Sugar Shot Weekly Activity Report: September 5-11, 2011‏

The following report was compiled based on input from Paul Avery, Rick Maschek, Chris King and Thomas Dittman:
Rick Maschek and Paul Avery arrived at the FAR test site Friday evening. The skies were overcast with the threat of rain. The forecast was similar for Saturday. As they were unable to access supplies that were locked in one of the storage lockers, work was deferred to the next day. Assembly of the propellant grains began Saturday morning. Rick reported that assembly of the 12 grains into two “unigrains” went well. Meanwhile Paul worked on assembly of the motor, while Chris King and Tom Dittman (who arrived early Saturday morning) set up the measuring equipment and calibrated the pressure sensors, with Paul’s help. Paul reported that assembly of the motor went well but took a lot longer than anticipated. There was only one significant glitch – an interference of the head of the Deluge Plug with the top of the propellant stack. This was resolved by local removal of some propellant. At around 5:30PM, the assembled motor was moved to the Large Horizontal Test Stand followed by final positioning and mounting. By the time this was completed, the weather had worsened. Storm cells with lightning approached, and for safety, the team retreated to shelters as rain began to fall. Rain continued, and the team waited for a break in the weather. The precipitation was a
mixed blessing, Rick later stated, as the wet ground minimized risk of brushfire in case of motor CATO. After about 2 hours, the break came, and the team quickly set about hooking up igniters and activating data recording. It was fully dark by this time and spotlights were used to illuminate the test site. The crew and all others present retreated to safety inside the concrete bunkers. At about 7:50PM, the “T minus 10 seconds” countdown commenced and at "zero" the motor was seen to fire up. Thrust buildup was slower than expected, but after about a second, the motor appeared to be at full thrust. Due to the darkness, a flame was clearly visible. The motor continued to burn well for another second or so when suddenly a violent CATO occurred. The aft chamber separated at the Midbulkhead and departed the test stand. A large fireball erupted from burning propellant, and pieces of burning propellant were seen to burn for several seconds. The firing crew decided to stay put in the bunkers for ½ hour as a precaution, since it was unclear whether propellant was present in the forward chamber or not. As well, rain once again started to fall, quickly extinguishing any fragments of burning propellant. Approaching the remains of the motor in the test stand, it was clear that the forward motor casing, which still had the Midbulkhead attached, was devoid of propellant and as such was not a potential hazard. After gathering the instrumentation, the team retired for the night.
The following day, Rick and Tom examined, photographed and collected various parts. The test stand suffered significant damage to the carriage and bracketry for retaining the motor. The Forward Bulkhead was damaged, having forcibly impacted the thrust plate. All sensors were damaged. Rick reported that the forward motor casing was “ballooned” noticeably, and oddly, was completely “clean” inside, devoid of any traces of propellant or casting tube material. The aft casing was recovered but was badly damaged at the forward end, having separated into several pieces.
The nozzle appeared to be undamaged. Rick also reported a vast “debris field” of unburnt propellant chunks and fragments. The sizeable pieces were collected and the smaller pieces buried out of safety concern. 
Chris was successful in recovering data from the load cells and pressure sensors. Both load cells appeared to provide a good trace. One pressure sensor (that believed to be for the aft chamber) recorded a slight pressure rise then dropped to zero well before the anomalous event. It would appear to have gotten blocked with combustion product residue (to be confirmed later). The other pressure sensor read zero until the anomalous event broke its electrical leads. It is believe the sensor leads may have gotten wet from the rain and as such malfunctioned.
Video of test firing:

A huge "thank you" goes out to the DSS ground crew members Paul Avery, Rick Maschek, Chris King and Thomas Dittman for the incredible effort they put into this static firing event, pouring their hearts and souls into making everything come together. This is the kind of rare dedication that will ensure victory in achieving our goal of reaching Space on the understated power (!) of sugar.
The Sugar Shot team owes a debt of gratitude to Ted Rothaupt (FAR secretary & Pyrotechnic Operator) and John Newman (Pyrotechnic Operator) for staying around so late Saturday night to oversee our project. FAR’s support is invaluable, providing such a rare and capable facility. SS2S will be donating $400 to FAR to help cover expenses incurred by our team and to show our support for such an outstanding facility. The SS2S team encourages our supporters to likewise make a donation.

Markus Bindhammer has been performing interesting experiments with novel propellant formulations, the latest being a eutectic mixture of KNO3 and NaNO3, with sorbitol. Markus found that the resulting formulation burns vigorously, and possesses a number of potentially useful traits. Markus’s report has been posted on our Documentation page.

Craig Peterson has completed construction of a vacuum chamber that will be used for component and assembled avionics testing of the DSS payload. The vacuum is intended to simulate the reduced air pressure at 33 km altitude (=1% that of ground level). The vacuum chamber, measuring 6” (150mm) ID and 40” (1000mm) long, also features an airtight 24-pin connector to allow interfacing of the test article to externally mounted equipment.
Jacob Ferriera reports that he has received the software disc sent by SolidWorks loaded with donated CAD based drawing and analysis tools. In return, Dassault Systèmes SolidWorks Corporation has been added to our Sponsor page.
The Documentation page has been updated with three DSS BP technical documents.

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