"Space Selfie" is a project that allows users to send a photo to a tiny satellite in low Earth orbit, which then takes a picture of the photo displayed on its screen with Earth as a backdrop, creating a "space selfie." The project, a collaboration between Crunch Labs and former Apple engineers, uses a small, low-cost satellite and emphasizes accessibility and a playful approach to space exploration. Users can purchase slots to upload their photos, and the satellite captures the images using a camera attached to a selfie stick. The resulting images are then sent back down to Earth and shared with the user.
This Astronomy Picture of the Day shows a simulated flyover of Pluto's surface, created using images and data from NASA's New Horizons spacecraft. The video highlights the diverse terrain of the dwarf planet, including nitrogen-ice plains informally known as Sputnik Planitia, rugged mountains made of water ice, and cratered regions. The simulated flight path takes the viewer across these varied landscapes, offering a stunning perspective of Pluto's complex geology. The coloration is exaggerated to emphasize the different surface compositions.
HN users discuss various technical aspects of the New Horizons flyby and the resulting imagery. Some express awe at the feat of navigating to Pluto and the detail captured. Several commenters analyze the image processing techniques, noting the use of range maps and digital elevation models to create the flyover effect. They also discuss the challenges of accurately representing the subtle color variations and the difficulty in interpreting geological features due to the unfamiliar terrain. Others compare the flyover visualization to older, less detailed representations of Pluto, highlighting the advancement in our understanding. There's also some discussion of the mission's power source, the use of plutonium, and its longevity.
Ed Smylie, a NASA engineer crucial to the Apollo 13 rescue, died at 95. He designed the makeshift carbon dioxide scrubber that saved the astronauts from asphyxiation after an oxygen tank exploded, famously using duct tape and other readily available materials based on instructions radioed from Mission Control. His quick thinking and ingenuity under immense pressure were essential to the mission's survival and became a legendary example of improvisation in the face of a life-or-death crisis.
HN commenters express admiration for Ed Smylie's ingenuity and quick thinking in devising the carbon dioxide scrubber adapter that saved the Apollo 13 astronauts. Several highlight the contrast between this crucial, life-saving hack and the advanced technology surrounding the mission, emphasizing the importance of practical skills and improvisation. Some commenters share anecdotes about meeting Smylie or hearing him speak, describing him as humble and down-to-earth. Others discuss the broader significance of the Apollo 13 mission and the collaborative effort that brought the crew home safely. A few users also correct minor details in the original article or provide additional context about the mission and the lunar module's life support systems.
Kosmos 482, a Soviet Venus probe launched in 1972, is expected to fall back to Earth sometime between 2023 and 2025. The mission failed shortly after launch, leaving the spacecraft stranded in Earth orbit. While some parts burned up upon initial re-entry, a heavily-shielded section designed for Venus's atmosphere survived and is now decaying in orbit. Experts predict this section, weighing roughly 1,000 pounds, will eventually survive re-entry and impact Earth, though the exact location and time remain uncertain.
Hacker News commenters discuss the uncertainty surrounding Kosmos 482's re-entry, highlighting the difficulty in predicting the exact time and location due to the chaotic nature of atmospheric drag. Some express skepticism about the claimed titanium pressure vessel surviving re-entry intact, citing the intense heat and forces involved. Others speculate about the scientific value of recovering the probe, pondering the insights it might offer into Soviet-era technology and the effects of long-term exposure to space. A few commenters share anecdotes about tracking space debris and the challenges of distinguishing it from other objects. The potential hazard posed by the falling debris is also mentioned, albeit downplayed due to the Earth's vast surface area.
This paper presents a real-time algorithm for powered descent guidance, focusing on scenarios with non-convex constraints like obstacles or keep-out zones. It utilizes a novel Sequential Convex Programming (SCP) approach that reformulates the non-convex problem into a sequence of convex subproblems. These subproblems are solved efficiently using a custom interior-point method, enabling rapid trajectory generation suitable for online implementation. The algorithm's performance is validated through simulations of lunar landing scenarios demonstrating its ability to generate feasible and fuel-efficient trajectories while respecting complex constraints, even in the presence of disturbances. Furthermore, its computational speed is shown to be significantly faster than existing methods, making it a promising candidate for real-world powered descent applications.
HN users discuss the practical applications and limitations of the proposed powered descent guidance algorithm. Some express skepticism about its real-time performance on resource-constrained flight computers, particularly given the computational complexity introduced by the non-convex optimization. Others question the novelty of the approach, comparing it to existing methods and highlighting the challenges of verifying its robustness in unpredictable real-world scenarios like sudden wind gusts. The discussion also touches on the importance of accurate terrain data and the potential benefits for pinpoint landing accuracy, particularly in challenging environments like the lunar south pole. Several commenters ask for clarification on specific aspects of the algorithm and its implementation.
