Eve ∞ (Hard)

[It'snorocketscience]

 

After starting an outpost on Eve, I remembered (much to my relief) that I remembered to build a return vehicle. However, it's completely disposable and only works once... not good for rotating crew on and off Eve! The cost to rotate crew would be astronomical...

Goal: Build a reusable vessel that can land on Eve, take a Kerbal to orbit, and repeat.

But wait! Before you dismiss this as impossible, let's make this easier: You don't have to build an Eve SSTO if you don't want to. You may discard stages, land them, and reassemble them on the ground with docking ports/Breaking Ground parts/by landing stages atop old stages. You may use a stage recovery mod. Also, to save your time, when you land or enter a stable orbit, you may simulate refueling with a mining vessel and cheat your fuel tanks back to 100%. You may teleport your vessel to Eve orbit and start from there.

Recommended mods: Hyperedit (to simulate refueling, make testing easier), Stage recovery mod.

Winning criteria:
Build a semi-reusable vessel that can shuttle 1 Kerbal from Eve's orbit to the surface, and vice versa. Completing the challenge earns you a spot here. If the design is an SSTO, it will be placed in a second category.

Winners: (Name, vessel name, link)

EveMaster's Eve Infinity https://kerbalx.com/EveMaster/Eve-Infinity

Brikoleur's Seraph https://kerbalx.com/Brikoleur/BAK-9900-Seraph

Rules:

1. You may cheat in pre-existing infrastructure. Your vessel may start at LEO. You can ignore commnet (built-in antennas will reach LEO anyways in a real game). You may simulate refuels with Hyperedit, but only when: 1) In a stable orbit around Eve (simulating refueling at a station) or 2) Landed on Eve (simulating refueling at an ISRU base).
2. Take screenshots. Upload your craft so we can use it too. I have several Kerbals stuck on Eve...
3. Pilot aid/build aid/stage recovery/planning/cosmetic mods are OK.

Good luck!

Edited September 7, 2019 by It'snorocketscience
Updated challenge winners

[AHHans]

3 hours ago, It'snorocketscience said:

Upload your craft so we can use it too. I have several Kerbals stuck on Eve...

So you just need a rescue mission and are just too lazy to design your own craft?

Hmmmm... I think a major part of the challenge will be to land on Eve without a non-reusable heatshield. Any ideas? Hmmm... Maybe a space-tug that stays in orbit.

[joshudson]

My attempt at Eve Rocks challenge was sea-level capable and didn't use a heat shield for landing on Eve. On the other hand I staged off all kinds of stuff so it doesn't get any closer to this challenge. Couldn't get it small enough to fit the circle of the VAB.

Edited August 14, 2019 by joshudson

[Reactordrone]

5 hours ago, AHHans said:

So you just need a rescue mission and are just too lazy to design your own craft?

Hmmmm... I think a major part of the challenge will be to land on Eve without a non-reusable heatshield. Any ideas? Hmmm... Maybe a space-tug that stays in orbit.

You could refuel in orbit from a Gilly based mining operation and use an entry burn to obviate the need for a heat shield. Provided the orbital section has enough delta-v to knock off about 3000m/s fairly quickly it should be ok.

[It'snorocketscience]

19 hours ago, AHHans said:

So you just need a rescue mission and are just too lazy to design your own craft?

Hmmmm... I think a major part of the challenge will be to land on Eve without a non-reusable heatshield. Any ideas? Hmmm... Maybe a space-tug that stays in orbit.

Well, err... I, uhhh

In all seriousness I have a return vehicle, but it only works once, for one kerbal. The landers are currently more expensive than the kerbals.

14 hours ago, Reactordrone said:

You could refuel in orbit from a Gilly based mining operation and use an entry burn to obviate the need for a heat shield. Provided the orbital section has enough delta-v to knock off about 3000m/s fairly quickly it should be ok.

For the purpose of this challenge, you can pretend you already have a orbital and ground-based refueling station. You don't have to manually refuel your craft if you don't want to, since it's already pretty time-consuming designing a reusable eve lander anyway.

