During my experiments with molten mixtures of ascorbic acid and sorbitol I found - if the mixture was heated to a certain temperature range - that a liquid condensed on the cooler parts of the glas which had a strong and sweet odor of bitter almond.
The experiment was then repeated with a distillation apparatus as shown below. The result after heating the mixture for 10 minutes at 140°C was a tar like residue and a yellowish liquid distillate. The distillate had a strong odor of bitter almond, the residue a caraway odor.
It could be also possible that salicylaldehyde or furfural has been synthesized as it has a bitter almond odor too.
Unfortunately the Fehling test was negative for the distillate as it is not sensitive enough for such small amounts.
Highlights of recent developments on the MiniSShot project
Flint Hapirat has completed a draft of the Launch Report for MSS-2, and has submitted the draft to Richard for review.
Highlights of recent developments on the DoubleSShot project
Richard Nakka and Blair Nakka have completed machining the Forward Bulkhead for the new DSS BPS motor.
The large 1.25" (3.2 cm) hole is for a frangible burst disc to prevent overpressurizing the cavity between the Forward Bulkhead and the Delay Plug in case of significant blow-by.
Paul Avery has completed the design of a new and more powerful pyrogen unit for the DSS BPS motor. Paul reports that he has decided on a size, and has:
1. ordered delrin mandrel stock
2. rolled several casting tubes
3. machined an aluminum base and top cap for a casting stand This past Sunday, an avionics telecon was held to report progress and determine upcoming actions. Participants in the telecon were Chris King, Rick Maschek, Matt Campbell, Hans Olaf Toft, Mattias Lampe, Craig Peterson and Richard Nakka. Chris reported that he has completed a draft of the revised DSS Avionics Requirements document, which was submitted to Richard for review. Chris also completed a draft of a test plan for "high altitude" testing of batteries that will tentatively be used for the DSS flight. The testing will be done by Craig utilizing the vacuum chamber that he recently built.Rick provided good input on potential video cameras for the flight, such as the USB "spy camera" model.
Mattias reported excellent progress on the ring antennas that he has prototyped. The first image shows the PCB with the antennas laid out. The third image shows the prototype ring antennas cut out. Mattias plans to conduct testing of the antennas in the near future, including an assessment of any interference with the GPS antenna that will be mounted forward of the ring antennas in the nose cone.The next avionics telecon will be on Sunday, Nov.6th.
Marc Davis has once again volunteered to produce CAD drawings of the DSS BPS motor parts. Marc has completed the casing drawing which was forwarded to Randy Dormans. Randy has procured the 6" (15cm) steel tubing for the casing and reports that "all hole locations are indexed and I am currently in the process of drilling to them to the final diameter (three passes each).The casing should be finished by this weekend."
Marco Torriani reports that the prototype DSS "test fins" have been mounted on a 400 mm four-layer fibreglass tube which he recently fabricated.Marco has bonded the fins' "foot" and laid carbon fibre over the aluminum foot to reinforce the attachment point. Marco also reports that he has performed an empirical load test on the fibreglass tube, loading 140 lbs (64 kg) with "no problem" Once the epoxy will be fully cured Marco will do a similar (ad hoc) testing of the fins with 100 (45 kg) lbs "just to make sure" before the fin/tube assembly is shipped to Bert Kimpe for official structural load testing.
Richard Nakka and Blair Nakka have begun machining the Forward Bulkhead for the new DSS BPS motor.
Paul Avery has begun designing a new and more powerful pyrogen unit for the DSS BPS motor. The new unit is roughly double the size of that used for the DSS BP motor to ensure a rapid start-up.
Markus Bindhammer has performed additional research into eutectic propellant formulations. The latest experiment deals with the production of Golden Powder, which refers to a mixture consisting ofpotassium nitrate as an oxidizer with ascorbic acid as a fuel: Eutectic Sugar Propellant Research Part V
Based on feedback, Hans has updated the report Flight Controller and Trajectory Map.This document deals with the pairing of pyro devices and flight controllers for the DoubleSShot flight, andadditionally deals with the nature of the recovery process.
