During development of the Deimos 2 and Deimos 3 vehicles, it was realised, that a series of small amateur hybrid rocket motor propelled vehicles would be useful as a tool to test hybrid motor designs and systems for the larger hybrid rocket motor powered vehicles, as well as for use as hybrid upper stages. This premise was the basis for the "Deimos Propulsion Test Vehicle" programme, or DPTV for short.
Deimos PTV1 was a small technology demonstrator, used to test the theory of an all-composite hybrid propulsion system. The motor was a 32mm diameter fibreglass/epoxy cased hybrid, mated to a 32mm diameter glass/epoxy oxidiser tank. The hybrid rocket motor worked perfectly, delivering around 8kg of thrust for 7 seconds+.
Deimos PTV2 was a larger motor/vehicle utilising a 58mm diameter oxidiser tank and hybrid combustion chamber, again, of glass/epoxy construction. This vehicle is currently undergoing both flight and static testing, and should provide a reliable workhorse hybrid rocket motor test vehicle that, using different injectors and oxidiser tanks, can deliver between 15 and 30kg of thrust for between 3 and 15 seconds.
MARS are planning to expand the DPTV series next to include a larger Deimos PTV3 hybrid rocket motor powered vehicle in the near future, giving the group a wide range of readily available hybrid boosters, capable of lifting small payloads to between 3000ft and 30,000ft for negligible per-flight cost.