# Testing an Eve launcher on Kerbin

I'd like to launch a rocket from the surface of Eve. From what I've read, Eve is significantly harder to launch from than Kerbin.

How can I test my Eve launcher design on Kerbin to see that it has sufficient delta-v for the job?

• I'm looking for an un-modded solution, something that works in KSP right out of the box.
• I'm only looking at a craft to get from Eve's surface to low Eve orbit. Don't worry about how to get that craft to Eve in the first place.

If you want to do this un-modded, you're going to need your thinking cap and a calculator. Because you'll need to work out your delta-v manually.

You're going to need around 11.5 Km of ΔV from sea level, less if you can get a higher LZ. Here's the delta-v calculation cheat sheet, you'll need to apply this to your ship prelaunch, don't forget to calculate for staging and fuel lines.

Then you'll need to make sure your ship will get off the ground, Eve has nearly double the ASL gravity of Kerbin. You'll need a Thrust To Weight (TWR) of at least 2. You can check this by running a test launch from Kerbin at 50% thrust and if can make orbit, you should be good.

I recommend using a mod like MechJeb or Engineer to calculate your TWR and Delta-V.

• While this answer is technically correct, I wouldn't do it. Get MechJeb and save yourself an hour of calculations per change. MechJeb can calculate the total and per stage ΔV and the per stage min and max TWR (since it changes during use). Commented Jan 27, 2015 at 6:22
• My personal preference is Kerbal Engineer, as MechJeb tends to make the game too easy with all the autopilot stuff. I'm not sure if MechJeb does this now or not, but Kerbal Engineer will display all the delta-V information you need for each body in the system when building the ship in the VAB. Commented Jan 27, 2015 at 16:15
• MechJeb has a dropdown to select planets / moons, yes. Also, in career mode MechJeb initially does not have autopilot unlocked. The major benefit IMO is that it saves you from launching almost-there designs. Those are a real waste in career mode. Commented Feb 11, 2015 at 21:35

So you are going to need about 12,000 m/s delta v to orbit Eve at sea level.

You need about 4500 m/s delta v to orbit Kerbin. If you want to test a design on Kebin before going to Eve, try getting to orbit 3 times on Kerbin (launch, land, launch, land, launch). If you can do that then chances are you have something that can get to Eve orbit.

I would suggest having something in orbit around Eve that has your return fuel.