ESLA Mk.1 - Eve Sea-Level Ascender

[evilwombat]

Hello. I had never published a craft before, but maybe this will be useful to someone. For anyone who is interested, I have built a craft capable of carrying an Mk.1 pod (with heat shield, decoupler, parachute, docking port, and occupant) into a stable orbit around Eve, starting from sea level. If launched from higher elevations, the final ascent stage typically has enough fuel left over to fly back to Kerbin and land. If launching from 1.7km ASL, I managed to return to Kerbin with something like 330m/s to spare. The craft relies on the mining capabilities introduced in v1.0 to avoid a refueling mission, or an enormous ascent stage. The resource mining also allows the lander/ascender's full fuel capacity to be re-used for the Eve transfer/descent. The only non-stock part is Mechjeb2 - it is recommended for efficient auto-staging, but is technically not required.

Suggested mission profile:

1. Launch from Kerbin into KLO, cutting away initial ascent stage as needed

2. Land on Minmus to mine and refuel

3. Ascend from Minmus (directly back into Kerbin SOI)

4. Transfer to Eve

5. Perform several progressive aerobraking manoeuvres (typically three-four passes, around 74k)

6. Begin final Eve entry

7. Use remaining fuel to avoid overheating during descent (a few basic fins might explode. That's fine.)

8. Parachute landing on Eve

9. Mine for resources and refuel (typically 120 days' worth)

10. EVA / science / admire the purple

11. Cut away mining equipment, landing gear, and fuel recirculation tank (this switches the ascender into asparagus mode)

12. Ascend from Purple Hell

Though the ascender is capable of reaching stable Eve orbit from sea level, you will need to land on terrain to mine resources and refuel. The ascender *does* have enough parachutes to survive a splash landing even when fully fuelled, but this would require an independent Eve transfer and entry stage, or a refuelling mission. These are left as an exercise to the reader.

Eve descent instructions:

1. Plan to aerobrake around 73-75km after the initial Eve transfer. Try to keep the craft pointed prograde if possible. Keep an eye on the orbit, and play with changing the orientation mid-braking to fine-tune things.

2. Around 85km, point retrograde and burn all your remaining fuel, to keep from overheating. A few Basic Fins may explode. That's fine - turns out these aren't actually needed. I'm just too lazy to go pull them off. If you aren't careful, you may lose a science instrument here, but aside from that, reentry tends to be rather uneventful. (NOTE: A suicide-burn entry from Eve orbit around 100km should work too).

3. Once out of fuel and going reasonably slowly (1200m/s?), point retrograde again and prepare for parachute descent. If you have Mechjeb2 installed, you must disable auto-staging prior to opening the parachutes.

4. Deploy landing gear, and activate the 'Brakes' action group to lock the landing gear suspension.

5. Land.

6. Deploy solar panels, start the drills, and activate the resource converter (buried in the center of the lander). Refuel.

Eve ascent instructions:

1. Make sure all ladders are retracted (using the '9' action group)

2. If using Mechjeb, under 'Attitude Adjustment', enable 'Use stock SAS'. Open Smart A.S.S. and select Surf -> UP. As of build #465 or earlier, Mechjeb's attitude controller tends to struggle with this craft while flying in atmosphere. Stock SAS does not have this problem. Make sure Auto-Staging is still disabled at this point.

3. If not using Mechjeb - activate SAS to point upwards.

4. Press 'Z' to throttle up all active engines.

5. Immediately afterwards, stage once to cut away the landing gear and mining equipment. This also cuts away a small recirculation tank, which will switch the whole ascender into asparagus / onion routing mode. The Stage delta-V display (if you have one) will now look a lot more sane.

6. One second after cutting away the landing gear, stage again to activate the remaining engines.

7. Mechjeb users- you should enable Auto-Staging at this point.

8. Ascend directly upwards until about 35-45k.

9. Perform your gravity turn starting from 35-45k. If using Mechjeb, this is a good time to activate the ascent autopilot. A target altitude of 100km should work. You may need to manually fine-tune the circularization by a few km. If you are past apoapsis, apply a small amount of radial burn (Rad+) to fix that, then wait until apoapsis and burn prograde for a tiny bit, to stabilize the orbit.

10. If you have ~1700m/s of dV remaining, go home. Else, use the docking port to add a splash of fuel first.

Craft files:

Complete craft, ready-to-fly: https://dl.dropboxusercontent.com/u/79740546/ESLA-Mk1-Full.craft

Eve ascender only: https://dl.dropboxusercontent.com/u/79740546/ESLA-Mk1-AscenderOnly.craft