Early Career Mun Landing

[Popestar]

I have seen multiple posts claiming that people can get to the Mun and back for cheap early on in career mode, and I've seen even a few of those suggest that you can land on the Mun and get back in early career mode. I'd like to put that to the test and see if it's really possible.  And so, I present to you...

The Kerbeagle Has Landed

This challenge is to see if people really can get to the Mun and back, with a landing, during early career in KSP.  People have claimed that they can do this, so I say to put your funds where your mouth is. 

As is customary with challenges, there have to be rules.  And so, I've come up with the following list of rules to be used for this particular challenge:

1. Career mode only!
2. The buildings allowed to be upgraded are the Astronaut Complex,, Mission Control and Tracking Station.  Having access to maneuver nodes is not challenge-breaking, and these end up being the first few buildings upgraded anyhow.  But no upgrading the VAB or Launchpad!
3. With no upgraded VAB or Launchpad, this limits part count to 30 and tonnage to 18.  Your Mun Lander needs to have the capacity to land on the Mun, then take off from the Mun's surface, and then get back to Kerbin.  Doesn't matter how you accomplish this task, so long as your get your Kerbals home.
4. No technology in the tech tree beyond level 4.  That gives you access to the following tech nodes:
   1. Level 1:  Start
   2. Level 2:  Basic Rocketry, Engineering 101
   3. Level 3:  General Rocketry, Stability, Survivability
   4. Level 4:  Advanced Rocketry, General Construction, Aviation, Flight Control, Basic Science
5. Mods are fine, so long as they do not alter the basic physics, part count, or weight of the parts available.  I am not familiar with most of the mods available, so I'll have to take your word for it!
6. No modifying save files or anything like that to alter part count or weight after build!  This is for fun and is on the honor system for completion, so please don't cheat!
7. You shouldn't have access to it, but I'll state it to be clear:  no refueling on the way to the Mun, on the Mun, or on the way back from the Mun.
8. You can use any pilot you have access to, but they must not be higher than level 1.  So they personally have no access to anything but Prograde or Retrograde (and you won't have unlocked a high-enough tier to get MechJeb access to those either, I believe).

So, how does one "win" in this challenge?  Simple - by getting to the Mun, landing, and returning back to Kerbin in one flight.  You must launch from the site of your choice, fly to the Mun, land, fly back to Kerbin, and land on the surface of Kerbin, all in 1 flight, without refueling.

How do we know you've won?  Screenshots, and lots of them!  Pictures of your vessel on the launchpad, the lander on the Mun, and then whatever you returned to Kerbin.

FULL DISCLOSURE:  I have not yet complete this myself, so to avoid this looking like me just wanting to pilfer builds from people, I will ask that entrants do NOT post their vessel specs.  If you want to post part count or weight, that's up to you, but I won't require it.  I am not looking to steal ideas on how to get this done, but rather I'm curious about seeing it in action.  People keep saying they can do it, so I want to see that happen.

If this challenge is not an acceptable one, or if the mods/admins/forum deities decide that this should not happen, please feel free to PM me and close the thread!

 

Completionists

1. @king of nowhere, on 10/16/2020
2. @Superfluous J, on 10/19/2020

Edited October 24, 2020 by Popestar

[Superfluous J]

I feel like I've done this before. I mean, I KNOW I've done this mission before but I think I've done a challenge very close to this challenge before.

But anyway, I'm in. I probably will used a totally untrained Jeb or Val just because I can't bother to get them the experience first, but I'm cheating in the cash and science to set my career up so all I have to do is the challenge. I assume that's okay?

[Popestar]

22 minutes ago, Superfluous J said:

I feel like I've done this before. I mean, I KNOW I've done this mission before but I think I've done a challenge very close to this challenge before.

But anyway, I'm in. I probably will used a totally untrained Jeb or Val just because I can't bother to get them the experience first, but I'm cheating in the cash and science to set my career up so all I have to do is the challenge. I assume that's okay?

I think that's ok.  I know a lot of people would have to start a new career over at the beginning to do this, so I would have no problem with you doing something to get you to the buildings/tech you need for this.

[Pds314]

" the Lander will have, at a minimum, 8 parts"

Hmmm..... not totally sure that's true.

[Superfluous J]

1 hour ago, Pds314 said:

" the Lander will have, at a minimum, 8 parts"

Hmmm..... not totally sure that's true.

Well considering it's @Popestar's challenge it's 100% true.

And in fact it's why I may bow out. requiring a heat shield hurts because heat shields don't allow crossfeed. Without that, you can't stack fuel tanks on top of the lander to double-dip on its engine.