Edited August 15, 2019 by It'snorocketscience

[AHHans]

On 8/15/2019 at 2:58 AM, Reactordrone said:

You could refuel in orbit from a Gilly based mining operation and use an entry burn to obviate the need for a heat shield.

That's kind of what I meant with the "space tug".  I was planning to not refuel on Eve's surface, in that case you don't want to do that 3000 m/s burn with the part that enters the atmosphere.

On 8/15/2019 at 5:16 PM, It'snorocketscience said:

The landers are currently more expensive than the kerbals.

That's not saying much, considering that you can actually get paid to collect more Kerbals in a career game.

[FuzzyHead]

Sounds interesting! I'll give it a try.

I just made a concept for my first attempt. It involves two Spaceplanes and two Bases on Eve. The First (Carrier) Spaceplane would carry the smaller one to about 40km above sea-level before the smaller Spaceplane would proceed to orbit. The Carrier would not even leave the atmosphere but land at a second refueling base. It could then be fueled and return to the main Base where the smaller spaceplane could also land after delivering the Kerbal(s). Refuel and repeat. Hopefully

No I just have to figure out, how the two spaceplanes will be docked together and how they'll survive the Re-entry. That seems to be the bigger problem than dV to reach Orbit to me.

[Pds314]

I think an Eve SSTO isn't completely beyond reason with hybrid electric props, some conventional engines, and nukes. I will have a go at this. Even if it's not an SSTO, air launch to orbit or a recoverable drop pod should be fairly doable.

Edited August 18, 2019 by Pds314

[It'snorocketscience]

44 minutes ago, Pds314 said:

I think an Eve SSTO isn't completely beyond reason with hybrid electric props, some conventional engines, and nukes. I will have a go at this. Even if it's not an SSTO, air launch to orbit or a recoverable drop pod should be fairly doable.

Just some food for thought:

This isn't my design, but this design (before stock props) is VERY light for a stock Eve SSTO. Pardon the music, not my video.

Maybe a reusable Eve shuttle isn't so far-fetched after all?

I tried it myself and it does work, although it's very picky with takeoff/ascent profiles.

Edited August 18, 2019 by It'snorocketscience

[Pds314]

2 hours ago, It'snorocketscience said:

Just some food for thought:

This isn't my design, but this design (before stock props) is VERY light for a stock Eve SSTO. Pardon the music, not my video.

Maybe a reusable Eve shuttle isn't so far-fetched after all?

I tried it myself and it does work, although it's very picky with takeoff/ascent profiles.

Wow. That's very simple. I was expecting to slowly haul a big vacuum rocket engine and a nuke to 30 km or something with a giant prop that folds into a cargo bay.

Edited August 18, 2019 by Pds314

[Pds314]

Ok. I currently have a plane that is capable of putting its pilot in orbit in one stage as long as the Kerbal jetpack doesn't count. Or, I would, if not for heat-related issues.

 

To be honest, with the profile I would need to fly to avoid burning the cockpit off, I might just use a rocket.

Edited August 18, 2019 by Pds314

[Pds314]

I think I am gonna go the air-launch route with some kind of prop plane... above 25 km the wolfhound becomes a viable engine choice I think. Especially if it's got some horizontal velocity and modest wings. Not too much higher and pure nuke planes might be viable.

Edited August 18, 2019 by Pds314

[EveMaster]

I designed a two stage reusable craft that can put 6 Kerbals into orbit. The lower stage has two Mammoth engines, a full mining equipment with a small Convert-O-Tron and a large mining drill and two seats, one for an engineer and one for an additional kerbal. The upper stage has two aerospike engines. The air intakes are closed and are just for the looks and for a reduced air resistance as Eve has no oxygenated atmosphere.

The craft is capable of flying non-stop and unrefueled from the Kerbal space center to the surface of Eve. The capture burn at Eve needs a combination of retro burning and aero braking. Then you lower your apoapsis using multiple aero brake passes. On the final descent you use up your final fuel in the upper atmosphere to reduce your speed. With an intermediate refueling stop at Mun, Minmus or Gilly you would have more delta-V so you could do a greater retro-burn which would make the eve descent easier. 

