Role and Function of Solid-State Mass Memory

Reliable storage solutions are crucial in the context of today’s space exploration, when technologies are continually reaching new and new heights, and people are increasingly using satellites for a variety of out-of-Earth missions. Considering the large data volumes stored and managed by spacecraft, coupled with growing downlink rates, SSMM (solid-state mass memory) proves to be the best solution for space projects. In this article, we explore how it functions, as well as reveal the benefits and applications of SSMM.

What Is Solid-State Mass Memory?

Solid-state mass memory is a type of storage unit used in spacecraft to handle large volumes of information during space missions. Unlike mechanical hard disk drives, SSMM does not have moving parts but uses flash memory chips (like those in USB sticks or SSDs in laptops). Therefore, data can be written, transferred, and removed electronically.

Solid-State Mass Memory Design

Although technical specifications of solid-state mass memory may differ depending on the spacecraft’s mission, the structure of SSMM units remains the same:

• Mass memory modules
• System controller
• Interfaces
• Power block
• Buffer memory block

How Does Solid-State Memory Work?

It consists of millions of small cells, each of which represents a bit of information. When data is written, electrons are pushed into the cells so that they can “remember” the information and store it for a long period. To read data, the solid-state mass memory unit checks whether a cell has a charge. The charged bits are presented as 1s, while 0s mean there is no information stored. Data removal from SSMM involves pulling the trapped electrons out of cells. The process usually implies erasing a whole block of cells at once.

Common Solid-State Mass Memory Applications

Space missions have grown in complexity and scale, increasing the need for storing, managing, and retrieving large data volumes onboard spacecraft. With that in mind, solid-state mass memory units find applications in numerous types of missions. Most often, they are used for storing:

• High-resolution images taken during planetary observations
• Scientific measurements (temperature, magnetic fields, radiation, etc.) collected by sensors and instruments
• Observation data (exoplanets, stars, galaxies, etc.)
• Telemetry data and commands needed for efficient spacecraft operation
• Telecommunication data (transmission and signal processing logs)
• Diagnostic data for detecting system faults
• Instructions for system recovery and troubleshooting
• Operational logs and system backups

Benefits of Solid-State Mass Memory

Solid-state mass memory stands out from other types of MMUs used in modern spacecraft. This is what makes it useful for a variety of space operations:

• High-speed information recording and reading: satellites handle great amounts of scientific measurements, system data, and high-resolution images, which makes efficient information processing and storage vital for real-time operations. SSMM boasts faster handling of large-scale data, and its writing and reading speeds are higher if compared to other types of memory units.
• Great reliability: since solid-state mass memory units have no moving components, they prove to be more resistant to different physical impacts, such as shock or vibration. This makes SSMM ideal for operating under extreme space conditions, as well as enables it to withstand launch forces. A lower chance of mechanical failures is critical for long and consistent performance – that’s why many space companies enhance their spacecraft with solid-state mass memory.
• Low power consumption: SSMMs are designed to be energy-efficient, so they consume much less power than other storage units. Why is it important? The point is that spacecraft have limited power resources, and there are many components and subsystems requiring a continuous source of energy for operation. By using solid-state mass memory, spacecraft can carry out missions longer, allocating more power for scientific instruments, communication, or other onboard systems.
• Lightweight and compact size: spacecraft have strict requirements for their weight and size since launching heavier objects into space is more costly. SSMM units are typically lighter and smaller than mechanical storage systems or hard drives, which allows spacecraft operators to save on launch costs and maximise payload capacity.
• Durability and long data retention: despite having different technical specifications, solid-state mass memory units are designed to withstand continuous read/write cycles and can store data for decades without losing their integrity. Such capabilities make them ideal for space exploration, as many missions last for years. At the same time, spacecraft are not always able to communicate with Earth, so it’s important to keep the collected data safe until it is retrieved.
• Flexibility: space missions vary greatly, affecting the technical specifications and needs of a spacecraft. Hence, solid-state mass memory comes with different storage capacities, allowing satellite operators to choose the best option depending on how much data will be collected. In addition, it’s possible to adjust the SSMM’s data writing and reading speeds according to mission goals, as well as enhance the solid-state mass memory unit with radiation protection.