AstroLux — Coping With The Infant Mortality of Satellites Due To Space Radiation
PART A: Analyzing space radiation towards commercial and space grade microelectronics and electrical power subsystems.
Space radiation is the main contributor to early satellite failure, causing 2 in 10 satellites to fail within the first 5 years of their operation. As a result, billions of dollars are lost annually. From improving global internet access, to ongoing governmental communications, the presence of satellites are becoming invaluable. However, current methods of radiation testing for satellite electronic subsystems and microelectronics are becoming costly and impractical. Several satellites launch without adequate radiation protection for their electronic subsystems, leading to 1 in 2 electronic components failing in the space radiation environment, the primary cause for early satellite failure. This article breaks down the impact of space radiation, the status quo for radiation testing, R&D for microelectronics in space, and current stakeholders managing the development of radiation protection.
Table of Contents
— Summary —
— Table of Contents —
— Part 1: The Importance of Satellites In Society —
1A: Services Provided By Satellites
1B: Overview of Early Satellite Failure and Its Consequences
— Part 2: Space Radiation…The Biggest Root Cause —
— Part 3: Breakdown of Space Radiation And Its Impact —
3A: Overview of Geomagnetic Radiation
3B: Overview of Solar Radiation
3C: Overview of Galactic Cosmic Radiation
— Part 4: Current Methods of Radiation Testing —
4A: Particle Accelerators
4B: SPENVIS
4C: Setbacks With Current Radiation Testing Methods
— Part 5: Gap Between Commercial Electronics and Radiation Testing—
— Part 6: Stakeholders In Radiation Protection Development —
— Conclusion —
Part 1: The Importance of Satellites In Society
There is something I mentioned in my previous article that I would like to mention again.
Satellites are the best pair of glasses I’ve ever worn.
They’re the best pair of glasses we’ve all ever worn, and rightfully so. Without satellites, much of the world’s infrastructure would not exist, something many governments and commercial brands aren’t taking for granted.
According to Reuters Impact, Canada plans to invest C$1.01 billion over the next 15 years for satellite technology development. This investment will primarily go to an increase in Earth and climate observations. And just this year, the Pentagon announced they will be investing $5 billion to build a satellite constellation in Low Earth Orbit (LEO).
These are only two examples. Several companies around the world are investing billions to put their satellites in orbit.
In this section, we’ll get into the main services provided by satellites, and how these services are impacted by Early Satellite Failure.
1A: Services Provided By Satellites
The following six applications are the most prevalent among satellite services, and are becoming essentials in society.
- GPS and navigation will become increasingly prominent in the next 10 years, helping us make sense of our environment.
2. Emergency response and disaster relief is becoming more efficient with satellite coordinates. Almost 73% of calls to emergency services are made through a mobile phone, making it easier to access the satellite coordinates!
3. Satellite TV and radio broadcasting have been less frequent in recent years, but have been an essential component to modern communication for decades.
4. Mobile communications with satellite technology is becoming more prevalent among mobile phones and other wireless devices. Rural areas are now getting access to wireless communications due to an increase in satellite technology development.
5. Broadband connection in space goes hand in hand with an increase in ML and AI models. Satellites make a massive contribution to edge computing, Internet of Things, and data warehousing.
6. Remote sensing and imaging is becoming a prominent foundation for all things space tech, and is even making strides on Earth too! Due to the rise of remote sensing, we’re able to conduct observations oceanography, geology, and weather in ways we couldn’t before.
1B: Overview of Early Satellite Failure
Due to space radiation, 2 in 10 satellites fail within the first 5 years of operation. The primary weakness a majority of these satellites carry is a lack of radiation protection solutions for satellite microelectronics. As a result, 1 in 2 microelectronics fail within the first 5 years of operation.
A more recent example of this is the failure of Imarsat — 6 F2 due to an unprecedented anomaly. The anomaly occurred due to radiation entering the electrical power subsystem of the satellite.
Imarsat — 6 F2, at the time of its launch, was claimed to be the most advanced commercial satellite ever launched. Now, its ranking lies among the many satellites that failed within the first year of operation. Due to Imarsat — 6 F2 experiencing total failure, Imarsat is expected to see a $350 million insurance claim.
Another recent example is SpaceX’s Starlink satellites. Just last year, SpaceX launched 49 Starlink satellites. A day after launch, 40 of the 49 satellites were wiped out due to a geomagnetic storm.
SpaceX did not expect this storm, and backup plans for putting their satellites into “safe mode” failed, causing all 40 failed satellites to burn in Earth’s atmosphere.
