Tips for my first interplanetary trip?

[SlabGizor117]

I have the very basics figured out with a transfer window planner and everything. My plan is to do a one way trip with a probe and try to orbit Duna. Next land, then rover, then probe return mission, then manned mission. So, how similar is this to docking in the practicing aspect of it, where it becomes second nature? Everything seems so finicky with interplanetary transfers D:

Thanks for the help guys!

-Slab

[Aerindel]

Sounds good to me, although you could skip the probe return mission and just do manned. Once you get used to it you will find yourself cruising back and forth to Duna without really thinking about it.

Your life will be a lot easier if before you send your manned mission you land a rover and then drive to a nice flat spot and use the rover as a landing target. Duna has a lot of hills and you can lose a perfectly good mission to a slope.

Also think about sending a backup unmanned ship into Duna orbit first, something with lots of fuel that can bring your kerbals back if your manned mission runs out of fuel.

Right now for my first 1.02 Duna mission I am building an automated fuel depot on Ike in preparation and then going to send a self fueling DAV (duna ascent vehicle) to my landing site so even if my manned lander breaks the kerbals will have a way home.

Remember, going to another planet isn't any harder than going to the Mun, you just need more fuel, and take the time to set up your Duna orbit several months before you get there when its cheap and you can fine tune it with RCS. If you just drop into its sphere of influence without looking you can use up all your fuel just trying to get into a decent orbit.

It took me an embarrassingly long time to figure out that my focusing the view on your destination planet you could do this.

[SlabGizor117]

Awesome, good idea with the rover, but I'm a whiner about sending kerbals anywhere without knowing what I'm doing, even though I'm playing Sandbox with reverting saves and quickloading XD

What's the best way to get my periapsis down for aerobraking and where should my Periapsis be for a balance between aerobraking and reentering? I'm still on 1.0.0 btw, I'm lazy.

[Starhawk]

It becomes simple after you've done it a few times. The biggest tip is to be patient setting up your maneuver node. You may have to play around with it for a while, and the adjustments can be very sensitive. Use the mouse wheel slowly while mousing over the direction to make fine adjustments.

Set up a maneuver node using the delta-v required in the transfer planner, and you can slide it around Kerbin's orbit to get the ejection angle just right. (It should be exactly along the dashed purple future orbit line for your craft.)

Once that's done, focus on Duna in map mode and turn the camera so you can see the maneuver node in the background. You can now look at the Duna orbit trajectory closely and fine tune it with the maneuver node.

Be prepared to make one or more small adjustment burns. As long as you get a good encounter, you can usually wait until you enter Duna's SOI before you set up a maneuver node to fine tune your periapsis.

Good luck and happy landings!

[SlabGizor117]

Ok, I'm getting towards Duna, but I need to figure out how low to set my Pe without burning up. What did the atmosphere change to on Duna? does 20km sound good?

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23km Pe set, hopefully this works out D:

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Turns out Atmosphere on Duna starts at 50km

[Aerindel]

Awesome, good idea with the rover, but I'm a whiner about sending kerbals anywhere without knowing what I'm doing, even though I'm playing Sandbox with reverting saves and quickloading XD

What's the best way to get my periapsis down for aerobraking and where should my Periapsis be for a balance between aerobraking and reentering? I'm still on 1.0.0 btw, I'm lazy.

By the time you land a rover you will know what your doing.

Best way to get your PE down is to use the aforementioned method of fine tuning your injection orbit until your PE is where you need it to be with only a minor in approach burn to fine tune it.

As to your altitude, I have no idea what it is now. You will have to play around. I would shoot for 30 KM for my first test.

And don't forget to reduce your parachute pressure to the minimum. On Duna depending on your altitude you can crash into the ground before your parachute even opens. For this reason low altitude landing sites are usually easier.

And get 1.02 before you get too far, it has several aspects that are radically different (and improved) from 1.00.

[SlabGizor117]

Lesson learned, 23km Pe didn't do crap. Trying to save it with a Retro burn, I have tons of fuel. If I reload I'll go for 10-15km.

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oh, just saw your reply. Yeah, going for 10km I have no parachutes, this is only an orbiter. Looks like I'll have plenty of fuel to use for a Plan B!

[Aerindel]

Good to know. Like I said, I haven't been there since .90

Wish I could go to Duna for the first time again. It was pretty exciting. I started playing back when orange tanks where the largest you could get, and the ships where so flexible it was like flying a spaghetti noodle. No way I could get a big enough ship into orbit so I built and refueled one with SIX docking missions, but I was able to send a science lab and two landers with that mission and return samples from both Duna and Ike.

Edited May 6, 2015 by Aerindel

[SlabGizor117]

Aaand, 10km is too low. XD 15km next!

[Laie]

Just saveload when entering Duna SOI and retry until you succeed -- you can adjust your PE by doing radial burns.

