"We are not losing those kerbals!"

[Jm419]

The Story

As the Munshot A lifter cleared the tower, with the now famous trio of Jebediah, Bill, and Bob Kerman aboard, many a Kerbal at KSC breathed a sigh of relief. The budget cuts handed down by the Senate had forced the scrapping of the glorious heavy lifters of the past, and the smaller rockets like the Munshot series didn't have all the bells and whistles of the larger vessels.

With the President pressuring KSC for a successful Mun launch, and the Senate slashing funding, the Munshot had been a rocket built more out of necessity than anything else, and the haste with which they were designed and built showed. All in all, they were lucky; now the Munshot A was in orbit, and everything was under control. Maybe if Jeb could plant a flag in the Munar surface and salute, the old patriotic fervor would return and the KSP would be a national darling again.

One thing everyone at the Cape knew was how tight the mission was going to be: the fuel and RCS were bare minimums for the flight ahead. There was one major flaw lurking ahead that no-one had forseen... they would soon find out just how difficult this mission was going to be.

_______________________________________________________________________________________________________________________

The Challenge

Your challenge is, in part, to complete the ingame tutorial "To the Mun, Part 1." It's in the Training section, under the "Start Game" menu.

Now, I know what you're all thinking. "I did that, way back when I was learning how to do transfer burns!" It is, frankly, an easy tutorial. You start off in Kerbin orbit, with this spacecraft:

Gene Kerman tasks you with flying this ship to low Mun orbit. Then, the tutorial ends. Though Gene says something along the lines of, "You can land this perfectly functional spacecraft if you're up to it," there is no ingame tutorial about how to land. I decided to see how true Gene's statement was, and my question creates the fundamental challenge here. "Is it possible to land this spacecraft on the Mun, rendezvous with the command module in Mun orbit, then return the crew safely to the surface of Kerbin?"

It is, I discovered, a very difficult task.

I like to think I'm a decent pilot. I typically overengineer my ships, true, but I like launching big rockets with plenty of fuel. My current Munship is probably Duna capable, and I have docking down to a science. This particular scenario, however, was incredibly challenging to me, and had me trying things I've not done before, just to get the crew home. It was the most fun I've had playing KSP in a while.

It's recommended that this is for advanced pilots only. If you think you've got what it takes, read on.

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Your challenge is as follows:

--You must land on the surface of the Mun and plant a flag there.

--You must return all three Kerbals safely to the surface of Kerbin. Use of the LM is not allowed for Kerbin reentry, as it would disintegrate.

In order for your entry to be considered a winner, you must fulfill the above requirements. To prove it, you'll need:

-An image of your landing site (or your flag... I didn't remember to take a shot before I took off, so all I have is the flag shot. Don't cheat here; it's no fun)

-An image of your ship, or its remains, on Kerbin with the crew standing (or swimming) outside it.

If you want to compete further, I'll grade whoever has the most fuel left at the end of the mission as the winner there. However, getting the crew home is your first priority; therefore, your spacecraft is expendable.

Rules:

As the whole stock vs. mods thing is moot here, considering you're not designing the spacecraft or putting it in orbit, I'll only make a brief note on this. As this is, essentially, a piloting test, Mechjeb or other auto-pilot programs are not allowed. Heck, I didn't even use maneuver nodes in my playthrough.

As for the rest; no config editing, no debugs, nothing like that. Just play the stock scenario through, land on the Mun, and come back home. Sound simple enough?

Why should I play this challenge?

You're very limited on fuel the whole trip, you have essentially no RCS (compared to what I usually fly with, anyway), a single stage lander with droptanks... and no parachutes.

It's a really tough challenge, but with a bit of talent on the piloting side of things, it's very rewarding.

MISSION SUCCESSFUL (CREW RETURNED SAFELY)

1. kookoo_gr

2. tavert

3. Jenkinz

4. RocketPilot573

5.

LEADERBOARD (FUEL REMAINING)

1. tavert (267 units fuel)

2. RocketPilot573 (44 units fuel, 53 units oxidizer)

3. kookoo_gr (10 units fuel, 25 units oxidizer) (Estimated)

4.

5.

Most Creative Solution

1. Nao (10 hr EVA, aerobraking a Kerbal... lol)

My entry coming up in the next post.

Edited June 6, 2013 by Jm419

[Jm419]

Here's my entry:

Since I was just fooling around at first, I don't have any of the early pictures from this flight. I started taking photos where it started getting awesome, as you'll see in a minute.

The first part of the flight went like a typical Mun mission. Point the ship at the Mun as it rises over Kerbin's horizon, and burn. Mun orbit insertion was no big deal, but I did have to redock on separation when I realized I'd burned all the LM's fuel during the insertion. I also had no RCS left; I tried to use it for an orbit correction and ran out.

