1. What is a Hohmann Transfer?

A Hohmann transfer is an orbital maneuver that moves a spacecraft between two circular orbits in the same plane using two engine impulses. It's the most fuel-efficient method for such transfers.

2. How Does the Calculator Work?

The calculator uses the Hohmann transfer equation:

Where:

• \( \Delta v \) — Required change in velocity (m/s)
• \( \mu \) — Standard gravitational parameter of the central body (m³/s²)
• \( r1 \) — Initial orbital radius (m)
• \( r2 \) — Target orbital radius (m)

Explanation: The equation calculates the delta-v required for the first burn to enter the transfer ellipse. A second burn is needed at apoapsis to circularize the orbit.

3. Importance of Delta-V Calculation

Details: Accurate delta-v calculation is crucial for mission planning in Kerbal Space Program and real-world spaceflight, ensuring spacecraft have sufficient fuel for maneuvers.

4. Using the Calculator

Tips: Enter μ (gravitational parameter) in m³/s², orbital radii in meters. For KSP, μ is 3.5316×10¹² m³/s² for Kerbin. Remember r2 must be different from r1.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between orbital radius and altitude?
A: Orbital radius is altitude plus the planet's radius. For Kerbin (radius 600km), a 100km orbit has r1 = 700,000m.

Q2: Does this include both burns of the transfer?
A: No, this calculates only the first burn. The second burn at apoapsis requires a similar calculation.

Q3: How do I find μ for different celestial bodies?
A: In KSP, μ = G×M where G is 6.674×10⁻¹¹ and M is the body's mass. The KSP wiki lists μ values for all bodies.

Q4: Can this be used for elliptical orbits?
A: The basic equation is for circular orbits. For elliptical orbits, more complex calculations are needed.

Q5: What about plane changes or inclination changes?
A: This calculator doesn't account for plane changes, which require additional delta-v.