NASA's Student Launch competition gives student rocketry teams a new payload mission each year, and the 2026 cycle asked teams to do something deceptively difficult: land a rocket, deploy a payload, and retrieve a 50 mL soil sample for on-site testing, all without modifying the rocket's nosecone.
The Alabama Rocketry Association (ARA), a student organization at the University of Alabama, took on this challenge with a payload that needed to obtain a soil sample and test it for nitrogen content, pH, or electrical conductivity. Since the competition rules treat the nosecone as part of the airframe, the team had to fit an entire sampling mechanism inside a space that was never designed to hold one.
Technical Specifications: For more info about the specific product used in this application, check out our P16-P Actuator Product Page
Engineering Constraints
The nosecone restriction created the hardest part of the design problem. A nosecone is small, tapered, and not built to house moving parts, so the team had to fit a multi-step sampling mechanism into a space that was never meant for one. They broke the problem down into three constraints they had to solve at once:
- Space: The actuator and motors had to share a tight, tapered volume without modifying the airframe.
- Motion sequence: Getting a soil sample meant combining several distinct movements: deploying out of the nosecone, angling the auger into position, and driving it into the ground.
- Survivability: Every component had to handle the G-forces of launch and the shock of landing, then still work correctly afterward.
Selected Solution
The team chose the Actuonix P16-P linear actuator, configured with a 150mm stroke and 64:1 gearing. According to the team, they spent several days looking for an actuator that hit both the stroke length and the compact housing they needed before landing on the P16-P.
The actuator handles two jobs in the final design. It provides the linear motion that lowers the auger into the soil and pulls it back out once sampling is done. It also works as a structural member, connecting moving parts of the payload to the rest of the assembly, which matters when there is no spare room for extra brackets or frames.
The full sequence runs through three DC motors working alongside the P16-P:
- One motor and a lead screw push the payload assembly out of the nosecone after the rocket lands.
- A second motor angles the auger system into drilling position, since the nosecone's taper means the auger can't sit straight.
- A third motor spins the auger while the P16-P lowers it into the ground.
Rotation, linear travel, and a set of deployable sleeves work together so soil can climb up into the payload, where the team measures it.
The team ran a demonstration launch ahead of the competition to test the assembled payload as a complete system, working through the full deployment, angling, and drilling sequence under real launch conditions rather than on a bench. That kind of end-to-end test is what gives a design team confidence going into competition day, since it surfaces any mounting or sequencing issue while there's still time to fix it.
Specification Snapshot:
- Actuator: Actuonix P16-P
- Stroke length: 150mm
- Gearing: 64:1
- Supporting motors: 3 DC motors (deployment, angling, auger rotation)
Pro tip for similar builds: When an actuator also has to act as a structural link between moving parts, keep side loading to a minimum. A linear actuator is built to handle force along its stroke, not from the side, so any off-axis load from vibration or impact should be carried by a separate bracket or guide rail wherever possible.
FAQ: Soil Sampling Payload Design
Why couldn't the team just modify the nosecone to fit a bigger mechanism?
NASA's Student Launch rules treat the nosecone as part of the airframe, so altering it isn't allowed. That rule is what pushed the design toward a compact actuator and a folding, multi-step deployment sequence instead of a simpler, larger mechanism.
Why use three separate motors instead of one mechanism doing everything?
Each motor handles a different kind of motion: deploying the payload, angling the auger, and spinning it. Splitting these into separate motors keeps each part simple and lets the team troubleshoot or replace one function without redesigning the whole assembly.
Why use the P16-P actuator?
The P16-P gives the team high force output in a relatively compact package, which is what driving an auger into compacted soil requires. For a payload squeezed into an unmodified nosecone, that balance of force and size matters more than raw speed. A faster but weaker actuator would have struggled to push the auger through the ground, while a stronger but bulkier one would not have fit the available space.
How do you know an actuator will survive launch G-forces?
The most reliable way is testing in the actual mounting configuration. For this kind of payload, that means running a demonstration launch before the competition itself, so any issue with vibration, shock, or mounting shows up early enough to fix.
Moving From Theory to Application
Tight spatial constraints and demanding load conditions are common across aerospace and competition-vehicle projects alike. Whether you're building a payload that has to fit inside an unmodified nosecone or a mechanism that needs to double as a structural member, the right actuator selection comes down to understanding the real trade-offs between force, speed, and size.
If you need assistance selecting a product that meets your application requirements, please contact our sales team for assistance. Actuonix can create custom designs for all OEMs.
