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For the first time, a Starship prototype roars to life with three engines - Ars Technica
SpaceX now likely to fully assemble spaceship for a 15km test flight.
As part of the Starship program, SpaceX began experimenting with earlier prototypes in late 2019 and early 2020, losing three vehicles during various proof tests. In May, the company successfully tested a full scale tank section of its Starship vehicle (SN4) for the first time with a single Raptor engine. It was later lost due to a ground-systems issue. Then, in August, and again in September, it flew two different vehiclesSN5 and SN6on short hops to 150 meters. These vehicles looked something like flying spray paint cans as they rose above the scrubby Texas coastal plain, but they provided valuable experience to the company's engineers, who learned to control the Raptor engine in flight and pushed the pressure limits on its fuel tanks. Since then, work has proceeded on developing SN8 to make a far higher flight. For this, SpaceX needed to add large flaps to the tank section, and a nose cone. This vehicle more closely resembles what the final Starship vehicle will look like. It will ultimately have six Raptor engines. This will include three engines optimized for thrust at sea-level, and three more with larger nozzles optimized for thrust in the vacuum of space.
- Ignition of SN5 on August 4, 2020.
- Starhopper looks on as SN5 lifts off for its 150m hop test.
- Roger, roger, SN5we see you hovering clear five by.
- SN5. In flight. Over Texas.
- Turning to orient for landing.
- SN5 coming in for a landing. Those legs!
This is what “war in space” probably would look like in the near future - Ars Technica
“Any conflict in space will be much slower and more deliberate.”
Enlarge/ Anti-Satellite Weapons from Mission Shakti are displayed during Republic Day Parade on January 26, 2020 in New Delhi, India. 51 with 39 posters participating The creation of the US Space Force has conjured up all manner of fanciful notions about combat in space. Will military satellites act like X-wings and Tie Fighters, zipping around and shooting at one another? Or perhaps will larger ships akin to the USS Enterprise fire photon torpedoes at enemy warbirds? Hardly. But even those with more realistic expectations for what could happen if nations went to war in spaceperhaps satellites using orbital kinetic weapons to attack other satellites?may not fully appreciate the physics of space combat. That's the conclusion of a new report that investigates what is physically and practically possible when it comes to space combat. Published by The Aerospace Corporation, The Physics of Space War: How Orbital Dynamics Constrain Space-to-Space Engagements lays out several basic concepts that are likely to govern any space combat for the foreseeable future. All of the physical constraints suggest battles will need to be planned far in advance. Unlike a war on Earth, which typically involves an effort by opposing forces to dominate a physical location, satellites in orbit do not occupy a single location. Therefore, the report authors Rebecca Reesman and James Wilson write, controlling space does not necessarily mean physically conquering sectors of space. Rather, control over the high ground involves reducing or eliminating adversary satellite capabilities while ensuring one retains the ability to freely operate their own space capabilities for communications, navigation, observation, and all the other increasingly essential ways in which militaries rely on space. When considering how to control space, the authors lay out the ways in which space combat is counter-intuitive for policymakers and strategists.
- Satellites move quickly, but predictably: Satellites in commonly used circular orbits move at speeds between 3km/s and 8km/s, depending on their altitude. By contrast, an average bullet only travels about 0.75km/s. They are here, and then gone.
- Space is big: The volume of space between low-earth orbit and geostationary orbit is about 200 trillion cubic kilometers. That is 190 times larger than the volume of Earth.
- Timing is everything: Within the confines of the atmosphere, airplanes, tanks, and ships can nominally move in any direction. Satellites do not have that freedom. Due to the gravitational pull of Earth, satellites are always moving in either a circular or elliptical path, constantly in free-fall around the Earth. Getting two satellites in the same spot is not intuitive. Therefore, it requires careful planning and perfect timing.
- Satellites maneuver slowly: While satellites move quickly, space is big, and that makes purposeful maneuvers seem relatively slow. Once a satellite is in orbit, it requires time and a large amount of delta-V to perform phasing maneuvers.
Pluto’s ice-capped peaks are like Earth’s—but not - Ars Technica
Methane ice is accumulating up there for another reason.
