How to NOT build a two stage model rocket

So… I don’t usually write blogs mostly because I thought I wasn’t the “blogging type” (whatever that means). Actually, this is my first one. But after what happened during our first two-stage rocket attempt, I figured — yeah, it’s probably worth writing about. If nothing else, maybe someone else can laugh, learn, and avoid making the same mistakes we did.

It started off like any good launch day. The rocket was prepped, the team was hyped, someone shouted “start!” (it was me) even though the rocket was somewhere in the shot — if you squint and use your imagination.

We began the countdown with full confidence.

3… 2… 1… LAUNCH!

What followed was… not flight. The rocket lifted maybe a few meters off the pad, sighed like it had second thoughts, and flopped over like a fainting goat. The motor technically fired — just not enough to impress anyone, including the rocket itself.

We stood there in silence. Someone clapped. We all laughed.

This blog is a mix of that story — and all the other things that went slightly or wildly wrong — wrapped up with actual lessons about what not to do when building a two-stage model rocket. If you’re a fellow enthusiast, a curious beginner, or just here for the explosions, welcome aboard.

The Dream

Before we talk about Venessa’s (yes, it was a concious decision to name the rocket Venessa) design, problems, and the oh-my-god-what-just-happened moments, let’s take a step back.

Why even build a two-stage rocket in the first place?

It’s simple—because it’s cool. But also because it’s hard. And that’s exactly what makes it worth doing. Two-stage rockets introduce a whole new layer of complexity compared to single-stage flights. You’re not just launching a rocket anymore—you’re launching a rocket that splits into two mid-air, and both halves need to do what they’re supposed to.

This complexity is exactly why we decided to build Venessa, our first two-stage rocket.

We weren’t chasing records or altitude this time. The goal was simple:
Design, build, and successfully execute a stage separation event—the part where the upper stage cleanly detaches and continues its journey after the first stage burns out.

That’s it.

This small but critical demonstration was meant to pave the way for Asthsiddhi, our larger and more capable two-stage rocket that’s currently in development. Venessa was a stepping stone— an experiment, and more importantly, a learning experience.

Our guiding principle from day one was:
“Do it in the simplest way that still teaches you the hard stuff.”

This philosophy shaped everything—how we built our motors, chose our materials, designed our avionics, and even decided which parts were worth overengineering (and which ones we could just glue together and pray for the best).

What followed was months of design, iteration, fabrication, failed tests, and re-dos.

But it all started with a single goal:

Can we design a rocket that breaks apart mid-flight—intentionally—and not get absolutely roasted by gravity?

Let’s see how that went.

Vanessa wasn’t about going higher or faster. It was about going smarter.

From the very beginning, the design philosophy was simple:
Focus on mastering stage separation, not perfection.

So instead of chasing every performance metric, we kept our sights on the core challenge—making a two-stage rocket separate mid-flight in a controlled and reliable way. Everything else—structure, propulsion, avionics—was built around that singular goal.

We knew there would be compromises. And we were okay with that. Not everything needed to be aerospace-grade. We didn’t need fiberglass or carbon fiber. What we needed was something that worked just well enough to get us to the learning moment.

At every step, we asked ourselves:

“What’s the easiest way we can build this and still learn the hard lesson?”

Sometimes that meant using a cardboard cut out part that could’ve been 3D printed. Sometimes it meant using a paper tube instead of an expensive composite body. Sometimes it meant letting a stage fall ballistically with no recovery system (RIP first stage, you did your job).

But that’s the beauty of a learning prototype—freedom to make mistakes on purpose.

Vanessa wasn’t a rocket built for glory—it was a rocket built to teach us.

Propulsion

When it came to propulsion, we decided to graduate from our unreliable PVC days and finally enter the metal age.

We designed solid rocket motors with a stainless steel casing, aluminum end cap, and a mild steel nozzle. Fancy, right? Turns out, PVC was never the move. It’s lightweight, yes, but also has the structural integrity of a soggy biscuit under pressure. Metal, while harder to work with, gave us something far more valuable—consistency and peace of mind (plus fewer heart attacks during static tests).