Once I landed near one of the anomalies, I got out, planted a flag, and hopped right back in. I had a little less than half the lander's fuel left over, but once I dumped the drop tanks, it looked like I was going to manage orbit. After rendezvous, I realized there was no hope of docking without RCS and using only main engines when I needed all the fuel I had, I just EVA'ed over the Kerbals; something I'd only done once before. I parked next to the CM and transferred Bob from the LM to the CM and I had Bill deorbit the lander and fly back. That's where I started taking pictures.

You can kinda see the lander falling back to the surface in the upper left quadrant of the image.

Here, we're on an escape trajectory past the landing site and on a free-return trajectory for home.

Here's the flag at Munar noon. It's the white KSP one; it just doesn't show up here because of the shadow.

It was about at this point in the challenge that I realized there weren't any chutes on this CSM. Clearly, the devs didn't mean for us to bring the crew back home.

After multiple aerobraking passes, I was ready to use the last of my fuel to slow myself down. The atmospere of Kerbin will actually slow almost anything to about 100 m/s when it hits the ground; that meant I only needed 100 m/s to land safely. Ideally.

I'd literally never seen this before, as I don't use solar panels; the panels just exploded during reentry. Pretty darn cool.

I ran out of fuel shortly after the last image was taken, resulting in a fall of about fifty meters down to the planet's surface... and this mess.

But, hey, everyone made it!

Mission report, for anyone who wants to see:

And that is a successful mission, right there. Everyone made it back home. Good day at KSC.

Now let's see your entries!

Edited June 4, 2013 by Jm419

[streff]

sounds like a challenge, will give it a shot later if I get time. Kudos on the succesful run, Bob looks surprised to have survived the landing shot

[kookoo_gr]

Here is my entry, very challengig but doable, here are my pics

Setting Munar transfer

En route the the Mun

Establishing Munar orbit

Fuel transfer for the landing

On the Mun

Night docking with the CSM

Leaving the Mun

Aerobraking at Kerbin (The crew's expresions are priceless)

Home at last

The final fuel i had during landing were about 10-25 units of fuel and ox, unfortuanetly i forgot to take any pics

[Jm419]

Very cool. It's amazing how close the fuel is on this one, isn't it?

Did you enjoy it?

[tavert]

This was a fun challenge, well except for the final landing on the Poodle without any gear. Took me a bunch of tries to land intact and avoid popping any Kerbals when I got out and jumped down (no ladders on the CSM), but here it is with 267 fuel units left on the ground (almost a quarter of the initial fuel load): http://imgur.com/a/O2dL1#0

I felt a little naked flying without MechJeb, but I can still do it in case anyone was wondering At least now we can find out vehicle mass in stock, which makes delta-V calculations much simpler. Some tricks I used to save fuel at every stage of the flight:

- Aim for as low a Munar periapsis as possible for Oberth-y goodness

- Leave the CSM in as eccentric an orbit as possible (apoapsis just barely inside the Mun's SoI), since only the lander needs to go any deeper in the gravity well.

- Leave the central tank of the lander empty. Just the 3 drop tanks give something like 1750 m/s delta-V, plenty to land and takeoff again even from the very eccentric orbit.

- Deorbit right around periapsis, going pretty much straight into the braking burn for landing. Almost all of the landing burn is horizontal since periapsis is so low, minimizing gravity losses.

- Turn immediately horizontal on takeoff, go into a very low circular orbit until the first rendezvous burn (setting up a phasing orbit to intersect next time around).

- After rendezvous and docking, hang out in the highly eccentric CSM orbit a few times around until the major axis of the ellipse points in the right direction for the escape trajectory to point retrograde relative to the Mun's orbit around Kerbin.

I only used 9~10 units of monopropellant to dock (I wish RCS and ASAS were not both enabled at the start of the scenario...), then just dumped the rest of what the CSM was carrying to speed up my aerobraking. I could've saved a few more units of fuel by being more aggressive with the RCS for the rendezvous or some of the orbital maneuvers, to use the main engine less.

Edited June 5, 2013 by tavert

[Jenkinz]

This looked fun, gave it a whirl.

Jeb and Bob planted their faces, then the flag.

Came back to rendezvous with Bill

And they all splashed down in the ocean west of the KSC. I'm lazy or I would have got them back at the KSC.

Certainly not for the beginner, but it was still fairly easy to do. I'd say the biggest challenge was docking without RCS (I didn't have any monopropellent available at the start). Even that wasn't too bad with how maneuverable the ships are.

Edited June 5, 2013 by Jenkinz

[tavert]

The scenario does start you with 50 units of monopropellant, but it also starts using it up immediately since both RCS and ASAS are enabled from the start. Turn off RCS as quickly as you can if you want to have any left when you need to dock.

[Nao]

One neat way to go would be to throw the John C. Houbolt's idea of LOR out and do a direct ascent with just the lander. Saving maybe even more than 500 l of fuel It would be reeeeaaallly hard thou.

