Search the Community

Taking a break from all my spaceplanes, I'm trying my hand at making a stock, recoverable two stage rocket. The booster stage has wings and will glide back to the space centre, before landing on parachutes. The upper stage also has stub wings (mainly to help it aim and slow down) and parachutes. The goal is to come up with something you can put on KerbalX and have the average joe just be able to fly it, without having to install mods or tweak physics range etc. As you can imagine, physics range is the bugbear. I keep finding one or other part of my rocket has gotten auto deleted before I can deal with the other. Each time i want to tweak separation altitude/ascent profile, means a complete redesign, moving propellant from one stage to the other then having to rebalance the aerodynamics so each component is stable on its own. If you guys can help with that, it will save a lot of time building iterations of this rocket. Attempt 1 My first iteration only had about 1000dv on the lower stage, but with 8 aerospikes the lower stage was pretty powerful (TWR 2.75) and launched steeply. Separation altitude was 20km and due to the steep ascent, the first stage didn't have a long glide to get back to the space centre. The upper stage had about 1900dv but only 0.5twr and i think i should have boosted that, in retrospect. The problem is, these engines only run for as long as i'm flying that vessel. They do take the upper stage's AP out of the atmosphere, but as i understand it, I have to switch back to the lower stage before it gets more than 2.5km away. EDIT - ok, it appears the non-focused stage is ok so long as it stays above 25km OR is within 2.5km of the flown vessel. When i switch to the lower stage, the upper stage's engines immediately stop and it is still well below orbital velocity. It completes the sub-orbital arc and falls below 25km and gets deleted before i can land the lower stage. Attempt 2 I tried adding extra fuel to lower stage and removing from upper. The lower stage now has 1700dv. Separation was at 950m/s at 35km in a 65 degree climb. The booster reached 65km before falling back. I still wasn't able to put enough velocity on the upper stage before having to switch back to the booster, and it fell back below 25km again just as the booster was opening its parachutes. I don't like adding more fuel to the booster, it means either a very inefficient lofted trajectory or being too far from the space centre to glide back at separation. So, it seems i need to give the upper stage some serious TWR so it can get close to orbital velocity much quicker. BTW, what happens if the upper stage is an SRB? Does that magically extinguish itself when i switch away from the vessel ? Just thinking out loud.