This PetaPixel article details the fascinating process of designing and building a custom star tracker for astronaut Don Pettit, enabling him to capture stunning astrophotography images from the unique vantage point of the International Space Station (ISS). The project originated from Pettit's desire to create breathtaking images of star trails, showcasing the Earth's rotation against the backdrop of the cosmos. Conventional star trackers, designed for terrestrial use, were unsuitable for the ISS environment due to factors like vibrations from the station's systems and the rapid orbital speed, which presents a different set of tracking challenges compared to Earth-based astrophotography.
Driven by this need, a collaborative effort involving Pettit, engineer Jaspal Chadha, and a team at the Johnson Space Center commenced. They embarked on designing a specialized star tracker dubbed the "Barn Door Tracker," referencing its resemblance to a traditional barn door. This ingenious device employs two plates connected by a hinge, with one plate fixed to the ISS and the other housing the camera. A carefully calibrated screw mechanism allows for precise adjustment of the angle between the plates, enabling the tracker to compensate for the ISS's orbital motion and keep the camera locked onto the stars.
The design process was iterative and involved meticulous calculations to determine the required tracking rate and the optimal screw pitch for the hinge mechanism. The team also had to consider the constraints of the ISS environment, including limited resources and the need for a compact and easily operable device. Furthermore, the tracker had to be robust enough to withstand the vibrations and temperature fluctuations experienced on the ISS.
The Barn Door Tracker's construction involved utilizing readily available materials and components, further highlighting the ingenuity of the project. Testing and refinement were conducted on Earth, simulating the conditions of the ISS to ensure its effectiveness. Once finalized, the tracker was transported to the ISS, where Pettit put it to use, capturing mesmerizing star trail images that showcased the beauty of the cosmos from an unparalleled perspective. The article highlights the unique challenges and innovative solutions involved in creating a specialized piece of equipment for space-based astrophotography, showcasing the intersection of scientific ingenuity and artistic pursuit in the extreme environment of the ISS. The successful deployment and operation of the Barn Door Tracker not only facilitated Pettit's artistic endeavors but also demonstrated the potential for adaptable and resourcefully designed tools in space exploration.
The blog post, titled "Tldraw Computer," announces a significant evolution of the Tldraw project, transitioning from a solely web-based collaborative whiteboard application into a platform-agnostic, local-first, and open-source software offering. This new iteration, dubbed "Tldraw Computer," emphasizes offline functionality and user ownership of data, contrasting with the cloud-based nature of the original Tldraw. The post elaborates on the technical underpinnings of this shift, explaining the adoption of a SQLite database for local data storage and synchronization, enabling users to work offline seamlessly. It details how changes are tracked and merged efficiently, preserving collaboration features even without constant internet connectivity.
The post further underscores the philosophical motivation behind this transformation, highlighting the increasing importance of digital autonomy and data privacy in the current technological landscape. By providing users with complete control over their data, stored directly on their devices, Tldraw Computer aims to empower users and alleviate concerns surrounding data security and vendor lock-in. The open-source nature of the project is also emphasized, encouraging community contributions and fostering transparency in the development process. The post portrays this transition as a response to evolving user needs and a commitment to building a more sustainable and user-centric digital tool. It implicitly suggests that this local-first approach will enhance the overall user experience by enabling faster performance and greater reliability, independent of network conditions. Finally, the post encourages user exploration and feedback, positioning Tldraw Computer not just as a software release, but as an ongoing project embracing community involvement in its continued development and refinement.
The Hacker News post for "Tldraw Computer" (https://news.ycombinator.com/item?id=42469074) has a moderate number of comments, generating a discussion around the project's technical implementation, potential use cases, and comparisons to similar tools.
Several commenters delve into the technical aspects. One user questions the decision to use React for rendering, expressing concern about performance, particularly with a large number of SVG elements. They suggest exploring alternative rendering strategies or libraries like Preact for optimization. Another commenter discusses the challenges of implementing collaborative editing features, especially regarding real-time synchronization and conflict resolution. They highlight the complexity involved in handling concurrent modifications from multiple users. Another technical discussion revolves around the choice of using SVG for the drawings, with some users acknowledging its benefits for scalability and vector graphics manipulation, while others mention potential performance bottlenecks and alternatives like canvas rendering.
