SARP’s current rocket, Pacific Impulse, is a student-designed and manufactured liquid bi-propellant rocket and is designed to compete in the Friends of Amateur Rocketry’s (FAR) Dollar Per Foot challenge (DPF). The rocket employs an oxidizer and fuel combination of nitrous oxide and ethanol, respectively. Its structures are manufactured from aluminum, fiberglass, and carbon fiber.

Due to the COVID-19 Pandemic, physical progress was halted in mid-March 2020, when the Propulsion and Structures teams were in the midst of manufacturing. Manufacturing started again in February 2021 and we are currently in the testing phase.

In its current state, Pacific Impulse will have an 8-inch outer diameter and will be 20 feet tall. It will weigh approximately 160 pounds dry and 190 pounds wet.

Structures

The vehicle will have a carbon fiber body with sections, including the nose cone, made of radio-transparent fiberglass so that signals can be transmitted to and from the internal electronics. Aluminum couplers attach the nosecone to the rest of the airframes as well as the recovery bay to the propulsion system assembly.

The vehicle’s fins will be manufactured from honeycomb core sandwich panels that are co-cured with a carbon fiber body tube using an integration ply stack.

The recovery system is a dual-deployment system with a student-manufactured toroidal drogue (6ft diameter) and main (13ft diameter) parachutes. The drogue is deployed by the nose cone ejection system which uses CO2 canisters to pressurize the parachute bay. The main is deployed by the parachute stage separator which uses a student-designed and manufactured system similar to the COTS Tender Descender. Both deployment systems use black powder and are triggered by two fully redundant altimeters (one Raven4, one Raven3).

propulsion

The rocket’s O-class motor will utilize an 75% ethanol/water blend as fuel, nitrous oxide as an oxidizer, and helium as an onboard pressurant to produce an average thrust of approximately 1200 lbf.

The propellant tanks are machined out of aluminum and welded. The onboard fluid routing system was designed for the pressurant, fuel, and oxidizer to safely flow through the rocket. The pressurant and oxidizer tanks are filled using a remotely operated fill stand designed by the team.

The thrust chamber assembly is made up of the aluminum combustion chamber, the pintle injector and its bulkhead, the phenolic pre-combuster, a rocket candy igniter, and the graphite conical nozzle.

avionics

The avionics on the rocket transmit signals to and from ground control, including valve actuation and tank pressures. Telemetry sent to ground control includes GPS location, vehicle orientation, angular velocity, acceleration, and barometric data. Onboard computers record data during flight to be retrieved post-recovery. The Avionics team is responsible for operating the remote fill stand to load pressurant and oxidizer to the rocket while on the launch rail and when all personnel are evacuated from the launch site.

payload

The payload will be an autonomous drone that maintains communication with and flies in close proximity to the descending rocket. A suite of sensors onboard the drone, including a camera, will allow for data collection throughout the flight.