Do I need to install anything?

No. It runs in any modern browser, free, with no account required.

For Engineers · Mission Planner

Mission Planner for a drug dose

Built for engineers using it for real design work. Go from concept to a running model in the browser, then scale to the cloud when needed. Simulate a drug dose live below — adjust the inputs and watch it respond, right in your browser.

Rocket Staging

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Rocket StagingLive

beating the tyranny of the equation

Controls

Presets

Number of stages

Mass ratio per stage

Specific impulse Isp (s)

The rocket equation grows delta-v only with the logarithm of the mass ratio, so a single stage hauling empty tanks all the way up is hopelessly inefficient. Staging drops dead weight along the way: each stage contributes ve·ln(mass ratio), and their sum easily clears the ~9.4 km/s needed for low Earth orbit.

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Data Inspector

Δv per stage4.76 km/s

Total Δv9.52 km/s

Reaches LEO?yes

Governing equation

Δ v = i = 1 \sum 2 v_{e, i} ln \frac{m _{0, i}}{m _{f, i}} = 2 \cdot 4.76 = 9.52 km/s

Reading this result: 2 stages at Isp 350s and mass ratio 4 each sum to 9.5 km/s — past the ~9.4 km/s LEO budget, since every stage adds ve·ln(ratio) after dropping dead weight.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Escape Velocity

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Escape & Orbital VelocityLive

how fast to leave a world

Escape velocity — Earth

11.19km/s

7.91

orbital km/s

1.00

surface g (× Earth)

Controls

Custom body

Presets

Escape velocity v = √(2GM/R) is the speed needed to break free of a body's gravity from its surface, ignoring air resistance. Circular orbital velocity is √(GM/R) — a factor of √2 smaller. Both depend only on mass and radius, not on the mass of the escaping object.

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Data Inspector

Escape velocity11.19 km/s

Orbital velocity7.91 km/s

Surface gravity9.82 m/s²

Governing equation

v_{e} = \frac{2 GM}{R} = \frac{2 ( 6.674 \times 1 0 ^{- 11} ) ( 5.97 e + 24 )}{6.37 e + 6} = 11.19 km/s

Reading this result: Leaving Earth takes 11.2 km/s no matter the spacecraft mass, while a circular orbit needs only 7.9 km/s — smaller by exactly √2 (about 1.41×).

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Orbital Transfer

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Orbital Transfer (Hohmann)Live

minimum-energy orbit change

Controls

Speed1×

The Hohmann transfer is the fuel-cheapest way between two circular orbits: one burn to enter the transfer ellipse, one to circularize. See the two Δv costs.

Presets

Inner orbit radius

Outer orbit radius

▶ Run in Python

Data Inspector

Δv burn 11.64

Δv burn 21.34

Total Δv2.99

Transfer time61.3

Governing equation

Δ v = \frac{μ}{90} (\frac{2 \cdot 200}{90 + 200} - 1) + \frac{μ}{200} (1 - \frac{2 \cdot 90}{90 + 200}) = 2.99

Reading this result: A moderate transfer (90 → 200, ~2.2×): burn 1 (1.64) enters the ellipse, burn 2 (1.34) circularizes. Bigger ratios cost more total Δv (2.99) and coast longer (61.3).

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Lagrange Points

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Lagrange PointsLive

restricted three-body problem

Controls

Presets

Mass ratio μ

Show effective potential

In a two-body system, five points let a small object stay fixed in the rotating frame. L1-L3 sit on the line through the two masses (unstable); L4 and L5 lead and trail the secondary by 60° and are stable for μ below 0.0385 — where Jupiter's Trojan asteroids live. JWST orbits the Sun-Earth L2.

▶ Run in Python

Data Inspector

μ = m₂/(m₁+m₂)0.150

L4/L5 stable?no

Points5

Governing equation

Ω (x, y) = \frac{1}{2} (x^{2} + y^{2}) + \frac{1 - μ}{r _{1}} + \frac{μ}{r _{2}}, μ = 0.150

Reading this result: At μ=0.150 the masses are too comparable: even L4 and L5 turn unstable, so every Lagrange point here needs active station-keeping to hold a spacecraft in place.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Frequently asked questions

Is this good for engineers?: Yes — this version of "Mission Planner for a drug dose" is framed for engineers using it for real design work. Go from concept to a running model in the browser, then scale to the cloud when needed.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.