By Aditya Ghanekar
Author Note
The monetary calculations done in this paper for fuel and materials are based on average prices of 2024-2025 and may be inaccurate in the future.
Abstract
This paper aims to talk about different ways to protect satellites from outer space radiation, mainly Coronal Mass Ejections (CME). It talks about what CMEs are and how they damage satellites. Different ways to deal with such kind of SPE are discussed in brief detail like Active shielding, Passive shielding, Radiation hardening and Redundancy. Passive shielding is focused on in this paper and comparison of different materials is done with different factors such as Cost, Shielding capability and Effectiveness.
Comparative Study Between Different Solar Radiation Shielding Materials Computers are the greatest innovation of the 21st century. They enable us to do many things earlier considered close to impossible by processing massive amounts of data with great precision and efficiency. One field that is heavily reliant on this is space applications. By simply sending computers in orbit around the earth in the form of satellites, we manage to achieve a number of feats. This includes but is not limited to: Telecommunications, outer space observation, Meteorology.
Nevertheless, regardless of how advanced or magical computers may appear, they remain highly delicate against harsh radiation received in outer space without the protection provided by earth’s atmosphere – in fact, the ionosphere further damages the circuits by bombarding it with hordes of electrons. There are mainly three different types of radiations that are damage inducing to satellite circuitry with the major ones being: Galactic Cosmic Rays (GCR), Coronal Mass Ejection (CME), and Solar Flares. In this paper, we will focus on protection against Coronal Mass Ejection as it poses more frequent threats to satellites as compared to the other two.
Coronal Mass Ejections are huge ejections of plasma from the sun’s corona with the help of a strong magnetic field, which consist of charged particles like protons, electrons, and other ionized heavy nuclei (Dobrijevic, 2022). It is speculated that they are formed by explosive reconfigurations of solar magnetic fields through the process of magnetic reconnection according to Moldwin and Mark (2025). As a CME’s propagation speed is dependent on many factors but not limited to solar wind, magnetic field at the time of the event; Their speed is highly unpredictable ranging from 250 kilometers per second (km/s) to 3000 km/s with times ranging from under 18 hours to over several days (Coronal Mass Ejections | NOAA / NWS Space Weather Prediction Center, n.d.). They share the same composition with solar wind but in much higher density compared to the same while also carrying magnetic fields of its own.
When CMEs impact Earth, they temporarily deform the magnetosphere which induces huge electrical ground currents in Earth and also induces magnetic reconnection in the magnetotail (Omatola & Okeme, 2012) which causes electrically charged particles like protons and electrons to be stripped off from the Earth’s geomagnetic field causing a sudden increase in density of charged particles near earth causing a Geomagnetic storm. Therefore, a circuit in space is exposed to both direct CME exposure and Proton-electron radiation as they mostly orbit in the geomagnetic field. According to Emmanuel E (2023), “These storms can damage satellites by destroying the sensitive equipment needed for them to function, degrading the solar panel that provide them with power, and even altering their orbits”. More specifically, it ionizes the material that the satellite is made of and cause degradation by displacement damage, and the buildup of electrons on the circuit can cause Electrostatic Discharge which overcharges the transistors and capacitors, resulting in short-circuit induced damage which poses a threat to the satellite’s functionality. When a satellite is damaged by a CME, functionality is not the only thing that is lost; valuable data, tons of expensive fuel, years of challenging work, millions of dollars for the building of rocket and satellite, research that could have changed the world; very important assets are lost.
As CME’s are a highly inconsistent phenomenon, we will use a standard historically relevant CME for all our calculations. It will be the September 1859 Carrington Solar Particle Event (SPE) with the data from NASA’s On-Line Tool for the Assessment of Radiation in Space (OLTARIS). We will also be using OLTARIS for our calculations in this paper.
