SSTO to laythe and beyond

[herbal space program]

Btw, if i plan to visit Bop and Pol alongside laythe, what is the most efficient order to do this in? Is it best to go to laythe 1st since i can do a direct laythe aerobrake from kerbin trajectory? Or is it best to leave laythe for last when im lower on fuel and hit the other planets 1st?

http://i.imgur.com/iRc1pOG.jpg

I would say visit Laythe first, because you can get on the ground there for next to no dV from your Jool approach if you set up your Tylo-Laythe capture correctly. From Laythe orbit, it's then about 680 m/s to set up a Tylo encounter that could put you just about anywhere in the Jool system. If you use that to get to Pol or Bop, I think it would cost you fairly little dV to drop yourself from those bodies back to a Tylo encounter, first to go from one to the other and then to send yourself home. Also, I think the lighter your ship is when you're trying to land on these airless bodies, the better.

[panzer1b]

I would say visit Laythe first, because you can get on the ground there for next to no dV from your Jool approach if you set up your Tylo-Laythe capture correctly. From Laythe orbit, it's then about 680 m/s to set up a Tylo encounter that could put you just about anywhere in the Jool system. If you use that to get to Pol or Bop, I think it would cost you fairly little dV to drop yourself from those bodies back to a Tylo encounter, first to go from one to the other and then to send yourself home. Also, I think the lighter your ship is when you're trying to land on these airless bodies, the better.

Ok, ill give it a shot, 1st visit laythe, then do what i can to mess with tylo and grav assists. Btw, i actually believe it is a bad idea to go tylo between Bop and Pol, since they are both in rather far orbits (and its takes ~200-300m/s dV total to get from one to the other based on older trips). Going to tylo is less then this, but dropping your PE so much and then having to essentially lift it to match the target takes ALOT of dV, more then it would take to just hohman from Pol to Bop/vice versa.

Now, what is the best method to actually land on these airless bodies? Should i go with a direct collision course suicide burn? Or is it more efficient to 1st get in orbit around said body before landing (this has the added benefit of giving me more choices as to where i land too)?

While i have landed on every body in KSP aside from the sun (keep exploding), jool (keep exploding) and moho (need to send something there so i can finally say ive been to every planet in game), i never really cared as much about efficiency since most of my games i tend to build completely overkill dV vessels in the 1st place (a good example would be the satelite network i set in medium kerbin orbits, these things are ion powered and have ~20K dV left, despite their only purpose being to stay in kerbin orbit until shot down or something). Need to get better at actually using dV effectively instead of returning from the mun with like 4000 dV left in the lander, as my last legit mun lander (that wasnt a SSTO or dropship carrying tanks) returned home on the bloody orbital insertion engines (i didnt even need the 2nd stage at all since the launcher got the 2nd stage AND the lander thing to mun and had excess dV but i ditched it as no way to land a massive rocket) with an excess of 4K dV left after reentering kerbin.

Although i have less effective dV then Nefrums and his insane 7.3K dV ion craft since some of that dV will be counted towards the laythe ascent even if its using much more efficint rapiers, i think i can pull off his amazing feat with grav assist to cut down the raw dV i need. Who knows, perhaps i can even pull off a minmus landing too on the way home (although that will be on fumes if at all possible).

Edited September 10, 2015 by panzer1b

[herbal space program]

Ok, ill give it a shot, 1st visit laythe, then do what i can to mess with tylo and grav assists. Btw, i actually believe it is a bad idea to go tylo between Bop and Pol, since they are both in rather far orbits (and its takes ~200-300m/s dV total to get from one to the other based on older trips). Going to tylo is less then this, but dropping your PE so much and then having to essentially lift it to match the target takes ALOT of dV, more then it would take to just hohman from Pol to Bop/vice versa.

Now, what is the best method to actually land on these airless bodies? Should i go with a direct collision course suicide burn? Or is it more efficient to 1st get in orbit around said body before landing (this has the added benefit of giving me more choices as to where i land too)?

