Short for “Pipeline Identification”. Messages are sent to “Pipes”. They’re like mailboxes that are unique to a given Task. Messages stack up in a queue (pipe) until they’re processed by whatever service owns it. What can be confusing initially is that Pipeline IDs are only unique on a given processor. If your system has two processors, there could be two Pipeline IDs called “112”. However, since Tasks run on their own threads on a given processor, Tasks don’t get confused. It’s like how there could be multiple houses with the address “123 Main St.” but since they’re in different zip codes, mail still gets delivered correctly.

Pipes are managed by the Software Bus service.

Short for “Packet”. A Packet, as defined by the CCSDS, has three parts: a primary header, a secondary header, and a data section. In other words, it states what type of data it holds, additional information (such as the time it was sent), and then the data itself. A packet is the smallest collection of organized data that you can send.

Short for “Programmable Read-Only Memory”. A PROM can be written to once with data and then be queried for that data “forever”. But you only get one shot… a PROM cannot be written to a second time. Despite this limitation, they’re important because you can reset the computer or store it for years and the data will still be there. This is great for parameters that will never change (like hardware configuration parameters) because PROM tends to be better protected against radiation, temperature, and other effects that other memory types can be wiped out by.

An alternative is EEPROM, which is “Electrically Erasable” PROM. EEPROM lets you rewrite the contents of the PROM.

Short for “Platform Support Package”. Sometimes called the “Board Support Package”. This is the layer of code closest to your hardware. It’s got the drivers, low-level execution code, and other software specific to your unique hardware. When you power on, it’s what the operating system and Core Flight Executive layers use to initialize and talk to the hardware.

Because hardware is always changing and different companies use different variations of hardware, this is an area you may find yourself focusing on for flight hardware. However, if you’re using common hardware (like a Raspberry Pi) then the PSP is already written for you. Vendors may also have PSP software for you already, too.