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[CHALLENGE] Kerbin-Jool Micro


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Easy: Get to Jool with the least amount of delta-v.

Medium: Get to Jool with the least amount of delta-v and come back.

Hard: Get to Jool with the least amount of delta-v, go into the upper atmosphere, release a spaceplane, fly that spaceplane for 90 seconds while your craft is descending, then achieve orbit and come back.

Ultra Hard: Get to Jool with the least amount of delta-v, go into the upper atmosphere, release a spaceplane, fly that spaceplane to space while your craft is descending, then achieve orbit, transfer to Vall orbit, escape, and then come back.

 

No Alt-F12 or HyperEdit. 

Rules:

"Upper Atmosphere" is designated as 100-200km.

You must release your spaceplane between 125-150km.

Only stock parts, Engineer, MechJeb, and KW Rocketry parts are allowed. (KW Rocketry for the big fuel tanks/powerful engines for hard/ultrahard)

"Vall orbit" is designated as a orbit within Vall's SOI and not going within 10km.

"come back" is designated as hitting, or landing Kerbin, or having a orbit with a periapsis of 70km or lower.

"least amount of delta-v" is designated as total dv.

You may not use a stock spaceplane.

People who have tried:

Easy:

PLAD [V0.90] - Vall capture. See post 7 for link. 1,017m/s.

PLAD, Attempt 3 [V1.1.1] - 916m/s.

Medium:

PLAD (again) - 1,012m/s back,

Hard:

Ultra Hard:

Gatecrashers:

PLAD, Attempt 1 [V0.23.5] - Thought that aerobraking-to-orbit was allowed.

 

 

Edited by Kaizen
plad again
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I've done a few low-dv missions to Jool in the past, here are my two best, would either of them qualify?

I did this one way back in KSP 0.23.5. LKO to Jool atmosphere with 1010m/s. I then aerobraked in Jool's atmosphere to capture into orbit, that would require a major heatshield with the latest KSP versions. After the aerocapture 1 more m/s put me in a stable Jool orbit, so 1011m/s from LKO to JO.

If the aerobrake nullifies the above entry, I did this one using a Tylo flyby to capture into a closed orbit about Jool. This one took 1018m/s from LKO to Jool orbit. I really like this one since the craft was an SSTO with only 8 stock parts plus Mechjeb. Although that was in version 0.90, so it wouldn't make Kerbin orbit with the modern Rapier. (Note it took 1024m/s from LKO to Laythe surface, though I see that's irrelevant to this challenge.)

I would suggest that entries have to give details on the route flown from Kerbin to Jool, showing major maneuver sizes and times so others can try the path.

Jool and return for the fewest m/s adds an interesting wrinkle to this...

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When you say get to Jool, do you mean flyby or closed orbit? For Easy it doesn't make much difference, because as PLAD pointed out you can capture at Tylo for free (hard to beat free!). But for the Med and up it should make a difference. Also, for Hard and Xhard, you intend for the mother ship to crash into Jool, yes?

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I felt bad about using an old mission for this challenge, so I did a new one using KSP 1.1.1. I used a technique I've wanted to try for a while, and it worked! Here's the entry, LKO to Jool orbit for 914m/s. I have trouble seeing the paths KSP draws on the screen, so I've enhanced some of the pictures to make them clear so that others can try this method. It's basically two tricks sewn together, it starts with a Mun multi-flyby path and jumps to a KEKKJ path. The hard part was the jump, but enough jabbering...

These are .jpgs, I'm curious if there will be a noticeable difference in load time.

There is still room for improvement, if I started with the 5-Mun-flyby method I used in my KX-to-Duna-and-back flight it could theoretically be done for about 15m/s less, and I made about 10m/s of mistakes, so in theory a perfect pilot could do this for about 890m/s. It won't be me though, once of this was enough. It is way too much work to save the 100m/s or so over a normal KEKKJ flight for anything but a challenge.

So this is my easy entry, I might try getting back to Kerbin (since the ship is in a useful orbit of Jool), but hard and ultra-hard are too much for me because I have a lot of trouble with spaceplanes.

 

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Am I allowed to use a mission for both the easy and medium-level entries? I continued my 914m/s easy-level entry from the point where that ended and I made it back from Jool orbit to Kerbin. The delta-V count depends on how you define 'hitting' Kerbin- do exploding fiery chunks raining down on Kerbin count as hitting it? (or a 'thermally suboptimal descent' as I call it) Or can an 'orbit with a periapsis of  <70km' be a hyperbola instead of an ellipse? If so, I made it from Jool orbit to Kerbin atmospheric interface for 49 m/s, added to the original 914m/s to get there gives 963m/s for the round trip.
 If the ship has to survive and get into a closed orbit around Kerbin, I did a modified ending of the mission where instead of piling it in at 4600m/s I flew J-K-K-E-K to arrive at a much more manageable 3400m/s. Then I let aerobraking do almost all of the work and got into a closed orbit around Kerbal with the periapsis lower than 70km for 96m/s of main engine dV, plus 3.4 units of monopropellant which adds another 2m/s, for a total of 98m/s plus the 914 to get there equals 1012m/s to get from LKO to Jool orbit and back to Kerbin orbit.

 

 

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On Thursday, May 26, 2016 at 7:35 PM, PLAD said:

Am I allowed to use a mission for both the easy and medium-level entries? I continued my 914m/s easy-level entry from the point where that ended and I made it back from Jool orbit to Kerbin. The delta-V count depends on how you define 'hitting' Kerbin- do exploding fiery chunks raining down on Kerbin count as hitting it? (or a 'thermally suboptimal descent' as I call it) Or can an 'orbit with a periapsis of  <70km' be a hyperbola instead of an ellipse? If so, I made it from Jool orbit to Kerbin atmospheric interface for 49 m/s, added to the original 914m/s to get there gives 963m/s for the round trip.
 If the ship has to survive and get into a closed orbit around Kerbin, I did a modified ending of the mission where instead of piling it in at 4600m/s I flew J-K-K-E-K to arrive at a much more manageable 3400m/s. Then I let aerobraking do almost all of the work and got into a closed orbit around Kerbal with the periapsis lower than 70km for 96m/s of main engine dV, plus 3.4 units of monopropellant which adds another 2m/s, for a total of 98m/s plus the 914 to get there equals 1012m/s to get from LKO to Jool orbit and back to Kerbin orbit.

 

 

Nice flying. And impressive patience setting it all up.

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