As to the first issue, I was thinking that there's a pretty big difference in orbital inclination between the two bodies, so it would take a lot of dV to do the plane change, but if that's not the case, then I agree dropping PE to Tylo is not necessary. Certainly if it's only a couple hundred m/s, then by all means straight from one to the other would be the way to go.

As to the second question, the most efficient way to land on a particular airless body in theory would be to cross into its SOI from behind at the minimum possible speed, on an approach trajectory that grazes the surface, then suicide burn at PE to bring horizontal velocity to zero. I believe that if you want to do this in stages, i.e. establish a highly eccentric orbit on the first pass and then lower its AP in stages from your low point, that would actually take roughly the same amount of energy as doing the whole suicide burn in one go. For Pol and Bop, as you pointed out, a lot of your energy budget will be spent matching orbital velocities, as their gravity is too feeble to change your speed very much.

[ManEatingApe]

This challenge was a lot of fun, really enjoyed designing smaller and smaller craft that could make it. Now the problem is that most of my Kerbals are on Lathe!

Ended up with this: https://dl.dropboxusercontent.com/u/23740747/Xenon%20No%20Object.craft

17.4 tons, 46 parts and 21000 xenon! Roughly 9200 dV from LKO.

With the aid of 10 gravity assists and a lot of luck made it to Minimus, Gilly, Pol, Bop and Laythe

http://imgur.com/a/8MhA1

[Red Iron Crown]

This challenge was a lot of fun, really enjoyed designing smaller and smaller craft that could make it. Now the problem is that most of my Kerbals are on Lathe!

Ended up with this: https://dl.dropboxusercontent.com/u/23740747/Xenon%20No%20Object.craft

17.4 tons, 46 parts and 21000 xenon! Roughly 9200 dV from LKO.

With the aid of 10 gravity assists and a lot of luck made it to Minimus, Gilly, Pol, Bop and Laythe

http://imgur.com/a/8MhA1

Incredible! Welcome aboard!

[Val]

This challenge was a lot of fun, really enjoyed designing smaller and smaller craft that could make it. Now the problem is that most of my Kerbals are on Lathe!

Ended up with this: https://dl.dropboxusercontent.com/u/23740747/Xenon%20No%20Object.craft

17.4 tons, 46 parts and 21000 xenon! Roughly 9200 dV from LKO.

With the aid of 10 gravity assists and a lot of luck made it to Minimus, Gilly, Pol, Bop and Laythe

http://imgur.com/a/8MhA1

Very impressive entry and ship. But I'm wondering, in all the pictures Valentina looks various degrees of happy or excited. Except the last one. She looks really displeased. What happened? Edited September 20, 2015 by Val

[Red Iron Crown]

Very impressive entry and ship. But I'm wondering, in all the pictures Valentina looks various degrees of happy or excited. Except the last one. She looks really displeased. What happened?

She realized there wasn't enough fuel for the trip back to Kerbin.

[ManEatingApe]

Incredible! Welcome aboard!

Thanks! Going to try making some massive Mk3 monster to rescue all my Kerbals now, will see how I get on.

Very impressive entry and ship. But I'm wondering, in all the pictures Valentina looks various degrees of happy or excited. Except the last one. She looks really displeased. What happened?

She realized there wasn't enough fuel for the trip back to Kerbin.

Ha, didn't notice that! Perhaps she's like Alexander, weeping for there are no more worlds to conquer, but I think Red Iron Crown's suggestion is more accurate.

[panzer1b]

Well ive officially switched to using monoprop tanks instead of FLT-100s.

Those tanks have a higher dry mass, and can fit 240 LF. Since im already clipping the tanks to death, volume logic falls out the door, but i refuse to not have dry mass be fair for fuel tanks, and since i cant edit the FLT-100's mass in the .cfg, ill just take the monoprop tank thats a bit more then twice the mass (and same size), and cram a bit more then twice the FLT-100s fuel into it. Satisfies fuel tank mass fraction, and actually lets me cut the stack of fuel tanks inside the MK2 bay from 35 to 15.