Enlarge/ What dusts the peaks of Cthulhu? is not an arcane riddle. 17 with 12 posters participating We can often use our knowledge of planet Earth to explain the things we see on other worlds, although we may have to tweak the physics to account for a different temperature or a tenuous atmosphere. But planetary scientists cant always assume that a familiar landscape feature formed in a familiar way. When the New Horizons spacecraft gave us our first close-up look at Pluto, there were alien wonders aplenty. But there were also mountaintops dusted with something bright, looking very similar to Earth's snowcapped peaks. On Earth, these snow caps are produced by enhanced precipitation as air rises over the mountains and cools, combined with the colder temperatures at higher elevations. On Pluto, that explanation cant work, for several reasons. First, temperatures generally increase as you go up a few kilometers from Plutos surface because of gases absorbing solar energy. Winds also tend to blow downslope since the colder surface chills the air near it, making it denser. So what forms the bright dusting and how does it get there? West of Plutos heart-shaped bright plain is a dark-colored region dubbed Cthulhu. Within that region there are some mountain chains that stand out due to their bright caps. Analyzing spectral data from imagery of this area, the researchers say that the bright areas are mostly methane ice. It also shows up on north-facing rims and walls of impact craters in the region. Enlarge/ For a terrestrial comparison, a satellite image of the Alps is on the right. To look at why methane ice would form in those locations, the researchers turned to a climate model of the dwarf planet. The model allowed ices of methane and nitrogen to form (or vanish by turning to gas), and the researchers targeted the conditions at the time of New Horizons visit. Just by putting in the physics and topography, the model successfully makes methane ice on the mountains and craters of Cthulhu. Many places can see some methane frost form at night but disappear during the day. But a greater concentration of methane gas at higher altitudes leads to a net accumulation on the mountain tops over that daily cycle.
Milla Jovovich, Tony Jaa take on vicious creatures in Monster Hunter trailer - Ars Technica
Director Paul W.S. Anderson is the creative force behind the Resident Evil franchise.
In the Monster Hunter role-playing games, players choose a Hunter character, along with custom armor and weapons. The characters don't have intrinsic abilities, like traditional RPGs; rather, whatever abilities they have derive from the choice of weapons and armor. Those choices are basic at first, and players collect additional resources from their quests to conquer various monstersincluding fashioning new assets from parts gleaned from the defeated creatures. In single-player mode, the Hunters are usually accompanied by a Felyne or sentient cat creatures known as Palicos for additional support.
- Milla Jovovich stars as Capt. Natalie Artemis, a member of a United Nations military team.
- A mysterious totem in the desert.
- They're caught in a supernatural sandstorm.
- And they end up in another world.
- Surely these are the bones of an extinct creature. Right?
- A giant monster rears its ugly head.
- The soldiers spend a lot of time gaping in this trailer.
- It's martial arts star Tony Jaa to the rescue.
- Peeved at being shown up by a bow and arrow.
- Apparently Drogon from Game of Thrones is moonlighting as the Rathalos in this movie.
The first PlayStation 5 teardown reveals some hardware secrets - Ars Technica
Easy-to-remove outer panels hide "dust catcher" holes and more.
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- The PlayStation 5 comes with everything seen here. Some assembly required. Batteries not included. From Sony!
- The entire rear of the system is pretty much one big air vent.
- The stand at the base of the (vertical) system is attached with a single large screw.
- The stand and the screw sit alone.
- In horizontal orientation, the stand snaps into place without tools.
- The white panels on the sides of the system can be slid off without tools.
- The cooling fan draws air from both sides of the system.
- The massive cooling fan itself.
- One of two "dust catcher" holes that should be easy to vaccuum out after extended use.
- This panel for PCIe storage expansion can be opened with a screwdriver.
SpaceX gets back on track with a stunning Starlink launch near sunrise - Ars Technica
SpaceX has now launched 775 total Starlink satellites.
49 with 43 posters participating, including story author
- Falcon 9 with 60 Starlink satellites flying directly in front of the Sun from Titusville, Florida.
- The launch took place shortly after sunrise.
- It followed a scrub on Monday due to poor weather.
- Conditions on Tuesday were much nicer for a launch.
Safety panel has “great concern” about NASA plans to test Moon mission software - Ars Technica
“Flight systems should be developed for success with a goal to test like you fly.”
