Deflection Methods

🛡️ Deflection Methods

CosmoRisk supports three asteroid deflection techniques based on real planetary defense research.

1. Kinetic Impactor (DART-style)

Principle: High-velocity spacecraft collision transfers momentum to the asteroid.

Δv = (m_spacecraft / m_asteroid) × v_impact × (1 + β)

Where β (beta factor) accounts for ejecta momentum enhancement (typically 1-5).

Usage

1. Select asteroid
2. Set impactor mass (kg)
3. Set impact velocity (km/s)
4. Set beta factor
5. Click "Apply Deflection"

Real-World Example

• DART Mission (2022): NASA's test on Dimorphos
• Impactor: 570 kg at 6.6 km/s
• Result: 32-minute orbital period change

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2. Ion Beam Deflection (IBS)

Principle: Continuous low-thrust beam slowly pushes asteroid over time.

Δv = F_thrust × t / m_asteroid

Advantages

• No contact required
• Continuous adjustment
• Works over months/years

Usage

1. Select asteroid
2. Set thrust magnitude (mN)
3. Set direction vector
4. Set duration (days)
5. Click "Apply Ion Beam"

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3. Gravity Tractor

Principle: Spacecraft hovers near asteroid; mutual gravity slowly deflects both.

F = G × m_spacecraft × m_asteroid / r²

Advantages

• No physical contact
• Works on rubble piles
• Very precise control

Disadvantages

• Requires years of operation
• Limited to small deflections

Parameters

• Spacecraft mass: 1,000 - 20,000 kg
• Hover distance: 50 - 200 m
• Lead angle: 0° - 45°

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Deflection Planning

Lead Time Requirements

Δv Required	Lead Time	Deflection @ Earth
1 cm/s	10 years	~1 Earth diameter
1 mm/s	20 years	~1 Earth diameter
10 cm/s	1 year	~1 Earth diameter

Key Insight: Early detection = smaller required Δv!

Mission Considerations

Factor	Impact
Asteroid size	Larger = harder to deflect
Density	Unknown for most NEOs
Rotation	Affects gravity tractor positioning
Orbit uncertainty	Monte Carlo analysis needed

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Comparison

Method	Speed	Precision	Technology Readiness
Kinetic Impactor	Fast	Low	TRL 9 (DART proven)
Ion Beam	Slow	High	TRL 4-5
Gravity Tractor	Very Slow	Very High	TRL 3-4

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