camacju

This is my newest long range SSTO. It can go from the runway to Kerbin orbit and back, eight times. Here it is during the third orbit.

@ralanboyle Sorry to revive this thread but this single stage mission might fit pretty well here. I do eight orbits in a single Rapier and Nerv powered SSTO.

@boolybooly I see my Advanced Pilot Precision Award x5 and raise myself Advanced Pilot Precision Award x8. In VAB, first lap Second through fourth laps Laps 5-8 I had 40-50 m/s of deorbit burn for each of my eight orbits for about 360 m/s wasted. I probably wasted another 200-250 m/s on orbital insertions. Maybe with a bit more fuel and better flight profiles I can fit in a ninth orbit but I probably won't attempt it. Edit: Instead of "Untitled Space Craft" can you call it "Relay Race 2"

Update: I tried to get a tank to orbit as efficiently as I could - 10.5 km/s left. With two extra Nervs I could probably get >9.5 km/s remaining, which would add a good amount of margin to your mission. I might try that later. Craft in VAB. 69.4 tons, with two Rapiers and two Nervs. 35 tons per Rapier is a good amount for an efficient craft that's still relatively easy to fly. I have 34.7 tons per Rapier which is close to that number. On runway This craft falls off the end of the runway, where I pitch up to stay level. This pitch gradually goes to zero as I gain airspeed and lift. Normally this high of a pitch causes significant drag losses but drag is lower at subsonic speeds anyway. I stay near sea level until 600 m/s. Note that I'm pointing completely horizontal here. The wing incidence is pulling me upwards but I want to build horizontal velocity. Passing 1 km/s, pitched up 10 degrees. I'll level off at about 21 km until the Rapiers' effective Isp drops to 800. In order to do this I compare vacuum delta-v to surface speed since KSP doesn't give effective Isp values. Another way to do this is to look at the thrust/drag ratio. This is a heavier craft than I'm used to so I have to be pitched up to maintain altitude. This increases drag so I have to turn on the nuclear engines at 1630 m/s instead of waiting another 30 m/s. Passing 2 km/s In orbit - 10.5 km/s left

I'm guessing it's not possible with your current design. By the time you reach Tylo your fuel levels and TWR won't be at the right value. You're basically trying to do a single stage to Tylo and back design (even though you stage the Rapiers) because of the single tank restriction. And those basically require oxidizer and ions. In the orange efficiency challenge reboot I had a design that could go anywhere except Tylo and Eve on one orange tank, and I'm pretty sure that you can't do Tylo on one fuel tank. (Hazard-ish had to cheat to do it). With some aerodynamic tricks you can do Eve on one tank however.

When you put two service bays on opposite sides of the root part and offset them into one another, each bay will occlude the other one, so they'll be both occluded. Additionally everything inside either bay will be occluded So you have a dragless and heat-proof craft edit: It seems mr. duckweed has ninja'd me

Yes, it can take a kerbal. Either in a command seat or in a small command pod

Mechjeb scripting module might be the easiest way to go here since so much stuff is already automated.

This makes the entire challenge trivial. Here's a Jool dive orbit using service bay stacking: Jool orbit - periapsis below Jool surface Reentry heating 120% Descent Periapsis Ascent

Here's a quick submission. Could be improved significantly but this is a pretty good start. In VAB. Three stages of Sepratron to adjust the thrust profile On runway Steep climb Final stage firing Apoapsis of 42 km. Not optimal by any means Pulled into a glide. Ideally I'd do this sooner but Mechjeb wasn't cooperating Wheels down Landed at 12min 31sec

Do it in stock using a bunch of KAL units, you won't Fascinating idea though. A direct ascent mission might actually be the easiest way to go here because it removes the docking aspect. Barring that, another relatively easy solution would be to have a mothership in Tylo or Laythe orbit.