Enlarge/ Teams at NASA's Michoud Assembly Facility move the Core Stage toward a barge in January that will carry it to a test stand in Mississippi. 9 with 8 posters participating An independent panel that assesses the safety of NASA activities has raised serious questions about the space agency's plan to test flight software for its Moon missions. During a Thursday meeting of the Aerospace Safety Advisory Panel, one of its members, former NASA Flight Director Paul Hill, outlined the panel's concerns after speaking with managers for NASA's first three Artemis missions. This includes a test flight of the Space Launch System rocket and Orion spacecraft for Artemis I, and then human flights on the Artemis II and III missions. Hill said the safety panel was apprehensive about the lack of "end-to-end" testing of the software and hardware used during these missions, from launch through landing. Such comprehensive testing ensures that the flight software is compatible across different vehicles and in a number of different environments, including the turbulence of launch and maneuvers in space. "The panel has great concern about the end-to-end integrated test capability plans, especially for flight software," Hill said. "There is no end-to-end integrated avionics and software test capability. Instead, multiple and separate labs, emulators, and simulations are being used to test subsets of the software." The safety panel also was struggling to understand why, apparently, NASA had not learned its lessons from the recent failed test flight of Boeing's Starliner spacecraft, Hill said. (Boeing is also the primary contractor for the Space Launch System rocket's core stage). Prior to a test flight of the Starliner crew capsule in December 2019, Boeing did not run integrated, end-to-end tests for the mission that was supposed to dock with the International Space Station. Instead of running a software test that encompassed the roughly 48-hour period from launch through docking to the station, Boeing broke the test into chunks. As a result, the spacecraft was nearly lost on two occasions and did not complete its primary objective of reaching the orbiting laboratory. Hill referred to a proprietary report by the NASA Engineering and Safety Center (NESC), published on September 8, which raised similar concerns about trying to run software tests across multiple centers and labs. "It is not evident to the panelists their current plan and processes take advantage of their lessons learned," Hill said. "The NESC report makes the excellent point that as much as possible flight systems should be developed for success with a goal to test like you fly in the same way that NASA's operations teams train the way you fly, and fly the way you train." In response to these concerns, a NASA spokeswoman said the agency would, in fact, be conducting end-to-end testingalthough she acknowledged it would be done across multiple facilities. "NASA is conducting integrated end-to-end testing for the software, hardware, avionics, and integrated systems needed to fly Artemis missions," said Kathryn Hambleton. "Using the agencys sophisticated software development laboratories, teams from SLS, Orion, and Exploration Ground Systems use actual flight hardware and software, as well as emulatorsversions of the software that each team employs to test their code and how it works with the whole integrated systemto support both system-level interface testing and integrated mission testing to ensure the software and avionics systems work together." After the Starliner mishap, she said, the NASA chief engineer established an independent review team to assess all Artemis I critical flight and ground software activities. Those recommendations have been folded into preparing for the upcoming Artemis missions, which may begin flying in late 2021, or 2022.
Air Force signals interest in Starlink as SpaceX set for another launch - Ars Technica
This will be the company's 11th Starlink mission so far in 2020.
Enlarge/ A Falcon 9 rocket launches a Starlink mission in January 2020. 34 with 24 posters participating SpaceX returns to its launch pad at Kennedy Space Center on Monday for its twelfth launch of operational Starlink satellites. The mission is scheduled to lift off from Launch Complex-39A at 10:22am ET (14:22 UTC). Weather conditions are 70-percent favorable for liftoff. The Starlink-12 mission will fly atop a Falcon 9 rocket first stage that previously launched the company's first crewed Dragon mission in May, and subsequently the Anasis-II mission in July. SpaceX will attempt to recover the booster on its Of Course I Still Love You drone ship. The mission, the company's 11th Starlink launch in this calendar year, brings SpaceX closer to offering a public beta of its service. It also comes as a potentially important customer, the US military, has signaled its interest in the service that provides broadband Internet from space. This week, during a roundtable with reporters, a senior Air Force official said initial tests of the Starlink system have gone well. "What I've seen from Starlink has been impressive and positive," Air Force acquisition chief William Roper said, according to Investor's Business Daily. "They're cleverly engineered satellites cleverly deployed. So, there's a lot to learn from how they're designed, and I think that there's a lot we can learn from them." SpaceX has pursued a strategy of attracting both consumer customersthe company has been collecting information from those interested in the serviceand institutional customers. Of those, the US military is likely the most lucrative. Roper indicated that the Air Force was willing to support efforts like Starlink that bring innovative communications services that are not otherwise available. "We can be the stability case for companies like SpaceX and others who want to sell communications worldwide," he said during the media roundtable. "(They) may not be thinking about customers over the ocean, but we've got our Navy there. (They) may not be thinking about customers up in the Arctic, but we have our airplanes there." A webcast for Monday's launch attempt will begin about 15 minutes before liftoff.
