The Retro Solar Rescue

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I'm trying to do this challenge with no Jool encounter: I will need more ∆v  but I can save time

If I succeed, how can I get the badge?

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17 minutes ago, CairoJack said:

I'm trying to do this challenge with no Jool encounter: I will need more ∆v  but I can save time

If I succeed, how can I get the badge?

If you succeed Physics Student will tell you can use the badge. Copy the address of the image and use it how you like (e.g. putting in the signature like Cpt kerbalKrunch did (and I pretend to do in a couple of centuries of game time))

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26 minutes ago, CairoJack said:

I'm trying to do this challenge with no Jool encounter: I will need more ∆v  but I can save time

If I succeed, how can I get the badge?

I'm curios about the bruth-force-method. My estimate for the delta-v requirement is about 35 km/s, maybe more.

for the badge, copy and paste the immage (not the link) into your signature after you succeeded.

Edited by Physics Student

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20 minutes ago, Physics Student said:

I'm curios about the bruth-force-method. My estimate for the delta-v requirement is about 35 km/s, maybe more.

I think I'll need less ∆v, but I must have a lot of heat shields

Edited by CairoJack

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Actually I was thinking about this, if I may interject, as I have sketched out high velocity returns before.  A layered design where a 3m heat shield and shortest 3m tank (with radial decel engines) was separated from the 1.25m return capsule by spars/struts to create a thin "air gap" to minimize heat transfer, plus a ton of radiators on the 1.25m capsule might allow a super-high velocity return.  Stability should not be an issue as the vast majority of the mass would be in that 3m fuel tank stage, and by the time it explodes hopefully you're down to 6k/sec.

(the Kerbal Astronaut Corps does not endorse or certify this technique)

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44 minutes ago, GarrisonChisholm said:

Actually I was thinking about this, if I may interject, as I have sketched out high velocity returns before.  A layered design where a 3m heat shield and shortest 3m tank (with radial decel engines) was separated from the 1.25m return capsule by spars/struts to create a thin "air gap" to minimize heat transfer, plus a ton of radiators on the 1.25m capsule might allow a super-high velocity return.  Stability should not be an issue as the vast majority of the mass would be in that 3m fuel tank stage, and by the time it explodes hopefully you're down to 6k/sec.

(the Kerbal Astronaut Corps does not endorse or certify this technique)

I have no idea if that would work or not, but it sounds awesome. I'd love to see it.

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I did a direct retro-grade probe insertion into Laythe at ~10km/sec and left my Jool Transfer Stage attached when I realized how insanely hot the entry was going to be, and was delightedly surprised when I realized it would survive.  Mind, the retro-grade velocities being discussed here are almost twice what I encountered (and I wasn't risking any lives of course!), but the result might be reproduce-able.  Especially if 3-4k of dV could be budgeted for terminal breaking, though I know that for the difficulty of the mission being discussed that would be an Awful lot of baggage to cart.

Edited by GarrisonChisholm

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8 hours ago, CairoJack said:

I'm trying to do this challenge with no Jool encounter: I will need more ∆v  but I can save time

If I succeed, how can I get the badge?

I first tried for a direct flip from Kerbin. I set up the maneuver and started spinning the mouse wheel. And kept spinning. For a while. Think I hit 13,000 when it finally reached the sun and flipped. Plus I still needed to raise my Pe, make the rendezvous, then flip again and come home. I got discouraged and set my sights on Jool. If you could pull it off though, you'd definitely win the time prize.

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For you, 8 km/sec was the fastest, most hair-raising reentry you've ever performed.

For me, it was Tuesday*.

*8 km/sec is a bit less than lunar reentry speed at 6.4x scale, which is what I've mostly played at. For the RSS players, it's LEO reentry speed.

I'm not sure I'll take this challenge on, but there are multiple ways to do it.

#1: Bi-elliptic transfer. Eject straight from Kerbin orbit out to a very elliptical heliocentric orbit: then, at apohelion (Sun apoapsis), reverse your course, and you've done the plane change. Granted, you're going to have Fun (tm) at your new perihelion, bringing your apohelion down to something that you can reasonably use to rendezvous with Burbarry, and then Fun (tm) again going for another bi-elliptic back into prograde solar orbit.