The craft can be separated into two pieces and docked again. The lower stage has two different from landing gears. The huge one is for take off and landing. The medium one is for docking with the upper stage and for rolling on the ground. With the medium front landing gear it is much easier to steer the craft when rolling. The craft contains autostruts because otherwise the docking connection with the small docking port would be much to wobbly. For docking the front landing gear of the upper stage must be retracted. This way the docking adapters line up correctly. 

I usually take off with this craft from 3°36' S, 172°27' west from an altitude of 6830m. This location is closer to the equator and flatter than the highest point on Eve. At this height the craft has a TWR of 1.01 when full on fuel. Before starting to orbit, the fuel cross feed  of the docking adapter must be turned off. To get to orbit, the craft takes off horizontally then gradually climbs to an angle of about 50°. I usually aim for an apoapsis of around 90 km, but at minimum of 80 km and try to reach the maximum horizontal velocity with the fuel of the first stage. Then I decouple and circularize with the second stage. The circularization burn of the second stage should start about 30 seconds before apoapsis. Its important that the time to apoapsis is around 0 seconds when finishing the circularization burn. When the time to apoapsis rises to fast, I throttle down or add a radial component to the burn, because I do not have the time to wait for too long when coasting to apoapsis. When the circularization burn is done, I immediately switch back to the first stage. The next thing to do, is to reduce the vertical velocity which is probably hundreds of m/s by using the lift of the wings. When down to a safe speed you can turn around to the starting location. Usually around two additional hops with refueling on the ground are needed to get back there.

Pictures of the craft:

Undocked: https://imgur.com/z6CIoMb

Docked: https://imgur.com/dxBlMCf

Second Stage in Orbit: https://imgur.com/Ks5pPXg

Edit:

I uploaded the craft here: https://kerbalx.com/EveMaster/Eve-Infinity

Edited August 20, 2019 by EveMaster
minor corrections

[AHHans]

I have a two (three) stage system: a carrier plane that can ascend to 11km with solar powered propellers and goes to ca. 20km with rockets. There it releases the ascent stage that can make it to orbit with the right ascend profile. While it does work, it doesn't fly nicely (yet?) so it's still WIP.

I still need to test it with Flight Manager for Reusable Stages (FMRS). Is using that mod is also fine?

 

[It'snorocketscience]

3 hours ago, AHHans said:

I have a two (three) stage system: a carrier plane that can ascend to 11km with solar powered propellers and goes to ca. 20km with rockets. There it releases the ascent stage that can make it to orbit with the right ascend profile. While it does work, it doesn't fly nicely (yet?) so it's still WIP.

I still need to test it with Flight Manager for Reusable Stages (FMRS). Is using that mod is also fine?

 

Of course, that mod is a stage recovery mod, which is allowed.

On 8/20/2019 at 2:25 PM, EveMaster said:

I designed a two stage reusable craft that can put 6 Kerbals into orbit. The lower stage has two Mammoth engines, a full mining equipment with a small Convert-O-Tron and a large mining drill and two seats, one for an engineer and one for an additional kerbal. The upper stage has two aerospike engines. The air intakes are closed and are just for the looks and for a reduced air resistance as Eve has no oxygenated atmosphere.

[...]

Pictures of the craft:

Undocked: https://imgur.com/z6CIoMb

Docked: https://imgur.com/dxBlMCf

Second Stage in Orbit: https://imgur.com/Ks5pPXg

Edit:

I uploaded the craft here: https://kerbalx.com/EveMaster/Eve-Infinity

Wow! Congrats on completing the challenge! I'll add you to the list of challenge winners.