Review of Literature
Passive Shielding
Passive shielding consists of protection from radiation with the help of radiation absorbing materials that act as a dispensable wall between the electronics and the surroundings. Most cases use this method as it is cost effective and does not consume any additional energy. Hydrogen provides the most shielding from cosmic radiation as it has only one electron in it, resulting to have the highest charge to mass ratio of any element which is essential to deflect proton radiation, but hydrogen by itself is not used as it is a gas and is highly combustible, posing another risk to the spacecraft.
Simonsen et al. (1991) uses water shielding for human lunar missions. Water contains 2/3rd parts hydrogen in it, so it is very ideal for shielding from ionizing radiation, but it is very difficult to transport and use as a shield as it is a liquid and provides no structural integrity. There are also studies being done that use organic material as a protection against radiation. Organic materials also contain a lot of Hydrogen and can be constructed in many ways catering to specific use-cases. For example, Single-walled Carbon nanotubes could be used for radiation shielding as they are a high tolerance material that is structurally sound and is also able to withstand extreme environments (Karthik & Shirvram, 2008). According to Karthik and Shirvram (2008), Carbon Nanotubes can withstand up to 300MeV in proton radiation.
Thibeault et al. (2015) also supports the claim that Hydrocarbons are a very effective tool for stopping radiation. We can also layer different materials on top of each other to get optimal radiation insulation. L. Varga and E. Horvath (2003) show the different variations of materialistic arrangements using Aluminum, PEEK carbon honeycomb, PEEK and Tantalum and effects of those arrangements on shielding and weight.
Active Shielding
Active Shielding is a type of shielding where magnetic fields are produced and used to deflect protons. This type of shielding is compact and can be adjusted in accordance with the SPE the spacecraft will face. Different methods can be used to generate the required electrical field. French (1970) used the plasma radiation shielding method. It is a shield which magnetically pulls electrons to the outer layer and makes the inner wall positively charged, this makes it into a capacitor structure and the positively charged ions that head towards it (solar flares) will get repelled or deflected, if they pass through, the energy that gets through will be Energy(flare)- Energy(capacitor).
Cocks and Watkins (1993) used Deployed high temperature super conducting coils (DTHSC) to produce large volume, low-intensity magnetic fields to produce shielding of manned spacecraft against solar flare protons which uses high temperature super conductors to produce the magnetic field instead of using electric and plasma shielding. Active shielding is ideal for manned missions where the safety of the astronauts holds more priority over energy consumption. This is not usually used in satellites because it has a relatively huge energy consumption and will reduce the runtime of the satellite making it approach its end-of-life much sooner than without active shielding.
Radiation Hardened Electronics & Redundancy
In addition to installing radiation shields outside to protect the spacecraft, we may also individually radiation harden the electronic circuits as an aid to further prevent failure of instruments. Radiation hardening is constructing the semiconductors with radiation insulated materials and using different functionality that rely more on reliability rather than latency. The electronic components go through extensive testing in order to ensure proper radiation hardening. This, in addition with low demand makes the electronics lag behind compared to their normal counterparts (Heyman, 2024). They are also very expensive and difficult to design optimally (Fettes, 2024b).
Another method to preserve functionality is redundancy where there are multiple parts performing the same function so that when one part is damaged by radiation, another part can take over. According to Chang (2025) “Redundancy is particularly vital as NASA estimates that a significant portion of spacecraft failures, around 80%, stem from power system anomalies”. But addition of back-up redundancy items and circuits increase the weight and make the circuitry more complex which has a very incremental effect on both the cost and time required to produce the satellite carefully.
Therefore, redundancy is only practical when an item is readily available and not too costly or heavy (Lisk, 2003).
Study pre-requisites/Methodology
The following materials shown in Table 1 arranged by Name, Density and Formula were cross compared in this paper:
To account for the radiation hardening and separate shielding inside the satellite for different components, we used a 1mm Aluminum layer as the base protection in every case. As in a real world scenario, there are multiple layers being used together to shield from radiation, we used 4mm maximum thickness of the desired materials.
