Kerbal X to the Mun... and back

[jake9039]

I keep seeing these, and think" man, not enough fuel? I could likely do it just fine, if I land at just the right spot"

Edited February 1, 2015 by jake9039
forgot the second"

[Boris here]

I actually managed it on Super Uber Hard Mode!!!

I hope these screenshots will be enough of proof

Ps. Sorry for my english, I'm not from an english-speaking country... Also, don't mind the FMRS mod window up there. You can check it, it didn't help me in this challenge in any way.

[GigaG]

Could I drain the MonoProp from the capsule? Or is that cheating? What about editing staging so the clamps go off when the engines ignite?

[Death Engineering]

When this thread floated back to the top after 0.90 dropped, I was surprised to learn that the Kerbal X was now truly a Munar return capable craft. My first test flight brought the crew back to Kerbin with ~24 units of fuel left, without really trying to be efficient - just being careful.

Flew it again today with more attention to efficiency and had over 50 units of fuel left at entry interface. The Kerbal X was loaded directly from the Space Center (did not enter the VAB) and flown completely stock - derpy staging and all. The only slight deviation was 'chute deployment as I wanted to bring back the fuel and Poodle, not just the command pod.

Perhaps didn't need a short burn at landing to slow down but did not want to break anything or tip over. Crew and command module recovered with 47.76 units of fuel remaining. There's the line in the sand.. who is going to beat that?

About 3 km south of KSC with 47.76 fuel remaining.

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[PLAD]

47.76, that's pretty good. I did a run with the 24.2 Kerbal X when it first came out and I discovered it could do the Mun-and-return. I had 71.27 units of fuel left just before I ditched the service module on re-entry. (It's the fifth entry in the thread.) Since I didn't land the service module I figure you should get a bonus (or I a penalty) for what you used landing, and I used Mechjeb for guidance and reporting, but I think I still beat that. I was judging mission efficiency by total dV expended which was 6869m/s (I later did it with 6809m/s with the .23.5 Kerbal X and a refuel but that is another story.)

I cross your line in the sand, sir!

(I can't beat your pose-with-the-flag photo though!)

[kookoo_gr]

First attempt, will try again and aim for Kerbin

Stats of Kerbal X

[Death Engineering]

Now that the Kerbal X can make it to the Mun and back.. I wondered, "what else can it do?" I flew it to Duna and got back into orbit but was about 170 ÃŽâ€v short to get back to Kerbin. Maybe draining the RCS and getting the kerbs to get out a push would get it back from Duna, but not really how I roll.

How about Ike? Used a Duna aerocapture but had to make a mid transfer course correction because even though the burn from Kerbin orbit showed a perfect Duna encounter, about a third of the way to Duna the encounter went mysteriously (recalculated itself) way off course. Appreciated thrust limiting for fine tuning the aero brake, though!

Other than visual mods, used Kerbal Alarm Clock and Trajectories (doesn't help as much around Duna but it's at least in the ballpark for aero brake maneuvers here). Kept the staging stock but deployed the 'chute with a mouse action instead of staging (to recover the upper stage) and tweaked its altitude and min pressure settings.

Kerbal X to Ike and Back - Recovered from Kerbin>Ike landing>Kerbin with 46.42 fuel remaining. That's very beatable..

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[PLAD]

Kerbal X to Ike and back. Not bad. But you know, the stock Kerbal X can legitimately make it to Duna's surface and back to Kerbin. It just takes a few extra tricks.

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It is interesting to consider all the bodies that the Kerbal X can get to. I think it can do a land-and-return to Mun, Minmus, Gilly, Duna, Ike, Bop, Pol, and Eeloo. And a safe landing (but no return) on Moho, Eve, Dres, Laythe, and Vall. Only Tylo's surface is beyond its reach.

[Death Engineering]

Kerbal X to Ike and back. Not bad. But you know, the stock Kerbal X can legitimately make it to Duna's surface and back to Kerbin. It just takes a few extra tricks.

http://imgur.com/a/cNG8P

It is interesting to consider all the bodies that the Kerbal X can get to. I think it can do a land-and-return to Mun, Minmus, Gilly, Duna, Ike, Bop, Pol, and Eeloo. And a safe landing (but no return) on Moho, Eve, Dres, Laythe, and Vall. Only Tylo's surface is beyond its reach.

