The "Whoosh Rocket" is a simple experiment demonstrating Newton's Third Law of Motion (for every action, there's an equal and opposite reaction). A plastic bottle, partially filled with water and pressurized with air, launches upwards when the air is released. The compressed air exerts force equally in all directions inside the bottle. When the stopper is removed, the air rushes out the opening, creating thrust. This downward force of the escaping air creates an equal and opposite upward force on the bottle, propelling it skyward. The amount of water affects the rocket's performance – too little and there isn't enough mass to be propelled efficiently; too much and the extra weight hinders its flight.
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.
NASA's SPHEREx mission, a near-infrared space telescope, is set to launch no earlier than June 2025. Its two-year mission will map the entire sky four times, creating a massive 3D map of hundreds of millions of galaxies and more than 100 million stars in the Milky Way. This data will help scientists study the early universe's expansion, the origin of water and other life-sustaining molecules, and the formation of galaxies.
Hacker News users generally expressed excitement about the SPHERX mission and its potential to expand our understanding of the universe. Several commenters discussed the implications of mapping such a vast number of galaxies for studying dark energy and cosmic inflation. Some questioned the $98M budget, wondering how it could be so low compared to other space telescopes. A few users highlighted the importance of near-infrared spectroscopy in SPHERX's mission, while others discussed the trade-offs between cost and scientific capabilities compared to larger telescopes. Technical details, like the use of a two-mirror, three-element unobscured anastigmat telescope, were also mentioned. There's a thread discussing the lack of detail in the NBC article and the need for more comprehensive reporting on scientific endeavors. Finally, some commenters expressed hope for discovering signs of extraterrestrial life or other unexpected phenomena.
To extend the Voyager probes' lifespans, NASA has turned off the Cosmic Ray Subsystem (CRS) instrument on Voyager 2. While the CRS has been crucial in studying the heliosphere and interstellar space, this power-saving measure is necessary to keep both Voyager 1 and 2 operating. Further power reductions are planned in the coming years as the probes' radioactive power sources continue to decay, with the goal of maintaining communication with Earth for as long as possible. Voyager 1's CRS was deactivated in 2022.
HN commenters express a mix of awe and sadness at the continued power-down of the Voyager probes. Several reflect on the incredible longevity and distance of the mission, marveling at the ingenuity of the engineers who designed them. Some commenters discuss the technical aspects of the power reduction, including the use of radioisotope thermoelectric generators (RTGs) and the diminishing power output over time. Others lament the eventual loss of contact, viewing it as a symbolic end of an era. A few suggest potential solutions, albeit highly speculative ones, like laser-based power beaming to extend the probes' lifespans. The overall sentiment is one of respect for the Voyager mission and its contributions to scientific understanding.
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.
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.
Powerful new magnets built for NASA's next-generation electric propulsion system have passed initial testing and are ready for space-like conditions. These magnets, made of a high-temperature superconducting material, are crucial to the Advanced Electric Propulsion System (AEPS) which aims to significantly shorten travel times for future deep-space missions like Mars trips. The magnets enable the Hall thruster to achieve higher power and efficiency compared to current technology, pushing spacecraft faster while using less propellant. They will now undergo rigorous testing in a vacuum chamber that simulates the harsh environment of space.
Hacker News commenters discuss the potential of the new magnet technology for electric propulsion. Some express excitement about the increased efficiency and power density offered by these superconducting magnets, envisioning applications beyond just the VASIMR engine, like fusion power. Others are more cautious, pointing to the challenges of maintaining cryogenic temperatures in space and the need for radiation shielding. Several commenters delve into technical details, comparing different thruster types (Hall effect, ion, etc.) and the specific advantages of high-temperature superconductors. There's also a thread discussing the complexities of testing in space and the long road to practical implementation for technologies like VASIMR. Overall, while acknowledging the hurdles, commenters seem optimistic about the progress and potential impact of this magnetic technology on space travel.
The James Webb Space Telescope has revealed intricate networks of dust filaments within the nearby galaxy IC 5146, offering unprecedented detail of the interstellar medium. This "cosmic web" of dust, illuminated by newborn stars, traces the distribution of material between stars and provides insights into how stars form and influence their surrounding environments. Webb's infrared capabilities allowed it to penetrate the dust clouds, revealing previously unseen structures and providing valuable data for understanding the lifecycle of interstellar dust and the processes of star formation.
Hacker News users discuss the implications of the Webb telescope's discovery of complex organic molecules in a young, distant galaxy. Some express awe at the technology and the scientific advancements it enables, while others delve into the specific findings, pondering the presence of polycyclic aromatic hydrocarbons (PAHs) and their significance for the possibility of life. Several commenters highlight the relatively early stage of these discoveries and anticipate future, even more detailed observations. A degree of skepticism is also present, with users questioning the certainty of attributing these complex molecules specifically to the early galaxy, as opposed to potential foreground contamination. The potential for JWST to revolutionize our understanding of the universe is a recurring theme.
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.
Summary of Comments ( 58 )
https://news.ycombinator.com/item?id=43402058
The Hacker News comments on the NASA "Whoosh Rocket" article largely focus on the surprising amount of thrust generated by this simple demonstration. Several commenters express fascination with the physics involved and the counterintuitive nature of the thrust being independent of the surrounding air pressure. Some discuss the educational value of the experiment, highlighting its simplicity and effectiveness in illustrating fundamental principles of rocket propulsion. One commenter provides further context by linking to a video demonstrating the experiment in a vacuum chamber, reinforcing the concept of thrust being generated solely by the expelled propellant. Another points out the historical significance of the experiment, linking it to a similar demonstration performed by Robert Goddard, considered the father of modern rocketry. There's a brief discussion comparing this type of rocket to other propulsion systems, and one user asks a clarifying question about the relevance of nozzle shape.
The Hacker News post titled "NASA Whoosh Rocket" links to an educational NASA article explaining the basic principles of rocket propulsion using a simple experiment involving a balloon. The discussion thread contains several comments exploring various aspects related to this principle.
One commenter highlights the educational value of this demonstration for children, mentioning its use at a local science museum and how it effectively illustrates Newton's Third Law of Motion. They further explain how the simplicity of the demonstration allows kids to grasp the concept easily.
Another comment thread discusses the concept of thrust and how it relates to the escaping air. A user clarifies that thrust isn't solely generated by the expelled air pushing against the external atmosphere but rather from the internal pressure acting upon the balloon's inner surface opposite the nozzle. This leads to a further discussion involving the difference in efficiency between a rocket in a vacuum versus in the atmosphere.
One user recounts their experience using a similar demonstration with a water rocket, emphasizing the surprising amount of thrust that can be generated and the resultant thrill. This anecdote adds a personal touch to the discussion, underscoring the practical application and excitement of experimenting with these principles.
Another comment dives deeper into the physics, highlighting the importance of the pressure difference between the inside and outside of the balloon and how this generates the force. This reinforces the earlier discussion about thrust generation being independent of the external atmosphere.
A different commenter focuses on the pedagogical approach, emphasizing the effectiveness of starting with a simplified model and progressively adding complexity. They suggest that this allows students to build a fundamental understanding before grappling with more nuanced details.
Finally, one commenter briefly remarks on the utility of the provided link, indicating its value as a teaching resource, specifically for introducing basic rocketry concepts.
Overall, the comments reflect appreciation for the simplicity and effectiveness of the demonstration in explaining rocket propulsion. The discussion touches upon the underlying physics, the educational merits, and personal experiences, providing a well-rounded perspective on the topic.