The February 1956 Webber SPE with the corresponding differential formula was chosen as the environment in OLTARIS (Singleterry et al., 2010).
The SPE was assumed to occur at 1 AU in free space and had 100 MV rigidity. Different slabs of above materials were created and were put through the simulation on top of the base 1mm aluminum slab. The graphs of Dose vs Depth were obtained from OLTARIS. Whereas costs as well as weights were obtained separately.
Control Satellite
Most scientific satellites and many weather satellites are in a nearly circular, low Earth orbit so Low Earth Orbit satellites will be used as the reference model in this paper. The height of the satellite is around 800 km from the surface of the Earth. The dimensions will be 2x3x2(m). Considering the Base aluminum of thickness 1mm and density 2.7g/cm3, the weight of the shielding comes out to be 0.864 kg.
According to an average of 2023-2025 rates $1.5 is the cost of aluminum per kg. $2.16 is the production cost to buy Aluminum and the average cost of launch per kilogram of payload is around $18,000 for small and medium launches (CSIS Aerospace Security Project (2022) – with minor processing by Our World in Data). Therefore, the total cost to launch the shielding is estimated to be around $15,552.
The calculated dose received by the electronics vs depth is shown in Figure 1 below:
Figure 1
It is observed that 2.511752×10^5 mGy is absorbed and 9.7948×10^3 mGy dose is received by the electronics.
Single Elemental Shielding
Aluminum
Aluminum is the most commonly used material in satellites because it also provides great cost efficiency by being abundant in nature and having a high strength to weight ratio ensuring lightweight bodies and structural integrity.
3 mm aluminum shield weighs 2.592 kg with the total structure weighing 3.11 kg. Using
the same statistics as earlier, the production cost is $4.66, and the launch cost is $55,987.2. After adding the base cost, the total cost comes out to be $71,543.86
Figure 2 shows the Dose vs Depth obtained from OLTARIS for 3mm Aluminum+1mm base:
Figure 2
It is observed that 2.578905×10^5 mGy dose is absorbed and 3.0795×10^3 mGy dose is received on the electronics. An off the shelf electronic circuit can typically take 1×104 mGy before starting to malfunction and may have significant loss in function by 5×105 mGy. So, the electronics get 30.795% dose of their maximum dosage limit. It is also noticed that the base aluminum slab does not reduce the radiation further by the same rate. This tells us about the nature of radiation absorption. There may be two possible theories for this. One says that the secondary radiation emitted might not be absorbed by aluminum properly and might pass through it unaffected.
Another theory suggests that materials may block high energy dose and low energy dose at different rates with the high energy ones being blocked more.
Tantalum
Tantalum is an almost chemically inert metal which has high strength and high melting point. It shares similarities with tungsten in shielding capabilities according to Adlienė et al. (2020) and is less dense and lighter than tungsten with its density at 16.69 g/cm3. It also has corrosion resistance. However, it is expensive with prices of $330.31 per kilogram! Hence, it is usually used as a coating for radiation shields.
3 mm Tantalum shield weighs 16.02 kg with the total structure weighing 16.8864 kg. The production cost is $5,292.35, and the launch cost is $288,403.2. After adding the base cost, the total cost comes out to be $293,695.55
Figure 3 shows the Dose vs Depth obtained from OLTARIS for 3mm Tantalum + 1mm base. It is observed that 2.6 × 10^5 mGy dose is absorbed and 9.3332×10^2 mGy dose is received on the electronics. The electronics get 9.333% of their maximum dosage in this configuration.
Figure 3
Titanium
Titanium, like Aluminum has a high strength-to-weight ratio especially at low temperatures. It is a durable material as it is highly resistant to corrosion and its properties do not vary significantly over changes in temperature. Titanium also has a low density which makes it a cost friendly material to use for space applications.
3 mm Titanium shield weighs 4.32 kg with the total structure weighing 5.184 kg. The production cost is $129.6, and the launch cost is $77,760. After adding the base cost, the total cost comes out to be $93,312.