Edited October 15, 2020 by Superfluous J

[Pds314]

Just now, Superfluous J said:

Well considering it's @Pds314's challenge it's 100% true.

And in fact it's why I may bow out. requiring a heat shield hurts because heat shields don't allow crossfeed. Without that, you can't stack fuel tanks on top of the lander to double-dip on its engine.

I'm not sure if it's intended as a rule or as advice.

[Superfluous J]

1 minute ago, Pds314 said:

I'm not sure if it's intended as a rule or as advice.

Oh I took it as a rule. if it's advice, my lander will be 4 parts: chute, pod, tank, engine.

[Pds314]

WHAT THE HECK PLANES HAVE NO BRAKES!!???

Literally the B key is not doing anything on my science plane.

EDIT: restarted and verified integrity of the files.

Edited October 15, 2020 by Pds314

[Superfluous J]

I have a ship that'll do it. I won't post specs but yeah, I could not do it with the heat shield and didn't need landing gear. I did include a battery as my vessel's COM did not line up with COT, so it needed SAS to keep a heading which would chew through electric charge. But Jeb got to Mun, landed, and came home with a whole 142 m/s left to slow down before atmospheric reentry.

It should be noted that while this is very possible and not exactly difficult, the margins are very tight and you have to both build and fly with an eye on very tiny margins. That's why i needed to drop the heat shield: My margins wouldn't allow for two Terriers when one would do.

Video eventually.

Edited October 15, 2020 by Superfluous J

[Pds314]

Alright. I have maxed out the first four layers of the tech tree in three flights by Year 1, Day 1, 1 hour, 1 minute. None of which actually went to orbit, although one went to space. Let's see if I can build a Mun mission.

[Pds314]

I'm pretty sure it's doable if you don't have the heat shield or landing legs. With them it should theoretically be doable but at least my current rocket design really throws away a lot of Delta-V to gravity losses. On the pad I have, theoretically, 5668 Delta-V. But by the time I'm in LKO I only have 2013. Seeing as getting to LKO doesn't normally take 3600 Delta-V I think I'm flying it at highly suboptimal efficiency.

I might try ditching the legs and the heat shield and adding more fuel, and also optimizing the flight profile a bit.

[Pds314]

I might just try the brute force route of orbital rendezvous and shove.

[Popestar]

It was intended as advice, because my mind is weird.  If you want to do reentry without a heat shield, go for it.

[Popestar]

I updated the Rules of the challenge to more accurately reflect what @Superfluous J had asked about.  When I wrote the rules, I made the (incorrect) assumption that everybody would have a lander that had at a minimum pod, chute, 3 legs, heat shield, engine, and fuel tank.  8 parts.  However, this is not the only way to go about doing this, so I updated the rules to state that it doesn't matter what your lander looks like, provided you are within the 30 total parts/18 total tons rule AND you can get your Kerbals onto the surface of the Mun and then back to Kerbin.  If you can do it without legs or a heat shield...go for it.

[camacju]

Are we allowed to upgrade the Astronaut Complex?

[camacju]

I'm getting 2300 ish delta-v in orbit, which isn't enough to get to Mun and back unless I can use the EVA pack.

[king of nowhere]

i am one of those that said early career, and indeed i've done it cheap enough, but i did have a level 2 launch complex. trying without will be challenging.

do the landings need to be manned or not?

[king of nowhere]

another question, am i allowed multiple flights?

 

and, do i have to plant a flag on mun, or just touch down? i can skip landing gear in the latter case

do the ship have to land back to kerbin, or just the astronaut? in the latter case, i can skip the parachute on the ship

EDIT: I take back all the questions. with astronaut complex level 1 i cannot make EVA, so i cannot plant flags, and i cannot eject my astronaut close to kerbin surface and let the ship crash on return. also my plan to have the first ship land on mun and get back to orbit, running out of fuel in the process, and have the astronaut get out of the ship, finish orbiting with the jetpack, and wait a second rescue ship, must be scrapped.

Edited October 15, 2020 by king of nowhere

[Popestar]

5 hours ago, camacju said:

Are we allowed to upgrade the Astronaut Complex?

Yes.  Just be careful that the pilot you use isn't more than level 1.

4 hours ago, king of nowhere said:

i am one of those that said early career, and indeed i've done it cheap enough, but i did have a level 2 launch complex. trying without will be challenging.

do the landings need to be manned or not?

Landings do not need to be manned, but you won't have access to the OKTO as that's in Electrics and Level 5 isn't allowed.  To answer what might be the next question - the LANDER has to return to Kerbin.