SpaceX saw a loss between $50–100 million.
The reason these examples are notable is because they are from the largest satellite brands on the market. Satellites that are claimed to be “the most advanced” can fail within the first few days or months after their launch.
Now imagine small or medium sized companies, without as many resources. 41% of all satellites in this cohort experience early satellite failure due to space radiation.
Satellite companies just getting off the ground experience more satellite failure than larger brands.
In the following section, we’ll be discussing root causes for early satellite failure, and why space radiation is the main contributor.
Part 2: Space Radiation…The Biggest Root Cause
When I was first researching early satellite failure, I came across three root causes.
- Satellite collisions: Orbital debris and intersections in satellite trajectory can lead to collisions among satellite constellations or satellites within the same orbit.
- Space radiation: Radiation against satellite subsystems, mainly electronics, can lead to satellite anomalies and failure.
- Atmospheric drag: Collisions with gas molecules can reduce the speed and altitude of the satellites orbit.
The more I researched, I realized satellite collisions and atmospheric drag are often byproducts of geomagnetic storms, a form of space radiation. They also don’t have as much of an impact compared to space radiation on microelectronics.
Solar flares, specifically those at the M-Class level (impacting orbital architecture), are directly correlated to an increase in satellite collisions and atmospheric drag.
Due to an increase in electrons among higher orbits, lower density gas particles get excited and move upwards. As a result, higher density gas particles from lower orbits replace the low density particles. Satellites have to fly through these high density areas, causing an increase in atmospheric drag.
The higher density particles can also impact the visibility of the satellite from Earth, making it more difficult to maneuver the satellite to safety. This is what can lead to an increase in satellite collisions, as the satellite’s orbit becomes uncontrollable.
One of the reasons atmospheric drag and satellite collisions have not been solved is a lack of data on the true root cause of a satellite’s failure.
The reason for this is how the radiation impact on satellite electronics during this time cause degradation on the satellite’s sensors and other electronics components. This makes it difficult to collect data on what the cause of failure is.
By increasing the radiation tolerance of microelectronics and other electrical subsystems, we would be able to observe satellite data during radiation events, making it easier to solve all three weak points leading to early satellite failure.
Part 3: Breakdown of Space Radiation And Its Impact
3A: Impact of Geomagnetic Radiation
Geomagnetic radiation occurs when high energy particles interact with Earth’s geomagnetic field. Therefore, geomagnetic radiation events are observed primarily in LEO, and impact satellite constellations.
The two main events that occur due to geomagnetic radiation are ionospheric storms and geomagnetically induced storms.
- Ionospheric Storms
Ionospheric storms have a 1 day duration and occur once every 27.3 days. Usually, their negative side effects lead to scintillations in satellite communications and navigation. Amplitude scintillation events are rapid fluctuations in radio frequency signals, and specifically impact Global Navigation Satellite Systems. Though significant, these scintillation events only occur during 1% of the total 1 day duration.
12.4% of the time, phase scintillation events occur, which are fluctuations in carrier phase measurement. Carrier phase measurement is the measurement in distance between a satellite and its receiver on Earth. These measurements are crucial to knowing a satellite’s location and managing its orbit.
2. Geomagnetically Induced Currents
Geomagnetically induced currents occur a continuous 360 days out of 11 years. Though not frequent, in the one year they occur, they can cause massive damages. These currents impact larger satellites which plan on staying in LEO long term.
When looking at electrical subsystems on satellites, geomagnetically induced storms can lead to overheating, resonance, voltage distortion, and overall equipment malfunction.
But it’s not just satellites that are impacted here. Even electric grids on Earth are impacted by geomagnetic storms. In 1989, a geomagnetically induced storm caused the Hydro-Quebec electric grid to shut down, leading to 5 million people living without power.
If radiation protection was accessible for space and Earth subsystems, we could prevent severe power outages such as these in the future.
3B: Impact of Solar Radiation
Solar radiation is radiation that comes from the Sun. Often, this will be in the form of solar flares, proton storms, coronal mass ejections, and sunspots. This type of radiation has equal impact on LEO and geosynchronous orbit (GEO)
- Solar Flares
Solar flares have different “moods”, if you will. When at solar minimum, solar flares are harmless and only occur a few times per month. However, solar maximum can lead to failure of transformers on satellites, and even failure of the electric grid on Earth!
During solar maximum, solar flares will occur frequently everyday, increasing the chances of electronics being impacted.
