Getting to Space Faster with EMA Simulation and Measurement
The fourth industrial revolution is here, and the space industry is leading the way. The Brookings Institution describes the fourth industrial revolution as the combination of technologies integrating the biological, physical, and technological spheres to transform economic, political, and social systems. The institute says that better technology and decreasing costs have made outer space more accessible than ever before, including to private companies, making accurate space simulation and measurement a smart business decision.
As of 2021, the global space industry was made up of more than 10,000 private space companies, 5,000 large investors, and 130 state organizations. As public interest continues to grow, Morgan Stanley estimates that the global space industry could generate more than $1 trillion in revenue in 2040. That is up from $350 billion currently.
Getting off the ground is no easy task. Testing has to be completed to make sure spacecraft and components can handle the harsh space environment. Historically time-consuming ground-based testing has been performed. However, with the proliferation of space this method has had difficulty keeping up with the advancement of industry.
“The time frame of a lot of the previous testing has been on the order of years or even decades,” EMA PhD. Senior Scientist Gregory Wilson says. “However, with the industry, it’s on the order of months and so because of that a lot of testing was foregone, which can lead to instances and circumstances when spacecraft have failed.”
EMA is available to anyone looking to learn more about the effects of the space environment on equipment. Our technology predicts how to prevent fundamental flaws, significant risks, and creates better designs on your timeline.
“One of the major goals of our lab is to not only facilitate that testing by combining all the different complex factors of the space environment, but also to do it on the same time frame that industry is running at, not in years, but in months and weeks,” Wilson says.
The Space Environment
Fig. 1. The FAA defines space as starting 81 miles above Earth’s surface.
Before you can start to think about heading to and testing in the space environment, you have to understand what space is. The FAA defines space as the altitude where an object will remain in orbit, even if it’s just for a day or two, before the upper atmosphere drags it back to Earth. This is typically 81 miles above the Earth’s surface.
Outer space is a harsh environment with several hazards that must be accounted for during the design process. This includes:
- Gravity
- Earth’s atmosphere
- Micrometeoroids
- Vacuum
- Radiation
- Charged Particles
Here we will be taking a closer look at electromagnetic (EM) effects.
Space is described as a near vacuum since there is still material present. At an altitude of 596 mi there are about one million particles per cubic centimeter. This near vacuum creates three potential problems for spacecraft: out-gassing, cold welding, heat transfer.
The main EM focus here is on out-gassing. Some materials used to build spacecraft can trap tiny bubbles of gas while under atmospheric pressure. These materials are typically composites such as graphite or epoxy. When the spacecraft experiences less pressure in the vacuum of space these gasses escape. This process is called out-gassing. These gases have the potential to coat sensors and lenses and cause electronic parts to arc. This arcing can be disastrous. This is one reason why materials must be carefully selected and tested before heading into space.
The sun puts out EM radiation and since there is no atmosphere to protect spacecraft it is more vulnerable in orbit than on Earth. This can lead to several problems such as heating on exposed surfaces, degradation, and solar pressure.
Prolonged exposure to ultraviolet (UV) radiation can degrade, or damage surface materials and electronics. This radiation is the reason why materials need to be hardened, or shielded, to survive the space environment. Determining how materials will perform and if they need to be hardened is essential to consider in the design process.
Fig. 2. Solar flares send charged particles
Charged particles could be the most dangerous part of the space environment. The primary sources for these particles are solar wind and flares, Galactic cosmic rays, and the Van Allen radiation belts. These charged particles are often tied together with EM radiation because their effects are similar. No matter where charged particles come from, they can harm spacecraft in several ways including charging, sputtering, and single-event phenomenon (SEP).
Spacecraft charging is when charges build up on parts of the spacecraft as it moves through highly concentrated areas of charged particles. When charges are built up, they can discharge at any time. These discharges can have catastrophic consequences, leading to damage on surface coatings, degradation of solar panels, loss of power, and switching off or permanently damaging electronics.
Sputtering can result in wear and tear in spacecraft components. This happens when charged particles move at a high-speed hitting the spacecraft, similar to sand blasting.
