Why Hardware Teams Need to Care

When spacecraft are launched into orbit, they leave behind the protective blanket of Earth’s atmosphere and magnetic field. The cosmic environment they enter is not empty, but filled with invisible hazards that can quietly cripple the very electronics we depend on to operate satellites and payloads. Radiation in space is relentless and pervasive, striking every surface of a satellite with high-energy particles. For mission designers and hardware teams, these particles represent one of the greatest threats to reliability and performance.

The costs of misunderstanding radiation are not hypothetical. Over the past decades, satellites worth hundreds of millions of dollars have failed prematurely because radiation was underestimated or poorly mitigated. Unlike mechanical failures, which can often be anticipated and tested on the ground, radiation effects are subtle, probabilistic, and only reveal themselves in orbit. That makes it critical for engineers to understand what space radiation is, where it comes from, and how it damages hardware over time.

What Space Radiation Is Made Of

Space radiation refers to a broad spectrum of high-energy charged particles and electromagnetic radiation present beyond Earth’s atmosphere. While “radiation” often brings to mind X-rays or nuclear fallout, the radiation relevant for spacecraft primarily involves subatomic particles traveling at nearly the speed of light. These include:

Protons: The most abundant particles, making up a majority of solar and trapped radiation. Despite their small size, their numbers and energies are sufficient to cause severe electronic disruptions.

Electrons: Lightweight but fast, electrons are highly penetrating and especially problematic in Earth’s radiation belts, where they exist in enormous fluxes.

Heavy Ions: Atoms like carbon, oxygen, or even iron nuclei stripped of electrons. These are less frequent but deposit large amounts of energy in a single strike, making them disproportionately damaging.

Unlike background radiation on Earth, which is attenuated by the atmosphere, these particles arrive in orbit with high energies ranging from a few mega-electron volts (MeV) up to multiple giga-electron volts (GeV). At such energies, they can pass through layers of material, deposit charge inside microelectronics, and even knock atoms out of place in a semiconductor lattice.

Where Space Radiation Comes From

The radiation environment in space is shaped by three dominant sources: galactic cosmic rays, solar particle events, and trapped radiation belts. Each has a different spectrum, intensity, and risk profile.

Galactic Cosmic Rays (GCRs)

Galactic cosmic rays are high-energy particles that originate from outside our solar system, accelerated by supernovae and other astrophysical events. They consist of protons and heavy ions traveling at relativistic speeds. Because of their extremely high energies, they are nearly impossible to shield completely. Adding more material often produces secondary showers of particles inside the spacecraft, complicating mitigation strategies. GCRs are most relevant for deep space missions beyond Earth’s magnetosphere, where there is no geomagnetic protection to deflect them.

Solar Particle Events (SPEs)

During solar flares and coronal mass ejections, the Sun can release intense bursts of high-energy protons and heavy ions. These events are relatively infrequent, varying cyclically with solar activity, but can dramatically increase radiation levels in orbit within hours. A single strong solar storm can deliver doses that exceed years of background exposure. Historically, major solar events have knocked out satellites, damaged power grids, and forced astronauts to shelter inside heavily shielded parts of spacecraft. For missions operating in LEO, MEO, or GEO, SPEs represent an unpredictable but critical design driver.

Trapped Radiation Belts (Van Allen Belts)

Closer to Earth, the magnetic field captures energetic protons and electrons, forming two donut-shaped regions known as the Van Allen belts. These regions are divided into two zones of high intensities: the inner (proton) belt and the outer (electron) belt. Satellites in low Earth orbit frequently cross the South Atlantic Anomaly (SAA), a region where the inner belt dips closer to Earth, subjecting spacecraft to higher fluxes of proton radiation. Satellites in medium Earth orbit, such as navigation constellations like GPS, encounter both trapped proton and electron exposure. In geostationary orbit, trapped electrons dominate and pose long-term degradation risks. These trapped regions are among the most well-characterized radiation environments, but they remain a persistent hazard for long-duration spacecraft.

How Space Radiation Affects Electronics

Radiation affects hardware in ways that are both immediate and cumulative.

Single-event effects (SEEs) occur when an individual particle strikes a sensitive node in a circuit. A single proton or heavy ion can flip a bit in memory (a single-event upset, or SEU), create a temporary short circuit (single-event latchup, or SEL), or destroy a power transistor (single-event burnout, or SEB). These failures happen in nanoseconds but can have outsized consequences, ranging from data corruption to total system loss.

Over longer timescales, cumulative damage builds up as components are exposed to constant flux. Total ionizing dose (TID) refers to the accumulation of free charges generated by ionization due to the energy imparted by radiation as it passes through matter.  Displacement damage (DD) occurs when particles physically knock atoms out of their lattice positions, reducing carrier mobility and degrading detector sensitivity or transistor gain. These forms of damage are insidious: they are not obvious at first, but they can reduce the lifespan of electronics by years if not properly mitigated.

The severity of both immediate and cumulative effects depends on orbit and duration. A CubeSat in LEO might only need to survive a few months and can tolerate occasional SEUs with error-correcting code (ECC). By contrast, a ten-year GEO communications satellite may accumulate tens of kilorads of dose even behind shielding, a level that would destroy unprotected commercial electronics. For missions beyond Earth orbit, where galactic cosmic rays dominate, shielding alone is insufficient and must be paired with architectural redundancy and fault tolerance.

Why Shielding Is Critical

Radiation shielding provides one of the most effective first layers of defense against these effects. By interposing material between the space environment and electronics, engineers can reduce the flux and energy of incoming particles, lowering TID accumulation and suppressing SEU rates.

Aluminum has traditionally served this role, doubling as both structure and shielding. While effective to a point, aluminum is not efficient against high-energy protons and electrons, and its mass quickly becomes prohibitive when additional thickness is added. This has led to the development of alternative strategies. Hydrogen-rich polymers and composites offer improved mass efficiency because hydrogen atoms are especially effective at stopping protons and mitigating secondary particle generation. Advanced composites, like Melagen’s MLC1, can be 3D-printed or applied as conformal coatings, enabling targeted shielding exactly where it is needed most—around processors, memory, or power regulators—rather than around the entire satellite.

Shielding is not a panacea. It must be paired with careful component selection, system-level fault tolerance, and in many cases, architectural redundancy. But without shielding, even the most robust systems are vulnerable to mission-ending failures.

The Engineer’s Perspective

For hardware teams, the practical lesson is that radiation is not simply a physics detail to be handled later—it is a fundamental design driver. The choice of orbit determines which types of radiation dominate. The mission duration sets the cumulative dose budget. The type of electronics used dictates how much shielding and redundancy are required. And the mass budget constrains how much material can be added before launch costs spiral out of control.

Every successful mission balances these factors. Shielding is one lever among many, but it is one of the most tangible and effective tools engineers have. Designing with radiation in mind from the start ensures that satellites do not just launch successfully, but remain functional long after reaching orbit.

Final Take

Space radiation is invisible, but its effects are unavoidable. It originates from galactic cosmic rays, solar events, and Earth’s own trapped belts, and it attacks electronics both instantly and over time. Shielding is one of the most important countermeasures available, especially as the industry increasingly relies on high-performance but vulnerable commercial electronics. For engineers and hardware teams, understanding space radiation is the first step toward building spacecraft that can thrive in the harsh realities of orbit and beyond.