Solar flares also lead to collisions and atmospheric drag, particularly for satellites in LEO. This is due to causes explained in Part 2.
2. Coronal Mass Ejections
Coronal mass ejections are very similar to solar flares. The only differences are that they occur hundreds of times annually, and have an impact equivalent to solar flares in solar maximum.
Like solar flares, coronal mass ejections lead to collisions and atmospheric drag. In the most extreme cases, they can cause satellites to reenter Earth orbit and burn in the atmosphere.
If we look at SpaceX’s Starlink launch failure (see 1B), a coronal mass ejection occurred. This led to a geomagnetically induced storm, which caused 40 satellites to reenter Earth’s atmosphere.
3. Proton Storms
Proton storms are one of the worst possible forms of solar radiation, simply because of how frequently they occur.
At their minimum, proton storms occur once a week, and at their maximum, they can occur up to a few times per day. Heavy protons directly penetrate electrical subsystems, and while they don’t cause immediate failure, electrical subsystems are guaranteed to go through gradual degradation (note: the level of degradation has yet to be determined).
3C: Impact of Galactic Cosmic Radiation
Galactic cosmic radiation is radiation coming from outside the solar system, typically caused by highly energetic events (i.e. a supernova). Though primarily having an impact on satellites in GEO, there is occasional impact on satellites in LEO as well.
Storms from galactic cosmic radiation are often placed in a single category. Their primary impact being Single Event Effects.
Single Event Effects can break an entire electrical subsystem in a matter of seconds. They can cause navigation errors, communication errors, and total loss of satellite data.
Due to mostly impacting GEO, Galactic Cosmic Radiation is a concern primarily for military, weather and other telecommunication satellites. A single one of these satellites costs up to $500 million to construct, and is essential to our daily lives.
Without protection from Galactic Cosmic Radiation, political and environmental systems could literally fall apart in a matter of days.
In the following section, we will discuss the current methods of radiation protection and testing to address these effects, including why these methods aren’t working.
Part 4: Current Methods of Radiation Testing
4A: Particle Accelerators
Particle accelerators are used to emit highly energetic beams of protons, neutrons, electrons, ions, and other subatomic particles. Most particle accelerators can range anywhere between 1–30 km in length. A notable particle accelerator would be The FAIR Facility, which is 3.5 km long and 20 meters deep.
Most particle accelerators work by emulating particles or ions at a speed resembling cosmic radiation particles. However, the majority of accelerators can only afford to test for 1–2 heavy ions, discounting the thousands of high energy particles a satellite will encounter.
These particles need to be in a wide variety, which facilities such as FAIR plan to simplify by simulating the full GCR spectrum through iron (Fe) ions.
Before coming in contact with the materials being tested, Fe ions will flow through these filters with very intricate patterns. This allows properties such as thickness, composition, and geometry to change.
The filters themselves are produced through Monte-Carlo simulations, which is producing different patterns at random. These simulations are then characterized by the output they produce, and recalculated accordingly.
Python and FreeCAD V0.17 were implemented to convert optimized weights (modulations) into a 3D CAD-based model.
The thickness, compositions, geometry, and charge of the Fe ions could rapidly change in under two minutes. Meaning that it’s possible to create an accurate simulation of GCR waves using only one type of ion. However, this method has been in the R&D phase for almost a decade and will likely be very costly when it comes to the market.
4B: SPENVIS
SPENVIS is a software where users can output predictions on a radiation environment, or impacts a radiation environment can have on space systems.
The software primarily operates on the ESPIRE and DICTAT program suites, which were developed by the European Space Agency (ESA) and the NASA Charging Analyzer Program (NASCAP) respectively.
ESPIRE’s goal is to assess the radiation environments in LEO, including the suitability of electrical subsystems in these environments. This is done through the following model packages.
- LEOPOLD: Parameters characterizing the LEO environment.
- SOLARC: Gives an idea of the collection and power losses experiences by a solar array in LEO.
- EQUIBOT: Evaluating the level of surface charging experienced by a spacecraft.
There are more packages, but all of them are level 3 in the ESPIRE program. Level 3 is considered computationally complex to run, and has been used by no company so far.
DICTAT’s goal is to deal with internal dielectric charging, which would include surface charging on electronics.
It blows my mind that as a high school student, I’m able to work with a program this advanced for free!
However, what blows my mind even more is how this tool existed since the early 2000s, but satellites are still failing due to space radiation.
Why hasn’t this problem been solved yet, despite all the advanced tools out there today?
