the "building a space station" world first

[king of nowhere]

I am trying the no contract career challenge, where i cannot accept contracts but can only get money from achieving world first stuff.

on of those is "we started building a space station in X orbit", which, as far as i can tell, just requires you to dock two things. even the smallest probes got me the achievement.

then again, if the two ships have already been joined in the past, there can be problems. I sent a lander and orbiter to mun, i joined them for the first time in mun orbit, got the achievement.

then i launched the same ship to minmus, landed the lander, did an EVA, started back, rejoined the lander and orbiter. but this time i got no space station achievement. i figured, since they were already joined in the past, the game would consider them still parts of the same ship. so i sent another cheap ship from kerbin to get it.

then i set up to explore all the outer planets, and to save money i set to use the same ship for all. again, a lander and orbiter, this time the orbiter is bigger and it has a nuclear engine, because all those interplanetary transfers are expensive. and i figured i would send other ships to get one docking in every orbit. sometimes cheap small probes just for the achievement, sometimes refueling missions (of course i have no isru available, as that would require unlocking the level 3 lab, which i can't afford in this challenge).

well, i joined the lander and orbiter in duna orbit, got the achievement all right. then i went to ike, grabbed a refueling mission, got the achievement. then i went to dres, and i arrived there a few months before the other ship (this time a small probe, as reaching dres is expensive). in the meanwhile i landed the lander, i got back to orbit, reunited with the orbiter... and to my surprise, i got the station achievement.

so i wonder why i got in in dres and not in minmus

 now that i think of it, on minmus i was on a suborbital trajectory, as the lander was missing 20 m/s to get back to orbit and i had to rescue it with the orbiter. i seem to remember i got the docking and rendez-vous achievement anyway, but i'm not sure. or, in the minmus case i just remained on the ground long enough to run the science and plant a flag, while in dres i decided to land near the canyon, make a long jetpack trip to the canyon, accidentally fall down into the canyon, tumble down a 2 km ravine, then come back with barely any fuel left. and i reloaded a few times in the process. so maybe this made the game "forget" that the lander and orbiter had been the same ship.

anyone knows the reason?

[IronMaiden]

The vessels need to be from two different launches. Did you launch them together for the Minmus one and then just pick up the Minmus lander to take to all the other destinations?

[king of nowhere]

28 minutes ago, IronMaiden said:

The vessels need to be from two different launches. Did you launch them together for the Minmus one and then just pick up the Minmus lander to take to all the other destinations?

i launched the mun/minmus orbiter and lander separately, because i assumed different launches may be required.

i recovered them after the mission and launched the interplanetary orbiter and lander separately too.

[IronMaiden]

3 hours ago, king of nowhere said:

i launched the mun/minmus orbiter and lander separately, because i assumed different launches may be required.

i recovered them after the mission and launched the interplanetary orbiter and lander separately too.

Huh, you got me then, that is really weird. I did a mission where I drug a capsule from a previous mission to many destinations, did the ol' release and catch, and got the station/base building milestone every time.

Edited September 20, 2020 by IronMaiden

[king of nowhere]

perhaps it really is because i was suborbital when i docked. i see no other explanation

[king of nowhere]

i expand on the original with a new related question:

i now determined that when i land and then come back to orbit, i always get the achievement. but! if i detach my ships, then attach them again, i get the docking and the space station, but not the rendez-vous.

i assume the ships must become separated by some distance in order to get a rendez vous achievement, but how much? i can't land in jool and sun orbit