The Elcano Challenge: Ground-Based Circumnavigation (4th)

[18Watt]

14 hours ago, Jack Joseph Kerman said:

Eve complete!

Leaderboard updated!  By the way, you've been added to two leaderboards with this entry- Eve and the Master Navigator leaderboards.  The Master Navigator is for folks who have circumnavigated both Kerbin and Eve.  It is a very short list, although I suspect I'll be adding another name to it soon.

Fantastic entry!  I enjoyed the video of the entertaining diversion you took at one of the poles.  Good luck at Gilly.

11 hours ago, Pouicpouic said:

How do you manage to be in warp x2 without breaking the propellers ?

I'm sure @Jack Joseph Kerman will also reply on this question, but here's a few things I do:

• I use the shortest propeller blades available.
• I attach them with 'Rigid Attachment' on.  You might need to enable Advanced Tweakables to find this option.
• I also attach them using auto struts.
• Edit- just thought of another possibility, offsetting the blades inward.  In aerodynamic challenges this could be considered an exploit, as you can reduce your electricity usage to zero by offsetting prop blades.  For Elcano, it’s fine, and might help allow 2X or perhaps even higher physics warp..

Even doing that, I think the diameter of the rotor disc does expand slightly at 2X warp, but it was workable for me.  One other side-effect is that using physics warp with robotics parts (including the electric rotors and propeller blades) can cause them to shift their position on your vessel slightly.  

 

Edited Wednesday at 08:29 PM by 18Watt

[Jack Joseph Kerman]

8 hours ago, Pouicpouic said:

How do you manage to be in warp x2 without breaking the propellers ? --> with a rotation speed <240 rpm you still reach >60m/s ?

I had the blades maxed out at only 210 RPM or so on the water, on land they could do around 230-240. Like @18Watt has said, I used the short ducted fan blades and auto struts to better hold them in place.

I did have a slight torque problem though, every couple minutes I’d have to correct the craft’s drifting attitude.

8 hours ago, Pouicpouic said:

Besides this memorable base-jumping moment, did you really do the rest without breaking anything and without reloading?

Sadly no, there were a fair few fails during the land part of the circumnavigation, probably about 6 or so. None of them involved the complete destruction of the rover however, most of the time it would be just a nosecone or landing gear breaking. Considering the length of the trip, however, which I want to say was 11-12 hours in real time, there really weren’t too many accidents.

Edited Wednesday at 05:54 PM by Jack Joseph Kerman

[18Watt]

2 hours ago, Jack Joseph Kerman said:

I did have a slight torque problem though, every couple minutes I’d have to correct the craft’s drifting attitude.

I didn’t notice your props were identical until @Pouicpouic pointed it out.  Counter-rotating props solves the torque problem completely.  If you need to mount the props on the centerline forward and aft props can accomplish the same thing.  It’s a little awkward getting them set up properly, but worth the effort in my opinion.

Sorry we waited until after you completed Eve to point that out..

[OJT]

11 hours ago, Pouicpouic said:

How do you manage to be in warp x2 without breaking the propellers ?

Lower the RPM of your motors. You can go to great lengths with adjusting motor RPM and prop angles. The endurance prop planes I've built were running their motors as low as 60 RPM, generating good thrust through adjusting prop angles and flying comfortably at 3x phys time warp. And that's on Kerbin, mind you: with Eve's souposphere you might go even lower if you want to

[Jack Joseph Kerman]

3 hours ago, 18Watt said:

Sorry we waited until after you completed Eve to point that out..

Honestly, I only found the torque issue to be mildly annoying; I was able to minimize it by constantly holding prograde.

Good to know that for when I go to Laythe though!

[Earthlinger]

I finished the designs for the Kerbin sea circumnavigation a couple of months back so I maaayyy put out something in the coming weeks.

[Pouicpouic]

Tylo finished!

step 1: climb a hill in a few minutes
step 2 : go down the trapping slopes as long as possible while keeping the inertia (be careful, this can last more than one hour at more than 80m/s)
step 3 : F9 or go back to step 1

Spoiler

Ok, I love speed in rover so I was not soft on my machine. Tylo punished me many times... But Tylo still rewarded me with my new PB in rover without propellants and in vacuum. A staggering 143.3 m/s.  (I even reached a second time more than 144m/s but lost the rover)

Rover destruction counter (Tylo) – Estimations
Speed	Reached*	Destructions*	Risk
0 – 95 m/s	Many	none	none
95 – 105 m/s	Many	2	very low
105 – 115 m/s	> 20	6	medium
115 – 130 m/s	~12	8	very high
130 – 140 m/s	4	2	suicide
> 140 m/s	2	1	?
*non cumulative		19

Spoiler

Every time you think you're taming Tylo, going at more than 100m/s without seeing any danger, you're wrong: the risk is always there. A deceptive shadow, a radical change of slope, a climb that is in fact a descent, a hidden rock or metallic concretion, etc.

