The remnants of a collapsed neutron star, called a pulsar, are magnetically charged and spinning anywhere from one rotation per second to hundreds of rotations per second. These celestial bodies, each 12 to 15 miles in diameter, generate light in the X-ray wavelength range. Researchers at the University of Illinois Urbana-Champaign developed a new way spacecraft can use signals from multiple pulsars to navigate in deep space.

"We can use star trackers to determine the direction a spacecraft is pointing, but to learn the precise location of the spacecraft, we rely on radio signals sent between the spacecraft and the Earth, which can take a lot of time and requires use of oversubscribed infrastructure, like NASA's Deep Space Network," said Zach Putnam, professor in the Department of Aerospace Engineering at Illinois.

"Using X-ray navigation eliminates those two factors, but until now, required an initial position estimate of the spacecraft as a starting point. This research presents a system that finds candidates for possible spacecraft locations without prior information, so the spacecraft can navigate autonomously.

Using a helicopter to catch a falling rocket is such a complex task that Peter Beck likens it to a "supersonic ballet.