[tavert]

If I'm calculating correctly, the scenario lander has 2261 m/s delta-V fully fueled and ditching the drop tanks once empty (are stages locked in the scenario for anyone else, or just me?). A tad more if you use RCS to help with a maneuver. And max TWR of 1.11, when nearly empty. So if you use the CSM to do most of the TMI burn, you could maybe undock en route to the Mun, land the CSM back on Kerbin with maybe up to a third of its fuel left, and take the LM all the way to the Mun and back and land it on fumes? Landing with such a low TWR would be treacherous though.

Edit: Oh yeah I guess you could rendezvous and dock back in Kerbin orbit after the Mun landing so you wouldn't have to land the low-thrust LM on Kerbin. Then the CSM might only need to do about half of the TMI burn...

Edited June 5, 2013 by tavert

[Jm419]

Leaderboard's updated. Jenkinz, I assume you didn't have any fuel left on landing, like me.

Tavert, I could edit the stage; I ditched the external tanks as soon as they were empty on my ascent burn. Interesting idea on returning the CSM, but remember, the LM couldn't survive reentry.

[RocketPilot573]

Mission Success!

44 Liquid Fuel, 53 Oxidizer

Undocking:

Landing:

Landed!:

Ascent and rendezvous:

Return trajectory:

Reentry:

Landed!:

[Jenkinz]

Leaderboard's updated. Jenkinz, I assume you didn't have any fuel left on landing, like me.

Actually, I had a tad under a quarter bar left. I wasn't paying attention and didn't look to see what the numbers were. I'm tempted to try again to make up for that.

[Nao]

Sooo, is almost 10 hour EVA, with aero-baking a kerbal in the spirit of the challenge ?

Because if yes then i have done a direct ascent mission with 534 litres of fuel remaining on ground.

[tavert]

Sooo, is almost 10 hour EVA, with aero-baking a kerbal in the spirit of the challenge ?

Because if yes then i have done a direct ascent mission with 534 litres of fuel remaining on ground.

Aka getting out and pushing with the infinite eva pack refuel trick? That's more than a little cheaty IMO. Not sure why you would need to aerobrake a Kerbal though...

[Nao]

Aka getting out and pushing with the infinite eva pack refuel trick? That's more than a little cheaty IMO. Not sure why you would need to aerobrake a Kerbal though...

Actually no.. i did think of that but until we get limited EVA RCS supplies in pods i consider it a hard cheat .

For my mission the lander stage was short 150m/s of Kerbin aerocapture, so i just did that "on foot" (7hr trip), and then spent another 3 hours trying to get to command module. Lastly deorbited with just RCS (which took many orbits as i had Pe of 60km) and used fuel from command module solely for landing.

Still i was just curious if it was possible, and orbital trips on EVA are always fun . I don't think there is better way than way you used, while keeping the spirit of the challenge.

[tavert]

Ah I see, so no refueling of the EVA pack, but also not getting the LM itself all the way back to dock. Did you use the CSM at all to help with TMI in the first place? If not, I'm impressed how far you got the lander fuel to stretch. If so, I guess helping by another 150 m/s would do the trick, right?

[Nao]

Yup, i pretty much undocked right away, and used all RCS for TMI. Adding a parking orbit of 3,5km and this:

ASPLOSIONS!

...way of landing (yep that's 350m/s 3meters of the ground and still sinking), with fuel gone from the spare tanks just as I came to a stop.

I thought about just getting CSM to have that 150m/s but then i would have to aerobrake with lunar module which still sounds iffy. (Although i could probably do it in several passes i guess, to not get reentry effects etc ) The main thing is that im procrastinating right now and should be working on my thesis >_< i'ts less than a month to exam and i'm still half way through haha.

[Jm419]

Actually, I had a tad under a quarter bar left. I wasn't paying attention and didn't look to see what the numbers were. I'm tempted to try again to make up for that.

Do it! It'd be fun to see how you do a second time, if you manage to do it even better.

Geesh, a quarter bar? You guys are all far better pilots than I am.

Sooo, is almost 10 hour EVA, with aero-baking a kerbal in the spirit of the challenge ?

Because if yes then i have done a direct ascent mission with 534 litres of fuel remaining on ground.

Ha... probably not, no. I tell you what - I'll give you a new category - most creative solution. Sound like a plan?

[Nao]

Ha... probably not, no. I tell you what - I'll give you a new category - most creative solution. Sound like a plan?

It's ON!

http://imgur.com/a/W1xXX/

It was a nice idea for a challenge with the tutorial mission, thanks OP!

[tavert]

Nice. #8 reminds me of the start of Odyssey 5, if anybody else watched that obscure show from a decade ago...

[thescientist]

Very good challenge! I always thought that were impossible to recover the three famous astronaut from this scenario! (yeah, with DRE the whole ship blow up during the reentry)

[Sirine]

Well, register my name please.

Note: The Mun landing part also, loaded F9 once...crash landed on >5000m, bad luck.

The last few picture are loaded F9, you can easily tell by the scenarios message.

Fuel left = 0 without parachute, 355 with parachute.

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Edited August 28, 2013 by Sirine
adding some detail.