It is observed that 2.58675 × 10^5 mGy dose is absorbed and 2.285×10^3 mGy dose is Figure 4 shows the Dose vs Depth obtained from OLTARIS for 3mm Titanium + 1mm received on the electronics. The electronics get 22.85% of their maximum dosage in this configuration.
Figure 4
Compound Shielding & Hydrocarbons
Carbon Nanotubes
Carbon nanotubes (CNT) are small tubes constructed out of graphene. Carbon nanotubes are very strong structurally and have tolerance for heat and large quantities of radiation. They can also act as a vessel to store hydrogen to further protect from radiation. We will use a specific type of CNT called as Single Walled NanoTube (SWNT) as suggested by Karthik & Shirvram (2008) to be the most effective variant to stop radiation. However, Carbon nanotubes are very hard to produce in large quantities effectively without breaking up so it is very expensive with around $600 per kg for a decent multiwalled carbon nanotube! It is in essence — sheets of graphene on top of each other. So, we have assumed the material to be graphene layered on top till it reaches 3mm thickness.
3 mm Graphene shield weighs 1.296 kg with the total structure weighing 2.16 kg. The production cost is $648, and the launch cost is $23,328. After adding the base cost, the total cost comes out to be $38,880.
Figure 5 shows the Dose vs Depth obtained from OLTARIS for 3mm SWNT + 1mm base. It is observed that 2.578815× 10^5 mGy dose is absorbed and 3.0785×10^3 mGy dose is received on the electronics. The electronics get 30.785% of their maximum dosage in this configuration, which is a very surprising result as it is only 0.1% better than base configuration
for SPE radiation.
Figure 5
Polyethylene
Polyethylene based compositions are very common since they have the highest concentration of hydrogen nuclei per cm3. But Polyethylene is unstable above 150-200°C and unstable above 70°C when in contact with a metal (Rojdev et al., 2009).
3 mm Polyethylene shield weighs 0.96 kg with the total structure weighing 1.824 kg. The cost comes out to be $32,832. The production cost is $123.84, and the launch cost is $17,280.
Figure 6 shows the Dose vs Depth obtained from OLTARIS for 3mm Polyethylene + 1mm base. It is observed that 2.564127 × 10^5 mGy dose is absorbed and 4.5473×10^3 mGy dose is received on the electronics. The electronics get 45.473% of their maximum dosage in this configuration.
Figure 6
Kevlar
Kevlar is lightweight and strong, able to withstand extreme temperatures and has high tensile strength. It also has excellent ballistic properties, making it so that it can also protect the satellite from space debris. It is a very common material to be used for space applications. For instance, it is widely used in the ISS.
It is a very common material to be used for space applications. 3 mm Kevlar shield weighs 1.3824 kg with the total structure weighing 2.2464 kg. The production cost is $467.85, and the launch cost is $24883.2. After adding the base cost, the total cost comes out to be $40435.2.
Figure 7 shows the Dose vs Depth obtained from OLTARIS for 3mm Kevlar + 1mm base.
Figure 7
It is observed that 2.56982× 10^5 mGy dose is absorbed and 3.9780×10^3 mGy dose is received on the electronics. The electronics get 39.78% of their maximum dosage in this configuration.
Lithium Hydride
Lithium hydride, is a great radiation shielding compound because it consists of 50% hydrogen that can deflect neutron radiation with good efficiency. It is also the lightest material on this list so it’s a very useful material for radiation protection and is often used.
3 mm Lithium hydride shield weighs 0.7872 kg or 787.2 grams with the total structure weighing only 1.6512 kg! The production cost is $1023.36, and the launch cost is $14,169.6. After adding the base cost, the total cost comes out to be $29,721.6.
Figure 6 shows the Dose vs Depth obtained from OLTARIS for 3mm Lithium hydride + 1mm
base.
Figure 8
It is observed that 2.557522 × 10^5 mGy dose is absorbed and 5.2078×10^3 mGy dose is received on the electronics. The electronics receive 52.078% of their maximum dosage in this configuration.