Focusing on these challenges in the design process helps get spacecraft into space faster and also gives manufacturers peace of mind that their product is not going to fail. EMA plays a role in mitigating these risks by combining simulation using Ansys Charge Plus and measurements in the state-of-the-art Space Environment and Radiation Effects (SERE) commercial test chamber.
Starting with Simulation
Fig. 3. Example of a satellite simulation in Ansys Charge Plus.
EMA starts the space measurement process with simulation and analysis. Once simulation is complete, targeted testing can begin.
“By merging both simulation and testing, you’re able to not only save time, but also save money and potential costly mistakes that could be done simply focusing on one or the other,” Wilson said.
Simulation is done using Charge Plus. The software uses a multiphysics approach to simulate charging and discharging phenomena. The time-domain solvers can simulate:
- Electric arcing
- Material surface and internal charging
- 3D particle transport
- Dielectric breakdown
- Excessive charge build up
- Material degradation
- Surface flashovers
- EM interference
- Plasma wake
Fig. 4. Plasma wake results as shown in Ansys Charge Plus
Charge Plus allows users to not only get a closer look at complex behaviors in the space environment but also the different space environments that exist.
“The low Earth orbit is far different than the GEO for example,” Wilson says. “The densities and plasma and the different currents change drastically the type of charging that’s observed, but also the type of situations that you need to be aware of.”
Charge Plus is based on Ansys Discovery and is integrated into a single workflow. Users are able to process the CAD, prepare the simulation, and run it right in the software.
“From there you can run different environments, you can run it with the different tool sets,” Wilson said. “Whether you’re trying to do just analytic environments or looking at particle-in-cell codes, we also have the ability to go even further beyond that.”
Physical Testing
Fig. 5. EMA Space Environment and Radiation Effects testing chamber
Once proper analysis has been done on a particular design, targeted testing is done using the SERE commercial testing chamber. SERE is capable of charging, radiation, and aging investigations.
“It’s important to do these radiation and charging studies on Earth so that you don’t run into any cataclysmic issue when you send your satellite up in space,” said EMA Staff Scientist Brian Wood. “You can kind of gauge and mitigate any risk.”
Each testing project is different and catered to each customer. To start the SERE team will establish what the issue is and what problems are anticipated.
Once all the materials have been collected, EMA will create custom mounts and cabling inside the SERE chamber. The team will discuss what kind of radiation exposure needs to be used and testing will begin.
Fig. 6. SERE radiation source (left) and a look inside SERE (right).
Materials are mounted on the door side of the SERE chamber. It comes with a 24-inch sample plate and is approximately a cubic meter in volume. The chamber can be pumped down to 10-8 Torr in about a day.
On the other side is where the instrumentation is housed. This includes an electron flood source, low plasma generator, and VUV Krypton arc lamp.
“We have the UV photon source to do neutralization and any aging studies,” Wood said. “Then we have the plasma source which can recreate the LEO (low Earth orbit) environment. With those we’re essentially able to mimic many of the environments that a satellite can be exposed to when it’s up in space.”
Once testing is complete, the SERE team will write up a report with its findings. You can find more detailed information about what capabilities SERE has by clicking here.
Benefits of EMA
EMA offers a one-of-a-kind experience for those looking to head to space by offering both simulation and measurement services. Wilson says generally companies focus on one or the other which means their expertise is limited to either simulation or testing leading to oversight in both areas.
“If you only look at the simulation side you may miss certain factors that lead to inaccurate results,” Wilson says. “If you’re just look at testing, you’re not necessarily looking at the full picture.”
Another aspect that makes EMA stand out is that we are a commercial company working for you and on your timeline.
“We’re available and we have the expertise to do unique testing… you know there are other places that do this, but we accomplish it faster and we do it, I think, more reasonably,” Wood said.
Since EMA is working on your timeline, we are your single point of contact for the entirety of a project.
“A lot of times in companies they go through the design phases and then once the design phase is completed that person or group often is tasked and moved on to another project or an entirely different disciple,” Wilson said. “We are able to retain a consistent perpetual experience and knowledge base that helps us remain as experts and leaders of the field.”
If you’re ready to get started or want to learn more about how we can help you, contact us here. We can’t wait to get started helping you reach your goals.
