GOES-R Magnetometer Boom Hot Thermal Deployment

This video demonstrates a successful deployment of the Magnetometer boom that will fly on the GOES-R satellite. This is a demonstration of a deployment of the boom at hot temperature (+55°C), to simulate the conditions in space. The Magnetometer boom will deploy after the GOES-R spacecraft launches, separates from its launch vehicle, and undergoes a series of orbit raising maneuvers. The Magnetometer will provide measurements of the space environment magnetic field, which controls charged particle dynamics in the outer region of the magnetosphere. These particles pose a threat to spacecraft and human spaceflight. The GOES-R Magnetometer boom completed development and testing in July 2014.

[@alphaadhito]

So how does the boom extend? Does it based on tension spring? Looks interesting though :-)

[@marckerger]

Where can you find more info on this how it really works?