Solar storms and satellite software: a preparedness checklist

Solar storms can disturb satellite operations, satellite navigation and power systems, so software that depends on them needs a plan for degraded service. NOAA publishes scales that describe what to expect at each level. Prepare by finding your dependencies, testing degraded modes and keeping update windows away from known storm periods.

What does NOAA say can happen?

NOAA's Space Weather Prediction Center rates events on three scales, geomagnetic storms (G), solar radiation storms (S) and radio blackouts (R), each from 1 to 5. We make no prediction about when any event will occur. The scales describe effects once one does.

Geomagnetic storms (G).

• Satellites: minor impacts are possible at G1. At G2, operators may need to correct spacecraft orientation, and changes in drag can affect orbit predictions. At G3, surface charging and increased drag on low Earth orbit satellites are likely. At G4, tracking problems join surface charging. At G5, charging, orientation, uplink and downlink, and tracking problems can be extensive.
• Satellite navigation: intermittent at G3, degraded for hours at G4 and for days at G5.
• Power systems: weak grid fluctuations at G1, and at the top of the scale, possible grid collapse or blackouts at G5.

Solar radiation storms (S). From occasional single event upsets in satellites at S2, to satellite noise, memory problems and loss of solar panel efficiency at S3 and S4. At S5 satellites may be rendered useless and permanent solar panel damage is possible.

Radio blackouts (R). Degraded or limited high frequency radio on the sunlit side at the low end, with brief loss of contact, up to a complete sunlit side blackout lasting hours and satellite navigation errors at R5.

Why is this a software question?

Software is where the effects land. A memory upset on a spacecraft is a data integrity event for its flight software. Weak uplink during a severe storm means you may not be able to send a patch when you want to. Degraded navigation signals matter to any system that uses them for position or time.

These are our reading of the NOAA descriptions, not NOAA statements, but they follow directly. If your software assumes the signal is always there, the failure mode is yours to design.

Ground systems are part of this too. NIST IR 8401, published in December 2022, applies the NIST Cybersecurity Framework to the ground segment of space operations, with a focus on command and control of satellite buses and payloads. It notes the space cyber ecosystem is high risk, high cost and hard to access, with interdependent segments. A weather event that already stresses operations is a bad moment to discover your command path has a weak point.

What is the preparedness checklist?

1. Find your dependencies. List every system that uses satellite navigation for position or timing, every service that relies on satellite links, and every vendor that runs on spacecraft.
2. Ask the vendors. What is the documented behavior at degraded service? How do they handle storm periods? Do they publish a bill of materials for flight and ground software?
3. Test degraded modes. Simulate loss or errors from navigation signals and satellite links. Check that systems fail safe and recover cleanly.
4. Plan timing. Do not schedule risky updates or manual commanding for periods when NOAA has issued a storm watch.
5. Patch ahead of time. If a fix must reach a spacecraft, plan for the possibility that uplink is poor when you need it.
6. Secure the command path. Review ground segment access, authentication and logging against NIST IR 8401.
7. Watch the official feeds. Subscribe to NOAA space weather alerts and decide who reacts and how.
8. Rehearse. Run a tabletop exercise on losing positioning or timing for several hours, and for several days.
9. Write the manual fallback. Know how operations continue without the signal.

Where Safeguard fits

For the ground software and services you build, a dependency inventory and reachability analysis show which known flaws sit in code that runs. That keeps your patch queue short, which matters when your update windows are limited. It does not replace spacecraft engineering or space weather forecasting.

Quick check

Sources

• NOAA SWPC, NOAA Space Weather Scales
• NIST IR 8401, Satellite Ground Segment: Applying the Cybersecurity Framework to Satellite Command and Control

Last reviewed: 18 October 2026.