AstronautiCalc

A scientific calculator for people who work with orbits.

What it does

Enter an altitude or radius and AstronautiCalc computes the orbital parameters that follow: period, semi-major axis, circular and escape velocity, revolutions per day, maximum eclipse duration, apparent Earth angular radius and range to horizon.

• Ground station visibility — maximum time in view and slant range at 0°, 5°, 10°, 15° and 20° elevation
• Delta-V — plane change per degree, and the burn to lower perigee for de-orbit
• A full scientific keypad, with base conversion between decimal, binary, octal and hexadecimal
• Physical constants one keystroke away
• Unit conversions, and time conversions between UTC, TAI, GPS, POSIX, Julian Date, MJD, Excel serial and day-of-year

Frequently asked

Does it need an internet connection?
No. AstronautiCalc has no networking code at all. Everything is computed on your device.

Does it collect any data?
No. See the privacy policy.

Is there an iPad version?
Not yet. The app runs on iPad in iPhone compatibility mode; a layout that makes proper use of the larger screen may come later.

Disclaimer

This application provides engineering calculations intended for preliminary analysis and educational use. Results have not been independently verified or validated for mission-critical or flight use. Users are solely responsible for verifying all outputs against authoritative sources and for determining suitability for any specific application.

Calculations are based on standard aerospace engineering formulations. While care has been taken in implementation, the software has not undergone formal verification and validation (V&V). Results are provided “as-is” and must be independently confirmed prior to use in any operational or mission-critical context.