The potential applications of Tldraw Computer also spark conversation. Some users envision its use in educational settings for collaborative brainstorming and diagramming. Others suggest applications in software design and prototyping, highlighting the ability to quickly sketch and share ideas visually. The open-source nature of the project is praised, allowing for community contributions and customization.
Comparisons to existing tools like Excalidraw and Figma are frequent. Commenters discuss the similarities and differences, with some arguing that Tldraw Computer offers a more intuitive and playful drawing experience, while others prefer the more mature feature set and integrations of established tools. The offline capability of Tldraw Computer is also mentioned as a differentiating factor, enabling use in situations without internet connectivity.
Several users express interest in exploring the project further, either by contributing to the codebase or by incorporating it into their own workflows. The overall sentiment towards Tldraw Computer is positive, with many commenters impressed by its capabilities and potential. However, some also acknowledge the project's relative immaturity and the need for further development and refinement. The discussion also touches on licensing and potential monetization strategies for open-source projects.
Within the bustling metropolis of Boston, Massachusetts, the imposing Brutalist edifice known as City Hall stands as a stark testament to a pivotal era in the city's architectural and political history. Its genesis, a complex tapestry woven with threads of urban renewal, political maneuvering, and architectural ambition, is a narrative worthy of extensive elucidation. The mid-20th century witnessed a pervasive fervor for modernization sweeping across American cities, and Boston, steeped in its venerable past, found itself grappling with the exigencies of a rapidly evolving urban landscape. Slum clearance initiatives, often controversially implemented, sought to eradicate dilapidated neighborhoods, making way for ambitious redevelopment projects. This period of urban upheaval provided the fertile ground from which the concept of a new City Hall would ultimately germinate.
The existing City Hall, a structure of dignified antiquity, was deemed inadequate for the burgeoning needs of a modern municipality. Its cramped confines and outdated infrastructure could no longer effectively accommodate the expanding bureaucracy and the increasingly complex demands of governance. Thus, the impetus for a new civic center, a symbol of Boston's forward-looking trajectory, began to gather momentum. A design competition, a hallmark of democratic processes and architectural innovation, was launched, attracting submissions from a multitude of architectural firms vying for the prestigious commission. The eventual victor, Kallmann McKinnell & Knowles, presented a design that boldly departed from the prevailing architectural norms of the time.
Their proposal, a monumental structure of pre-cast concrete, embraced the Brutalist aesthetic, a style characterized by its raw, unadorned surfaces, massive forms, and exposed structural elements. This architectural choice proved to be highly divisive, sparking a maelstrom of public debate and critical commentary. Detractors lambasted the building's austere aesthetic, deeming it an affront to the city's historical character and a concrete behemoth ill-suited to the human scale. Proponents, however, lauded its audacious modernity, viewing it as a powerful expression of civic pride and a symbol of Boston's progressive spirit. The ensuing controversy, a clash between traditional sensibilities and the avant-garde, became emblematic of the broader societal tensions surrounding urban renewal and the evolving definition of architectural beauty.
The construction of Boston City Hall, a protracted and costly undertaking, further exacerbated the existing divisions within the city. Disputes over budgets, construction delays, and the displacement of communities in the name of progress fueled the flames of discontent. Despite the controversies that engulfed its creation, Boston City Hall ultimately became an undeniable landmark, an indelible fixture in the city's skyline. Its imposing presence, a constant reminder of the complex interplay of ambition, vision, and compromise, continues to evoke strong reactions, serving as a perpetual catalyst for discussions about architecture, urban planning, and the legacy of urban renewal. Its story serves as a potent microcosm of the challenges and triumphs inherent in shaping the urban fabric of a dynamic and ever-changing city.
The Hacker News post titled "How Boston City Hall was born," linking to a Boston Globe article about the building's history, has a modest number of comments, leading to a somewhat limited discussion. The comments do not offer dramatically different perspectives but rather expand on specific aspects touched upon in the article or offer related anecdotal information.