[EveMaster]

I tried tested some variations of my craft: with the same two stages approach:

• Upper stage with Mk1 for 1 Kerbal, 2400m/s left in orbit, then flying back to KSC runway unrefueled.
• Upper stage with Mk2 for 18 Kerbals from highest point of Eve to orbit and back.
• Upper stage, with mining equipment, can reach Gilly, has 4000m/s if fully refueled.

I think with the third design it will be possible to make a grand tour, visiting the surface of every planet and moon. If I can find the time I will try this.

[Reinhart Mk.1]

next challenge: land on the sun

[AHHans]

Quick update here. AHTech's reusable Eve transportation system is still in development. Unfortunately recent testing has been plagued by Kraken attacks.

Here is the result of dropping a small, empty fuel tank from the bottom of the carrier plane:

The accident investigation is still ongoing. After finding only low to moderate amounts of part clipping, the investigators are currently looking into the Kraken attracting properties of autostruts.

[Guest]

I have a submission. Full stock + DLC. Carries one (1) kerbal to orbit and back again. Everything is reusable... in theory. You "just" need a bunch of ground infrastructure to mount the orbiter module on the nose of the lifter module, refuel it, and re-pack the parachute. 

I have not built that infrastructure and haven't used this in career mode, but I have done several round trips when iterating on it.

Mission profile, quoting from the KerbalX craft page:

"The Seraph’s six pairs of rotary wings are powered by three heavy rotors mounted on freewheels along the spine of the vessel. She uses them to take off – very carefully – then climb to 26 kilometres or so. Climb peaks at around 15 m/s vertical speed between 13 and 15 km or so, and the craft takes about 40 minutes to reach its ceiling.

"After it has reached its operating ceiling, it disengages rotors and sets collective to 90 degrees, lights up its Vector, and gets into a parabolic arc that peaks at over 70 km. It launches its orbiter, which flies to orbit.

"After the orbiter is safely injected, the lifter falls back to the surface, initially braking with its rotors flat against the air, subsequently by autorotation. It then autorotates to a soft landing.

"The orbiter will return to Eve. It is designed to withstand the thermal and physical stresses of re-entry, can glide to its final landing spot, and uses its parachute for the last bit of the way.

"The whole mission from surface to orbit and soft landing for the lifter stage will take over an hour real time, as the Seraph is not physics warp friendly, but it is doable and not too difficult."

https://kerbalx.com/Brikoleur/BAK-9900-Seraph

 

 

 

[It'snorocketscience]

On 9/5/2019 at 11:34 AM, AHHans said:

Quick update here. AHTech's reusable Eve transportation system is still in development. Unfortunately recent testing has been plagued by Kraken attacks.

Here is the result of dropping a small, empty fuel tank from the bottom of the carrier plane:

The accident investigation is still ongoing. After finding only low to moderate amounts of part clipping, the investigators are currently looking into the Kraken attracting properties of autostruts.

In light of AHTech's press statements, Periapsis Co. would like to remind all builders that auto-strutting to the root part is "not to be trusted" when docking vessels. Consider auto-strutting to the heaviest part, or better yet, the grandparent part.

 

Sorry I had to roleplay lol.

[It'snorocketscience]

On 9/5/2019 at 3:35 PM, Brikoleur said:

I have a submission. Full stock + DLC. Carries one (1) kerbal to orbit and back again. Everything is reusable... in theory. You "just" need a bunch of ground infrastructure to mount the orbiter module on the nose of the lifter module, refuel it, and re-pack the parachute. 

I have not built that infrastructure and haven't used this in career mode, but I have done several round trips when iterating on it.

Mission profile, quoting from the KerbalX craft page:

"The Seraph’s six pairs of rotary wings are powered by three heavy rotors mounted on freewheels along the spine of the vessel. She uses them to take off – very carefully – then climb to 26 kilometres or so. Climb peaks at around 15 m/s vertical speed between 13 and 15 km or so, and the craft takes about 40 minutes to reach its ceiling.

"After it has reached its operating ceiling, it disengages rotors and sets collective to 90 degrees, lights up its Vector, and gets into a parabolic arc that peaks at over 70 km. It launches its orbiter, which flies to orbit.

