Using old-fashioned steam power, two cubesats executed the first coordinated maneuver in low-Earth orbit.
The propulsive movement happened after one of the twin spacecraft — with help from the ground — commanded the other to close the 5.5-mile (8.85-kilometer) gap separating the cubesats. Each spacecraft carries fuel tanks filled with water, which thrusters converted to steam to help the cubesats move closer together.
NASA says the maneuver shows the potential for small spacecraft to work together on future missions, even though for this initial demonstration, human operators made the call about when the satellites should move.
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"Demonstrations such as this will help advance technologies that will allow for greater and more extended use of small spacecraft in and beyond Earth-orbit," Roger Hunter, program manager of NASA's small spacecraft technology program, said in a statement.
This steam-powered movement is part of the extended mission for the Optical Communications and Sensor Demonstration mission, which aims to demonstrate how spacecraft can maneuver in swarms and while operating in close quarters. In the distant future, such groups of spacecraft could be deployed into deep space and work autonomously to examine distant worlds or perform other science in the outer reaches of the solar system.
After more than 15 years of Earth-orbit operations, cubesats are starting to move across the solar system. NASA deployed the first Martian cubesats last year, to watch the landing of the InSight lander. And the agency is planning to send cubesats on Artemis 1, which will be an uncrewed mission of the Space Launch System rocket and Orion spacecraft in 2020 or so to the moon.
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