It was so exciting that I couldn't resist testing the limits from beginning to end

Spoiler

Endurance in its raw state, where my rover is at its maximum capacity: probably where it is most adapted in the whole kerbol system. No fear jumping at 100m/s if the landing is in a nice slope.

When the complete challenge will be finished, I will come back here with the same rover purified of all the superfluous to try to pass the 150m/s, it is capable of it, it is certain.

6d2h48 IGT, nothing remarkable.

Spoiler

But, I warped twice to avoid driving at night for a total of 3d5h03, which gives a travel time of 2d3h45 (15h45)! This means a raw average speed of 67m/s --> adjusted for the actual distance traveled, the value is more like 71m/s (+or- 2m/s). If we also count the 30 or so stops assigned for routing and quicksaves, I have no doubt that we have this average. It's quite simple, I rode for hours at more than 90m/s. Awesome!

This time I passed the 2/3 of the whole challenge in km to cover (close to 19000 out of 28000). No repair kits used here: each time it broke more than a single wheel.

Preparing for transfer toward Bop.

Edited Thursday at 01:01 PM by Pouicpouic

[Jack Joseph Kerman]

Gilly complete! Definitely the easiest circumnavigation I've ever done; I want to say I did it from start to finish in about 45 minutes.

The Eve Ascent:

Spoiler

Of course, in order to get to Gilly, the crew still had to get off of Eve, something made more difficult by the fact that I was launching from sea level. The ascent was pretty finicky and took a few attempts to get right, but we made it in the end.

Waluigi ascent vehicle preparing for liftoff from Eve

10..9..8..7..6..5..4..3..2..1.. Liftoff! You can see the EELP still floating in the sea, as well as what's left of the flotation system, if you look closely.

Side booster separation. I started losing a little bit of velocity at this point due to the high drag, but quickly made it up later.

Second stage activation. At this point, I had to start a really aggressive gravity turn, as my TWR was very high, meaning that I would get an insanely high apoapsis if I did not. Something funny that I also forgot to mention is the fact that the Kerbals' heads are sticking through the service bay doors, as I appear to have placed the command seats too far apart. I was initially worried about this, but it turns out that they produce no drag and are safe from aerodynamic heating as long as the service bay doors are shut.

Gravity turn

Third stage. For some reason, the third stage's delta-V wasn't included in the in-game calculations until I had actually activated it.

Ran out of fuel about 100 m/s short of orbit. It's jetpack time!

I had to time the jetpack burns carefully; if I spent too long on one kerbal, the others would not have enough time to reach orbit before they fell back into Eve's atmosphere. As such, I got Bill and Jeb about halfway to orbital speed, with a time to apoapsis of around 2 minutes, this giving Bob enough time to accelerate to orbital velocity entirely.

Bob then set up a rendezvous with the transfer vehicle, which he barely made it to with 0.09 units of EVA fuel remaining.

Once that had been done, Bill and Jeb followed suit.

Getting to Gilly:

Spoiler

Getting to Gilly was fairly easy; all I had to do was boost the mothership up into a higher orbit and rendezvous with the MicroGee Gilly rover, which had way more delta-V than necessary.

I still had to time my burns carefully, though, as my TWR was so low that if I started my burn at halfway to the maneuver node time, I would just go flying straight past Gilly.

Orbit achieved

Landing was very easy, if a little annoying thanks to Gilly's absolutely nonsensical time warp altitude limits.

Circumnavigation & Return to Kerbin:

Spoiler

As I said before, the actual Gilly circumnavigation did not take very much time to complete at all, and as such there aren't very many screenshots.

Everise

Getting dark already

Casually flung myself almost into orbit. I had to have the ion engines on almost constantly just to stay on the ground.

Gilly Rift

Another Everise

Somehow managed to break a wheel on Gilly. It's alright though, I had literally 5 kilometers to go at this point.

Circumnavigation finished!

Once that was done, Bill went over to the lander and attached the rover's command seats to it, as this would be how they would get back to the transfer vehicle.