#2: Bi-elliptic transfer with gravity assists. Ignoring the fact that you're leaving poor Burbarry alone in a capsule for years, this would be how I'd approach the problem, probably trying something like Kerbin->Eve->Kerbin->Jool->apohelion reversal->Jool->Eve (with a braking maneuver at Eve) -> Burbarry -> Eve -> Kerbin -> Jool -> apohelion reversal -> Jool -> Kerbin/Eve braking -> Kerbin return. Doing the big burns in the SOIs of Eve and Kerbin gives you some benefit from Mr. Oberth, because X velocity added or removed inside their SOIs can translate to more than X added or removed once you escape their SOIs.

Granted, that's a vastly more ambitious set of slingshots than I've ever actually pulled off.

#3: Massively staged nuke/ion spam: a brute force approach.

#4: Playing a fun game of gravitational ping-pong inside the bounds of the Kerbol system, which is most of Cpt Kerbalcrunch's strategy.

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With NFP it is not that hard - using SMURFF and 10x I made a ship with 100 km/s of delta-V. That is enough to do that rescue in 10x AFAIK. The key is ion spam (lol). Without ions it is insanity - or dare I say "Kerbal."

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4 hours ago, Starman4308 said:

probably trying something like Kerbin->Eve->Kerbin->Jool->apohelion reversal->Jool->Eve (with a braking maneuver at Eve) -> Burbarry -> Eve -> Kerbin -> Jool -> apohelion reversal -> Jool -> Kerbin/Eve braking -> Kerbin return

that route sound similar to my plan. yesterday i came that far:

Spoiler

LKO --> Eve --> Kerbin --> Kerbin --> Jool

turned out my aphelion was not high enough to flip the Orbit at Jool (Or I just don't know how). I see 3 solutions here:
-adding energy at second kerbin assist.
-using the jool assist to lower the perihelion for a third Kerbin assist.
-using the jool assist to lower the perihelion for a second Eve assist.

As soon as I have reversed my orbit I will try a Eve assist to lower the apohelion for a rendevouze with Burbarry.

now the fun can begin... maybe several aerobraking maneuvers at Eve to reverse the Orbit again (the Speed would be around 24000 m/s, and I should bleed off around 15000 m/s) And set a course for a Moho gravity assist to rise the aphelion and perihelion. Probably I will Need a other Eve Assist to get back to kerbin.

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So ... @cratercracker made a really nice looking logo for this mission (see at the top of the OP), but apparently I'm too stupid to figure out how to make it fit into the signature. I modified it into an octagonal shape (.png format with transparency) which would make a good looking ribbon to put into your signature but no matter what I do, it won't be displayed.

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Just now, Physics Student said:

So ... @cratercracker made a really nice looking logo for this mission (see at the top of the OP), but apparently I'm too stupid to figure out how to make it fit into the signature. I modified it into an octagonal shape (.png format with transparency) which would make a good looking ribbon to put into your signature but no matter what I do, it won't be displayed.

Do you have the original one? If you do. Put it into your signature,and right/left click on touchpad/mouse. As the frame appears,scale it u to 100 or 200. It will fit perfectly.

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I'm going to take on this, doubt I'll complete this as I know myself but at least I'll try

Welp, I just planned everyzhing to test it out, and warped 50 days after my node

Edited by Numerlor
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15 hours ago, Numerlor said:

I'm going to take on this, doubt I'll complete this as I know myself but at least I'll try

Welp, I just planned everyzhing to test it out, and warped 50 days after my node

I've held strong to a "no mods" style of play. After about a month, I had to concede to "no mods except Kerbal Alarm Clock".

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So ... I hope you haven't given up on Burbarry, guys. I feel like I have to do it again!

Here's a pro tipp: get as far away from Kerbol as you can before flipping your Orbit. If you want to do gravity assists, don't even bother with Eve. I know, it's nice and massive but it's also way too close to Kerbol. Flipping your Orbit at Eve isn't going to work, it has to be Jool.

Remember Scotts tutorial on changing your inclination? It takes way less delta-v when you're far away from the body you're orbiting. Flipping your orbit is also just an extreme inclination-change.

