Is there a way to fly/control/put in autopilot three kerbals on EVA at the same time?

[juanml82]

I landed a rover with three kerbals on Tylo without enough fuel to get back to orbit. Obviously, the easiest way out is to send more fuel from Kerbin, refuel the rover and take off. But, what's the point in making it the easy way?

So, I've used Bon Voyage to travel to Tylo's highest point (or near enough that it doesn't matter) at around 11,000 meters (it is kind of cheating, as the rover can't climb those slopes, but Bon Voyage doesn't take that into account). Fortunately, my engineer happens to have a KAS drill on hand, so if I remove everything that isn't needed nor I planned to stage away plus I remove the outer fuel tanks in flight I can squeeze juuuuuuust... nope, not enough fuel. I'm short of some 200-300 dV, so the kerbals can use their eva packs to get into orbit where I can later rescue them with the return ship.

But Tylo being Tylo, I have enough time to send one or maybe two kerbals to the safety of orbiting an alien body millions of kilometers away from home and protected from the void of space by just their spacesuits. But the third one will always crash before I get to him.

Now, if I could get the three on EVA at the same time and keep them within physics range, they can theoretically burn prograde and achieve orbit. The problem is that manually jumping from one kerbal to the other wouldn't work, because the moment I loose control of a kerbal, the eva suit would shut down. So I need to somehow assemble them into a single "ship" (but they can still use their eva packs. Kerbals grabbing each other during evas?) so I control them manually, or I need some sort of autopilot which works with kerbals on EVA (I haven't tried MJ autopilot yet, would it work?) or something that keeps them firing their eva suits prograde while I'm not piloting them. .

So, is it possible?

 

Oh, album, because pictures

https://imgur.com/a/2yfsF

[Geschosskopf]

The "Burn Together" mod MIGHT work for 3 simultaneous jetpacks, but I really don't know--never tried it.

In general, though, I think there are better ways to escape Tylo.  Getting back into orbit from Tylo is actually pretty easy, it's landing that's the hard part   All you need to do is get to about 20km, high enough to clear the mountains, and you're golden.  So just fly nearly horizontally right off the ground until your Ap is 20km or so, then circularize.  This doesn't take very much at all in the way of a ship.

I also do not recommend the idea of getting very far off the equator.  The further from the equator you are, the more inclination you'll end up with.  Which makes rescue from orbit VERY expensive because any sort of inclination change in Tylo orbit needs lots of dV.  The ideal launch site to leave Tylo is on the equator and on the western end of a fairly wide plain.  Altitude of the ground doesn't matter.  With no hills for a long way east of you, you can put all your thrust into a very shallow, nearly horizontal ascent for a long way before having to clear any obstacle.  The rescue ship will then have to come down to about 20km and back up, which isn't cheap but also isn't prohibitively expensive.  It's certainly way cheaper than making 2 significant inclination changes (1 to rendezvous, 1 to get back to the ecliptic).

2-stage, single-use landers work well on Tylo.  Put a minimal ascent stage (like with command chairs) on top of a beefy 1-use descent stage.

Edited October 8, 2017 by Geschosskopf

[Palaceviking]

Got any ladders to attach Kerbals to?

Edit, sorry missed the point, I think burn together mod will do this though and sounds like a proper kerbal activity! 

Edited October 8, 2017 by Palaceviking

[juanml82]

35 minutes ago, Geschosskopf said:

The "Burn Together" mod MIGHT work for 3 simultaneous jetpacks, but I really don't know--never tried it.

In general, though, I think there are better ways to escape Tylo.  Getting back into orbit from Tylo is actually pretty easy, it's landing that's the hard part   All you need to do is get to about 20km, high enough to clear the mountains, and you're golden.  So just fly nearly horizontally right off the ground until your Ap is 20km or so, then circularize.  This doesn't take very much at all in the way of a ship.

I also do not recommend the idea of getting very far off the equator.  The further from the equator you are, the more inclination you'll end up with.  Which makes rescue from orbit VERY expensive because any sort of inclination change in Tylo orbit needs lots of dV.  The ideal launch site to leave Tylo is on the equator and on the western end of a fairly wide plain.  Altitude of the ground doesn't matter.  With no hills for a long way east of you, you can put all your thrust into a very shallow, nearly horizontal ascent for a long way before having to clear any obstacle.  The rescue ship will then have to come down to about 20km and back up, which isn't cheap but also isn't prohibitively expensive.  It's certainly way cheaper than making 2 significant inclination changes (1 to rendezvous, 1 to get back to the ecliptic).

2-stage, single-use landers work well on Tylo.  Put a minimal ascent stage (like with command chairs) on top of a beefy 1-use descent stage.

I just don't have enough dV in the rover, it's not a matter of flight profile. I had plans to refuel the rover's transfer stage while in Tylo's orbit so the rover landed with tanks nearly full... but I forgot about that part.

I'll try "Burn together" either later today or tomorrow!

 

Uh... Burn Together seems to require a part, so it shouldn't work for kerbals on EVA, unless they can grab the part using kis or a MM patch can add whatever module that mod uses to kerbals on eva?

Edited October 8, 2017 by juanml82

[Spricigo]

Ok so you have 3 kerbals (lets call then Jeb, Bill and Bob) . Their craft will run out fuel 300m/s from orbit.

So far what you tried and the result were: Jeb does a 300m/s burn and is in orbit, Bill does a 300m/s burn and get in orbit, Bob try to do his burn and crash.

 

How about: Jeb does a 100m/s maneuver, then Bill and Bob do the same. Repeat it three times and everyone get in orbit.

 

[bewing]

As spricigo says, the closer you are to orbital velocity, the more time you have. Instead of his 9 burns, I'd suggest 5. Jeb burns for 150, Bill burns for 150, Bob burns for 300, Jeb burns for 150, Bill burns for 150.

Additionally, I find that the EVA RCS thrusters are independent. So you can add some radial out RCS thrust at the same time as you are thrusting forwards (prograde). Just a bit of radial out thrust on Jeb and Bill -- to add a few more seconds of time.

Edited October 8, 2017 by bewing

[Spricigo]

8 minutes ago, bewing said:

 Instead of his 9 burns, I'd suggest 5.  

Actually I'd try those 5 too. However the idea becomes more evident with 9.  

[juanml82]

Oh well, Burn Together doesn't work with EVA packs and splitting the burns means the kerbals crash because they have little TWR relative to Tylo. Rescue mission it is.

[Palaceviking]

8 hours ago, juanml82 said:

Oh well, Burn Together doesn't work with EVA packs and splitting the burns means the kerbals crash because they have little TWR relative to Tylo. Rescue mission it is.

It was always going to be a rescue mission anyway, but you still don't need a lander, just a truly crazy rendezvous manoeuvre! 

[Kryxal]

It might be interesting to go with a refueling lander, that way just get it down and add some fuel to your other craft.