Weekly Challenge #11 - Juice!

[Ghostii_Space]

 

Hello Kerbonauts!

This week, we challenge you to recreate the ESA Juice mission in #KSP2 and explore the moons of Jool!

•  Primary: Visit Jool
• Stretch: Visit Jool and Tylo
• Jeb: Visit Jool, and all of Jool's moons
• Val: Use one or more gravity assists to complete the level 3 goal.

 

Good luck! 

[The Aziz]

The feeling when Val level is actually the cheapest way to do Jeb level.

[PyroSA]

1 hour ago, The Aziz said:

The feeling when Val level is actually the cheapest way to do Jeb level.

Is it that much cheaper?

From what I could tell: KSP MGA Planner (krafpy.github.io)

Kerbin-Jool at year 3 should take about 4910m/s and arrive on the 6th year

Kerbin-Eve-Eve-Jool can pull it off leaving immediately and reaching Jool in the 4th year with 4674m/s

Is there a cheaper route?

[The Aziz]

57 minutes ago, PyroSA said:

Is there a cheaper route?

If you use assist from Tylo you can get a capture around Jool for free. With some finetuning you can save yourself all the fuel you'd normally use on approach. From there it's just a matter of timing your next steps.

[PyroSA]

I clearly do not have the patience for Xenon...

Build one with something like 50kDv, but burn times... eish.

Then I tried to create multi-engine ones, hardly helping as you need so much energy generation you don't effectively increase the thurst unless you sacrifice dV.
Ran into a bug where draining the battery means the torque wheels never come online again...

So I settled for a Jet-assisted launch, to get to Jool. Used Tylo to shave a little off, but that probably only saved me like 500 m/s. Total trip direct was about 5000dV in to a stable, with 1400 to spare.

Then I detached my satellite and headed to Laythe direct. Getting down to a stable orbit at 500km  Burned like 2000dV of the 4400 I packed on to it.

No way I'm visiting all the moons this way... So I'll settle for a stretch this time.

An interesting thing I did in the first stage - A sustainer rocket with 12 ?scramjets? - Taking a very shallow ascent the jets burn until about 22km, with LOTS of horisontal speed already.
Power on the rocket was 1750kN, but with scramjets it peaked somewhere over 5000kN, and it burns a fraction of the fuel since you don't need oxidizer.

Edited May 7, 2023 by PyroSA

[Well]

To prevent possible antenna failure, Bob decided to be part of the trip of my Juice style mission. After some years of flight, he decided to lithobrake on Vall for Science.

[Starhawk]

This is my Val level submission.

Here is the probe, Loupe, named after the jeweler's device.

Here's the craft trajectory showing Tylo-assisted gravity capture at Jool.

The above trajectory did take more dV to set up than I would normally use.  Normally, I would do the correction burn deep in interplanetary space and it would cost on the order of 10 or 20 m/s dV.  But the trajectory prediction across SOI boundaries bug hits here, too, so I had to make the adjustment just after entering Jool's SOI.  I estimate that the maneuver still saved on the order of 1000 m/s dV.

This shot shows Jool and all three inner moons.

And here we are near Tylo performing the gravity assisted capture.

Matching inclination with the inner moons.

And setting up a rendezvous with Vall.  (pronunciation rhymes with ball, call, fall, etc)

And here we are at Vall.

And here is Loupe visiting Laythe.

Leaving Laythe, we planned a close pass around Jool and an assist out to Pol's orbit.

Here's the close pass to Jool.

And entering Pol's SOI.

A visit to Pol.

After leaving Pol's SOI, I performed an inclination burn and got a surprise - an immediate rendezvous with Bop.

And, finally, the probe is put into orbit around Bop.

That was a very fun mission!
 

Happy landings!

[18Watt]

On 5/5/2023 at 1:10 PM, The Aziz said:

If you use assist from Tylo you can get a capture around Jool for free. With some finetuning you can save yourself all the fuel you'd normally use on approach. From there it's just a matter of timing your next steps.

Expanding on @The Aziz, practicing my arrivals to Jool to take advantage of gravity assists was perhaps the biggest 'AHA!!' moment in KSP, for me.  With a few m/s DV enroute to Jool, you can end up with circularization at Jool for almost zero DV.  With some careful planning, you can end up with an orbit which will give you an encounter with any of Jool's moons, again for next to zero DV.

On 5/7/2023 at 11:39 AM, Well said:

To prevent possible antenna failure, Bob decided to be part of the trip of my Juice style mission.

That is awesome!

On 5/7/2023 at 11:39 AM, Well said:

After some years of flight, he decided to lithobrake on Vall for Science.

Kerbals never seem to get bored on long journeys.  However, lithobraking at Vall may not be the wisest move..

On 5/7/2023 at 4:36 PM, Starhawk said:

But the trajectory prediction across SOI boundaries bug hits here, too, so I had to make the adjustment just after entering Jool's SOI.

Oh, I dearly hope that gets corrected soon.  For me, it's almost the whole point of playing KSP..

On 5/7/2023 at 4:36 PM, Starhawk said:

And here is Loupe visiting Laythe.

 

Jool offers some spectacular screenshot opportunities.  That one is awesome!

On 5/7/2023 at 4:36 PM, Starhawk said:

After leaving Pol's SOI, I performed an inclination burn and got a surprise - an immediate rendezvous with Bop.

Always better to be lucky than good!  

On 5/7/2023 at 4:36 PM, Starhawk said:

That was a very fun mission!

Loved it!