Notes on payload and avaionics bay design and construction

The following notes show the design and evolution of a payload bay for high power rockets. Initially, the specification was for a universal payload bay, but with each test launch, it became apparent, that a universal design is too much of a compromise, and one will never gain the advantages of a design optimised for a particular vehicle size.

A universal design will either be:

Learning all this through (at times frustrating) practical experience, it became apparent though, that although a universal payload bay itself was a compromise, there were a number of simple techniques that could be applied on any size payload bay, that would make elements within the payload bay more modular, and far easier to work on. Examples of this include:

  • 1. Rechargeable battery packs - moving to rechargeable battery packs means batteries do not need to be plugged in and out before and after each launch.

  • 2. Common power connectors for altimeter connections

  • 3. Terminal posts permanently attached to each bulkplate to wire up ejection charges, and with cables soldered to the terminal posts.

    Benefits: Ejection charges can be attached to full sealed up payload bays, reducing prep time, and increasing safety, due to there being less cables to disturb without needing to slide in and seal up the payload bay with ejection charges fitted.

  • 4. Common ejection charge connectors attached to the Terminal Posts, for connection to altimeters.

    Benefits: Reduced prep time, and improved modularity.

  • 5. A common wiring harness - using a common wiring harness in each payload bay, means regardless of payload bay size, the only components that need to be transferred between payload bays are altimeters, payload bay trackers and rechargeable batteries

  • 6. A built in avionics port for ground based serial communications and power charging.

    Benefits: A built in avionics port enables communication with onboard altimeters and charging of batteries without removing them from the payload bay. Both conditions normally result in considerable time taken to open up the payload bay, so the benefits of not having to open up the payload bay, and being able to plug in, are considerable. This has a major benefit of faster prep time for rapid turnaround between launches.

  • See Also

    Hybrid Rocket Science, Hybrid Rocket Help Clinic, Amateur Hybrid Motors, Amateur Liquid Rockets, Guidance, Gimballed Motors, Launch Controller, UK Rocketry Vendors, UK Rocket Groups, UK Space Organisations