🚀 Two-Stage Rocket — Tsiolkovsky Equation & Staging

Configure two rocket stages — thrust, specific impulse, propellant and dry mass — then launch. Watch stage separation, observe the ΔV budget in real time, and see why staging is key to reaching orbit.

🟠 Stage 1

Thrust 2 000 kN Isp 310 s Propellant mass 200 t Dry mass 20 t

🔵 Stage 2

Thrust 100 kN Isp 420 s Propellant mass 40 t Dry mass + payload 5 t

⏸ READY

Telemetry

Altitude—

Velocity—

Acceleration—

Mass now—

ΔV remaining—

Time—

Stage—

Tsiolkovsky:
ΔV = Isp·g₀·ln(m₀/m₁)
F_net = Thrust − mg − D
ρ(h) = ρ₀·e^−h/8500
Orbit ≈ 7800 m/s at 200 km

Why Two Stages?

The Tsiolkovsky rocket equation ΔV = I_sp·g₀·ln(m₀/m₁) shows that ΔV depends on the mass ratio m₀/m₁. Once Stage 1 exhausts its propellant, its heavy empty tanks are dead weight. Dropping them (staging) dramatically improves Stage 2's mass ratio and its ΔV contribution. A single stage carrying the same propellant and payload would need a huge structural fraction, reducing the mass ratio and making orbit nearly impossible. Real launch vehicles like the Falcon 9, Saturn V and Soyuz all use this principle. Reaching low Earth orbit requires about 9–10 km/s of ΔV including gravity and drag losses.