According to Captain Bertrand R. Brinley's 1960 book, Rocket Manual for Amateurs, chapter 3, page 96-97, increases the power of an explosive as the cube of the weight. "Two ounces of an explosive is 8 times as powerful as one ounce. Three ounces is 27 times as powerful. Five ounces is 125 times as powerful."
We have seen how 3g 170°C hot liquid eutectic KNO3-NaNO3-Mannitol deflagrates. If this rule of thumb is true, 1kg liquid eutectic KNO3-NaNO3-Mannitol would be around 3333 = 36926037 as powerful as 3g. Difficult to imagine, but if it is even much less, hot liquid eutectic KNO3-NaNO3-sugar alcohol could be considered (and used) as an explosive. Solid eutectic KNO3-NaNO3-sugar alcohol is cheap, very easy to manufacture and safe to handle.
Liquid eutectic KNO3-NaNO3-sugar alcohol could be cast in an according heat- and pressure-proof container. The container would then be closed after the eutectic KNO3-NaNO3-sugar alcohol is hardened and encased with a heat up charge (end burner configuration). While the heat up charge burns away it would heat and liquefy the eutectic KNO3-NaNO3-sugar alcohol inside the container. It would need to be determined, which effect the pressure increase in the container has on the melting point of the KNO3-NaNO3-sugar alcohol. However, the pressure increase will increase the burn rate further.
Ignition of the liquid KNO3-NaNO3-sugar alcohol can be finally done by an electric match or reaching the auto ignition temperature of the sugar alcohol by the heat up charge.
Highlights of recent developments on the DoubleSShot project
The design is currently underway for a replacement static test motor. This motor, deemed DSS BPS (Boiler Plate Single-phase), will be essentially identical to the BP motor recently test fired. Except that it will be a single burn motor. This will allow us to test the design concept of the star grain, gather performance data, and to verify the behavior of the Delay Plug. The investigation into the BP anomaly has pointed to a breech of the Midbulkhead as a probably cause. Hot gases in the aft chamber pressure port channel (drilled into the Midbulkhead) likely caused a fracture of the Midbulkhead ablative liner, allowing the hot exhaust flow into the forward chamber, thereby igniting the grain (specifics of the likely cause of the anomaly will be detailed in a Test Report to be published in the future). The new motor will be fitted with the Midbulkhead at the forward end, with the Delay Plug cast into place. A "forward bulkhead" will be added to seal off the chamber forward of the Midbulkhead, fitted with a pressure sensor to detect any possible breech of the Midbulkhead seal.
Rick has completed his examination of the DSS BP motor's parts and has determined that the nozzle and Midbulkhead are in good condition and will be used for the new motor. The Midbulkhead ablative liner was found to be completely missing.View of Midbulkhead:
View of the interior wall of Midbulkhead:
(photos courtesy Rick Maschek)
Rick has completed measurements of the circumference of the "ballooned" forward casing. It is clear that the forward casing experienced particularly high pressures (>2000 psi) which severely strained the metal. The permanent strain was significantly more than the aft casing, as is seen in the following table and graph:
Randy Dormans has kindly agreed to drill the precision located nozzle and bulkhead attachment holes (75 total)in the motor casing. Randy reports that he has obtained a length of the 6" schedule 10 pipe for the motor casing and will start work on this task very soon. Randy had similarly procured and prepared both motor casings for the DSS BP motor.
Craig Peterson has kindly agreed to once again machine the custom modified cap screws for the nozzle and bulkhead attachments (75 plus spares).
Paul Avery has agreed to work on repairing or replacing the static test stand for the new motor. Paul has also taken on the task of developing a new, more powerful pyrogen unit for igniting the motor.
Alberto has updated the documentation page of the SS2S website with the four reports written by Markus Bindhammer on eutectic sugar propellant research.