Graphical Overview
Figure 9: The farther up and left the material is the better
If we look purely at the shielding aspect and ignore the cost Elemental materials outrank Compound materials. Tantalum performs the best. It is followed by titanium which is followed by CNT and Aluminum which are at the same Dosage absorbtion with Aluminum being better by only 19 mGy. Which is then followed by Kevlar, Polyethylene and lastly, Lithium hydride.
However, in terms of cost, Compound Materials are cheaper than Elemental materials and are all in similar prices with the ranking being Lithium hydride followed by Polyethylene followed by CNT and finally kevlar. Meanwhile Elemental materials are very expensive with each being marginally more expensive compared to the last where Aluminum is the cheapest but still more expensive than all compound materials, followed by Titanium; after which, by a huge margin, Tantalum is the most expensive material.
To better compare both the cost and shielding properties, we can compare the effectiveness of the materials.
Figure 10: The higher the better
Observing Figure 10, it is determined that Lithium Hydride with efficiency of 8.6 is the most efficient in terms of absorption to cost ratio followed by polyethylene with efficiency of 7.81. Kevlar with 6.33 and Carbon Nanotubes with 6.63 come next with almost equal effectiveness where CNT ranks just a bit higher. It is followed by aluminum with 3.6, Titanium with 2.77 and finally Tantalum being the least efficient with a 0.83 efficiency.
Rebuttal/Counter-argument
It can be argued that other methods of protecting satellite from radiation should be used instead of passive shielding to save the weight of the satellite and ultimately — fuel. The other methods include but are not limited to: Active shielding, Radiation hardening and redundancy. Active shielding provides much better protection from radiation as it generates its own magnetic field to deflect the CME as opposed to taking it head on. However, it consumes a lot of energy and it should be used for manned missions or missions with a really short operating time. It is not recommended for satellites as it will reduce the duration of the mission significantly. Radiation hardening is the making of electronic components by using special techniques which are much more resistant to radiation than normal ones. However, this method is very slow and hard to do and thus radiation hardened electronics are often very behind on technological advancements.
Redundancy is creating extra components which perform the same function as backups in the satellite. This makes it so that when one component is damaged, the other one can take over. I actually support using this as fail safes are very important in any system. However, there is the disadvantage of added weight which can increase the cost of the satellite and complex circuitry required for redundancy.
Conclusion
From this study, we can conclude that Compound materials are the cheapest and the most efficient but if we have enough budget, we can settle for elemental materials as they are much better at shielding radiation. There is also an interesting observation that the first layer of the shield blocks majority of the radiation, and then the layers after it, no matter what they are or how much radiation is imminent, don’t block the dose that effectively. We can see this in the slope of the figures. Here is another instance of the same effect happening with 3 layers in Figure 11:
Figure 11
is that one type of radiation is being converted into another. For example, proton radiation when Further research can be done on this effect and how to avoid it. I believe the reason for this effect interacting with materials gets converted into electron radiation. Each radiation needs a different type of material to shield it. Therefore, in conclusion, we should use all types of radiation shielding techniques like active shielding, redundancy, radiation hardening, etc. to achieve maximum protection of electronics and not lie on one method and if we do use passive shielding, we should put the best material towards the outside.
Sources
Dobrijevic, D. (2022, June 24). Coronal mass ejections: What are they and how do they form? Space.com. https://www.space.com/coronal-mass-ejections-cme
Moldwin, & Mark. (2025, March 14). Coronal mass ejection (CME) | Definition & Effects. Encyclopedia Britannica. https://www.britannica.com/science/coronal-mass-ejection
Coronal mass ejections | NOAA / NWS Space Weather Prediction Center. (n.d.). https://www.swpc.noaa.gov/phenomena/coronal-mass-ejections
Omatola, & Okeme. (2012). Impacts of solar storms on energy and communications technologies. Archives of Applied Science Research, 4(4), 1825–1832.