Voyager 1, despite being billions of miles away, experienced an anomaly where its attitude articulation and control system (AACS) sent garbled telemetry data, even though the probe remained operational. Engineers diagnosed the issue as the AACS inadvertently sending data through a defunct onboard computer, which corrupted the information. The team successfully commanded Voyager 1 to switch back to the correct computer for telemetry, resolving the anomaly. Though the root cause of why the AACS routed data through the wrong computer remains unknown, Voyager 1 is now functioning as expected, sending back clear telemetry.
The Hacker News comments express admiration for the Voyager team's ingenuity and perseverance in diagnosing and fixing the anomaly from such a vast distance. Several commenters highlight the impressive feat of debugging a 50-year-old system with limited telemetry and communication. Some discuss the technical aspects of the problem and solution, including the use of the AACS's articulation test mode and the likely cause being a faulty component sending erroneous commands. Others reflect on the historical significance of Voyager and the dedication of the engineers involved, both past and present. A few commenters mention the emotional impact of the mission's continued success and the awe-inspiring nature of exploring interstellar space.
NASA's Athena lander successfully touched down near the lunar south pole, within a permanently shadowed crater. While the landing was considered a triumph, the extreme cold of -280°F (-173°C) presents a significant challenge for the mission's scientific objectives, which include searching for water ice and characterizing the lunar environment. The frigid temperatures will limit the lander's operational lifespan and complicate data collection. Despite this, the mission team is optimistic about Athena's ability to return valuable data from this unexplored region of the Moon.
Hacker News users discuss the surprisingly low temperature of -280°F (-173°C) recorded by Astrobotic's Peregrine lander, named Athena, after landing in a permanently shadowed crater. Several commenters point out that this temperature, while cold, isn't unexpected for a permanently shadowed region and is well above absolute zero. They discuss the possibility of finding water ice at such locations, with some speculating about its potential uses for future lunar missions. The discrepancy between Celsius and Fahrenheit scales is also mentioned, highlighting the importance of context when discussing extreme temperatures. Some users express skepticism about the viability of commercial lunar missions given Astrobotic's struggles.
The Astrobotic Technology's Peregrine lunar lander mission, carrying NASA's Athena scientific payload, failed after a propellant leak shortly after launch. The spacecraft lost control and ultimately tipped over on the lunar surface, ending any hope of deploying its instruments designed to study the moon's exosphere and surface composition. While Peregrine did achieve lunar orbit, the mission is considered a loss for NASA and its partners, marking a setback for commercial lunar exploration efforts.
HN commenters express disappointment at the loss of Athena, with some questioning the wisdom of not designing the lander for such a contingency. Several point out the difficulty and expense of space missions, highlighting that failure is an inherent risk. One commenter notes the irony of the lander's name, Athena, the Greek goddess of wisdom, being associated with such a seemingly avoidable mishap. Others discuss the possibility of a future mission salvaging usable components from Athena, though this is considered unlikely. Some speculate about the root cause of the tipping, suggesting issues with the landing site or deployment mechanisms. A few lament the broader lack of investment in space exploration, while others emphasize the importance of learning from these failures for future endeavors.
NASA has successfully demonstrated the ability to receive GPS signals at the Moon, a first for navigating beyond Earth’s orbit. The Navigation Doppler Lidar for Space (NDLS) experiment aboard the Lunar Reconnaissance Orbiter (LRO) locked onto GPS signals and determined LRO’s position, paving the way for more reliable and autonomous navigation for future lunar missions. This achievement reduces reliance on Earth-based tracking and allows spacecraft to more accurately pinpoint their location, enabling more efficient and flexible operations in lunar orbit and beyond.
Several commenters on Hacker News expressed skepticism about the value of this achievement, questioning the practical applications and cost-effectiveness of using GPS around the Moon. Some suggested alternative navigation methods, such as star trackers or inertial systems, might be more suitable. Others pointed out the limitations of GPS accuracy at such distances, especially given the moon's unique gravitational environment. A few commenters highlighted the potential benefits, including simplified navigation for lunar missions and improved understanding of GPS signal behavior in extreme environments. Some debated the reasons behind NASA's pursuit of this technology, speculating about potential future applications like lunar infrastructure development or deep space navigation. There was also discussion about the technical challenges involved in acquiring and processing weak GPS signals at such a distance.
Firefly Aerospace's Blue Ghost lander successfully touched down on the lunar surface, making them the first commercial company to achieve a soft landing on the Moon. The mission, part of NASA's Commercial Lunar Payload Services (CLPS) initiative, deployed several payloads for scientific research and technology demonstrations before exceeding its planned mission duration on the surface. Although communication was eventually lost, the landing itself marks a significant milestone for commercial lunar exploration.