"After the orbiter is safely injected, the lifter falls back to the surface, initially braking with its rotors flat against the air, subsequently by autorotation. It then autorotates to a soft landing.

"The orbiter will return to Eve. It is designed to withstand the thermal and physical stresses of re-entry, can glide to its final landing spot, and uses its parachute for the last bit of the way.

"The whole mission from surface to orbit and soft landing for the lifter stage will take over an hour real time, as the Seraph is not physics warp friendly, but it is doable and not too difficult."

https://kerbalx.com/Brikoleur/BAK-9900-Seraph

 

 

 

That's a really cool concept, although the floating control surfaces make takeoff look like witchcraft. Do the surfaces need to be offset that far? Otherwise the rotors/autorotation are great.

I'll add it to the list, witchcraft isn't against the rules .

[Guest]

Just now, It'snorocketscience said:

That's a really cool concept, although the floating control surfaces make takeoff look like witchcraft. Do the surfaces need to be offset that far? Otherwise the rotors/autorotation are great.

They could probably be pulled in a bit closer. It's also possible to add cosmetic struts without noticeably affecting performance. This was such a beast to develop I didn't get to the cosmetics... 

[EveMaster]

@Brikoleur Nice craft. I have no experience myself with propellors myself.

 

A modified version of my craft is now capable of performing a grand tour:

 

[Guest]

I made a rocket plane too! Uses the same orbiter as the Seraph so it's much smaller than yours, and only carries one kerbal in a command seat.

This isn't an official entry as I haven't actually completed the round trip -- my trial ended up with a too-energetic orbit (ca 110 km) with only about 150 m/s to spare, and my re-entry module didn't survive the return trip; however I have tested the same module with the Seraph from 91 km and she did survive that, so I'm confident it'll work. The lifter stage performed beautifully, very easy to fly both up and down, with plenty of time to fly the orbiter to orbit before switching back.

https://kerbalx.com/Brikoleur/BAK-9011-Raphael

[EveMaster]

12 hours ago, Brikoleur said:

I made a rocket plane too! Uses the same orbiter as the Seraph so it's much smaller than yours, and only carries one kerbal in a command seat.

This isn't an official entry as I haven't actually completed the round trip -- my trial ended up with a too-energetic orbit (ca 110 km) with only about 150 m/s to spare, and my re-entry module didn't survive the return trip; however I have tested the same module with the Seraph from 91 km and she did survive that, so I'm confident it'll work. The lifter stage performed beautifully, very easy to fly both up and down, with plenty of time to fly the orbiter to orbit before switching back.

https://kerbalx.com/Brikoleur/BAK-9011-Raphael

Nice design. Is the craft destroyed on reentry by overheating or by mechanical  forces? For me it helped to increase the wing area on the lower stage to slow down faster. I also try to avoid fast turning and rotate the craft to distribute the heating. I also avoid pointing prograde for too long because this causes the docking adapter to overheat. If canards or control surfaces break off due to high stress I found it useful to set the control limit to a lower value.

Unfortunately I cannot load your craft because it uses the Vernier Engine from the making history DLC in the upper stage and I don't own this DLC.

Edit:

I replaced the Vernier Engines with 24-77 "Twitch" Liquid Fuel Engines and your plane and it still works.

I was able to bring the upper stage to orbit and land the lower stage back at the starting location. After takeoff, I quickly put the nose up around 80 degrees. When the speed reached 300m/s I switched to prograde. When the speed hit around 1200m/s I had to throtttle down to avoid overheating. Once the apoapsis reached 100km I decoupled the upper stage and started burning towards the horizon. Then I switched back to the lower stage and burned in the backward direction towards the horizon to be able to land back at the starting location. Before the upper stage went out of pyhsical range I switched back to it and finished circularization. After the lower stage was landed I deorbited the upper stage and landed it on top of the lower stage.

To be reusable you would just need some ground infrastructure to refuel and to be able to dock the two parts back together.

 

Edited September 8, 2019 by EveMaster