Integration and Delivery of the Deployable Optical Receiver Aperture (DORA) Cubesat

The Deployable Optical Receiver Aperture (DORA) experiment is a pathfinder for large-scale space-based radio interferometry with experiments addressing scalable laser communications within swarms and precision low frequency radio astronomy instruments. The collection of prototype instru-ments will characterize background noise which might limit future optical links and radio astronomy measurements. The DORA laser terminal concept uses arrays of solid state optical/ infrared sensors to form a wide-field high sensitivity detector theoretically capable of speeds up to 1 Gbps at a range of up to 1000 km between cubesats without requiring precision pointing. The freedom to rotate as needed for science or power purposes, without interrupting data transfer, will enable future swarm radio arrays of free-flying antennas operating as a single correlated array. The first DORA mission aims to test fly a silicon photomultiplier sensor and measure background light from reflected sunlight, moonlight and city lights. DORA's radio pathfinder aims to flight-test compact solid-state radio technol-ogy needed for precision low-frequency receivers targeting the cosmic dawn and epoch of reionization. Solid-state RF (radio frequency) switches and related elements which have not yet been demonstrated in space at the precision necessary have been formed into a dual-mode radio spectrometer attached to a deployable monopole antenna. A filter bank VHF (very high frequency) spectrometer provides continuous monitoring from 20 to 180 MHz spectrum in 20 MHz channels while a miniature software defined radio makes high spectral resolution scans of the same band. The satellite was built and tested by students in Arizona State University's (ASU) Low frequency Cosmology Lab and ASU's Interplanetary Initiative Lab (IPL). Vacuum testing, vibration testing, and day-in-the-life testing were all performed at ASU. The design and build began during the Covid pandemic which had many effects on the availability of people and components. As a result, late changes to payload, structure, and power systems were necessary. During testing, there were several component failures, all of which were resolved before delivery. These can ultimately be traced to late changes and provide instructive examples for future projects. DORA was aboard Northrop Grumman's 21st Cygnus flight on August 4th and was deployed on October 8th, 2024. Connection to DORA was maintained until November 27th, 2024, and on December 1st, it is estimated to have re-entered Earth's orbit. [1]