Innovative and imaginative radio amateurs as career professionals continue to advance science, the state-of-the-art and make news. Hope you enjoy the story. 73, John, WØPV Excerpts from NASA Tech Breathes Life Into Potentially Game-Changing Antenna Design Some 30 years ago, a young engineer named Christopher Walker aka @K7CKW was home in the evening making chocolate pudding when he got what turned out to be a very serendipitous call from his mother. Taking the call, he shut off the stove and stretched plastic wrap over the pot to keep the pudding fresh. By the time he returned, the cooling air in the pot had drawn the wrap into a concave shape, and in that warped plastic, he saw something – the magnified reflection of an overhead lightbulb – that gave him an idea that could revolutionize space-based sensing and communications. That idea became the Large Balloon Reflector (LBR), an inflatable device that creates wide collection apertures that weigh a fraction of today’s deployable antennas. Now, with an assist from NASA’s Innovative Advanced Concepts (NIAC) program, funded by the agency’s Space Technology Mission Directorate, which supports visionary innovations from diverse sources, Walker’s decades-old vision is coming to fruition. ... The story continues in more detail on this link. “There was no place other than NIAC within NASA to get this off the ground,” says Walker, now a astronomy and optical engineering professor at the University of Arizona in Tucson. “At first, I was afraid to share the idea with colleagues because it sounded so crazy. You need a program within NASA that will actually look at the radical ideas, and NIAC is it.” ... In 2018, Freefall Aerospace, a company co-founded by Walker to develop and market the technology, demonstrated the LBR’s potential aboard NASA’s stadium-sized stratospheric balloon, which carried a 3.28-foot scale model to an altitude of 159,000 feet. “The technology demonstrated by CatSat opens the door to the possibility of future lunar, planetary and deep-space missions using CubeSats,” said Walker. It might be difficult to believe this all started because a young engineer’s idea of dinner one evening was what most would consider dessert. Then again, one could say the proof was in the pudding.
Addendum: I was remiss at not noticing that the three members of the CatSat team that are identified and speak on the video are also FCC licensed radio amateurs: Hilliard Paige aka @W7HIL Shae Henley aka KK7JDD Walter Rahmer aka @KK7IOV Congrats & 73 to them too. John, WØPV
Mission | CatSat (arizona.edu) Will use WSPR transmissions from 'ham radio operators" as part of science package. About proposed launch provider -Firefly Aerospace Successfully Launches U.S. Space Force VICTUS NOX Responsive Space Mission with 24-Hour Notice (prnewswire.com) So far, 1 out of 3 launches has made orbit.
Firefly-Alpha (Firefly-α) - Gunter's Space Page (skyrocket.de) CatSat - Gunter's Space Page (skyrocket.de) Looks like 'maybe' 2024 launch date. If the outfit doesn't fold, again.
I don't get it. A spherical dish (or mirror) is not the same shape as a parabolic dish (or mirror). A spherical dish has a variable focal point. It seems that a tradeoff is being made, gain (of a parabola) for ease of deployment (of a sphere). Is that the idea?
Inflatable ground based antennas are already thing these days as well, see: Inflatable Satellite Antenna | Cubic these showed up in production prior to 2014, so the CATSAT is unique only because it is used in space, the inflatable part is hardly "ground breaking" Inflatable radar reflector date to the mid 1980. US6963315B2 - Inflatable antenna - Google Patents source patent for antenna in image.
Correct. Balloons have been used in many ways. Forty years ago we used to take weather balloons and foam up half of their shape, deflate the balloon , apply aluminum foil, and place them in a mount similar in design to the Edmund Scientific Astroscan 2001. Kind of a Dobsonian I would imagine. Took several tries because the foam would break off. You just use a line feed if you need to maximize. Arecibo was a portion of a sphere. They had line feeds, and a Gregorian feed system in later years. But no balloons;-)
Why a sphere and not catenary? (which is quite close to a parabola in practice) Never mind, Mrs. Google told me why.
