CubeSat Collision Avoidance: A Complete Guide for University Teams

Your university team spent two years building a CubeSat. You raised the funding, passed the reviews, and got a ride to orbit. Now your 3U satellite is circling Earth at 7.5 km/s alongside 14,368 other active objects — and you have no propulsion system.

CubeSat collision avoidance doesn't mean your satellite can dodge. For most university CubeSats, it means knowing when something is coming close, understanding the risk, and fulfilling your responsibility as an operator to contribute to space safety. This guide covers everything a university satellite team needs to know about monitoring and managing collision risk.

Why Small Satellite Safety Is Your Problem

There's a common misconception that CubeSats are too small to worry about. The logic goes: space is big, my satellite is tiny, the odds are negligible. This is wrong for several reasons.

Regulatory Requirements Are Real

The FCC, ITU, and national licensing authorities increasingly require orbital debris mitigation plans as a condition of launch. The FCC's 2022 rule update mandates that LEO satellites deorbit within 5 years of mission completion. The UN COPUOS Space Debris Mitigation Guidelines recommend collision avoidance as a fundamental practice for all operators.

Even if your CubeSat can't maneuver, you're expected to monitor conjunction events and coordinate with operators who can.

Your CubeSat Creates Risk for Others

A 3U CubeSat masses about 4 kg. At orbital velocities, a collision with a 4 kg object releases energy equivalent to detonating several kilograms of TNT. The resulting debris cloud threatens every satellite in similar orbits.

On February 9, 2026, OrbitGuard's screening of the active catalog found 441 collision risks in 24 hours. Many involved small satellites. The Hubble Space Telescope — a $16 billion asset — had 3 close approaches with Starlink satellites, the closest at 6.2 km. Hubble can't maneuver either. A CubeSat close approach with Hubble would create the same impossible situation.

Reputation and Responsibility

The university satellite community is built on trust. Future launch opportunities depend on demonstrating responsible operations. Teams that ignore collision monitoring damage the reputation of the entire academic small-sat ecosystem.

Understanding Your CubeSat's Collision Risk Profile

Your collision risk depends on several factors:

Orbital Altitude

The most congested region of LEO is 750-900 km altitude, where many sun-synchronous satellites operate. If your CubeSat is in this band, collision risk is significantly higher than at 400 km (where atmospheric drag naturally clears debris within years).

The popular ISS deployment orbit (~400 km) is safer from a long-term debris perspective, but has plenty of traffic from other ISS-deployed CubeSats, resupply vehicles, and the station itself.

Orbital Inclination

Sun-synchronous orbits (97-98° inclination) are especially congested because so many Earth observation satellites share this regime. Polar orbits see higher relative velocities at conjunction — objects can meet nearly head-on at combined speeds exceeding 14 km/s.

Cross-Section and Detectability

Smaller objects are harder to track accurately. A 1U CubeSat (10 cm × 10 cm × 10 cm) is near the edge of reliable tracking for the Space Surveillance Network. This means TLE data for your satellite may be less accurate than for larger objects, increasing uncertainty in conjunction predictions.

Setting Up University Satellite Monitoring

Here's a practical, step-by-step guide for university teams to establish CubeSat collision monitoring:

Step 1: Register on Space-Track.org

Create an account on Space-Track.org. As a satellite operator, you can request "owner/operator" status, which gives you access to Conjunction Data Messages (CDMs) for your specific objects. This is free.

Step 2: Identify Your NORAD Catalog Numbers

After deployment, your CubeSat will be assigned a NORAD catalog number by the 18th Space Defense Squadron. This may take days to weeks. Work with your launch provider to correlate your satellite with the correct catalog entry — early deployments from a shared deployer can be ambiguous.

Step 3: Set Up Automated Screening

Don't rely on manually checking Space-Track. Set up automated conjunction screening that runs at least every 8 hours. Options include:

• Self-hosted OrbitGuard: The open-source OrbitGuard tool can screen the entire catalog in 5.8 seconds. Run it on any Linux machine (even a Raspberry Pi) with a cron job. It uses SGP4 propagation with KD-tree spatial indexing for speed.
• OrbitGuard plan: For teams that don't want to maintain infrastructure, the $199/month plan provides automated screening with email/webhook alerts. Well within most university project budgets.
• Space-Track CDM alerts: Configure your Space-Track account to receive email notifications for CDMs involving your objects.