NASA wants a big budget increase for its Moon plans. Is Congress biting? - Ars Technica
Space agency needs Christmastime funding for landers to keep Moon plan on track.
Enlarge/ NASA Administrator Jim Bridenstine says that competition is good for the Artemis Moon program. 16 with 13 posters participating The odds of NASA sending humans back to the Moon by 2024 are longnot zero, but pretty close. Probably the biggest near-term impediment the space agency faces is funding. Specifically, NASA requires an additional $3.2 billion in fiscal year 2021 to allow contractors to begin constructing one or more landers to take astronauts down to the Moon's surface from a high lunar orbit. This is a 12 percent increase to NASA's budget overall. The 2021 fiscal year begins in a week, on October 1. The US Congress recently passed a "continuing resolution" that will keep the government funded through December 11. By that time, after the 2020 election, it is hoped that the House and Senate can agree on a budget that would fund priorities for the remainder of the fiscal year. NASA Administrator Jim Bridenstine said this week that funding the Artemis Moon Program before the end of this year would be workable. "If we can have that done before Christmas, we're still on track for a 2024 Moon landing," he said in a call with reporters. The real question is whether Congress, if it can agree on a fiscal year 2021 budget in this sharp partisan era, is so inclined to support funding for the lander. This is a brand-new program that will eventually require many billions of dollars to reach fruition. In deliberations earlier this year, the US House provided only $600 million, or less than one-fifth of the budget NASA said its needs for the coming year. So says the Senate Wednesday provided the first opportunity to assess, publicly at least, whether the Senate will be more supportive of the Artemis Program and its aggressive 2024 goal. In his opening statement, the Kansas Republican who chairs the Senate subcommittee that oversees NASA's budget, Jerry Moran, had kind words to say about Artemis. But he noted that NASA's request for a larger budget came amidst the backdrop of a pandemic and resulting financial crisis. "Our world has significantly altered since the initial release of the budget, and I look forward to discussing how NASA is adapting to our new and unprecedented environment while pushing forward with Artemis," Moran said. The ranking Democratic member of the committee appeared to be even less supportive. New Hampshire's Jeanne Shaheen noted that NASA's proposed budget again cut funding for STEM education and did not support the Nancy Grace Roman Space Telescope. "We know that NASA needs to be about more than just a single Moonshot," she chided Bridenstine. Shaheen characterized the 12 percent budget increase sought as "generous." Later during a question-and-answer period, Moran asked Bridenstine whether it might be more practical for NASA to quickly pick a single contractor to build the lander so the agency could concentrate its resources. Bridenstine pushed back on this, citing the value of competition. Earlier this year, the space agency selected three teamsled by Blue Origin, Dynetics, and SpaceXto flesh out lander proposals and tell NASA how much government funding they thought would be needed to complete the projects by 2024. With this information, NASA plans to "down-select" from this initial group of three landing teams in February. One, two, or three? There has been chatter in the aerospace community, in recent months, that one or more of the lander teams are pushing for all of the funding in this February down-select by intimating that the other teams cannot possibly meet the technical challenge. But Bridenstine seems committed to moving forward with two or more teams. "I worry about going down to one," he said. "When you eliminate the competition, you end up with programs that inevitably get dragged out and face cost overruns." With at least two providers competing, Bridenstine said, NASA would end up in a "virtuous cycle" where the teams are investing their own money and pushing as hard as they can. For a recent model of success, he cited the commercial crew program, in which SpaceX and Boeing competed to fly astronauts to the International Space Station. SpaceX won that competition and did so within the "fixed price" contract NASA awarded it back in 2014. Having two competitors spurred the companies to keep moving despite the technical challenges, Bridenstine said. As they consider whether to fund Artemis, lawmakers will finally have some hard numbers to consider for the program. In an "Artemis Plan" document released Monday, NASA for the first time put specific dollar figures to the projected cost of landing on the Moon by 2024: $27.9 billion. $16.1 billion of that would go toward the cost of developing an "initial" Human Landing System. These are the funding requirements through fiscal year 2025.
Chitin could be used to build tools and habitats on Mars, study finds - Ars Technica
The manufacturing process would require minimal energy and no specialized equipment.