Edited by Physics Student
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I've been making efforts all week, and will share when I'm finally victorious.  My last ship failed not because of physics, but because my computer froze by the time it was about 20m off the launch pad.  I guess that a 4000-part monstrosity is just a tad too much.  I have family functions to attend today, but some time this afternoon I'll be getting back to work on this challenge.

Edit: The previous attempt (of which, in retrospect, I shouldn't have wiped the screenshots when I failed, since the album could have been fun) wound up a few thousand m/s of delta-V short of my targeted mission profile.  It was a sad, sad error that I didn't realize I'd made until I was flying past Kerbin on the return trip, burning as hard as I could, and unable to establish an orbit.

Edited by Aetharan
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1 hour ago, Physics Student said:

So ... I hope you haven't given up on Burbarry, guys.

Giving up?!  How such thing passed your mind!

NO KERBAL LEFT UNASSISTED!!

Well, unfortunately I have a life,  such things like "family",  "friends"  and "work"  tend to rob the time from my very important space program.  And to make things worse I designed my mission in such way that after 50 years I'm yet to rendezvous with Valentina (Jebediah reminder me all the time she's remaining in space longer than he.  For Oberth,  she's stranded!)  At least I already reversed my orbit.

About gravity assist: Eve it's not so good for orbit reversal,  but for setting up the encounter with Jool it can help with a fair amount of deltaV.... If you don't mind the extra mission time.

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Conceptually, reasonably easy.

A 3.6 ton ion drive rescue ship (that's mass in high Kerbin orbit, about 1000km!)

Burn prograde with kerbin orbit, head out to the deeeeeeep reaches of space:  3600 m/s

Wait 9 years to get to apogee.

U-turn, 1830 m/s

9 years later, intercept Res-Q vehicle.

Intercept requires 4200 m/s

To return, you basically reverse the procedures..

1830 u-turn at distant apogee

this bring you to an atmospheric meeting with Kerbin at mission time ~ 36 years, and a velocity of some 5.5km/s

As my vehicle is nothing more than a command chair on an octo, on an Ion Drive, I chose to use propulsive braking rather than aerodynamic breaking.

a messy 6000m/s of burn later, my pilot is safe in a 100x100 orbit around Kerbin.

The launcher is a very simplistic thing, just a can and some 'chutes on a Vector.

Serves as launch-to-1000Km, and also many years later as recovery-and-landing vessel.

Below is the Rescue ship. busy dropping droptank 2 of 5. It is just about out of kerbin on its way to deeep space.

And this is the sort of orbit you need to play with, to make the u-turn cost effective.

Know what was my biggest obstacle?

Getting the power needed for that single ion drive, while at 4x Eeloo orbit distance.

it. re.qui.red.a.lot.of.pat.ie.nce.and.st.op.and.st.art.of.the.ion.dr.ive.

Next time, I'll sacrifice another 2000m/s of delta-v (i've got plenty to spare, total load is over 26k),

and go much less far out.

And yes, maybe next time invest in some RTG instead, to heck with the cost!

This one weighs in at 123846 cost, and masses 63.4 tons (of which 60.5 tons is launcher/lander)

Edited by MarvinKitFox
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13 hours ago, Physics Student said:

So ... I hope you haven't given up on Burbarry, guys. I feel like I have to do it again!

I thought I was the only one crazy enough to want to try it again. It was such a tough mission, the payoff when you finally succeed is similar to what I felt on my first Mun landing (we all remember how good that felt). I'm sure I could do better the second time (now that I know what to do and how to go about it), but I think I'd try it a different way.

If my first mission had failed, I had an idea to try something kind of crazy. Not sure if it would work, but, if it did, it would definitely win the creative prize. In the middle of an Eve landing now, as well as about a dozen lesser missions, but if I can find time, I may give it a shot. As @Spricigo mentioned, real life constantly gets in the way. I work a ton of hours and we've got four kids to boot. It's a major drag on my KSP time.

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11 hours ago, MarvinKitFox said:

Wait 9 years to get to apogee.

U-turn, 1830 m/s

9 years later, intercept Res-Q vehicle.