https://www.scholarsresearchlibrary.com/articles/impacts-of-solar-storms-on-energy-and communications-technologies.pdf
Mayaka, Emmanuel E. (2023, July). Solar Storms and Their Effect on Man-made Satellites. University of Nairobi, I56/37253/2020. University of Nairobi Digital Repository. http://erepository.uonbi.ac.ke/handle/11295/164421
Simonsen, L. C., Nealy, J. E., Sauer, H. H., & Townsend, L. W. (1991). Solar flare protection for manned lunar missions: Analysis of the October 1989 proton flare event. SAE Technical Papers on CD-ROM/SAE Technical Paper Series. https://doi.org/10.4271/911351
K., & Shirvram, B. (2008). Protection of Communication System From Solar Flares. 22nd Annual AIAA/USUConference on Small Satellites.
https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1419&context=smallsat
Varga, L., & Horvath, E. (2003). Evaluation of electronics shielding in micro-satellites. Defence R&D Canada-Ottawa. https://cradpdf.drdc-rddc.gc.ca/PDFS/unc06/p519025.pdf
Thibeault, S. A., Kang, J. H., Sauti, G., Park, C., Fay, C. C., & King, G. C. (2015). Nanomaterials for radiation shielding. MRS Bulletin, 40(10), 836–841.
doi:10.1557/mrs.2015.225
French, F. W. (1970). Solar flare radiation protection requirements for passive and activeshields. Journal of Spacecraft and Rockets, 7(7), 794–800. https://doi.org/10.2514/3.30043
Cocks, F. H., & Watkins, S. (1993). Magnetic shielding of interplanetary spacecraft against solar flare radiation. NASA Technical Reports Server (NTRS).
https://ntrs.nasa.gov/citations/19940019861
Heyman, K. (2024, September 17). SRAM scaling issues, and what comes next. Semiconductor Engineering. https://semiengineering.com/sram-scaling-issues-and-what-comes-next/
Fettes, J. (2024b, August 15). Radiation Protection for Space - Space Technology Future Science Platform. Space Technology Future Science Platform.
https://research.csiro.au/space/radiation-protection-for-space/
Chang, E. (2025, February 4). Redundancy and reliability in satellite systems -TelecomWorld101.com. TelecomWorld101.com.
https://telecomworld101.com/redundancy-satellite-systems/
Lisk, R. (2003). NASA preferred reliability-practices for design and test. NASA, 7–11. https://doi.org/10.1109/arms.1992.187793
Singleterry, R. C., Blattnig, S. R., Clowdsley, M. S., Qualls, G. D., Sandridge, C. A., Simonsen, L. C., Slaba, T. C., Walker, S. A., Badavi, F. F., Spangler, J. L., Aumann, A. R., Zapp, E. N., Rutledge, R. D., Lee, K. T., Norman, R. B., & Norbury, J. W. (2010). OLTARIS: On line tool for the assessment of radiation in space. Acta Astronautica, 68(7–8), 1086–1097. https://doi.org/10.1016/j.actaastro.2010.09.022
CSIS Aerospace Security Project (2022) – with minor processing by Our World in Data. “Cost of space launches to low Earth orbit” [dataset]. CSIS Aerospace Security Project, “Cost of space launches” [original data]. Retrieved April 9, 2025 from
https://ourworldindata.org/grapher/cost-space-launches-low-earth-orbit
Adlienė, D., Gilys, L., & Griškonis, E. (2020). Development and characterization of new tungsten and tantalum containing composites for radiation shielding in medicine. Nuclear Instruments and Methods in Physics Research Section B Beam Interactions With Materials and Atoms, 467, 21–26. https://doi.org/10.1016/j.nimb.2020.01.027
Rojdev, K., Atwell, W., Wilkins, R., Gersey, B., & Badavi, F. F. (2009). Evaluation of Multi Functional materials for deep space radiation shielding. National Space & Missile Materials Symposium.