3 hours ago, king of nowhere said:

another question, am i allowed multiple flights?

 

and, do i have to plant a flag on mun, or just touch down? i can skip landing gear in the latter case

do the ship have to land back to kerbin, or just the astronaut? in the latter case, i can skip the parachute on the ship

EDIT: I take back all the questions. with astronaut complex level 1 i cannot make EVA, so i cannot plant flags, and i cannot eject my astronaut close to kerbin surface and let the ship crash on return. also my plan to have the first ship land on mun and get back to orbit, running out of fuel in the process, and have the astronaut get out of the ship, finish orbiting with the jetpack, and wait a second rescue ship, must be scrapped.

You are not allowed multiple flights.  It should really be 1 launch to get you there and back.

The ship has to make it back to Kerbin.  But, as I pointed out above, you can upgrade the Astronaut Complex.

[Pds314]

5 hours ago, camacju said:

I'm getting 2300 ish delta-v in orbit, which isn't enough to get to Mun and back unless I can use the EVA pack.

The only way to use the EVA pack is getting out of the vehicle on the ground.

21 minutes ago, Popestar said:

Yes.  Just be careful that the pilot you use isn't more than level 1.

Landings do not need to be manned, but you won't have access to the OKTO as that's in Electrics and Level 5 isn't allowed.  To answer what might be the next question - the LANDER has to return to Kerbin.

You are not allowed multiple flights.  It should really be 1 launch to get you there and back.

The ship has to make it back to Kerbin.  But, as I pointed out above, you can upgrade the Astronaut Complex.

"Are we allowed to upgrade the astronaut complex"

"Yes"

 

That's a serious rules change. It means " get out and push" strategies are viable to get that last 150 m/s of Delta-V or whatever.

[king of nowhere]

7 hours ago, Pds314 said:

The only way to use the EVA pack is getting out of the vehicle on the ground.

"Are we allowed to upgrade the astronaut complex"

"Yes"

 

That's a serious rules change. It means " get out and push" strategies are viable to get that last 150 m/s of Delta-V or whatever.

he said that the lander has to come back to kerbin, so returning with the eva astronaut is not an option.

i have managed to stretch my fuel to 2550 in orbit, which is just enough to make the full trip. unfortunately, my ship is so aerodinamic, i crashed on coming back because it didn't aerobrake enough. and adding a decoupler after the command module would already be enough extra weight to stop me; I came back to kerbin with 12 m/s left. working on improvements

Edited October 16, 2020 by king of nowhere

[king of nowhere]

Done!

I made an awesome attempt using all the tricks I could conceive with a 3 stage vehicle. I had 100 kg left of weight to add, not enough for an extra tank, so I used a 100 mt high launch stability enchancer to clear up some atmosphere.

I repeated the launch several times to get the best outcome. i pushed every manuever to the limit, landing on mun and orbiting from it with less fuel than was needed according to the deltaV map; it entailed reaching below 1 km altitude still at full orbital speed. in the end, i arrived back on kerbin's atmosphere with 12 m/s left. there i spent a long time deorbiting, but when i entered the low atmosphere the reaction wheels were too weak to keep the ship pointed retrograde. it would flip prograde, and then it was too aerodinamic to slow down, crashing into the sea before the parachutes could deploy.

So I went back to mun orbit and instead of using the 275 m/s burn needed for a kerbin reentry, i gave myself a small nudge to stay in a high orbit around kerbin. there, i used multiple mun gravity assists to gradually lower my periapsis, and after 100 days of orbiting i managed to reenter atmosphere with 33 m/s left! not much to slow down from orbital speed, but the terrier engine has gimbaling and can be used to help the reaction wheel pointing the ship correctly. still, not enough. I still would flip around 1000 m/s. I also tried altering the ship attitude to gain some lift, but it was useless; at the altitude where i could do it, there was too little drag to make it worthwhile (considering without solar panels battery power was very limited); and at altitudes where the drag was useful, it was impossible to manuever around without spinning the ship. I reached 2000 m altitude still at 500 m/s. there, in desperation,  i would deploy the parachute while still in red. it would deploy without breaking. then it would open without breaking. the ship would suddenly slow down... and at around 300 m/s, the parachute would finally snap, sending the ship to its doom. I repeated this thing many times.

Of course I could not detach the engine and fuel tank. the 40 kg of the decoupler would make me lose some 50 m/s of deltaV, and I could not afford them.