Cool to see a "hi-miler" gravity assist approach. When I was less than 170 ÃŽâ€v from returning to Kerbin with standard Hohmann transfers, it did occur that with Eve and Tylo nearly anywhere would be accessible.

[pvtnum11]

IKE WITH THE X - HOLY KRAKEN.

I'm seriously impressed.

[MarvinKitFox]

IKE WITH THE X - HOLY KRAKEN.

I'm seriously impressed.

Mostly, it's because of the rather extreme nerfing of the game difficulty.

Back in .19 or so, this feat would have been ludicrous^2

Now it is just very very hard.

[Whirligig Girl]

Since 0.24 buffed the Isp of the Mainsail, and lowered the mass of the Poodle, this is a super-easy challenge. It's literally too easy to go to the Mun with it! I want my Mun rockets to be big and bulky.

EDIT: And this is an old challenge from before the buff.

[Coga19000]

So... are we supposed to do the challenge now, or not?

[pvtnum11]

It's still a good test to see if a player has learned efficient ascent into orbit and good orbital maneuvers. A number of folks I challenged with on FB this were unable to do it for several tries and only just barely were able to pull it off. So what's easy for an experienced player is indeed a challenge to the inexperienced ones, or the players who are used to the "MOAR BOOSTERS" school of thought when conducting Mun missions.

[von Ziegendorf]

I also made it to Duna and back. It's based on PLAD's concept but I tried more direct approach.

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[PLAD]

Von Ziegendorf, that is freaking brilliant. You didn't even need to remove the monopropellant from the ship to make the trip, even with it you would have had about 28m/s left at the end. I had thought it was not quite possible to make the trip without Vector's multi-Mun-flyby trick, but you did it. I see several of my tricks are obsolete. Some observations-

-You got into orbit for only 4354m/s. That is the best I've ever seen for the Kerbal-X. Thanks for showing the ascent profile so I can use it from now on!

-Your landing about 500m higher than me on Duna cost about 7m/s on the landing (assuming I'd done it as perfectly as you did, which I didn't) but saved about 33m/s on the return to orbit. This suggests there is a perfect altitude to land at that is somewhat higher than 1200m.

-Your path took 102m/s more to get from Kerbal's surface to Duna's atmosphere than mine (in 8 years less time!), but 80m/s less to get from there home. This shows it is possible to do the Kerbin-Duna-Kerbin round trip for only 7072m/s.

I've dreamed of having a 'Kerbal-X to anywhere' challenge, where entries would try to land the stock Kerbal-X on the various bodies (or land-and-return) with the least dV used or most fuel left. (This to the Mun... and back thread would be a subset of it.) My worry has always been that the next version of KSP would change the X's specs and make comparisons difficult. Well, and that there would be no entries for most bodies. Maybe when KSP 1.0 comes out.

Food for thought-Metaphor got from Kerbal's surface to a Moho landing for 7217m/s. The Kerbal-X has 7202m/s of dV available, taking isp losses during ascent into account. Now that would be a challenge...

[von Ziegendorf]

Thanks. Here we meet again. It seems there are only few people in KSP who mastered gravity at this level

Moho is definately within reach. You just need to perform Kerbin gravity assist (MESSENGER's Earth) which Metaphor skipped. This will save about 200m/s. The hardest part would be the actual landing on the surface. This may be tricky even with MechJeb assistance. The ascent to LKO is interesting and I'm sure that Ascent Guidance isn't the one for the job. Finding the most optimal launch profile is of course doable but then we would need some kOS script to execute it. Moho landing can also be optimized (possibly a lot) by using good GNC script.

PS: changing turn start altitude to 9km lowers dV to 4350m/s

edit

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Edited March 23, 2015 by von Ziegendorf

[PLAD]

In my LKO to Jool orbit for 1051m/s thread I made it from LKO to Eve on 993m/s. In this thread Vector made it from LKO to Eve for 873m/s! So I bet 7217m/s to Moho can be beaten by more than 300m/s with a but it would be an epic task.