I don't really have the motivation to do the Moho mission right now, but I did try to get the orange tank to orbit as efficiently as possible: This is definitely more than enough to do a Moho mission

It's definitely impossible without a pretty significant design change. The Rapier's specific impulse is really low and the TWR of the Nerv is too low also. This means that the craft probably won't even be able to handle the Tylo landing - you'll either run out of fuel or not be able to slow down. As it is a Tylo SSTO requires lots of optimization that just isn't possible with the restriction of having to use only one orange tank.

I was using figures from some Moho missions I previously did. The 1050 m/s quote is from an elliptical Moho orbit, not low circular orbit, which means that if you use the circular orbit figure, your capture burn will be larger. Maybe I'm overestimating how hard it will be, but a Moho SSTO is pretty hard by itself. I don't know how the additional restriction of having to use one orange tank will play into it. That's not really correct. The only challenge with Moho is getting there in the first place, which is still pretty hard if you don't use gravity assists. However with gravity assists it becomes much easier to manage. Tylo requires more delta-v to land and return, just because of its high gravity. You need minimum 4200 m/s to land on Tylo and return to orbit, plus another 1600-2000 to capture and escape. That's not even counting the Kerbin->Jool transfer, which is 2000 more m/s if you don't use gravity assists, and 850 if you don't. Eve is harder than Tylo because of the high gravity and thick atmosphere. You lose a lot of fuel to drag. Eeloo is also harder to get to with a direct transfer since it's so far away. Since I can use gravity assists, encounter at periapsis is always better.

I realized - there's actually one more destination that needs to be addressed: Moho. And the margins might be really tight. I might actually need to stage some parts off for the required delta-v. Assume I have 5200m/s in LKO since that's what I had last time, 840-850 m/s to Mun transfer, assume 850 - 4350 m/s left Kerbin-Eve-Kerbin-Eve-Moho gravity assist chain - 1050 m/s to capture using deep space maneuvers and Moho gravity assists- 3300 m/s left (This might be an overestimate. Last time I did this strategy I encountered Moho's orbit at a bad point in the orbit. Likely this will be better if I encounter Moho at periapsis) Moho orbital velocity at this point is 1050 m/s, so assume 1150 m/s to land and 1100 m/s to take off Then 1050 m/s to get back to Eve and then back to Kerbin - 50 m/s left (!) This is going to be super close and if I lose any efficiency on the Moho landing then the mission's lost, assuming a single stage. However I think that staging will increase delta-v significantly. Comparing the vacuum delta-v of the fully fueled craft with all the plane parts, and then with none of them: 6642 m/s vs 8619 m/s Comparing the vacuum delta-v of the craft with a realistic amount of fuel drained in LKO: 5168 vs 6868 m/s This means that a staged design has a good chance of being able to execute a Moho return mission. TWR at low Moho orbit will be about 1.7 which will be fine for a good landing profile.

Another option would be to make a Laythe lander that can do Laythe in a single stage, and reuse that for Tylo. Alternatively if you want to use nuclear engines, then having a nuclear engine and a bunch of Mk0 fuel tanks can land on Tylo and return to orbit on one stage.

Theoretically category 2 would only require very minimal corrections since you'd just need to coast from Kerbin to Moho. You could do it with an ant engine and a dumpling / oscar-b tank probably. Category 1 would require less than 1100m/s of dv in the payload - my Moho encounter wasn't quite optimal I think. I'm not sure whether ions or a spark booster would be lighter but for that amount of delta-v it might be close.