Step 4: Define Your Response Protocol

Even without propulsion, you need a protocol for conjunction events:

1. Alert threshold: Define what miss distance triggers a review (e.g., < 5 km)
2. Notification chain: Who gets alerted? PI, mission operations lead, faculty advisor?
3. Assessment: Review the conjunction details — miss distance, relative velocity, time of closest approach (TCA), probability of collision
4. Coordination: If the other object can maneuver, contact their operator. CDMs identify both objects.
5. Documentation: Log every conjunction event for your mission report and post-mission analysis

Step 5: Contribute to the Community

If you have GPS data or precision orbit determination capability, share your ephemeris data. More accurate orbits mean better conjunction predictions for everyone. The ESA Space Debris Office and Space-Track both accept supplemental data.

Collision Avoidance Options for Small Satellites

While most university CubeSats can't actively maneuver, the landscape is changing:

Propulsive CubeSats

Several companies now offer CubeSat-compatible propulsion systems:

• Cold gas thrusters: Simple, low delta-V, suitable for basic collision avoidance
• Electrospray thrusters: Higher specific impulse, more delta-V per unit mass
• Green monopropellant: Higher thrust for more aggressive maneuvers

If your next CubeSat mission can include propulsion, the capability to perform collision avoidance maneuvers significantly improves your safety posture and regulatory compliance.

Drag-Based Maneuvering

Satellites with deployable drag surfaces can slightly adjust their orbit over time by changing their cross-sectional area relative to the velocity vector. This is too slow for emergency collision avoidance but can help with long-term orbit management.

Passive Compliance: Monitoring + Deorbit Planning

For non-maneuverable CubeSats, the best strategy is:

• Active monitoring throughout the mission (collision screening every 8 hours minimum)
• Low deployment orbit (< 500 km) to ensure natural deorbit within 5 years
• Drag augmentation at end of life to accelerate deorbit
• Coordination with other operators when conjunctions arise

Cost Comparison: CubeSat Monitoring Solutions

For most university teams, the Scout plan at $199/month is the sweet spot — automated screening, email alerts, and a dashboard, without the overhead of maintaining your own infrastructure. Many university programs already spend more than this on ground station maintenance per month.

Real-World Examples: What Close Approaches Look Like

To make this concrete, here are examples from OrbitGuard's February 9, 2026 screening run:

A university CubeSat in a similar orbit would face the same predicament. The difference is that Hubble is continuously monitored by NASA. Is your CubeSat continuously monitored?

Integrating Monitoring into Your Mission Operations

Collision monitoring shouldn't be an afterthought. Build it into your mission operations concept from day one:

Pre-Launch

• Register on Space-Track.org
• Set up your monitoring tool (OrbitGuard or equivalent)
• Write your conjunction response protocol
• Brief the team on collision risk basics — read our complete guide to satellite collision risk assessment

Early Operations (First 30 Days)

• Confirm your NORAD catalog number
• Verify TLE accuracy against your GPS data (if available)
• Run initial full-catalog screening
• Establish baseline — how many conjunctions per day is normal for your orbit?

Routine Operations

• Automated screening every 8 hours minimum
• Review alerts within 4 hours
• Log all conjunction events
• Monthly summary report for your PI/advisor

End of Life

• Continue monitoring until deorbit
• Activate any deorbit mechanisms
• Notify Space-Track when the satellite is no longer operational

The Bigger Picture: Small Satellite Safety in a Crowded Orbit

The small satellite revolution has democratized access to space. University teams that once could only dream of building satellites now routinely deploy CubeSats. But with access comes responsibility.

The NASA Orbital Debris Program Office estimates that the LEO population will continue growing for decades. Every new satellite — including every university CubeSat — adds to the collision risk for everyone. Small satellite safety isn't just about protecting your mission. It's about preserving the orbital environment for future missions.

The tools to do this responsibly are affordable and accessible. OrbitGuard screens the entire active catalog in 5.8 seconds. It's open source. There's no excuse not to monitor.