The scientists said the agency used an S-310-36 sounding rocket fairing to conduct the experiment - which took place last March aboard a research aircraft in temporary microgravity conditions. The deployment system is considered a possible precursor for large-scale space-based microwave transmission antennas.

The approach of using small satellites to hold the edges of mesh or membrane structures is called the Furoshiki - or "wrapping cloth" - satellite method. Using Furoshiki, the scientists said, it is possible to extend structures up to several kilometers wide. Using conventional unfolding and extending technology, the practical size limit for such structures is only a few hundred meters.

One particularly promising application would be for phased-array antennas, which require multiple structures to be carried by spacecraft. JAXA scientists consider phased-array antenna technology, which works even with moving-antenna elements, to be indispensable for deployment of ultra-large space antennas needed for applications such as deep-space solar-powered satellites, ultra-high-speed communications and precision radar.

Furoshiki is not without technical challenges, however, such as how to fold and stow the mesh or membrane material within a small space; how to deploy a structure automatically without entangling it, and how to maintain the main spacecraft's proper position and orientation while the mini-satellites pull out the structure's edges.

In the experiment, scientists used one main satellite and three sub-satellites stowed already linked together with the mesh inside the rocket fairing.

When deployment began, a gyroscope on the main satellite cancelled the residual spin from the sub-satellites, which were released via a spring at an initial speed of about 1.2 meters (four feet) per second at an angle of 120 degrees perpendicular to the plane of the rocket body axis.

Radiowave sensors monitored the deployment dynamics, measuring the distance between main and sub-satellites. A Ku-band telemetry downlink confirmed the deployment process via images shot by cameras aboard the main satellite, and another camera on one of the sub-satellites directed at the main satellite.

During and after deployment, scientists conducted various phased-array antenna experiments using microwave transmitters and receivers installed on the main satellite and the sub-satellites. The scientists said the experiment demonstrated that, with the adoption of the retro-directive transmission method - as it is called - antenna characteristics were maintained even though the sub-satellites experienced some disturbances in attitude and position.

Scientists also tested one-axis attitude control, in which a sub- satellite positioned the main satellite in the center of its camera using gyros and image data, and thruster control on two of the sub-satellites to prevent any bound back after the mesh deployment.

When the mesh deployed and stabilized - after about two-and-a-half minutes - the team then tested a mesh-moving system, which was installed on top of the main satellite and crawled out onto the mesh. The system used permanent magnets to maintain the up/down position of its driving mechanism. The scientists said the system worked without problems in the microgravity environment.

Researchers at the University of Tokyo and Kobe University participated in the effort with JAXA.

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