Delta-V Budget Calculator

Mission Inputs

Mission Name

Mission Requirement (m/s)

Reserve Margin (%)

Gravity Loss (m/s)

Drag Loss (m/s)

Steering Loss (m/s)

Maneuver Segments

Enter up to five sequential burns or mission phases. Delta-V is computed from the rocket equation for every filled segment.

Segment 1 Label

Segment 1 Initial Mass (kg)

Segment 1 Final Mass (kg)

Segment 1 Isp (s)

Segment 2 Label

Segment 2 Initial Mass (kg)

Segment 2 Final Mass (kg)

Segment 2 Isp (s)

Segment 3 Label

Segment 3 Initial Mass (kg)

Segment 3 Final Mass (kg)

Segment 3 Isp (s)

Segment 4 Label

Segment 4 Initial Mass (kg)

Segment 4 Final Mass (kg)

Segment 4 Isp (s)

Segment 5 Label

Segment 5 Initial Mass (kg)

Segment 5 Final Mass (kg)

Segment 5 Isp (s)

Example Data Table

Segment	Initial Mass (kg)	Final Mass (kg)	Isp (s)	Approx. Delta-V (m/s)
Launch Ascent	500,000	210,000	300	2,552.18
Parking Orbit Circularization	210,000	185,000	320	397.76
Transfer Injection	185,000	90,000	348	2,459.02
Orbit Trim	90,000	82,000	325	296.69
Landing Reserve	82,000	78,000	290	141.70

This sample closes a representative mission budget when compared against the default requirement and reserve assumptions shown in the form.

Formula Used

Segment delta-v:
Δv_i = Isp_i × g₀ × ln(m_0,i / m_f,i)

Total available delta-v:
Δv_available = Σ Δv_i

Required budget:
Δv_required = (Mission Requirement + Gravity Loss + Drag Loss + Steering Loss) × (1 + Reserve Margin / 100)

Net margin:
Margin = Δv_available − Δv_required

The calculator uses standard gravity g₀ = 9.80665 m/s². Mass values must stay in the same unit system, and each segment must have initial mass greater than final mass.

How to Use This Calculator

Enter the mission name and the ideal mission delta-v requirement.
Add gravity, drag, and steering losses in meters per second.
Enter a reserve margin percentage for design conservatism.
Fill the segment table with initial mass, final mass, and engine specific impulse for each burn.
Submit the form to see total available delta-v, required budget, and remaining mission margin above the form.
Download the result as CSV or PDF for trade studies, reviews, or reports.

Frequently Asked Questions

1. What does this calculator measure?

It estimates the total available delta-v from multiple maneuver segments, then compares that value against required mission delta-v, modeled losses, and an engineering reserve margin.

2. Why do I need both mission requirement and segment inputs?

Segment inputs estimate available performance. The mission requirement and loss values estimate demand. Comparing both sides shows whether the design closes with margin or falls short.

3. What units should I use for mass?

Use any consistent mass unit, though kilograms are typical. Because the rocket equation relies on a ratio, only consistency matters between initial and final mass.

4. What is specific impulse?

Specific impulse is a propulsion efficiency measure in seconds. Higher Isp means the engine extracts more delta-v from the same propellant mass ratio.

5. Why are gravity and drag losses separate?

They represent different penalties. Gravity loss comes from fighting gravity during finite burns, while drag loss comes from atmospheric resistance during ascent.

6. What happens if my net margin is negative?

A negative margin means the mission budget does not close. You may need more propellant, higher Isp, lower dry mass, or reduced mission losses.

7. Can I model staging or separate burns?

Yes. Enter each stage, burn, correction, or reserve block as a separate segment. The calculator sums all segment delta-v values into one available budget.

8. Are the exports useful for documentation?

Yes. The CSV file supports spreadsheet review, and the PDF captures summary metrics plus the segment table for meetings, design notes, or internal reports.