The Roll OutSolar Array, known as ROSA, is a solar array designed by NASA. This new type of solar array provides much more energy than the old solar arrays. Traditional solar panels used to power satellites can be bulky with heavy panels folded together using mechanical hinges. When launching into space, mass and volume are everything, and ROSA is 20 percent lighter and four times smaller in volume than rigid panel arrays. It is a flexible and rollable solar array like a measuring tape wound on its spool. The new solar array design rolls up to form a compact cylinder for launch with significantly less mass and volume, potentially offering substantial cost savings as well as an increase in power for satellites. Being smaller and lighter than the traditional solar panels, ROSA has a center wing made of a flexible material which support the strings of photovoltaic cells that churn out electrical energy. Both the sides of the wing have a narrow arm that extends through the length of the wing to provide support to the array, called a high strain composite boom. The booms look like split tubes made of a stiff composite material, flattened and rolled up lengthwise. The array does not need any motor to unfurl. This is achieved using the energy stored in the booms that is released as each boom transitions from a coil shape to a straight support arm. Those solar wings are then deployed due to strain energy in rolled booms that are present at the two ends of the structure.
Patent
Brian R Spence, and Stephen F White are the first persons to come up with the idea of Roll Out Solar Array on Jan 21st, 2010. They received a patent for this work on April 1 of 2014
History
NASA tested the ROSA technology in vacuum chambers on Earth several years ago, but still decided to test it in space on June 18 of 2017. Over the weekend of June 17–18, 2017, engineers on the ground remotely operated the International Space Station's robotic Canadarm2 to extract the Roll Out Solar Array experiment from the SpaceX Dragon resupply ship. After the observation the mechanism was not planned to be retrieved back to earth. The solar array unfurled June 18, extending by tensioning booms on both sides of the 1.6-meter-wide wing. NASA decided to conduct continuous tests for a week and observe its consequences. Engineers observed the behavior of the solar array as it was exposing it to extreme temperature swings through the ISS's orbit. Vibrations and oscillations were also mechanically introduced to assay the array's response to structural loads. Subsequent to the experiments, ground controllers were unable to lock the solar panel in its stowed configuration. The solar array was therefore jettisoned from the International Space Station.
Applications
ROSA being very compact in size and due to its large power generation capacity it is reliable for future missions and majorly for interplanetary travels which need a huge amount of energy.