Yes this is technically outside of the game limits, but since i do not consider swapping LFO tanks for pure LF a cheat, i see no reason why i cant swap monoprop tanks for LF too.

Ohh, and ive managed to BARELY pull off ~7K dV with a fully armed ship. Its so painful to lift 38 tons with 1 rapier, i think 40 MIGHT be doable, but it isnt looking very likely.

Finally, ive managed to pull off 7.7K dV in lko with JUST nuke propulsion. If i can get that up to 8K ill be happy (and i think thats about the absolute maximum that can even be done without refueling via SSTO craft that doesnt have an excessively bad TWR.

Edited September 25, 2015 by panzer1b

[ManEatingApe]

Ohh, and ive managed to BARELY pull off ~7K dV with a fully armed ship. Its so painful to lift 38 tons with 1 rapier, i think 40 MIGHT be doable, but it isnt looking very likely.

38 tons on a single rapier is pretty nifty. I can barely contemplate 20!

[ManEatingApe]

So just for fun tried the challenge again, but with a twist - rescue the 5 Kerbals stranded on Laythe from 3 previous attempts. Fortunately by sheer fluke the 1st and 2nd attempt ended in the same spot so only 2 landing sites to visit in total.

Ended up with a hybrid Mk2/Mk3 design (Mk 2.5?) dubbed "Space Whale"

Getting into orbit from Laythe's surface was much more straightforward than anticipated. However due to some over-exuberant use of the throttle when pootling around Laythe I had only 1,100 m/s of dV left for the return trip. Getting back required patience and time. And Tylo. Lots and lots of Tylo.

Album here for the curious: http://imgur.com/a/U2HZH

[Val]

So just for fun tried the challenge again, but with a twist - rescue the 5 Kerbals stranded on Laythe from 3 previous attempts. Fortunately by sheer fluke the 1st and 2nd attempt ended in the same spot so only 2 landing sites to visit in total.

Ended up with a hybrid Mk2/Mk3 design (Mk 2.5?) dubbed "Space Whale"

http://i.imgur.com/sqIQN5V.png

Getting into orbit from Laythe's surface was much more straightforward than anticipated. However due to some over-exuberant use of the throttle when pootling around Laythe I had only 1,100 m/s of dV left for the return trip. Getting back required patience and time. And Tylo. Lots and lots of Tylo.

Album here for the curious: http://imgur.com/a/U2HZH

Impressive, especially the return trip. Not seen it done like that before.

[ManEatingApe]

Impressive, especially the return trip. Not seen it done like that before.

Thanks, I was inspired by your epic Mk3 entry that delivered both a rover and plane to Laythe's surface.

I considered taking the same approach of packing a mini jet into a cargo bay but gambled that the distance between the 2 landing sites was close enough that the fuel used by the entire craft would be roughly equivalent to the mass of the bay+mini jet. Incorrectly, as it turned out it took 9.85 tons of liquid fuel to make the hop, but a CRG-50 + say 5 ton jet would have been only 8 tons total. And possibly with a bit of cunning I could have crammed a smaller jet into a CRG-25 for at least another 1.5 ton savings.

The triple Tylo assisted orbit took about 500m/s to setup, and thanks to Jool's massive gravity well had a rather leisurely period of 1 year, 229 days. The 4th Tylo assist had enough velocity to drop the PE to Eve's orbit. I messed around with Eve intercepts for a while but found 2 problems:

• Even brushing the atmosphere meant instant fiery oblivion.
  
• With Eve's 2 degree inclination it was tricky to setup a subsequent Kerbin intercept. Anything I could manage still came in too quickly for an aerocapture.
  

In the end, intercepting Kerbin and skimming the atmosphere was roughly as effective, and allowed me to stay in the plane of the ecliptic for easier followup intercepts.

[Val]

Thanks, I was inspired by your epic Mk3 entry that delivered both a rover and plane to Laythe's surface.

I'm honored to have been an inspiration.