Hacker News users discussed Firefly's lunar landing, expressing both excitement and skepticism. Several questioned whether "landing" was the appropriate term, given the lander ultimately tipped over after engine shutdown. Commenters debated the significance of a soft vs. hard landing, with some arguing that any controlled descent to the surface constitutes a landing, while others emphasized the importance of a stable upright position for mission objectives. The discussion also touched upon the challenges of lunar landings, the role of commercial space companies, and comparisons to other lunar missions. Some users highlighted Firefly's quick recovery from a previous launch failure, praising their resilience and rapid iteration. Others pointed out the complexities of defining "commercial" in the context of space exploration, noting government involvement in Firefly's lunar mission. Overall, the sentiment was one of cautious optimism, acknowledging the technical achievement while awaiting further details and future missions.
Firefly Aerospace's Blue Ghost lunar lander successfully touched down on the moon, marking a significant milestone for the company and the burgeoning commercial lunar exploration industry. The robotic spacecraft, carrying NASA and commercial payloads, landed in the Mare Crisium basin after a delayed descent. This successful mission makes Firefly the first American company to soft-land on the moon since the Apollo era and the fourth private company overall to achieve this feat. While details of the mission's success are still being confirmed, the landing signals a new era of lunar exploration and establishes Firefly as a key player in the field.
HN commenters discuss the Firefly "Blue Ghost" moon landing, expressing excitement tinged with caution. Some celebrate the achievement as a win for private spaceflight and a testament to perseverance after Firefly's previous launch failure. Several commenters question the "proprietary data" payload and speculate about its nature, with some suggesting it relates to lunar resource prospecting. Others highlight the significance of increased lunar activity by both government and private entities, anticipating a future of diverse lunar missions. A few express concern over the potential for increased space debris and advocate for responsible lunar exploration. The landing's role in Project Artemis is also mentioned, emphasizing the expanding landscape of lunar exploration partnerships.
NASA's video covers the planned lunar landing of Firefly Aerospace's Blue Ghost Mission 1 lander. This mission marks Firefly's inaugural lunar landing and will deliver several NASA payloads to the Moon's surface to gather crucial scientific data as part of the agency's Commercial Lunar Payload Services (CLPS) initiative. The broadcast details the mission's objectives, including deploying payloads that will study the lunar environment and test technologies for future missions. It also highlights Firefly's role in expanding commercial access to the Moon.
HN commenters express excitement about Firefly's upcoming moon landing, viewing it as a significant step for private space exploration and a positive development for the US space industry. Some discuss the technical challenges, like the complexities of lunar landing and the need for a successful landing to validate Firefly's technology. Others highlight the mission's scientific payloads and potential future implications, including resource utilization and lunar infrastructure development. A few commenters also mention the importance of competition in the space sector and the role of smaller companies like Firefly in driving innovation. There's some discussion of the mission's cost-effectiveness compared to larger government-led programs.
Lox is a Rust library designed for astrodynamics calculations, prioritizing safety and ergonomics. It leverages Rust's type system and ownership model to prevent common errors like unit mismatches and invalid orbital parameters. Lox offers a high-level, intuitive API for complex operations like orbit propagation, maneuver planning, and coordinate transformations, while also providing lower-level access for greater flexibility. Its focus on correctness and ease of use makes Lox suitable for both rapid prototyping and mission-critical applications.
Hacker News commenters generally expressed interest in Lox, praising its focus on safety and ergonomics within the complex domain of astrodynamics. Several appreciated the use of Rust and its potential for preventing common errors. Some questioned the performance implications of using Rust for such computationally intensive tasks, while others pointed out that Rust's speed and memory safety could be beneficial in the long run. A few commenters with experience in astrodynamics offered specific suggestions for improvement and additional features, like incorporating SPICE kernels or supporting different coordinate systems. There was also discussion around the trade-offs between using a high-level language like Rust versus more traditional options like Fortran or C++. Finally, the choice of the name "Lox" garnered some lighthearted remarks.
NASA's Parker Solar Probe is about to make its closest approach to the Sun yet, diving deeper into the solar corona than ever before. This daring maneuver, occurring in late December 2024, will bring the spacecraft within 7.3 million kilometers of the solar surface, subjecting it to extreme temperatures and radiation. Scientists anticipate this close flyby will provide invaluable data about the Sun's magnetic field, solar wind, and coronal heating, potentially unraveling longstanding mysteries about our star's behavior.
Hacker News commenters discussed the practicality of calling the Solar Probe Plus mission "flying into the Sun" given its closest approach is still millions of miles away. Some pointed out that this distance, while seemingly large, is within the Sun's corona and a significant achievement. Others highlighted the incredible engineering required to withstand the intense heat and radiation, with some expressing awe at the mission's scientific goals of understanding solar wind and coronal heating. A few commenters corrected the title's claim of being the "first time," referencing previous missions that have gotten closer, albeit briefly, during a solar grazing maneuver. The overall sentiment was one of impressed appreciation for the mission's ambition and complexity.