So long, Gilly!

Heading back down into lower Eve orbit

Rendezvous and crew transfer

Lander de-orbit

Burning for Kerbin after waiting a while for a transfer window. The trajectory I took here was a little bit unconventional, as my starting orbit was pretty eccentric. I still had enough delta-V to make it work, however.

Kerbin re-entry

Parachute deployment

Back on terra firma

Jeb poses with both the Mun and Minmus behind him

 

[Pouicpouic]

7 hours ago, Pouicpouic said:

No repair kits used here

I was wrong... When docking with the transfer vessel, a wheel was broken. I preferred to fix it rather than try several times with potentially worse results.

Spoiler

fixing on Bop. With the 2 for this wheel, there are 6 left in the rover and 12 in the transfer ship (so for 9 repairs), but I'm slowly starting to worry about that anyway.

After the repeated destructions on Tylo, I really wanted to have a smooth trip on Bop. It took me a little while to get used to the new gravity, but in the end I managed to maintain a good 35m/s average without any fear.

Spoiler

But was scared by Bop's rift

Well, I can be careful and patient, it is possible, rarely, but possible.

2 800m to 17 000m...

Bop circumnavigation no losses.

Spoiler

a weird circumnavigation for a weird moon

Yes, I hate small moons in rover, it is confirmed and definitive.

Let's get out of this hell. reffuel, catch, gas!

Spoiler

Next and last of joolian system : Vall

 

[18Watt]

9 hours ago, Pouicpouic said:

Tylo finished!

Leaderboard updated!

9 hours ago, Pouicpouic said:

I warped twice to avoid driving at night

I find rovering at night to be extremely risky.

8 hours ago, Jack Joseph Kerman said:

Gilly complete! Definitely the easiest circumnavigation I've ever done;

Leaderboard updated!  Personally, I found using wheels on Gilly very frustrating.  So I gave up and did something different.

8 hours ago, Jack Joseph Kerman said:

Ran out of fuel about 100 m/s short of orbit. It's jetpack time!

Reminds me of sometimes being offered contracts to take ore from Eve and deliver it somewhere.  Took me nearly 6 years to figure out how to get a Kerbal to Eve orbit.  Nice job getting 3 Kerbals into orbit with jetpacks!  I'm sure there was some frantic keyboard action to make that happen.

51 minutes ago, Pouicpouic said:

fixing on Bop. With the 2 for this wheel, there are 6 left in the rover and 12 in the transfer ship (so for 9 repairs), but I'm slowly starting to worry about that anyway.

I think you'll make it.  But if not, don't forget that it is absolutely fine to deliver spare parts, or even a replacement rover.  I know you want to do the whole thing with a single rover, but don't forget you can deliver more repair kits if needed..

55 minutes ago, Pouicpouic said:

Bop circumnavigation no losses.

Leaderboard updated!

@Jack Joseph Kerman, by my count Laythe is the only stock CB you have left?

Also, as always please double-check the leaderboards to make sure I'm getting all the entries added correctly.  You guys are doing these so quickly I'm worried I'll forget an entry somewhere.

 

[Pouicpouic]

8 hours ago, 18Watt said:

@Jack Joseph Kerman, by my count Laythe is the only stock CB you have left?

I bet that the L.E.L.P under construction (with counter-rotative propellers), will go so well on Laythe that its wake will cause tsunamis!

[Jack Joseph Kerman]

15 hours ago, 18Watt said:

 

@Jack Joseph Kerman, by my count Laythe is the only stock CB you have left?.

 

Yeah, only one more to go. I really intended to get to Laythe much earlier, but sometimes that’s not how things work out. 

7 hours ago, Pouicpouic said:

I bet that the L.E.L.P under construction (with counter-rotative propellers), will go so well on Laythe that its wake will cause tsunamis!

Since this is going to be my final circumnavigation, I may or may not have something “special” planned.

[Pouicpouic]

Small review for the 2nd important milestone: 20 000 km covered with the rover.