Intercept requires 4200 m/s

To return, you basically reverse the procedures..

Intersting approach, nice and "easy", extremely light. Maybe you should have invested in a RTG to make the aphelion burns less tedious.

Your mission report begins and ends in Kerbin Orbit, what did your launch vehicle look like? I assume you had a return pod on the LV to recover Burbarry?

Edited by Physics Student

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@Physics Student Fun challenge! Nice work on using Jool to completely flip your orbit - I hadn't even considered that was possible.

Went for the brute force and ignorance approach: 36,000 m/s dV, packed into 484 tons, costing 216,084 funds.

Total mission time 1 year 93 days.

Burbarry has enough dV in his jetpack to make a Kerbin intercept - I found this made it easier to rendezvous and saved about 2000 m/s dv as I was able to use my LKO velocity. The Catcher's Mitt lay in wait in LKO until Burbarry entered Kerbin's SOI.

No subtlety here - just a large stack of liquid fuel tanks and nukes

A few days past Kerbin's SOI, Burbarry rendezvoused with the rescue shuttle

Half an orbit later, back at Kerbin

Burbarry hopped into the rescue pod left in orbit earlier and was back at the KSC in no time

Full mission album

@Cpt Kerbalkrunch You complete lunatic!  Using only chemical engines was an impressive feat.

Stay tuned - I'm currently trying a cheapskate approach using chemical engines only. Using the K-E-K-K-J route you can get kicked out deep into the expanse for about 1,200 m/s dV. You can then flip your orbit really cheaply - however @Spricigo you're dead right about how ineffective gravity assist are when you're going retrograde. 5 reverse Eve assists barely dented my orbit, so my velocity relative to Bubarry was still 3,400 m/s. Back to the drawing board for now..

Edited by ManEatingApe
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@ManEatingApe Nicely done!

What a brave move of Burbarry to completely eyeball such a close flyby of Kerbin. on one picture, you can see that the Mun-encounter and Kerbin Periapsis are only 11 minutes apart. He must have had a nice view there.

I added the new Badge made from the artwork of @cratercracker . I made it into an irregular octagonal shape, hope you like It.

Edited by Physics Student
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I've done it!  Burberry is on the ground in the grasslands west of KSC on Year 1 Day 316 at 4:53.  Sadly, the craft file is too large to upload to KerbalX.  That's why I've stuck it on Google Drive, so you can download it here.

Unlike others in this thread, I tend to subscribe to the 'mod it till you break it' style of gameplay, but I've done my best to minimize that for this mission.  MechJeb is present (via MechJeb and Engineer for All rather than adding a part), and is used for the ascent until shortly past max Q, for calculating circularization burns a couple of times, and for several 'match velocity at closest approach' calculations, but otherwise the maneuver planner is reserved for clicking 'execute next node' on one that I worked out myself.  The ship itself uses only stock parts, arranged with the help of EditorExtensionsRedux and Hangar Extender, with the LFO tanks having been reskinned via the combination of Color Coded Canisters and Fuel Tanks Plus.

Edited by Aetharan
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Wow.

Not too sure about Germany (we'll have to ask @Physics Student), but the sound of the collective slapping of foreheads of everyone involved in this challenge could be heard all the way here in Chicago.

Been stuck at work all day, so I absolutely couldn't wait to get home to congratulate the mad genius known as @ManEatingApe. Great job. I saw that you were following the thread, but you'd been quiet. No wonder. Locked yourself away in your mad-scientist lab and went to work.

Unbelievable. I was so focused on getting to Burbarry that it never even crossed my mind to just bring Burbarry to me. I've been walking on air all week, brimming with confidence, after my rescue was a success. I just got brought back down to Kerbin. I spent 13 years and 2,000,000 bucks, and you spent a fraction of that.

I. Love. This. Game.

There simply is no "best this" or "best that". There's always another way. And other people are guaranteed to think of something that would've never occurred to you. If other challenges are as awesome as this one, I think I might've found my new obsession.

Can't wait to see who else pulls this off, and what their mission looks like. I had an idea that I thought might win the creativity prize, but I doubt it now. What can top bringing Burbarry home superman-style?

Edited by Cpt Kerbalkrunch
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