staged

The two files below are a couple of designs I made in Open Rocket. What I don't quite understand, is that the single stage version reaches a higher altitude than the two stage version. I understand that the two stage version has extra drag due to the additional set of fins to maintain stability...

This one has a D12-0 booster that air-starts a two 18mm motor second stage (and an optional third stage, 18mm or 13mm). With the vent holes (see pics), it’s two for two on air starting both second stage motors. I wish I was a better artist - the paint job and decals leave much to be desired.

Cold weather has forced me indoors for the winter to build. I got all my parts for my 3 stage last week. All airframe, couplers, anf bulkplates are from PML. Hardware is from Ace Hardware. My goal is to create a modular system around 54mm airframe with interchangeable electronics bays and...