 

So, I went back to the drawing board to get more deltaV, and I used my old trick of putting stages on top instead of bottom. the old design had a first stage with a reliant that would push it to around 20000 m and 700 m/s, then a terrier would finish circularizing, and the third stage had a second terrier to shed the weight of the empty tank. of course this uses 3 engines. worse, the terrier is not powerful to push stuff in orbit. in order to reach orbit with that low twr, i had to make a less steep gravity turn, which was less efficient.

Instead, I placed the second stage tank on top of the command pod. this way it would save one terrier engine. with the half ton saved, i was able to add a small fuel tank, and i added it to the first stage, giving some extra power to the reliant. because of this - and because the second stage was now lighter, having the same fuel but one less terrier engine - i had enough twr to execute a perfect gravity turn. I didn't adopt this configuration at first because i was worried about aerodinamics, but it actually flies well. the parachute is unbalanced, and it was a small issue on some manuevers, but by putting it on the east side, i was able to make the parachute's asymmetrical drag a natural part of the gravity turn

here i just disengaged the reliant

here i am getting into orbit with close to 3000 m/s remaining. I could stop posting here, as I think we all know that with 3000 m/s in orbit you can go to mun and back with a safe margin.

i pushed for a close intercept, for more oberth effect and less altitude to prepare for landing (i actually ended up at 6500 m periapsis). i also positioned very carefully the manuever to reach mun with the minimum speed.

here i temporarily stopped the injection burn to shed the second stage tank

i circularize on a very low orbit

i prepare for landing. to save fuel i make a very gradual fall. I picked the area just southwest of the big crater to land because there is a nice stretch of relatively flat land with few craters; it's one of the best landing spots on mun

at 1 km from the ground i still have not braked. but don't worry, due to my trajectory i still have some 30 seconds before impact. the terrier is much oversized for this small lander, but having a high twr allows me to make those kind of manuevers.

getting closer

touchdown! the lander is small enough that it can eschew landing legs. I landed with exactly 580 m/s. I managed 570 in my earlier try, here i've been a bit wasteful on the last part (and it turned out i could have waited a few more seconds before braking)

to show that the ship is actually stable and i'm not holding it in place with SAS, i decided to go out and plant a flag.

leaving mun. again, for greater efficiency i use a very inclined trajectory. the high twr helps.

It took 587 m/s to get back into orbit. i could have been a bit more efficient, but the asymmetric parachute is making my ship tilt to the side; I unintentionally gave a bit of inclination to the orbit, losing some efficiency. it's the price for placing the second stage over the third. I will still have almost 400 m/s left.

it turned out having an open node in the front of my capsule didn't hamper my aerodinamics as much as i was hoping, and the lateral parachute makes me more prone to flipping. i have to use the rocket to keep pointing retrograde; if the rocket flips, i won't be able to recover it and it won't slow down enough for the chute. the rocket still flipped, but slower than in the other attempt, so the chute didn't break.

yes, i could have just added a decoupler to jettison the engine and tank, and the capsule alone would aerobrake all right. but i like recovering parts.

did I just end on a river?

no, i ended on a ravine. the engine exploded because of the impact (i should have saved a bit of fuel to cushion it, but i was more concerned at increasing my chances of saving the pilot). the tank exploded rolling down the incline. luckily the command pod itself is sturdier.

and i stop in the river.

 

It was an interesting challenge at first, though once i found the right rocket to maximize deltaV, the rest became mostly trivial.

also, it was poorly named. this has little to do with early career. no upgrade on the launchpad makes little sense. it is much cheaper than other upgrades. a much more realistic "early career" scenario is to have a level 2 launchpad and a level 1 tracking station. heck, last challenge career i made, i went to the mun that way; and i did it with my second flying mission, so it certainly qualifies for "early career".

the mass limit is the only real limitation. adding just a few tons of allowed weight would mostly trivialize the challenge, even with no tracking station and a level 1 pilot.

[ralanboyle]

So, clearly a Mun landing in early career mode is possible. Thanks to @king of nowhere for showing us how to do it within the limits that @Popestar laid out. Because this challenge seems to have come from a genuine interest in the concept of early career mode Mun landings I want to show Popestar how I got there on the 3rd launch of my career mode speed run. I upgraded buildings after my second launch so it disqualifies me from this challenge.  

 

[vyznev]

Inspired by @king of nowhere's run, I also decided to give this a try. I actually flew this mission in Science mode (since I happened to have an existing save with all tech nodes up to tier 4 unlocked, just for challenges like this), but I made sure to respect the part count and launch mass limits and not to use any SAS modes other than attitude hold, prograde and retrograde. Up to Popestar if they want to count this as a valid entry or not.

