EVA landing on Mun and return to orbit

[Yakky]

EDIT: Nobody was responding to this challenge as originally written, so I've dramatically simplified it as follows. Achieve any one of the following:

Category 1: Reach Munar orbit from the surface using only the EVA pack. Your score is the difference, in meters, between your orbital periapsis and your take-off altitude. That's it! You may use Hyperedit to position yourself for the start. (Yes, this challenge is actually possible without cheating or boosts. See Hints below.)

High Scores:

1. Yakky - 6345.8 (see post 8 below)

2.

3.

Category 2: Land from Munar orbit using only the EVA pack. Your score is the difference, in meters, between your orbital periapsis and your landing altitude. That's it! (The only restriction here is no use of the inverted Kerbal trick to survive unrealistically harsh impacts.) You may use Hyperedit to position yourself for the start.

High Scores:

1. Yakky - 2603.4 (see next post)

2.

3.

Category 3: Same as Category 1, but with the stipulation that you have at least 0.1 units of EVA fuel remaining after reaching orbit. This will be our proxy for a reasonable minimum reserve that would be required for orbital rendezvous under good conditions.

High Scores:

1. Yakky - 6345.8 (see post 8 below)

2.

3.

[--------original challenge text follows--------]

This is a new twist the old question about what's possible with Munar EVAs. It was inspired by the question of whether a more complete version of chicknblender's recent EVA Grand Tour would have been possible.

It's been proven to be just barely possible to get into orbit from the Munar surface using only the EVA jetpack. Since the physics are equivalent, this means it's also possible to land on the Munar surface from orbit with only a jetpack (EDIT: I confirmed this by doing an EVA landing from orbit -- see next post).

That leads to this challenge: Descend from Munar orbit to the surface using only a jetpack, plant a flag, refuel in a capsule on the ground, and ascend back to orbital rendezvous with your low Munar orbit capsule. And do it from the highest possible starting orbit. This is a test of optimization and piloting finesse. It looks like it should be possible, but as far as I know it has never been done -- so this is your chance to score a world first in KSP! (Please let me know if it's been done before.)

More specifically, here's what you need to do:

1. Drop a crew capsule somewhere on the Munar surface. This will be your EVA refueling base.

2. From stable low Munar orbit in another capsule, go on EVA, descend, and land near the surface capsule using only your jetpack.

3. Plant a flag, refill your jetpack fuel in the capsule you dropped earlier, rest and have some snacks.

4. Ascend back to orbit and rendezvous with your orbital capsule again.

Fine Print:

-- No piloting of the orbital capsule from the moment you depart it until you return. It must remain in a totally passive and unchanging orbit.

-- The capsule must be in a stable and safe orbit, i.e. zero chance of impacting any terrain.

-- You have to make it back inside the orbital capsule at the end.

-- No assisted takeoffs from the Munar surface. The Kerbal may run and jump, but that's it.

-- No cheating, cheats, or mods that change the stock game physics. Mods that have no bearing on the Munar environment (i.e. are irrelevant for this challenge) are OK.

-- You may use Hyperedit to get your craft into low Munar orbit initially, but you have to manually land both the refueling capsule and the EVA Kerbal on the surface from LMO.

-- No use of the inverted Kerbal trick to survive a ridiculously hard landing. The Kerbal must touch down body-first at a reasonable speed. Inverted Kerbals are a cheat as far as this challenge is concerned.

-- Show enough pics to confirm the data of your orbital parameters, landing/takeoff points, and intercept/rendezvous achievement on return to orbit. It would also be helpful to have a pic showing your speed just before touchdown.

Scoring:

Your score is just the difference between your orbital periapsis and your touchdown/takeoff altitude. This rewards people who can reach higher orbits from their starting point.

So for example if your orbital periapsis is 8,000m and you land on the surface at 4,600m, your score is 3,400. If your takeoff altitude is different than your landing altitude, use the higher of the two. So in the same example if you land at 4,600 but take off at 4,610, your score is only 3,390.

Hints:

1. It really is possible to reach orbit from the Munar surface using only a jetpack. I've done it as have many others (see this post). But you won't have much fuel left over for orbital rendezvous afterward, so be very careful.