Enlarge/ Scientists mixed chitinan organic polymer found in abundance in arthropods, as well as fish scaleswith a mineral that mimics the properties of Martian soil to create a viable new material for building tools and shelters on Mars. 17 with 17 posters participating Space aficionados who dream of one day colonizing Mars must grapple with the stark reality of the planet's limited natural resources, particularly when it comes to building materials. A team of scientists from the Singapore University of Technology and Design discovered that, using simple chemistry, the organic polymer chitincontained in the exoskeletons of insects and crustaceanscan easily be transformed into a viable building material for basic tools and habitats. This would require minimal energy and no need for transporting specialized equipment. The scientists described their experiments in a recent paper published in the journal PLOS ONE. "The technology was originally developed to create circular ecosystems in urban environments," said co-author Javier Fernandez. "But due to its efficiency, it is also the most efficient and scalable method to produce materials in a closed artificial ecosystem in the extremely scarce environment of a lifeless planet or satellite." As we previously reported, NASA has announced an ambitious plan to return American astronauts to the Moon and establish a permanent base there, with an eye toward eventually placing astronauts on Mars. Materials science will be crucial to the Artemis Moon Program's success, particularly when it comes to the materials needed to construct a viable lunar (or Martian) base. Concrete, for instance, requires a substantial amount of added water in order to be usable in situ, and there is a pronounced short supply of water on both the Moon and Mars. And transport costs would be prohibitively high. NASA estimates that it costs around $10,000 to transport just one pound of material into orbit. So there has been much attention on the possibility of using existing materials on the Moon itself to construct a lunar base. Past proposals have called for 3D-printing with Sorel cement, which requires significant amounts of chemicals and water (consumables), and a rocklike material that would require both water and phosphoric acid as a liquid binder. And back in March, a paper by an international team of scientists suggested that astronauts setting up a base on the Moon could use the urea in their urine as a plasticizer to create a concrete-like building material out of lunar soil. As with the Moon, any plan to set up a habitable base on Mars must employ manufacturing technologies that make use of the red planet's regolith. But the authors of the current paper point out that most terrestrial manufacturing strategies that could fit the bill typically require specialized equipment and a hefty amount of energy. However, "Nature presents successful strategies of life adapting to harsh environments," the authors wrote. "In biological organisms, rigid structures are formed by integrating inorganic filler proceed from the environment at a low energy cost (e.g., calcium carbonate) and incorporated into an organic matrix (e.g., chitin) produced at a relatively high metabolic cost." Enlarge/ Building a model with a 3D-printed lander module illustrates a possible scenario of fabricating habitats on Mars. Fernandez and his colleagues maintain that chitin is likely to be part of any planned artificial ecosystem because it is so plentiful in nature. It's the primary component of fish scales and fungal cell walls, for example, as well as the exoskeletons of crustaceans and insects. In fact, insects have already been targeted as a key source of protein for a possible Martian base. And since the chitin component of insects has limited nutritional value for humans, extracting it to make building materials "does not hamper or compete with the food supply," the authors wrote. "Rather, it is a byproduct of it." For their experiments, the researchers relied on fairly simple chemistry. They took chitosan derived from shrimp, dissolved it in acetic acida common byproduct of both aerobic and anaerobic fermentationand combined it with a mineral equivalent to Martian soil to create their chitinous building material. They tested its properties by fashioning various objects out of it, most notably a functional wrench, which they tested by tightening a hexagonal bolt. While acknowledging that this would be unlikely to replace metallic tools for certain critical space applications, it proved hardy enough to sustain sufficient torque for small daily tasks. Next, the team tried molding the material in various geometries to study its potential as a building material via additive manufacturing, ranging from cylinders and cubes to objects with both rounded and angular shapesincluding a little humanoid Martian figure. The scientists also demonstrated that the biolith could be used as makeshift mortar to effectively plug a small hole in a pipe. The pipe subsequently went several weeks without leakage. Finally, they built a full 3D-printed model of one possible design for a Martian habitat; it took just under two hours to complete. The researchers concluded that their results demonstrated the feasibility of such "closed-loop, zero-waste" solutions on Mars. "Bioinspired manufacturing and sustainable materials are not a substituting technology for synthetic polymers, but an enabling technology defining a new paradigm in manufacturing, and allowing to do things that are unachievable by the synthetic counterparts," said Fernandez. "We have demonstrated that they are key not only for our sustainability on Earth but also for one of the next biggest achievements of humanity: our transformation into an interplanetary species." DOI: PLOS ONE, 2020. 10.1371/journal.pone.0238606 (About DOIs).