1. What is a Hohmann Transfer Orbit?

A Hohmann transfer orbit is an elliptical orbit used to transfer between two circular orbits in the same plane with the least amount of delta-v (change in velocity). It's the most fuel-efficient method for orbital transfer between two circular orbits.

2. How Does the Calculator Work?

The calculator uses the Hohmann transfer time equation:

Where:

• \( T \) — Transfer time (seconds)
• \( r_1 \) — Initial orbital radius (meters)
• \( r_2 \) — Target orbital radius (meters)
• \( \mu \) — Standard gravitational parameter (m³/s²)

Explanation: The equation calculates the time required to complete half of the elliptical transfer orbit between two circular orbits.

3. Importance of Hohmann Transfer Calculations

Details: Accurate calculation of transfer time is crucial for mission planning, fuel requirements, and spacecraft trajectory design in orbital mechanics.

4. Using the Calculator

Tips: Enter orbital radii in meters and the standard gravitational parameter (μ) in m³/s². For Earth, μ is approximately 3.986004418×10¹⁴ m³/s².

5. Frequently Asked Questions (FAQ)

Q1: What are the assumptions of Hohmann transfer?
A: It assumes instantaneous impulse burns, circular initial and final orbits in the same plane, and only two-body gravity.

Q2: How accurate is this calculation for real missions?
A: It provides a good first approximation but real missions must account for perturbations, finite burn times, and orbital inclinations.

Q3: Can this be used for interplanetary transfers?
A: The basic principle applies, but interplanetary transfers typically use patched conic approximations instead.

Q4: What's the difference between radius and altitude?
A: Orbital radius is measured from the planet's center, while altitude is from the surface. Remember to add planet radius to altitude.

Q5: How does μ vary between celestial bodies?
A: Each planet/moon has its own μ value. For example, Sun: 1.327×10²⁰, Moon: 4.905×10¹² m³/s².