2. Most importantly, it won't be possible to reach orbit if you are making heavy use of two jetpack thrusters at once, for example if you're thrusting forward and up simultaneously. This is because the thrusters are perpendicular to each other and consequently are wasting some thrust pointing in inefficient directions. Only use one EVA thruster at a time, and make sure it's darn near perfectly prograde all the time for maximum efficiency. Then all you have to do is fly an optimal ascent profile.

3. Kerbal Engineer may be useful to monitor your height above terrain and vertical speed.

4. I found it useful to put the camera onto Orbital view (with V key) in order to prevent shifting camera angles from re-orienting my Kerbal all the time.

Good luck!

Edited August 4, 2015 by Yakky
simplified the challenge

[Yakky]

Some pics to prove an EVA landing from stable Munar orbit is possible. Unfortunately I dramatically overshot my refueling base!

My orbital periapsis was 7215.8m and my landing elevation was 4612.4m. So if I had completed the challenge from the same altitude (which I did not), my score would have been 2603.4 in this example.

EDIT: This score qualifies for Category 2 under the simplified rules.

Javascript is disabled. View full album

Edited August 4, 2015 by Yakky

[Sirine]

Picture 6 altermeter shows that you are dropping over 10m/s.

Edited July 26, 2015 by Sirine

[Yakky]

Yep, the landing was a little rough because my descent was sub-optimal. I didn't lose altitude early enough and then had to drop rapidly later on to avoid running out of fuel before getting close to the ground. Fortunately he walked away from it.

BTW on another pass I tried, I ran out of fuel too high and he hit at 24 m/s, which killed him. So the critical speed is somewhere around 20 m/s. Anything in the teens m/s range seems pretty survivable based on my tests.

Edited July 26, 2015 by Yakky

[Deddly]

I was just wondering about one of the points in the fine print:

-- The capsule must be in a stable and safe orbit, i.e. zero chance of impacting any terrain.

What's the reasoning behind that? Surely if it survives long enough to EVA, land, return to orbit and rendezvous, it should be considered a huge feat in itself, no?

[Yakky]

I was just wondering about one of the points in the fine print:

-- The capsule must be in a stable and safe orbit, i.e. zero chance of impacting any terrain.

What's the reasoning behind that? Surely if it survives long enough to EVA, land, return to orbit and rendezvous, it should be considered a huge feat in itself, no?

It's a fair point. Any EVA landing and return is a major achievement since it's so rarely (if ever) been done. My thinking was that in order to consider the problem of EVA descent and return, solved, the orbit really should be high enough to allow an indefinitely long surface mission. Also, it somehow doesn't seem quite complete if the mission requires the spacecraft to temporarily duck into a dangerously low orbit. Seems a bit akin to orbiting Kerbin below the top of the atmosphere. Lastly, the amount of delta-v required to get from, say, 5 km to 7km is not very large, and orbits of at least 8 km are definitely possible.

All of that said, I will post your result with an asterisk if you can complete it from a too-low orbit, especially since no one seems to be posting any entries here.

[KandoKris]

Different Sounds like an interesting challenge done the up part before but never then down ( I like to return kerbals to Kerbin in EVA every now and then for giggles) interesting that its only 24m/s before they go poof. on Kerbin I bounce even at much higher speeds so long as they hit land

will give this a go over the weekend. What’s the highest orbit done so far just your 7km ?

No bonus points for docking ? i suppose with no entries yet there be no point ...... I hope to change that

Wow that is some vid... what a mathematical nightmare to work out and to be able to fly it OMG hat is off to Cory

Edited July 31, 2015 by KandoKris

[Yakky]

Update: Nobody was responding so I dramatically simplified the challenge (see revised 1st post). If there are still no takers, I will give up here. Surely I'm not the only one who finds this possibility interesting?

Here is my demonstration that EVA-to-orbit is achievable with plenty of fuel margin. Starting from a randomly chosen surface elevation of 3861 m, I reached a 10km x 12km Munar orbit with 0.15 units to spare. This gives a score of 6345.8 and I could have gone higher.

Javascript is disabled. View full album

Edited August 4, 2015 by Yakky