I don't know if it's my imagination but I have the impression that the parts are fatiguing :
- the outer wheels do not touch the ground anymore when stopped (in low gravity)
- it turns slightly to the right when accelerating
- it seems to me less resistant during shocks
- even the SAS seems less efficient
Well, maybe it's also because I have less fun than expected on Vall. hint: I can't make jumps as big as anticipated

Spoiler

Elcano Challenge	diameter (m)	perimeter (km)	%circu	km estim	Max Speed (m/s)	AvSpeed estim (m/s)	Minimum dur. (h)	IGT (Days)	Fun  /10*
Kerbin	600000	3770	1,06	3996	74,5	57	19,5	3,25	8* (6)
Minmus	60000	377	1,05	396	70,2	53	2,1	0,35	3
Mun	200000	1257	1,08	1357	72,6	50	7,5	1,26	10
Duna	320000	2011	1,2	2413	76,3	53	12,6	2,11	7
Ike	130000	817	1,1	898	93,8	62	4,0	0,67	6
Dres	138000	867	1,02	884	60,8	43	5,7	0,95	6
Eeloo	210000	1319	1,05	1385	85,1	57	6,8	1,13	5
Laythe	500000	3142	1,04	3267	76,3	44	20,6	3,44	7* (4)
Pol	44000	276	1,2	332	35,5	22	4,2	0,70	2
Tylo	600000	3770	1,06	3996	143,3	71	15,6	2,61	8
Bop	65000	408	1,2	490	54,4	33	4,1	0,69	3
Vall	300000	1885	0,6	1131	124,0	55	5,7	0,95	7
Moho	250000	1571	0	0		40	0,0	0,00
Gilly	13000	82	0	0		8	0,0	0,00
Eve	700000	4398	0	0		45	0,0	0,00
TOT mini		25949		20546	total km		108,5		*not counting
TOT approx		28025		73,31 %					water time

20 000km with a single rover... its crazy.

So far no superfluous refueling, but the series should end after Vall. Can I consider a transfer Vall --> Gilly ? I don't think so.

In raw calculation, 20500km/109h= 52,5m/s on average --> this is at the level of my initial expectations (I wanted 50m/s)
But, if we consider the 90 reloads (at least) that I had to do, we should be able to add 10h easily, maybe even 15...

After having rediscovered 8 kits hidden in the cabin... (it seemed to me that I had stashed them everywhere), I used 50% of my wheel repairs (including the one done on vall). 12 out of 24? I'm pretty sure i filled all the slots at the beginning... if yes, that makes 48 kits. But I seem to have given the value of 40 at one point so I'm lost. Anyway, I'm reassured with that I have 12 repairs left. 9+4=13 (-1 vall = 12).

Less than 10 000 km to go  !

[damerell]

In the past people have had trouble with parts shifting on rovers during long expeditions. It may not be your imagination.

[Pouicpouic]

Even if the rover was below my expectations on Vall, it was a nice trip. Circumnavigation done.

Several sessions >10min at more than 80m/s on the large icy expanses.

Spoiler

But it requires constant attention for rock avoidance maneuvers: the white death, which can decimate 4 wheels in one impact. At least 30 emergency maneuvers in total, less than 1/4 second to react. 2 broken wheels were fixed here.

Monstrous jumps to the limit. About 10h30 of driving. But I had a hard time finding my rhythm, I expected to be able to do like on Tylo, but it was not so simple to keep the inertia: forced to brake to avoid damage.

It's time to enjoy the colors of the joolian system one last time !

Spoiler

Finally I wanted to try the Vall-Gilly link: I have a backup and it would be a good starting point to go to Moho.

Spoiler

almost 4700m/s left in low Vall orbit, it must be enough.

I'm far from being an expert of multiple gravity assists...but for once I was tempted!

Vall - Tylo assist 1 - Tylo assist 2 and here I am expelled

A 1200m/s maneuver gives me a meeting : Eve assist 1 - Eve assist 2 and finally insertion in Eve's orbit with an ideal angle to catch Gilly in flight.

A little more than 300m/s remaining in orbit of Gilly, largely sufficient to land. Perfect, well perfect for my goal but probably very bad in optimisation since I did everything by eye.

However, I need to bring back the network in orbit, otherwise I won't have access to kerbnet.

I prepare myself psychologically for the worst experience of the challenge

[Pouicpouic]

Gilly...

9m/s on average, with an incredible peak of 13.5m/s! If you don't accelerate time, it's impossible to stay awake...   for me, it's not a moon, if only one CB had to be destroyed : I vote for Gilly !

Spoiler

I slept for a few minutes, just enough time to dream: I was in a rover and see usain bolt running past me without putting on the indicator. Luckily he was stopped by the Gilly police.

Detailed view of the rover from above and below :

I almost hit the ship at the end... it takes miles to brake on this thing.

Let's see if I can reach Moho now.