1. What is Orbital Period?

The orbital period is the time a given astronomical object takes to complete one orbit around another object. For Earth satellites, it's the time to complete one full orbit around Earth.

2. How Does the Calculator Work?

The calculator uses Kepler's third law:

Where:

• \( T \) — Orbital period (seconds)
• \( a \) — Semi-major axis (meters)
• \( G \) — Gravitational constant (6.67430 × 10⁻¹¹ m³/kg·s²)
• \( M_{earth} \) — Mass of Earth (5.972 × 10²⁴ kg)

Explanation: The equation shows that the orbital period squared is proportional to the semi-major axis cubed (Kepler's third law).

3. Importance of Orbital Period Calculation

Details: Calculating orbital periods is essential for satellite operations, space mission planning, and understanding celestial mechanics.

4. Using the Calculator

Tips: Enter the semi-major axis in meters (distance from Earth's center to satellite's farthest point). The value must be greater than Earth's radius (~6,371 km).

5. Frequently Asked Questions (FAQ)

Q1: What's the period at geostationary orbit?
A: At ~35,786 km altitude (42,164 km from Earth's center), the period is exactly 1 sidereal day (23h 56m 4s).

Q2: How does altitude affect period?
A: Higher orbits have longer periods. Doubling the orbital radius increases the period by about 2.8 times.

Q3: What's the minimum orbital period?
A: The theoretical minimum is about 84 minutes (just above Earth's surface), but atmospheric drag makes low orbits impractical.

Q4: Does the satellite's mass affect the period?
A: No, the period depends only on the primary body's mass (Earth) and the semi-major axis.

Q5: How to convert to hours/minutes?
A: Divide seconds by 3600 for hours, or by 60 for minutes. For example, 5400s = 1.5h = 90m.