One commenter focuses on the Brutalist architectural style of Boston City Hall, mentioning its divisive nature and how opinions on it haven't softened much over time. They also highlight the poor public reception of many Brutalist buildings, leading to their demolition in some cases, while noting Boston City Hall has managed to avoid this fate.
Another commenter draws a parallel between the architectural style of Boston City Hall and similar concrete structures in the UK, suggesting a common aesthetic and possibly shared influences. They mention the prevalence of such buildings in British town centers and university campuses, hinting at a broader trend in that era.
Building on the theme of public perception, a different commenter shares a personal anecdote about their father, an architect who worked on a Brutalist-style library. This commenter notes their father's eventual regret over the project, feeling it contributed negatively to the surrounding urban landscape. This personal story adds a human dimension to the discussion of Brutalist architecture and its impact on communities.
A further comment pivots slightly to discuss the urban planning decisions of the time, linking them to the then-prevalent theories of architect Le Corbusier. The commenter suggests that the creation of plazas and the separation of pedestrian and vehicular traffic, as seen around City Hall, were influenced by Corbusier's ideas, although their execution might not have always been successful.
Finally, a commenter provides some contextual information about the political and social climate of Boston in the 1960s, highlighting the influence of Mayor John Collins and his focus on modernizing the city. This adds a layer of historical understanding to the discussion, connecting the architectural choices to the broader political and social forces at play.
While the discussion doesn't delve into highly technical or complex architectural critiques, it provides some interesting personal reflections, historical context, and observations about the broader trends in architecture and urban planning during that period. The comments, while limited in number, paint a picture of the ongoing debate surrounding Brutalist architecture and its place in the urban landscape.
Summary of Comments ( 3 )
https://news.ycombinator.com/item?id=42701645
Hacker News users generally expressed admiration for Don Pettit's ingenuity and "hacker" spirit, highlighting his ability to create a functional star tracker with limited resources while aboard the ISS. Several commenters appreciated the detailed explanation of the design process and the challenges overcome, such as dealing with vibration and thermal variations. Some discussed the technical aspects, including the choice of sensors and the use of stepper motors. A few pointed out the irony of needing a custom-built star tracker on a space station supposedly packed with sophisticated equipment, reflecting on the limitations sometimes imposed by bureaucracy and pre-planned missions. Others reminisced about previous "MacGyver" moments in space exploration.
The Hacker News post "Designing a Star Tracker for Astronaut Don Pettit to Use on the ISS" has generated several comments, discussing various aspects of the project and Don Pettit's ingenuity.
Several commenters praise Don Pettit's resourcefulness and "hacker" spirit, highlighting his ability to create tools and conduct experiments with limited resources in the unique environment of the ISS. They appreciate his commitment to scientific exploration and his willingness to improvise solutions. One commenter specifically refers to Pettit as a "MacGyver in space," encapsulating this sentiment.
A thread discusses the challenges of astrophotography from the ISS, focusing on the difficulties posed by the station's movement and vibration. Commenters explore the technical intricacies of compensating for these factors, including the importance of precise tracking and stabilization. The original design of the "barn door tracker" and its limitations are also discussed, along with the advancements achieved with the newer, electronically controlled tracker.
Another commenter notes the interesting detail about using parts from a Russian cosmonaut's treadmill for the barn door tracker, further illustrating the improvisational nature of work on the ISS. This anecdote sparks a brief discussion about the collaborative environment on the station, where astronauts and cosmonauts from different nations work together and share resources.
Some comments delve into the technical specifics of the star tracker, discussing the choice of motors, control systems, and the challenges of operating equipment in the harsh conditions of space. The use of off-the-shelf components versus custom-designed parts is also touched upon.
Finally, a few commenters express their admiration for the ingenuity and dedication of the individuals involved in designing and building the star tracker, acknowledging the complexities of creating a device that can function reliably in such a demanding environment. They also appreciate the opportunity to learn about the behind-the-scenes challenges and solutions involved in space exploration.