I fiddled with the Kerbal-X launch parameters and found that using all the ones you used except for dropping the acceleration limit from 25to 22m/s^2 gets you to a 75x75 orbit for 4344m/s. How low can this go?!?

[von Ziegendorf]

That's why I wrote that ascent is interesting. Maybe we should really do a research and find the ultimate trajectory (not using MechJeb's guidance)?

As for the further goal to achieve, I think that roundtrip to Gilly, Mun, Minmus, Ike, Bop, Pol can be done without much trouble. We've done Duna as well. This Moho landing can be done now, this 200m/s gained on Kerbin departure is more than needed. And perhaps all those deep space burns can also be minimized. What I think is that the biggest challenge is mission to Eeloo and back.

[PLAD]

I got a little 12-ton SSTO from Low Kerbin Orbit to Eeloo landing and back for 2897m/s. In a separate 1-way trip I shaved 21m/s of the K-E leg of the trip, so I'm sure an Eeloo landing and back can be done for 2876m/s. With these new Kerbal-X ascent trajectories it has ..2876m/s available in LKO. Considering the required starting window there just isn't much room for improvement on this (I flew just 200 meters over Mun's surface on its flyby!). So Kerbal-X to Eeloo surface and back would be the most epic trip of all, I agree. I don't think Vector's trick can be used because you would have to do 5 Munar flybys and 13 orbits around the Sun and then arrive at Kerbin in a 12-hour window (to then head on to Eve). Maybe Metaphor could do it.

Heh. You know, your resounding victory in Jasonden's old flyby challenge was a big motivation for me to write Flyby Finder. Have you ever used it?

I like to use Mechjeb for ascents because it is repeatable, so I can vary one parameter at a time and see the result. Someone would have to go theoretical to do better. I know there are a couple of autopilot scripts out there, has anyone already developed an optimized ascent algorithm?

And here's a Kerbal-X to the Mun addendum challenge- is it possible to Launch from Kerbin, land it on both Mun and Minmus, and return it to Kerbin? I think it's about 150m/s short, but just maybe there's a way.

[DMSP]

Once my CPU works, my idea is:

Wait for the right time.

Launch straight up, save fuel.

(If necessary, use packs for transfer burn)

Decelerate.

Land.

Wait.

Launch into orbit and relax.

Send a tanker, 'cause that thing is finishing the mission it started.

- - - Updated - - -

Oops...

I just read the last couple of pages....

New target:

Eeloo!

[von Ziegendorf]

I've seen your Flyby Finder but I played mostly on RSS last year. You released RSS version when I already landed almost everywhere

In your SSTO trip you didn't flew by Jool in its nodes with Eeloo orbit. If I see correctly you came with some normal velocity to Eeloo. Maybe here is something to improve?

Also I figured out how to get to Dres and back. You have to get to Jool, get captured there, and the depart to Dres into its orbital plane (day 11610). This should reduce difficulty from impossible to Eeloo level. The only problem is that Kerbals would have to wait 8 years on Dres for another good widow to Jool (day 14811).

This ascent optimization sounds like ordinary variation problem. We have a trajectory which is a function of pitch angle vs time and perhaps throttle control vs time. We would like to maximize the mass in orbit which is a value of some integral dependent of those two functions. The only problem here is that this mass function does not have any equation. It has to be evaluated numerically. I think I can do that but as for now I don't have any idea how to start.

And unfortunately I think that Mun-Minmus run is impossible You can't make landing cheaper than SOI escape velocity which is 775m/s for Mun and 239m/s for Minmus. To land and return each of them must be expended twice. The burn from 75km LKO to inner edge of Mun's SOI is 839m/s. All those together sum up to 2867m/s which is the absolute minimum.

[oriramikad]

Can I have the rocket stay in orbit while my Kerbal goes down and back up again?

[Musicrafter]

Have to post an Imgur library. Putting an image from your hard drive won't show up on anyone elses computers

[Roerk]

Holy crap... I dunno how I did this, but I did.

Been playing KSP for a long time. I don't think any of my mods affect stock parts, but if they do, I just cheated. Sorry.

Created a forum account just for this.

EDIT: Never mind, this was in 1.0, all these others were in 0.90. I'm an idiot

Edited December 30, 2015 by Roerk
Fixing my idiotism