Authored by John McHale, Editorial Director with Military Embedded Systems
Defense and space agency budgets remain flat while commercial small-satellite opportunities are heating up, all forcing radiation-hardened (rad-hard) electronic component designers to tackle reduced size, weight, and power (SWaP) requirements as well as re-examine the viability of using commercial-off-the-shelf (COTS) equipment in space environments. Meanwhile, radiation testing and qualification requirements are getting tougher and embracing TOR standards.
Radiation-hardened electronics designers, facing the heat of reduced SWaP requirements in satellite programs and customer budget constraints, find they need to be even more innovative and open-minded to deliver commercial-level capability to space systems in low-cost packages.
The government segments of the space market look to be flat or slow-growing for the foreseeable future, even as the development of mega constellation small satellites begins to heat up. Meeting the needs of one doesn’t necessarily meet the needs of the other; as a result, companies are diversifying their rad-hard product lines and even considering the use of commercial-off-the-shelf (COTS) technology.
"Military space customers want smaller and lighter components with higher levels of overall performance while also reducing cost," says Monty Pyle, Vice President of Sales and Marketing at VPT in Blacksburg, Virginia. "This can definitely be an engineering challenge. The budget constraints many integrators in the military space market face forces them to take a hard look at what exactly is needed in terms of radiation resistance within individual programs and try to strike a balance to help reduce the costs. In other words, for areas that require only minimum rad-tolerance, they are moving away from using devices with maximum rad-tolerance and more toward components that fit the exact need. It’s too expensive to make every component with maximum radiation resistance in modern space systems and it’s not necessary."
"A big trend right now is to reduce size and weight, a demand which will only increase with the rise of CubeSats, where weight is critical especially when using a ‘pound for launch’ cost metric," says Philip Chesley, Senior Vice President, Precision Products at Intersil in Palm Bay, Florida. Regarding reduced size and weight, Intersil offers a rad-hard temperature sensor called the ISL71590SEH, he adds. The device is a two-terminal temperature-to-current transducer that is accurate over time, temperature, and radiation exposure – specifically with a ±1.7 °C accuracy over temperature and less than –1 °C change in accuracy over low-dose-rate radiation. "Developers of the most advanced next-generation satellite systems require temperature sensors that provide accuracy over the mission life of a satellite, eliminating the need for expensive radiation lot acceptance testing or spot shielding," Chesley notes. The Intersil device is qualified over the full military temperature range and to over 50 krad (Si) low-dose-rate and 300 krad (Si) high-dose-rate irradiation.
COTS in space
Budget constraints and the growth of the CubeSat market is also giving commercial electronic suppliers confidence that they can succeed in the space markets, although some have their doubts.
"Folks are trying to bring COTS technology to space," Chesley says. "This industry is cyclical in that way. Every ten to 15 years the pendulum swings to trying a COTS approach to meet budget constraint challenges, which is true today as the pressure to use more COTS is actually coming from government programs rather than commercial satellite systems as government outlets are facing pressure to slash costs."
"The barrier of entry in this market is huge and to be successful companies need to build up a heritage of product success as the customer base is very conservative," says Danny Gleeson, Business Development Manager for Space Market at Curtiss-Wright in Dublin, Ireland. "Our move into space began with SpaceX using our modular avionics data acquisition device – the KAM-500 – in the flight test phase and then it was retained for the production vehicle and we found that it met all the necessary requirements." The product also has a Microsemi ProAsic FPGA that is inherently rad-tolerant."
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