Would it help if I got out and pushed? (Yes, it does.)

[tfabris]

A funny thing happened last night:

I was trying out the new Career Mode they implemented in 0.22. I'd gotten enough parts to make it to the Mun, and I managed to collect a ton of science points on the trip. I was keen to get some particularly big groups of science points back home in full 100 percent force rather than transmitting them at a reduced percentage, so I was planning my return trip carefully. I was able to fly the ship back from the Mun successfully, but just barely. I ran out of fuel with my Kerbin perigee pointed at 50k altitude.

50k is fine for a return to Kerbin, because the atmosphere starts at about 70k, so it means that I was aerobraking on each orbit and would eventually reach Kerbin. The problem was, the air at 50k is so thin that it was taking far too many orbits to get any serious amount of altitude reduction. Pass after pass, and my altitude would only decrease a small amount each time. It was taking forever.

My ship had no rocket fuel left, and no RCS thrusters because I hadn't gotten that far in the tech tree yet. So I couldn't use direct thrust to get my perigee any lower.

So I tried something that I wasn't sure if it would work: I got out and pushed.

I pointed the ship in the retrograde direction at apogee, did an EVA, jetted around the to tail end, bumped up against the engine nozzle, and just thrusted forward with the jetpack.

It did take me a few tries of going back into the capsule, checking my perigee, then going back out again. Also at one point I had pressed CTRL-ESC so that I could get back to the Windows desktop, and this left me with a stuck CTRL key in the game, and since CTRL is jetpack-thrust-down, it made Jeb shoot away from the capsule at high speed. It was a tense moment getting him back to the capsule, but I made it.

In the end, it worked. At apogee, it took just a few rounds of jetpack thrusting, getting back in the capsule and checking my perigee, then going back out again. I successfully reduced the altitude at perigee a few K, enough so that the aerobraking had some bite to it, and I reentered normally and landed safely with parachutes. I landed the entire lander from the Mun surface, including landing legs and everything, landing vertically in a gentle touchdown. Total science points from the trip: 900! I had a great shopping spree when I got back. It only worked, though, because I was already on a reentry orbit path that was good, and all I needed was a slight tweak to the overall orbit. And small speed changes at apogee result in big altitude differences at perigee, and vice-versa.

Still, it made me think of Leia chiding Han in TESB: "Would it help if I got out and pushed?" "It might!"

[epima09]

Yes, i tried it too and it definitely have an influence.

But i don't think it will help that much.

I was above 150km trying to push my ship back to kerbin, but it's push was too small for me to continue.

[Commander Zoom]

I haven't saved any missions this way (one I did salvage by using the RCS fuel, after the main tanks had run dry), but I have seen a few forum posters who have. Now including you.

[Superfluous J]

I just tried this recently but decided it was a better use of my time to send up a rescue craft.