We plan to implement a “soft stow” flight configuration during our vibration testing campaign, meaning that hardware components will be restrained with soft, flight-equivalent materials such as foam and bubblewrap. We selected a soft stow profile as it reduces the risk of over-constraining or harming sensitive components during testing, and also better simulates an actual in-flight environment. Furthermore, items within the soft-stow configuration do not experience intense mechanical shock, eliminating the need for a standalone shock test and thus minimizing costs, as well. It is important to note that the choice of stow configuration is also dependent on the decisions of the deployer or launch provider. We will only effectuate a “hard stow” profile if external specifications require as such. Our vibration testing program consists of the application of broadband vibration to three perpendicular axes for 1 minute, with a frequency band spanning from 20 Hz to 2000 Hz, and the acceleration spectral density (ASD) spanning from 4e-2 g2/Hz to 2.6e-3 g2/Hz.

Sinusoidal vibration testing—in particular, low-level sine sweep testing—will be implemented into our testing program if required by our deployer or launch service provider. This type of testing involves slowly sweeping through a range of frequencies to detect structural resonances and ensure no abnormal responses. If we receive instructions to perform a low-level sine sweep on our flight hardware, we will conduct the test prior to random vibration testing, as the former involves harsher vibrational conditions that may attack any hidden vulnerabilities; the low-level sine sweep would essentially act as a “pre-check” routine in our vibration testing scheme.

Thermal vacuum cycling simulates the LEO rapid temperature swings in a vacuum cycle. It is a crucial component of our thermal testing campaign and the verification of a flight-ready spacecraft as it will match the heat transfer conditions of space, allowing for proper detection of hardware and manufacturing defects, and confirmation of expected component functionality. These tests also include thermal balance tests; instead of reproducing rapid, extreme temperature swings, the balance tests will hold the spacecraft at a steady-state hot and cold temperature. In sum, the balance tests act as a calibration check for our thermal design, allowing us to verify that our thermal control system’s components remain within temperature limits under both worst-case hot and cold conditions. The vacuum cycling tests will be performed at vacuum levels of 10 x 10-4 Torr. The maximum temperature range will be set to be MPE +/- 5℃, the minimum range -9 -3/+0℃, and the minimum temperature rate of change will be 5℃/min. The number of cycles will be 4, with a dwell time of one hour at extreme temperature after thermal stabilization.

The thermal vacuum bakeout test is a crucial component of contamination reduction for the spacecraft hardware. Outgassing—the release of volatile compounds from materials such as adhesives or plastics—risks degrading performance as vaporized contaminants may condense on sensitive surfaces. In order to protect our lenses, sensors, heaters, and similar vulnerable components, we will utilize a residual gas analyzer to determine outgassing levels and remove any possible volatile contaminants that hinder our mission’s success. The bakeout test will be performed at vacuum levels of 1 x 10-4 Tor, at a minimum temperature of 70℃. We aim to ensure a minimum temperature rate of change of less than 5℃/min, with a minimum dwell time of three hours after thermal stabilization. In terms of safety requirements for the bakeout test and recorded outgassing values, all non-metallic materials that will be exposed to the vacuum environment must be documented in the spacecraft’s Bill of Materials (BOM). Each listed material shall comply with outgassing limits defined by NASA’s materials standards, specifically a Total Mass Loss (TML) of no more than 1.0% and a Collected Volatile Condensable Material (CVCM) content of no more than 0.1%. No exceptions will be granted based on the anticipated duration of vacuum exposure, as the spacecraft will operate in the vicinity of the International Space Station (ISS), where contamination control requirements are strictly enforced. We will also utilize the BOM in the formation of a Material Identification Usage List (MIUL) to reinforce compliance with enforced regulations. All materials deemed by toxicologists to be above THL 2 will be noted in our Ground Safety Package in compliance with toxicity safety regulations.

Our electronic burn-in test, necessary for the detection of defective components, will consist of long-term, continuous operation of the spacecraft’s electrical parts. The sustained burn-in conditions will allow us to detect any early-life failures of the spacecraft before launch, and to verify the spacecraft’s long-term, in-orbit operational stability and overall survival. The burn-in test consists of the combined duration of all other thermal testing—that is, vacuum cycling and bakeout—with an additional burn-in period of at least 100 hours. If the spacecraft maintains its functional and structural integrity over these 100 hours failure-free, then we will be able to verify the completion and success of the test. Note that this test may be performed at ambient pressure.