I considered taking the same approach of packing a mini jet into a cargo bay but gambled that the distance between the 2 landing sites was close enough that the fuel used by the entire craft would be roughly equivalent to the mass of the bay+mini jet. Incorrectly, as it turned out it took 9.85 tons of liquid fuel to make the hop, but a CRG-50 + say 5 ton jet would have been only 8 tons total. And possibly with a bit of cunning I could have crammed a smaller jet into a CRG-25 for at least another 1.5 ton savings.

The triple Tylo assisted orbit took about 500m/s to setup, and thanks to Jool's massive gravity well had a rather leisurely period of 1 year, 229 days. The 4th Tylo assist had enough velocity to drop the PE to Eve's orbit. I messed around with Eve intercepts for a while but found 2 problems:

• Even brushing the atmosphere meant instant fiery oblivion.
  
• With Eve's 2 degree inclination it was tricky to setup a subsequent Kerbin intercept. Anything I could manage still came in too quickly for an aerocapture.
  

In the end, intercepting Kerbin and skimming the atmosphere was roughly as effective, and allowed me to stay in the plane of the ecliptic for easier followup intercepts.

Using aerobraking as part of setting up a capture takes a lot of skill, some really good tools for calculating trajectory, or a lot of reloads. Either way, it is really very impressive.

[Bomaye]

My Space Bus..... :-)

[Bomaye]

Crap forgot the no refuel part........(or just lazy and didnt read)

[parzr]

The rules say SSTO, does this mean staging is allowed after getting into orbit?

[Teilnehmer]

The caption says: “Single stage: to orbit, to Laythe, and beyondâ€Â. So no staging

[Lothsahn]

This challenge was a lot of fun, really enjoyed designing smaller and smaller craft that could make it. Now the problem is that most of my Kerbals are on Lathe!

Ended up with this: https://dl.dropboxusercontent.com/u/23740747/Xenon%20No%20Object.craft

17.4 tons, 46 parts and 21000 xenon! Roughly 9200 dV from LKO.

With the aid of 10 gravity assists and a lot of luck made it to Minimus, Gilly, Pol, Bop and Laythe

http://imgur.com/a/8MhA1

Picking my jaw off the floor. Insane.

That is all.

[Guz]

here's my attempt:

Single Stage flight to Laythe, the Kraken, Duna and back to Kerbin.

V1.04 / no mods

[Val]

here's my attempt:

Single Stage flight to Laythe, the Kraken, Duna and back to Kerbin.

V1.04 / no mods

That is a very interesting and capable design, Guz, and a very cool trip you did.

But, unfortunately, the first rule of the challenge states that refueling is not allowed.

[ManEatingApe]

here's my attempt:

Single Stage flight to Laythe, the Kraken, Duna and back to Kerbin.

V1.04 / no mods

Nice craft, insane TWR! I haven't seen a 3.75m entry before. I wonder if you replaced the ISRU with liquid fuel and ditched the heavy heatshields would you have enough dV to make it to Laythe directly without refuelling, perhaps with some cargo left over.

That video was slick, loved the Kerbal gymnastics at 8:47 LOL

[zolotiyeruki]

That is a very interesting and capable design, Guz, and a very cool trip you did.

But, unfortunately, the first rule of the challenge states that refueling is not allowed.

Maybe the rules need to be clarified a bit then--no refueling from another craft, and no ISRUs. I think he at least deserves an Honorable Mention, if for nothing else than the idea of sticking heat shields on the nose of a space plane. That's just brilliant!

I'm halfway done--I finally stuck the landing on Laythe. Note to self: land on the shore, perpendicular to the shoreline--the terrain tends to have a simple upward pitch.

[Red Iron Crown]

Don't know how the rule could be clearer:

"*Craft must be SSTO and land on laythe without any refueling or use of IRSU."

[zolotiyeruki]

"*Craft must be SSTO and land on laythe without any refueling or use of IRSU."

Ah, I got caught looking at the wrong line in the rules. My bad--sorry!