much (not like Eve!)

I'd say adding rovers, science package stuff and the "lander fits inside a fairing" clauses would do a lot to add to the challenge.

Especially the fairing bit XD

Doubly so if you score off of the radius of the fairing

Also, scoring for the number of Kerbals landed...

That's all I can think of right now.

I really am enjoying this challenge so far. It's the kind of challenge that encourages play different from what you normally would do (I really hadn't played with the ion engine much except on paper before this).

Edited September 3, 2013 by WafflesToo