In 4C, we’ll go into the financial and technical gaps of current solutions, and why these gaps exist.
4C: Setbacks With Current Radiation Testing Methods
Particle accelerators have three main gaps for commercial companies and startups.
- Accessibility of current solutions is very low, which prevents companies from testing their electronics.
- The computational power required to simulate ions is high and hard to produce.
- The accuracy of particle accelerators is low, because the simulations are too simple.
On average, particle accelerators cost anywhere between $800–5000/hour. A single electronic component (i.e. a MOSFET) would need to be tested for a few days or weeks before getting a tangible result. If the goal is to test all electronic subsystems in a satellite, the testing process often piles up to years or even decades.
Not to mention the millions of dollars that would be poured into testing. What’s worse is how particle accelerators often have long lead times, deprioritizing commercial companies and startups.
Testing can be faster, but this would be at a minimum of $5000/hour, making the option of faster testing even more expensive than regular options on the market.
SPENVIS, as good as it is, also has several setbacks.
- SPENVIS makes no calculation towards the electronic structure of components, and only focuses on the materials science aspect. As a result, several false positives occur through the software, which leads to continuous failure rates.
- Companies have to input in-depth data on the materials and dielectric properties. However, this data isn’t always available, leading to minimal results.
Both methods lead to false positives. Particle accelerators, for a lack of heavy ions, and SPENVIS, for not considering electronic structure.
In the next section, we’ll look at the industry level shift from space grade electronics to commercial electronics. Specifically, we’ll look at the need for testing methods that can work for commercial electronics, and how this gap is the main contributor to the overall problem.
Part 5: Gap Between Commercial Electronics and Radiation Testing
Right now, there’s an industry level shift from space-grade electronics to commercial electronics.
A little bit about each…
Space-grade electronics: Electronics made to be in space for a specific purpose.
Commercial electronics: Electronics used on Earth.
The reason the industry wants to make a switch from space-grade to commercial is because of both computational power and speed.
Space grade electronics take a long time to develop. As a result, the electronics are quite outdated. By using commercial electronics, satellites can stay up-to-date with the latest tech, allowing for better integration of different software or code.
Companies such as SpaceX, Immarsat, and OneWeb have already made the transition from space-grade to commercial. However, this also means that their satellite failure rates have skyrocketed.
The problem is how current radiation testing methods are made for space-grade electronics. They’re not made to introduce a pre-built electronic component and assess its suitability.
With SPENVIS, the entire point is to assess electronic materials, rather than electronic structure. As a result, SPENVIS cannot account for changes in electronic structure with time. Even if two electronic components have a completely different structure, they are evaluated the same way if they are made of the same material.
Particle accelerators cannot provide accurate results. They’re also too expensive for companies, commercial electronics or not.
If we look at Moore’s Law, technology is evolving at a rapid pace, and satellite companies feel the need to keep up. Gradual changes in electronic structure through Moore’s Law are hard to keep track of, and it’s hard to tell if a component will react to radiation just as its predecessor did.
The gap between commercial electronics and radiation testing is not testing for an electronic’s structure, and how these structures can evolve with time.
Part 6: Stakeholders In Radiation Testing and Protection of Electronic Subsystems
There are three stakeholders in radiation testing and protection for electronics.
- Aerospace companies launching or maintaining satellites.
- Suppliers for commercial electronics.
- Consumers accessing satellite services.
From the perspective of aerospace companies, radiation costs ~$1000/hour on average.
Being that electronics are tested for 10–20 years, this amounts to ~$90 million for a single electronic design, making space grade electronics undesirable.
Brands supplying commercial electronics find it challenging to meet the demands of aerospace companies. These brands are also afraid of being held liable, as 1 in 2 of the electronics they supply normally fail.
Currently, satellite services are more expensive to consumers compared to methods on Earth. This is highly attributed to the costs of radiation testing and protection development. If these costs could be reduced, satellite services would be more desirable for consumers.
Conclusion
Satellite services are essential for humanity in day to day life, but they’re not being used to their full potential. 2 in 10 satellites will fail due to radiation on electronics, and this number increases with the adoption of commercial electronics. This article highlights a variety of radiation impacts, showing how electronics launched must be built to withstand the predicted risks. Making the transition from space grade to commercial electronics requires new radiation testing methods. Specifically, methods are needed which assess electronic structure in radiation environments across Earth orbit.
If radiation testing for electronic structure is improved, testing for commercial electronics would yield greater accuracy, and show a decrease in early satellite failure.
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