Authored by John Keller at Military & Aerospace Electronics.
Rugged data storage is dominated today by solid-state disks, yet there is still room for rotating hard disks, with emerging requirements for data security and sharing storage devices on networks.
The need for rugged data storage in military and aerospace systems is growing constantly, as manned and unmanned reconnaissance and surveillance sensors proliferate at an astonishing rate and drive the need for robust and reliable storage for crucial video, signals intelligence information, and multispectral sensor data.
Data storage technologies are evolving quickly, offering many choices for systems integrators who must quickly store terabytes of video, imagery, signals intelligence (SIGINT), and other data-intensive applications. While solid-state storage has become dominant in mission-critical aerospace and defense applications, there is still room for rugged rotating data storage media, while integrators are keeping an eye on new 3D solid-state storage to see if this promising approach becomes rugged enough for military uses.
Data security, meanwhile, represents a growing trend in military data storage not only to ensure that sensitive data doesn't fall into the wrong hands, but also to assure the quality of recorded data, and to make sure that no one has tampered with recorded information.
At the same time, vestiges of cloud computing and big data are making their way into military and aerospace data storage, as Ethernet-based network-centric storage is helping to reduce size and weight by eliminating the need for each sensor to have its own dedicated data storage system.
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Data storage media
Solid-state drive (SSD) technology dominates today's aerospace and defense applications that typically are subject to shock, vibration, temperature extremes, and other demanding environmental factors. It's reliable, fast, space-efficient, and can record ever-larger amounts of data. Its downsides, however, involve longevity and price.
Solid-state storage, which relies on various kinds of Flash memory, has a tendency to wear out - not quickly, mind you, but its maximum number of read and write cycles are numbered. Systems designers must keep that in mind, especially for applications that write small bits of data over and over again.
Compared with rotating media, "solid-state devices wear out faster in a transactional environment like a database where you have many small records that are being accessed, written, and erased; that is the worst-case environment for a solid-state disk," says Amos Deacon III, president of data storage specialist Phoenix International Systems in Orange, Calif.
On the other hand, solid-state storage "lasts longer where you have continuous data flow like video, telemetry, or radar," Deacon says.
The cost of solid-state storage has been coming down as its popularity increases, yet it still is relatively expensive - particularly for the ultra-reliable, single-level-cell (SLC) NAND Flash technology favored by those designing high-reliability aerospace and defense systems.
Nevertheless, solid-state storage has taken a lead role in the ruggedized storage market. "We have seen the move from rotating drives to solid-state drives. We almost never use rotating drives anymore," says Paul Davis, director of product management at the Curtiss-Wright Defense Solutions Division in Dayton, Ohio. In addition to its advantages in size and reliability, solid-state storage technology also is moving forward at a rapid clip. "The amount of data you can get in a certain size is doubling about every 18 months," Davis says.