Kerbal Space Program - Returning to Earth From Duna

[collinsmark]

... Continued from part 14.

The Sands of Duna

Part 15: Coming in fast

Collinsmark is not affiliated with Squad nor Kerbal Space Program

We are coming in fast. Really, really fast.

Might was well fold up the solar arrays. There's areobraking in the near future.

[Figure 122: Coming in fast. Retract solar arrays.]

And it's time to burn!

[Figure 123: Coming in fast. Time to burn]

It's not possible to show how fast we are coming in with just these images. But if you can imagine what it's like approaching a planet with "time warp" it's like that. But with no time warp.

Maybe this "fast return path" wasn't such a wise idea.

[Figure 124: Coming in fast. Really fast.]

Need to watch the periapsis. It can't be too high or we won't get enough atmospheric braking, in which case we'll run out of fuel and shoot out of Kerbin's SOI. Too much and we'll smash into Kerbin, with enough gs to kill the kerbals.

I'm hoping to at least get an elliptical orbit so that we can land on the daytime side of Kerbin. (Better images that way.)

[Figure 125: Keep an eye on the periapsis.]

[Figure 126: Oh, my. This is so fast.]

[Figure 127: Scary fast.]

[Figure 128: C'mon atmosphere.]

[Figure 129: Almost out of fuel!]

[Figure 130: Every little bit counts.]

[Figure 131: And we've established an elliptical orbit. Thanks goodness!]

That was close. Too close. And we're out of fuel.

Fortunately we have some monopropellant left. That should be enough to deorbit on the daylight side of Kerbin.

To be continued. ...

 

[collinsmark]

... Continued from Part 15.

The Sands of Duna

Part 16: Conclusion

Collinsmark is not affiliated with Squad nor Kerbal Space Program.

Part of our orbit is still in the atmosphere, and we have a little monopropellant left. Used together, we should be able to bring the ship down on Kerbin's daylight side if we're careful.

[Figure 132: A little more atmospheric braking and monopropellant thrust]

[Figure 133: A little more orbital adjustment]

[Figure 134: Oops. Better ditch the service module.]

Although if this were KSP version 0.24 or later, we might have considered an attempt to bring it back with us for recovered funds.

[Figure 135: Chutes deployed (1/2)]

[Figure 136: Chutes deployed (2/2)]

[Figure 137: Chutes opened]

[Figure 138: Near touchdown]

[Figure 139: The crew are home]

Lessons learned:

• Regarding this "fast return path" thing: My advice is don't do it. At least don't do it the way I did it. It's a big waste of fuel, and that last bit coming on Kerbin so fast is scary and dangerous.
• If you do something like a "fast return path" at least wait long enough such that you can do a gravity assist with Eve. The strategy is to wait for an Eve encounter such that you can create a Hohmann-like transfer orbit between Eve and Kerbin. You do not want to stop and orbit Eve, that's not what I mean. Rather you just want to encounter Eve (shooting past Eve) and make adjustments such that you get a Kerbin encounter on the opposite side of the Sun from the Eve encounter, such that the Eve encounter is at the new periapsis and the Kerbin encounter is near the new apoapsis. [Edit: And of course you'll have to wait until Kerbin and Eve are aligned properly for this.] This might take patience and experimentation with maneuver nodes, but it's better than the way I did it in this story.
• Some have notified me that "fancy-shmancy" should be spelled "fancy-schmancy" with a "sch-." To that I say, 'sounds like a fine choice to me. Whatever floats your boat.*

*("Whatever floats your boat" is American vernacular for "Ah, yes good sir. Please weigh the options and make the choice based on your best judgement. Jolly good then.")

The End

Full Series
Part 1: Introduction and Basics
Part 2: Efficient Launch Into Orbit
Part 3: Rocket Design Basics
https://www.physicsforums.com/threads/kerbal-space-program-rocket-design-and-orbital-mechanics.970334/
https://www.physicsforums.com/threads/kerbal-space-program-getting-to-the-mun.970335/
https://www.physicsforums.com/threads/kerbal-space-program-getting-to-the-mun-part-2.970336/
https://www.physicsforums.com/threads/kerbal-space-program-preparing-to-land-on-the-mun.970337/
https://www.physicsforums.com/threads/kerbal-space-program-mun-touchdown.970338/
https://www.physicsforums.com/threads/kerbal-space-program-staying-on-the-moon.970339/
https://www.physicsforums.com/threads/kerbal-space-program-preparing-to-leave-lander.970340/
https://www.physicsforums.com/threads/kerbal-space-program-walking-on-the-mun.970341/
https://www.physicsforums.com/threads/kerbal-space-program-leaving-the-mun.970342/
https://www.physicsforums.com/threads/kerbal-space-program-rendezvous-and-docking.970343/
https://www.physicsforums.com/threads/kerbal-space-program-prograde-retrograde-and-approach.970344/
https://www.physicsforums.com/threads/kerbal-space-program-prepare-for-docking.970345/
https://www.physicsforums.com/threads/kerbal-space-program-docking-and-lander-reunion.970346/
https://www.physicsforums.com/threads/kerbal-space-program-heading-home.970347/
https://www.physicsforums.com/threads/kerbal-space-program-entering-Earth's-orbit.970348/
Part 19: Landing Back on Earth
Part 20: Launch for Duna
https://www.physicsforums.com/threads/kerbal-space-program-duna-probe-launch.970351/
Part 22: Duna Rocket Launch
https://www.physicsforums.com/threads/kerbal-space-program-duna-burn-and-periapsis.970354/
https://www.physicsforums.com/threads/kerbal-space-program-duna-oberth-effect.970355/
https://www.physicsforums.com/threads/kerbal-space-program-duna-mid-course-corrections.970356/
https://www.physicsforums.com/threads/kerbal-space-program-using-gravity-to-orbit-duna.970357/
https://www.physicsforums.com/threads/kerbal-space-program-landing-on-duna.970358/
https://www.physicsforums.com/threads/kerbal-space-program-exploring-duna.970359/
https://www.physicsforums.com/threads/kerbal-space-program-launching-off-duna.970360/
https://www.physicsforums.com/threads/kerbal-space-program-fast-return-path-from-duna.970361/
Part 31: Advanced Duna Flight Math
https://www.physicsforums.com/threads/kerbal-space-program-burn-2-to-escape-duna.970363/
Part 33: Returning to Earth From Duna