Outward Bound

[Salda007]

This one\'s simple: achieve Kerbol-escape velocity. As in, an escape trajectory from the sun.

For what it\'s worth, back-of-the-napkin math based on Kerbin\'s orbital parameters says that from Kerbin\'s orbit, escape velocity is 13,130.27 m/s.

If you can do it stock-parts, my hat is off to you. If not, I\'ll understand. I\'ll think somewhat less of you, but I\'ll do it in an understanding manner.

Also, no 'fly through the singularity at the heart of the sun' shenanigans. That\'s not completing a challenge, that\'s exploiting a bug.

[Salda007]

So, proof that it\'s possible, although I admit I didn\'t pull this off with stock parts. *thinks less of himself*

NovaPunch and Down Under were used in the creation of this launch.

[NovaSilisko]

Used 3 Intrepid II fuel tanks, and two 5 segment SRBs + decouplers and nosecones from the Intrepid SLS.

By the time I emptied the first tank and SRBs I was already on a kerbin escape trajectory...

[sneakeypete]

For what it\'s worth, back-of-the-napkin math based on Kerbin\'s orbital parameters says that from Kerbin\'s orbit, escape velocity is 13,130.27 m/s.

That\'s not so bad, really. it already orbits at 9000m/s, escape velocity is around 3300m/s, you only need to find another 1000 or so m/s ontop of that if you aim your escape in the same direction as kerbin is orbiting.

With my stock parts moon rocket i managed to get into a kerbol orbit of 11000m/s by doing a kerbin escape maneuver from its dark side (aiming with the momentum of kerbin basically) and then trust my way to an escape, 13100m/s was the point where i reached escape velocity like you calculated. Got upto 15000m/s, i was getting out of there fast.

[Entroper]

Did this one with stock parts. It\'s like sneakeypete said, if you use Kerbin\'s orbital and angular momentum, you\'re already most of the way there.

I skipped the launch and low-Kerbin orbital insertion, so the video is only the upper stage: http://youtu.be/UZbZqVci2wk

[Salda007]

I skipped the launch and low-Kerbin orbital insertion, so the video is only the upper stage: http://youtu.be/UZbZqVci2wk

Huh, I think that\'s the first time I\'ve ever been the first person to watch a video on YouTube.

Anyway, this challenge is one that would be much easier if we had proper launch-window control. The giant stack of SRBs I was using (my self-imposed penance for using mod parts: no LFEs) could only do a direct-ascent profile--the launch stages didn\'t have enough push to get the final stage into an orbit; the last stage went from sub-orbital to Kerbol escape in one burn.

First efforts were two-stage designs basically launched straight up from the pad, which put several pods into Kerbol orbits with very low periapses, because the pad\'s position caused me to leave Kerbin\'s SoI at about 6km/s. I finally had to go from a two-stage design to a three-stage one, and went with a westward launch profile: first stage lifts the rest out of the atmosphere almost straight up and slightly to the west (basically just enough to counter Kerbin\'s rotation); second stage pushes the final stage west into optimal firing position; final stage goes for the gold. The loss from the western launch was made up for by not needing to get the final stage 3/4ths of the way around the planet before firing.

But, yeah, I think this is the first mission since .12 where I\'ve gone with a western launch profile.