Delfi-PQ

TU Delft’s 3P technology pathfinder

Delfi-PQ was a $3\text{P}$ PocketQube ($50\times 50\times 178\text{mm}$, $545\text{g}$, backplate $58\times 192\times 1.6\text{mm}$) developed at Delft University of Technology (TU Delft) as the successor to Delfi-C³ and Delfi-n3Xt[1][2]. Launched on 13 January 2022 aboard SpaceX Falcon 9 Transporter-3 from an AlbaPod v2 deployer into a $525\text{km}$ Sun-synchronous orbit, it operated continuously until atmospheric re-entry on 6 January 2024 after $723\text{days}$ in orbit[3].

The PQ9 bus and thermal-structural verification

Delfi-PQ established three engineering references for the PocketQube community:

1. PQ9 subsystem standard: Internal $42\times 42\text{mm}$ boards were interconnected via the open PQ9 nine-pin stack header carrying a differential RS-485 data bus and switched power lines[4].
2. Thermal-structural design: Uludağ et al.[2] and later flight-data comparisons[5] documented the structural loads on the $192\text{mm}$ sliding backplate, the $4\text{mm}$ lateral clearance envelope and the in-orbit temperature profiles of the $3\text{P}$ stack.
3. Orbital decay benchmark: Because Delfi-PQ ($545\text{g}$, $3\text{P}$) and Grizu-263A ($237\text{g}$, $1\text{P}$) separated from the same Transporter-3 deployment cluster into the same $525\text{km}$ orbit during the rise of Solar Cycle 25, their observed lifetimes ($723\text{days}$ vs $628\text{days}$) provide a direct pair of ballistic-parameter calibration points[3].