Flieger, grüß' mir die Sonne, grüß' mir die Sterne und grüß' mir den Mond. Dein Leben, das ist ein Schweben, durch die Ferne, die keiner bewohnt! - Hans Albers, F.P.1 antwortet nicht (Adaptation in the 80s: Extrabreit)

Tuesday, 23 June 2015

Tour de Kerbin 2.5

Checking my mission contracts in Kerbal Space Center, I have to realize that the task to put a space station into Minmus orbit is still unfulfilled. This means that the Omniscient somehow did not get recognized as such. I was so sure I had built it after I accepted the contract, but I cannot verify this anymore, because I only keep about 10 safe files and regularily update them. So, at some point, I will need to build a new big ship which can try again to be that required space station. The question is whether it should be another Scientia-class ship or an updated Omniscient-class, maybe once I have access to nuclear engines. This should be soon, once I have received all scientific data which is still floating around in my spaceship fleet.

Anyways, now to the tasks at hand.

I was totally in doubt whether I have enough fuel left for my flagship, the Omniscient, to get out of the sphere of influence of Kerbin into solar orbit and fired that question into the game´s forum. Yep, should be doable with 700m/s deltaV, they said. But I don´t trust my piloting and will fuel up with what´s possible from the Fuel Ship.

But first, I have some science to do! Hopping around on Minmus´ surface with a four-Poodle-engine ship is a waste of fuel. But I have found a work-around: I let my Kerbonauts do the hopping! A little accidental drop while dismounting made me realize that the RCS from the Kerbonauts can make them practically fly here on Minmus.

- Superkerbo flying across a beautiful scenery

Since I know that there are two different Biomes close by, I can at least collect science from an EVA report and a surface probe from each. Indeed, my Kerbonaut does not have to fly around like Superman for long. I even find three adjacent Biomes (lowland, highland, midland) and send two Kerbonauts to each. As usual, one set of data will remain on the ship´s Mobile Lab, one set will go back to Kerbin for instant science.

- ... and back home we fly, with some science points aboard. It is handy to have engineers, which lets me see the in-flight data from my KER-mod

After those funny little excursions, it´s time to get down to some serious piloting. Launch into low Minmus orbit depletes the Omniscient´s deltaV from 719 m/s to 509 m/s.

- I probably could have launched at a flatter angle

 - at 16kmx16km orbit, the Lander comes to rendez-vous again

 - docked! uh, wait... wrong location!

 - that´s better!

 - next rendez-vous is sceduled with the Fuel Ship

- refueling 1080 units (three 360 tanks): deltaV of 1234m/s for the Omniscient, 726 m/s are left for the Fuel Ship for its return to Kerbin. PERFECT!


 - takes some time to find a both fast and efficient maneuver node out of Kerbin SOI; then, engage!

 - delta V down from 1234m/s to 1109m/s; ETA for solar SOI, 8d34h

- the Fuel Ship is sent back to Kerbin

So, for once, everything went very smoothly this session. There is just one little problem. That darn suborbital flight around the sun. Only one tourist out of the 10 which are on board requires this. My plan was to put him into the Lander and briefly adapt course for a suborbital heading and then reverse and redock. However, testing the required deltaV with a satelite, which I had sent into solar orbit some time ago and arrived there some hours ago, shows: A freaking deltaV amount of 7,596 m/s is required to just drop the solar orbit to a suborbital level! And there I thought the lander´s 3,500 m/s would be aplenty!

This means, there is no way I can fulfill this last mission requirement with my current ship configuration. I need to bring the tourist back and devise a very much specialized craft in order to pull this one off. Some questions in the game forum and research on the game´s wiki gives me two hints: A bi-eliptical transfer could get dV requirements down to ~4,000m/s. Kerbol "low orbit" starts at 1,000km, so a fly-by well below 1,000km could count as a sub-orbital flight. Not sure though. I will have to try it out with a seperate mission once I have brought the Omniscient back to Kerbin. The only annoying thing about this is that this single tourist is part of a mission contract with five tourists; so I cannot cash in that substantial contract until this last tourist has had its due.

Things remain challenging, it seems.

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