Amateur radio operators successfully detected the faint signal of Voyager 1, the most distant human-made object, using the Dwingeloo radio telescope in the Netherlands. Leveraging Voyager 1's predictable signal pattern and the telescope's sensitivity, they confirmed the spacecraft's carrier signal, demonstrating the impressive capabilities of both the aging probe and the terrestrial equipment. This marks a significant achievement for the amateur radio community and highlights the enduring legacy of the Voyager mission.
Hacker News commenters express excitement and awe at the ingenuity involved in receiving Voyager 1's faint signal with the Dwingeloo telescope. Several discuss the technical aspects, highlighting the remarkably low power of Voyager's transmitter (now around 13.8W) and the sophisticated signal processing required for detection. Some marvel at the vast distance and the implications for interstellar communication, while others share personal anecdotes about their involvement with the Voyager missions or similar projects. A few commenters clarify the role of ham radio operators, emphasizing their contribution to signal processing rather than direct reception of the raw signal, which was achieved by the professional astronomers. There's also discussion of the signal's characteristics and the use of the Deep Space Network for primary communication with Voyager.
Voyager 1, currently over 15 billion miles from Earth, successfully transmitted data using a backup thruster control system not activated since 1981. NASA engineers recently rediscovered the system's functionality and tested it, confirming Voyager 1 can still send scientific data back to Earth via this alternative route. This extends the spacecraft's operational lifespan, though using the backup system requires slightly higher power consumption. While the primary thruster control system remains functional for now, this rediscovery provides a valuable backup communication method for the aging probe.
Hacker News commenters generally expressed awe and excitement at Voyager 1's continued operation and the ingenuity of the engineers who designed and maintain it. Several commenters highlighted the remarkable longevity and durability of the spacecraft, given its age and the harsh environment of interstellar space. Some discussed the technical details of the trajectory correction maneuver and the specific hardware involved, including the attitude control thrusters and the now-resurrected TCM thruster. A few questioned the phrasing of "breaking its silence," pointing out that Voyager 1 continues to send scientific data. Others reflected on the historical significance of the Voyager missions and the small, but important, course correction that ensures continued communication with Earth for a few more years.
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https://news.ycombinator.com/item?id=44084892
HN commenters were generally unimpressed with the "Space Selfie" project. Several pointed out the environmental impact of sending a chrome sphere into orbit, filled with selfies, calling it "littering" and "pointless". Others questioned the actual "space" aspect, as the satellite appears to orbit at a relatively low altitude, still within the Earth's atmosphere and thus subject to decay and eventual re-entry. The high cost of the project ($10 million initially projected) was also criticized, with commenters suggesting more worthwhile uses for that money. Some dismissed it as a publicity stunt with little scientific or artistic value. There was a minor thread discussing the technical aspects of the satellite's construction and orbit, but the overall sentiment leaned heavily towards disapproval.
The Hacker News post titled "Space Selfie" links to a project allowing users to upload a photo that will be displayed on a small screen attached to a weather balloon and sent to near-space, taking a "selfie" with the Earth in the background. The comments section on Hacker News contains a mixed bag of reactions.
Several commenters express skepticism about the feasibility and value of the project. One user questions the claimed altitude of 100,000 feet, suggesting it seems improbable given the balloon's size and payload. Another doubts the actual visibility of the uploaded image from that height, even with zoom, calling it a "gimmick." Further skepticism targets the photo quality, with some predicting blurry and unimpressive results.
Concerns about the environmental impact are also raised. Commenters point out the potential for the balloon and its payload to become litter, falling back to Earth and polluting the environment. They question the sustainability and responsibility of such projects, especially if they become popular.
Despite the doubts and criticisms, some commenters find the project intriguing or amusing. One commenter simply expresses a desire to see the actual photos taken. Another humorously remarks on the idea, creating a fictional scenario of future archaeologists finding these space selfies and misinterpreting their purpose.
Some users shift the discussion to alternative methods of achieving a similar effect, such as using high-altitude drones or even attaching a camera to a model rocket. They debate the advantages and disadvantages of each approach in terms of cost, complexity, and environmental impact.
A few comments delve into technical details. One user provides insights into the regulations related to high-altitude balloons, highlighting the need for obtaining proper authorization. Another discusses the possibility of live-streaming video from the balloon, though acknowledges the challenges involved.
Overall, the comments on Hacker News offer a diverse range of perspectives on the "Space Selfie" project, from excitement and curiosity to skepticism and environmental concern. While some are captivated by the novelty, others question its practical value and ecological impact. The discussion provides a balanced view, highlighting both the potential and the drawbacks of this unconventional approach to photography.