Difference between revisions of "Tutorial:Returning From Eve"

Revision as of 16:47, 30 September 2013

Because of the extreme difficulty concerning any return attempt from Eve, I have decided to write a separate tutorial.

Returning from Eve

Despite being the closest planet relative to Kerbin, it is extremely difficult to get a lander back into orbit around Eve. Additionally, you must overcome Eve's large gravity well in order to successfully return home, requiring even more Delta-V. As a result, many Kerbals have been lost in attempts to investigate their distant neighbor.

Though getting your crew home from the surface of Eve is extremely difficult, it's not impossible.

Specifications

• Length: 1-3 hours
• Difficulty: Very Hard
• For version: 0.20

Additionally, you will need a good understanding of orbital mechanics (see Tutorials section), angles, and a lot of patience. Some knowledge about aerobraking and Advanced Rocket Design might also be useful. Ships described below don't feature lauch vehicle, so any experience in building them is desired.

Method 1 : Rendezvous and Crew Transfer

Designing your Landing Rocket

Ascent rocket will use asparagus staging (see Tutorials) with Upper and Middle Stage in a core and multiple Booster stages grouped in pairs.

Upper Stage

This stage has to get above the atmosphere and accelerate itself to orbital velocity. It's important to keep it as lightweight as possible. First choose is a command pod. The best idea is to put single Kerbal in a EAS-1 External Command Seat. Next (but much worse) would be Mk1 Lander Can. I recommend first option and a following stage design:

• EAS-1 External Command Seat
• Inline Advanced Stabilizer // not necessary if you feel confident in piloting
• FL-T400 Fuel Tank
• LV-909 Liquid Fuel Engine

Middle Stage

This stage will propel the ship through middle atmosphere (20km-35km). It's engine should be activated with all lower stage boosters and fed from their tanks:

• TR-18A Stack Decoupler
• FL-T800 Fuel Tank
• LV-T45 Liquid Fuel Engine

Booster Stages

There are two possible ways to build them. One is to use 2xFL-T800 Fuel Tank and LV-T30 Liquid Fuel Engine. Second is: FL-T400 Fuel Tank, FL-T800 Fuel Tank and Toroidal Aerospike Rocket. They have very similar performance but I think aerospikes are better because they lower ship's drag coefficient. The basic rocket will have 3 pairs of aerospike boosters attached around the core stack.

Additional Equipment

You may also need parachutes and landing gear.

• To save weight you can put LT-2 Landing Strut on a TT-38K Radial Decoupler.
• You may need Mk25 Parachute and it's best to put them on top of the boosters.
• For touchdown I used 24 Mk2-R Radial-Mount Parachute mounted on 12 TT-38K Radial Decoupler, two on each booster.
• Don't forget the ladder and some electric gear!

If you want to send lander alone to Eve, add somewhere a probe.

Designing your Return Rocket

Assuming that we sent ascent rocket alone the return rocket could be as simple as this:

• Mk16-XL Parachute
• Mk2 Lander-can
• TR-XL Stack Separator
• Advanced S.A.S Module, Large
• Rockomax X200-16 Fuel Tank
• LV-N Atomic Rocket Engine

Such rocket has Delta-V of almost 6km/s which is enough for departing Kerbin's orbit, Eve capture, rendezvous with ascent ship and then return to Kerbin. It's advisable for this ship to stay in highly elliptic Eve orbit to make plane changes cheaper.

Landing on Eve

Ascending from Eve

Rendezvous with Recovery Vehicle

Interplanetary Transfer back to Kerbin

Method 2 : Single Rocket Landing and Return

Follow the steps of the two rocket method, ignoring the Rendezvous step.

Rocket Design

Upper Stage

Middle Stage

Lower Stage

Special Considerations