Hot & Cold: The FINCH Thermal Simulator

Thermal modelling is an integral part of thesatellite design process. However, detailed simulations require high-fidelity models and resources that are not readily available in the preliminary design stage. To gain insight into the on-orbit temperature ranges and heatloads that FINCH, a 3U hyperspectral imaging CubeSat, will experience, a six-node numerical model was developed in MATLAB. This model was developed as an alternative to industry modelling software during preliminary design stages. The model: Allows teams to conduct rapid iteration of thermal design with reduced barrier to entry. Provides a platform to make informed decisions early in the design cycle. Encourages a first principles understanding of heat transfer and thermal modelling

HERON: Demonstrating a Novel Biological Platform for Small Satellite Missions

Long-duration deep space missions pose a significant health risk for both humans and their resident microorganisms. The GeneSat, PharmaSat and O/OREOS missions have previously explored biological questions regarding the effects of spaceflight on S. cerevisiase, B. subtilis, and E. coli. However, there currently exists both a knowledge and an accessibility gap in small satellite biological experiments. These payloads require precise instrumentation and complex platforms that are usually reserved for large research organizations. This makes it difficult for smaller organizations to perform biological research in low Earth orbit (LEO). To address these challenges, the University of Toronto Aerospace Team (UTAT) Space Systems Division is currently developing the HERON CubeSat. HERON houses a payload platform which measures the effects of the LEO environment on the gene expression and drug resistance of Candida albicans, a yeast commonly found in the human gut microbiome. Previous research has suggested that C. albicans might display increased pathogenicity and drug resistance in response to microgravity, which has important implications for long-duration human spaceflight. The yeast cells are housed in custom acrylic microfluidics chips containing 32 wells with channels for media and drug delivery. A measurement printed circuit board (PCB) contains custom optics capable of measuring minute changes in cell fluorescence. The entire payload stack is then housed in a temperature- and humidity-controlled 2U pressure vessel. Space Systems as a whole is an undergraduate student-led and student-funded design team, dedicated to the development of small satellite missions with a focus on education and undergraduate learning. HERON is scheduled to launch Q1 2022 into a Sun-synchronous orbit via a SpaceX Falcon 9 rocket at an altitude of approximately 550 km. Our platform is open-source and can serve as a low-cost template for future biological CubeSat missions. This paper serves as a technical and scientific description of the platform, along with the lessons learned during the payload design, assembly, and validation processes

Inspiring the Next Generation: Challenges and Strategies for Onboarding and Retention in an Undergraduate CubeSat Design Team

The University of Toronto Aerospace Team (UTAT) Space Systems Division is a fully student levy-funded, student-led undergraduate design team that develops CubeSats with research-oriented payloads. UTAT’s mission is to provide undergraduate students with unique opportunities to develop engineering design skills outside of the classroom, and therefore has a distinct focus on member growth and education. As an undergraduate student team, UTAT faces a unique set of challenges in onboarding members and maintaining a strong knowledge base on the team. These challenges include onboarding members with limited technical experience, equipping them with satellite design skills, and maintaining high interest levels among volunteer members with limited time to contribute. The team has implemented a wide range of strategies related to onboarding and member development over the past two years. Notable examples include hosting workshops and regular work sessions, and employing practice projects for technical skill development. This paper presents these practices in depth and evaluates their impacts using both quantitative and qualitative metrics of team success including retention rates, team demographic data, and individual perceptions of team dynamics. It also evaluates these practices against scientifically backed models, while evaluating the effectiveness of these models in the student team environment. Lessons learned include the importance of emphasizing a culture of inclusivity and psychological safety as well as utilizing workshops and skill-building modules both in the onboarding phase and throughout the year to generate and maintain interest in the team. The practices presented here are relevant and transferable to similar organizations including student teams, industry projects, and research initiatives

Targeting acute myeloid leukemia by dual inhibition of PI3K signaling and Cdk9-mediated Mcl-1 transcription

Resistance to cell death is a hallmark of cancer and renders transformed cells resistant to multiple apoptotic triggers. The Bcl-2 family member, Mcl-1, is a key driver of cell survival in diverse cancers, including acute myeloid leukemia (AML). A screen for compounds that downregulate Mcl-1 identified the kinase inhibitor, PIK-75, which demonstrates marked proapoptotic activity against a panel of cytogenetically diverse primary human AML patient samples. We show that PIK-75 transiently blocks Cdk7/9, leading to transcriptional suppression of MCL-1, rapid loss of Mcl-1 protein, and alleviation of its inhibition of proapoptotic Bak. PIK-75 also targets the p110α isoform of PI3K, which leads to a loss of association between Bcl-xL and Bak. The simultaneous loss of Mcl-1 and Bcl-xL association with Bak leads to rapid apoptosis of AML cells. Concordantly, low Bak expression in AML confers resistance to PIK-75–mediated killing. On the other hand, the induction of apoptosis by PIK-75 did not require the expression of the BH3 proteins Bim, Bid, Bad, Noxa, or Puma. PIK-75 significantly reduced leukemia burden and increased the survival of mice engrafted with human AML without inducing overt toxicity. Future efforts to cotarget PI3K and Cdk9 with drugs such as PIK-75 in AML are warranted