Anyway, here's my lander (craft file on pastebin):

It's based on what's basically my standard early-game manned Mun lander design, with a five part core (parachute, command pod, decoupler, FL-T200 fuel tank, Terrier engine) and a pair of side-mounted FL-T400 drop tanks, stripped of any unnecessary stuff like science experiments and landing gear. The booster stage consists of two FL-T800 tanks (and a partially filled FL-T100 at the bottom, just to max out the mass limit and squeeze a few dozen extra m/s of delta-v out of it), a Reliant engine and four basic fins for stability.

Obviously, nobody would even think of launching such a… ballsy rocket in real life. But it works great in KSP. 

Mission screenshots below (more on imgur):

Spoiler

Here's the rocket on the launch pad. The initial TWR isn't great, but it's above 1, which is enough. It'll rise rapidly once the rocket gets lighter and the air gets thinner.

Starting a fairly aggressive gravity turn to maximize delta-v left in orbit. I'm basically aiming to get almost all the way to orbital velocity while still inside Kerbin's atmosphere.

Booster burns out at about 20 km and the upper stage takes over from there. At this point my pitch is down to about 40°, which is right about where it should be.

At this point I'm basically watching the time to apoapsis, trying to keep it between 30 to 120 seconds. I notice it dropping a bit too low, so I switch SAS mode temporarily from prograde lock to attitude hold to try to push the apoapsis up a bit. (If it went too high, I would've throttled down instead.)

Eventually the time to apoapsis starts rising again, and shoots up to 5 minutes once the orbit gets close to circular (which is also fine and normal). The remaining circularization burn needed is only 47 m/s.

At this point I'm in 75 km Kerbin orbit with 2704 m/s of delta-v left. I make a quicksave and start planning the Mun transfer.

I overshot the planned burn by just the tiniest bit, and ended up with a Mun periapsis of 718 m instead of the 7 km I'd been aiming for. Honestly I could've just gone with it and done a direct landing (since that's basically what I ended up doing anyway in the end), but I decided to play it safe and spend a tiny bit of delta-v on a radial correction burn to push my periapsis into a (marginally) safe altitude.

Executing the correction burn very carefully, with the thrust limiter lowered way down to avoid accidentally overshooting it. (This was the second attempt; the first time I wasn't so careful and accidentally pressed Z when I meant to press X, leading to a massive overshoot.  Fortunately I had a quicksave from before the burn.)

The fuel in the side tanks runs out about 2/3 of the way through the circularization burn at periapsis. The tanks are decoupled as soon as the delta-v on that stage hits 0 m/s, and end up becoming space debris on highly elliptical Mun orbits. (In real life, they'd probably crash into the Mun after a few orbits due to perturbations, but in KSP stable orbits will remain stable forever.)

I ended up dropping my periapsis a bit too low for comfort, so I finished up with a tiny radial burn to raise it above 7 km. The final orbit is quite nice and circular.

At this point, I start thinking about the best place to land, and realize that the ideal spot — on the equator, on the sunny side — is right where the lander will be in about a minute. So I slap in a quick maneuver node for a ballpark estimate and prepare for a braking burn.

Landing is fairly ordinary and uneventful. I could've optimized it to save a few dozen m/s of delta-v, but I figured I probably had enough anyway.

I ended up landing on a slight slope, and it turned out that, with no landing legs, the lander isn't quite stable enough to stay upright without SAS on. It is, however, stable lying on the ground with the nose pointed downslope.

Fortunately, the magic reaction wheels in the command pod are more than strong enough to flip the lander back upright again for takeoff. 

After circularizing at about 8 km, I had 286 m/s of delta-v left. Is it enough to return to Kerbin? Luckily, it turns out the answer is yes.

We're homeward bound with 13 m/s of spare delta-v left, and Jeb didn't even have to get out and push! This is also a good time to check and adjust the parachute settings.

Decoupling the engine and the fuel tank before entering Kerbin's atmosphere. I like my re-entry vehicles aerodynamically stable, thank you.  

Coming down on what looks like a nice tropical beach, complete with Baobab trees.

The water looks inviting, so Jeb decides to swim ashore.

And here we are, back home on Kerbin again.

All in all, this wasn't that hard of a mission, although the delta-v margin certainly is a bit tight. As king of nowhere noted, even just a few tonnes more allowed launch mass would make this significantly easier. Still, even with these constraints, I made some noticeably unoptimal choices during various parts of the flight and still made it home without having to resort to gravity assists or EVA pushing or any other tricky maneuvers.

[Popestar]

@vyznev, unfortunately that doesn't count.  Career mode only.