The Role of Electrical Engineers in Space Exploration

Electrical engineering has always been a critical component of spacecraft development. In many respects, space exploration has accelerated the advancement of electronics technology beyond its natural progression. Notably, the early development of transistors and integrated circuits was largely driven by missile and space programs. The nature of space exploration brings a level of discipline to engineering that enables increasingly complex projects.

While early space programs drove the leading edge of space electronics, today’s latest technology remains for use on Earth. Given that smaller geometries are more susceptible to radiation and other effects of space, electrical engineers are challenged to design efficient systems with fewer resources. Current space exploration technology often uses components older than a decade because terrestrial technology is not yet robust enough for the harsh environment of space.

The Discipline of Engineering in Space Exploration

Designing space systems requires expertise across disciplines. Here, exploration hardware must be low-power, lightweight, and high-functioning. Electrical engineering teams are experienced in power systems design, communications and high-speed radio frequency (RF), and sensor and instrumentation design to ensure these parameters.

Electronics designed for space exploration must account for lifecycle requirements and environmental settings that do not exist on Earth. With no repair depots in deep space, engineers must design fault tolerance, backup systems, and flexibility. To facilitate this, electrical and software engineers collaborate to ensure long-term missions can be maintained and repaired with software.

Power Supply and Distribution

Power is one of the most critical factors for electrical engineers. Typically, power systems include a solar or nuclear radioisotope-based source. Although solar power is more cost-efficient, it requires electromechanical tracking systems to keep arrays pointed at the sun. Solar power additionally includes batteries to power the spacecraft in the event of panel misalignment or celestial occlusion. In contrast, nuclear systems supply unbroken power, but their nuclear output diminishes over the years in space. Electrical engineers must be able to selectively route power once a system’s supply is insufficient to drive the entire spacecraft.

Communications and Navigation Systems

Space exploration systems design involves at least three types of communications systems, including:

• Local low-speed communications as commands to thrusters, motors, and actuators
• Internal system-to-system high-speed data, such as video to CPU
• Radio communications between the Earth and the probe

All three communications systems require different types of electrical engineering expertise. Low-speed communications are within the purview of most engineers, while high-speed systems bus and RF communications demand specialized electrical engineering skills. With data bus systems, electrical design engineers have developed high-speed systems with adequate shielding. Other innovations have reduced crosstalk and noise, allowing data to move through locations with limited degradation. Along with signal integrity, advances in error detection and correction enable higher-performance electronics for space exploration.

RF communications bring extra challenges for electrical engineers—as radio signals dissipate with distance. To accommodate this challenge, engineers are designing extremely low-noise, high-gain amplifier systems for both probe side and earthbound receivers. Alongside this, NASA has been experimenting with focused laser communications. These laser transceivers are showing great promise in delivering higher bandwidth communications for space exploration.

In addition to low noise, electrical engineers also need to contend with frequency change due to the Doppler effect. Engineers must design transceivers to account for frequency shifts caused by a spacecraft’s speed. Frequencies change as a spacecraft accelerates, decelerates, or changes lateral speed.

Space Exploration Electronics in the Coming Decades

Most space missions have decades or more mission profiles, whether orbital satellites or exosolar system deep space probes. Voyagers 1 and 2, launched in 1977, will have been in operation for 50 years by 2027, while Pioneer 6 operated for 34 years before its last contact in December 2000.

Scientists have proposed a new deep space exploration mission called “Interstellar.” This mission will travel twice as fast as Voyager, studying deep space at 1,000 astronomical units (AU) out—six times the current Voyager 1 distance. The mission has a planned lifespan of over 50 years, which appears achievable based on the Voyager probe’s history. To ensure that modern semiconductors are up to the task, electrical engineers will need to design systems for conditions 93 billion miles away.

Interstellar is still in the proposal stage and has an unknown fate. What is certain is that electrical engineering will remain critical for furthering space exploration.