The CubeSat standard (CubeSat Design Specification Revision 13) requires that CubeSats have a remove before flight (RBF) pin that "shall cut all power to the satellite once it is inserted into the satellite." Most space missions require an RBF pin in order to protect the operators who integrate the spacecraft into the rocket's payload bay.

Pumpkin's pricing list (pgs. 10, 22) includes a custom, Pumpkin RBF bracket kit and pin, and this forum suggests some ideas for using non-switches as the RBF pin. However, I want to know: are there standard, mass-market electronic switches that come in a pin inhibit form that spacecraft developers use or are most RBF pins custom made by the spacecraft developer?


1 Answer 1


I'm sure there are several types of standard RBF designs available by vendors and that you can get recommendations and good prices from other CubeSat makers or CubeSat satellite bus makers. But before a specific RBF design is selected, I suggest you think through all the requirements and design constraints on your particular RBF device.

You have the key functional requirement that an RBF pin system be used and that it shall cut all power to the satellite. I think there's also an accessibility requirement in the design spec you referenced above. I don't know what a non-switch is or a switch with pin inhibit, so before you select make sure you go through how it's going to be used.

The RBF pin should be designed to fit tightly when inserted and secured so that an accidental pull on the flag doesn't pull it out. It should also fit tightly during transportation and handling. Also note that a pin is often required to protect spacecraft bus flight hardware from damage from your payload hardware as well as personnel. When the pin is removed, it might be by you or perhaps by someone else who is not as careful. The pin should pull out clean and the switch or whatever it was protecting should close firm and clean.

If the pin has to be reinserted, it has to be accessible and testable. That task also needs to be firm and clean. Once the pin is out, the switch or whatever needs to close and remain closed for the remainder of the mission. I elaborate about firm and clean device operation because of comments I read elsewhere in this stack exchange suggesting use of modified clothes-pins or handmade plastic parts, which would save money and maybe mass but which I would strongly recommend against because of the criticality of this device.

My answer is qualified by the fact that I have not done mechanical or electrical design, but I've been in the spacecraft to launch vehicle integration business for 35 years, and have experience on both sides of that interface in high level system engineering and project management roles.

Good luck.


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