Edit: ninja'd by OP. Sweet.

[SlabGizor117]

Lol! I keep missing the new posts. yeah, I did 15km, then warped past it at 1,000x because the in-atmosphere 4x limit on time warp decided to take a day off. D:<

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Wow, Still too low. Maybe 18km this time.

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Wow, I just remembered the Trajectories mod! Is that updated for 1.0??

[Fr8monkey]

Not yet.

[technion]

It becomes simple after you've done it a few times. The biggest tip is to be patient setting up your maneuver node. You may have to play around with it for a while, and the adjustments can be very sensitive. Use the mouse wheel slowly while mousing over the direction to make fine adjustments.

I'm not in general one to advocate mods for doing things, but, particularly when you go further and try to plan a path to Jool, I don't understand how people can plan these without the Precisenode mod. Being able to +-1 one point of dv is hugely helpful.

[Wanderfound]

I'm not in general one to advocate mods for doing things, but, particularly when you go further and try to plan a path to Jool, I don't understand how people can plan these without the Precisenode mod. Being able to +-1 one point of dv is hugely helpful.

This is what RCS is for; rockets for the bulk of the burn, but the last few m/s are done with taps on the translation controls and the view focused on the target planet.

[Laie]

This is what RCS is for; rockets for the bulk of the burn, but the last few m/s are done with taps on the translation controls and the view focused on the target planet.

This isn't about doing the burn, but about planning the maneuver. And while the stock node pully-thingy is quite intuitive and easy to understand, it doesn't lend itself too well to fine adjustments. Being able to zoom in on the destination while clicking +-1 on a node editor is priceless.

[seaces]

I did my first trip to Duna in .90 with probe on ion engines it had instruments for different atmospheretic observation. At the end I figured out that I could go to ike too for some science. The mission was a success and it ended by deorbiting probe to duna to gather some science from low altitudes before it crashed and for that I had to use big transmitter to be able in time to transfer all data back. I suggest that you send a probe that would look as close as possible to the manned Lander that you would send later one. Just to see how it behaves on Duna how responsive it is etc. Like good test vehicle and some maybe science collection from the atmospehe layers if you want.

[TheXRuler]

Just a little sidenote in general. I did a rescue mission to duna (screwed up my amount of life support, only had 80 days left on arrival) sending a payload more or less vertically up from kerbin (11km/s burn on one nuke xD) and tried aerobraking into duna orbit, however with ferram and deadly reentry there was no way I could aerocapture at ~9km/s relative velocity. What I did was burn retrograde shortly before entering the atmosphere to sth like 5km/s and then aerocapture, all in all I got there with 3 hours and 17 minutes to spare, lucky kerbals ^^

[SlabGizor117]

Just a little sidenote in general. I did a rescue mission to duna (screwed up my amount of life support, only had 80 days left on arrival) sending a payload more or less vertically up from kerbin (11km/s burn on one nuke xD) and tried aerobraking into duna orbit, however with ferram and deadly reentry there was no way I could aerocapture at ~9km/s relative velocity. What I did was burn retrograde shortly before entering the atmosphere to sth like 5km/s and then aerocapture, all in all I got there with 3 hours and 17 minutes to spare, lucky kerbals ^^

Wow, nice.

[78stonewobble]

I must admit, I have a tendency to restart my games when I reach the interplanetary stage or play something else when I get that far, but I wanted to cheer Slapgizor117 on. *does the wave or possibly a panicking kerbal imitation*

[madcat1968]

Lol! I keep missing the new posts. yeah, I did 15km, then warped past it at 1,000x because the in-atmosphere 4x limit on time warp decided to take a day off. D:<

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Wow, Still too low. Maybe 18km this time.

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Wow, I just remembered the Trajectories mod! Is that updated for 1.0??

I found through experiments that setting the aero-capture periapsis at 16,750 km is ideal height for my space craft configuration. I point the craft retro-grade while during aerocapture manuvers (YMMV). I do radial burns for rough adjustments of the periapsis (fuel efficient), and pro-grade/retro-grade burns to fine turn the periapsis (0.1 dv or less).

[SlabGizor117]

I must admit, I have a tendency to restart my games when I reach the interplanetary stage or play something else when I get that far, but I wanted to cheer Slapgizor117 on. *does the wave or possibly a panicking kerbal imitation*

Haha, thanks man!

I found through experiments that setting the aero-capture periapsis at 16,750 km is ideal height for my space craft configuration. I point the craft retro-grade while during aerocapture manuvers (YMMV). I do radial burns for rough adjustments of the periapsis (fuel efficient), and pro-grade/retro-grade burns to fine turn the periapsis (0.1 dv or less).

Good idea! I'm working on sending a rover, too. I have RCS on it this time, so I can do better fine tuning adjustments. I found out that around a 17km Pe did it for my first orbiter.