Space engineering calculators
Delta-v, rocket equation, Hohmann transfer, orbital period, ground track and link budget calculators that run in your browser.
Calculators
- Delta-v budget
- Adds up the velocity changes for a mission: launch to low Earth orbit (about 9.4 km/s with losses), plane changes, LEO to geostationary orbit (about 4.1 km/s) and any extra manoeuvres.
- Rocket equation
- Tsiolkovsky: Δv = vₑ · ln(m₀ / m_f). Enter exhaust velocity and wet and dry mass to get the delta-v a stage can deliver.
- Hohmann transfer
- The two burns needed to move between circular orbits of radius r₁ and r₂, and the transfer time.
- Orbital period
- T = 2π √(a³ / μ) for a circular orbit at a given altitude, with orbital velocity and orbits per day.
- Ground track
- How far a satellite's ground track shifts west each orbit as Earth rotates underneath it.
- Link budget
- Received power and margin from transmit power, antenna gains, frequency and distance, using free-space path loss.
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About the space engineering calculators
Free, in-browser calculators for the core equations of spaceflight. Everything runs on your device; nothing is sent to a server.
- What is the Tsiolkovsky rocket equation?
- Δv = vₑ · ln(m₀ / m_f): the change in velocity a rocket can achieve equals its exhaust velocity times the natural log of its initial mass divided by its final (dry) mass.
- What is a Hohmann transfer?
- The most fuel-efficient two-burn transfer between two circular orbits: one burn to enter an elliptical transfer orbit and a second to circularize at the target altitude.
- How much delta-v does it take to reach orbit?
- Roughly 9.3 to 10 km/s to reach low Earth orbit once gravity and drag losses are included, and about 4 km/s more to go from LEO to geostationary orbit.
Data may be delayed. Not financial advice.