@Hotel26 Here's my mission. Mass with reusable booster is 7465 kg, mass of just payload is 4550 kg. Entire craft in VAB Just payload Edited into Kerbin orbit, Mun assists plotted Second Mun assist plotted Mun flyby This Mun assist is carefully tuned to make the sum of my apoapsis and periapsis equal to 3.02 * 10^10 meters, which means I have an intersection with Kerbin plotted six years and five orbits later. I wrote a calculator program that uses Kepler's third law to achieve this. I also have another Mun assist plotted, to gain some extra velocity because the Kerbin assist alone won't give me any extra energy. This Mun assist is adjusted to give me an apoapsis and periapsis that sum up to 2.292 * 10^10, which corresponds to another intersection with Kerbin and Mun after 5 orbits and 4 years. I get another assist from Mun, giving me a plane change and dropping my orbit below Eve. This gives me an intersection with Eve. Booster separation Booster sets up a Mun assist that gives a good aerobraking trajectory. Booster aerobrakes Booster is captured in a stable orbit ready to be reused I use the Eve encounter to increase my Kerbin relative velocity, which gives me a Kerbin assist that I use to increase Eve relative velocity. I use the remainder of the gravity assist for a plane change, to line up the descending node with Eve with the intersection with the planes of Eve and Moho. I also take care to put this near Moho's apoapsis for a smaller capture burn. I use another Eve assist to drop my orbit and give a plane change, lining up my plane with Moho. This sets up a third Eve encounter in a few orbits. Setting up Moho encounter at Moho periapsis Moho encounter set up with a pretty big plane change but I have lots of margin Moho capture Moho orbit

Oops, I did some course corrections with the booster and not the payload. However, my margins are far more than enough - I could have done this with the payload as well. I'll post my mission when I wake up, hope that's acceptable

Would it be acceptable to not detach before Kerbin escape but still capture within Kerbin SOI? I'm thinking of a series of gravity assists Kerbin-Eve-Kerbin-Eve-Moho so I could have it capture on the second Kerbin assist instead, which I think would still fit the spirit of the mission. This should be more specific. Otherwise I could already be on an escape trajectory since that's technically a Kerbin orbit. Barring that, I could be in a very eccentric elliptical orbit, which practically amounts to the same thing. I would suggest "a Kerbin orbit with no part over 90 km" or whatever limit you choose.

Tylo flyby Laythe flyby Kerbin encounter Kerbin aerocapture KSC is in the wrong place so I do a boost-glide trajectory to skip around Kerbin Final reentry Approaching KSC Landed Mission summary: Landed on Minmus, Eeloo, Laythe before coming back to Kerbin Flybys of Mun, Eve, Tylo, Jool I think this has conclusively proven that taking a single orange tank to any body other than Tylo and Eve is possible. I highly doubt that an Eve landing will be possible with just one orange tank, same with Tylo.

Ascent from Eeloo Jool transfer Laythe encounter Aerobraking. The landing gear extension means that the plane adopts a strong nose down attitude, which is good for slowing down quickly. Because of the inclination from the Eeloo transfer, I had come down a bit south of the equator, so I'm turning north to land as close to the equator as possible. Landed on Laythe. I landed within 10' of the equator which is pretty good Laythe ascent. I take a different and more efficient ascent path since I start from a lower elevation. I try to level off at 23 km but the plane is too light for its wing area at this point so I can't be as efficient as possible. I turn on the nuclear engine at 1730 m/s and the rapier cuts out around 1800. In Laythe orbit, with >1000 m/s left. Laythe escape burn Tylo and Laythe assists

You're proposing a fuel tank that stores air... which contains oxygen to use as an oxidizer... and which will combust with liquid fuel in an engine... I believe that already exists in the game. In fact there are tanks that can combine both resources in one!

Mun transfer to 1:1 resonance with Kerbin. This is a pretty high energy transfer so I can eject with a lot more radial velocity than normal Swing around Kerbin and Mun again to intersect Eve's orbit Mun assist Eve assist After another Kerbin assist I arrive at Jool, where I use a Tylo assist to reduce Jool relative velocity Jool is in a very bad place for a good Eeloo transfer so I encounter Jool again where the planes of the orbits intersect Tylo assist Jool close pass Setting up second Jool-Tylo assist Eeloo encounter Landing burn Landed with some assistance from wheel braking again

Mun transfer burn, 1 of 2 Mun assists to Minmus Minmus encounter Minmus capture burn Suborbital Saved 70m/s of wheel braking Burning to orbital speed on the flats In orbit of Minmus - almost 4k delta-v left. Next stop will be Eeloo probably