Haloship

Launch video

We planned to launch on the second day of the competition. Weather and final system checks moved the flight to day four.

The video follows most of the flight, though the camera loses focus just before the main parachute deploys.

Designing around the constraints

Assembly and recovery

Building a sounding rocket in the UAE meant working with limited access to pyrotechnics and solid fuel grains, then transporting the finished rocket to the United States. Those constraints shaped two parts of the design: the structure and the recovery system.

For recovery, we wanted a release mechanism we could reset and test without replacing explosive charges or shear pins. We developed a mechanically and electrically redundant hold-down and release mechanism (HDRM), and used simulations to study its behavior under flight loads and as its components wore over time.

For the structure, we wanted to avoid committing to permanent joints early in development. Mechanical subassemblies let us adjust the layout while keeping modifications to the airframe small. We could disassemble Haloship, pack it into a suitcase and put it back together in a few hours in New Mexico. After the flight, we took it apart for the journey home.

Modeling before manufacture

We modeled the full assembly in CAD, including the fasteners, and linked components to supplier part numbers in a bill of materials. That gave us a record of what went into the rocket and a way to source replacement parts while traveling.

The assembly also supplied center-of-gravity and moment-of-inertia estimates for trajectory simulations. We connected it to structural and aerodynamic models to study the loads we expected in flight and revise the design before manufacture.

We could not launch the rocket in the UAE, so simulation played a large part in preparing the release mechanisms for their first flight. The launch in New Mexico was the opportunity to see those mechanisms operate under flight conditions.

The structure

Taperbushes

Taperbushes let us mount internal components without drilling through the airframe or bonding a bulkhead in place. They also let us reposition components during assembly.

Each taperbush uses two interlocking rings. Tightening them together wedges a slotted outer ring against the inside of the airframe. The angle between the rings determines how the tightening force translates into radial clamping force.

We used versions of this arrangement near the ends of tube sections to secure metal 3D-printed couplers, and around the fins to grip both the airframe and the motor mount tube.

Fin brackets

Self-aligning brackets clamp the fins to the motor mount tube without an epoxy joint. They help control fin cant, which can induce roll, and allow us to change the fins to suit different stability requirements.

The brackets cap the taperbushes at both ends to limit axial movement. Multiple attachment points distribute the loads and help resist fin flutter.

Aluminum couplers

We used aluminum to keep the couplers short. The joints are held in compression during flight, with grooves that prevent adjoining sections from rotating relative to one another.

The male couplers attach to the electronics bay and provide mounting points for the HDRMs. The female couplers center the parachute tubes and guide spring pistons. During deployment, those pistons push against the male couplers to separate the sections.

Threaded rods

Threaded rods run the length of each rocket section. Anchored by taperbushes at both ends, they hold the airframe tube in compression. Lips on the couplers bear against the phenolic tubing, completing the load path.

The rods also provide mounting points for the avionics, payload and recovery assemblies.

Inside the rocket

Haloship has three main sections: the motor section, the electronics bay and the payload section. Two HDRMs hold them together until parachute deployment.

Motor section

The motor section houses the drogue parachute and the spring pistons that push the sections apart during deployment. A tensioning mechanism keeps the coupler joint compressed before release. The HDRM holds the joint closed; the springs supply the separation force.

Electronics bay (e-bay)

The electronics bay houses the avionics and two mirrored HDRMs. The lower mechanism connects to the motor section, and the upper one connects to the payload section.

The avionics sit on separate plates for power distribution and regulation, flight computers and GPS tracking, and servo interfaces. We arranged the plates in a triangular frame, inspired by the inside of Apple’s cylindrical Mac Pro.

Shaft collars attach the frame to the threaded rods, so we can adjust its position and replace individual plates without dismantling the whole assembly.

Payload and nose cone section

The payload section carries the main parachute, its deployment springs, a tensioning mechanism and the payload itself.

A taperbush rests against an internal edge of the nose cone and connects to the threaded rods. It transfers parachute deployment loads into the nose cone shoulder and airframe. As a backup, a thicker rod extends to the nose cone tip, where it connects to an adhesive stud mount embedded in epoxy.