12″ diameter (304.8mm), 2 Bates grains, 260lbs (117kg) of propellant!
Be interesting to know the thrust and chamber pressures achieved in this test, they seem to have figured out any grain cracking issues that could arise and over pressurize the motor, looking forward to seeing more tests of this size in the future!
Video Caption: 2 grains 12×20
260 pounds of propellant
Motor by Rick Maschek and Eric Beckner
Video Caption: Casting the second 12″ x 20″ (300mm x 500mm) sugar propellant grain at the FAR site. Each grain will have a 3″ (75mm) core and approximately 130 pounds (55 kg) of propellant with an expected motor burn time of 16.7 seconds. The Phoenix launch was a small 100mm 2-grain sugar motor with 1″ (25mm) cores used for inexpensively flight testing propellant, electronics and other components. Each Phoenix flight cost three dollars…what a bargain!
I was recently made aware of Team Ursa, who are building some very cool rockets and hardware and have been doing so for a few years now.
Team Ursa’s mission as stated on their website,
Team Ursa and its partner, Mavericks Civilian Space Foundation, find space exploration to be a potent motivator for students and adults alike. By using the sub-orbital aerospace platform, Team Ursa works with Mavericks to inspire students and communities to invest in STEM through the development of open-source reference designs. These reference designs are intended for the educational and research community’s use to further younger generations’ involvement in STEM, and aid in making sub-orbital space a more accessible laboratory for students.
The team started out as 6 University of Maine senior capstone students who got together to build their first rocket, Ursa 1.0. Ursa 1.0 was a 2 stage solid propelled rocket designed to achieve 100,000ft in altitude, as shown below.
Video Caption: A 4″ (100mm) ‘K’ impulse 2-grain sugar motor. The airframe was made from salvaged and scrounged materials from other rockets. The propellant was KNSB with a 1″ (25mm) core. Launched November 5, 2016 from the FAR site, Mojave Desert.