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  1. FCC has “serious doubts” that SpaceX can deliver latencies under 100ms SpaceX can apply in low-latency tier, but FCC says it faces “substantial challenge.” Enlarge Getty Images | Shulz 122 with 66 posters participating The Federal Communications Commission said it has "serious doubts" that SpaceX and other low-Earth orbit (LEO) satellite providers will be able to deliver latencies of less than 100ms. As we reported yesterday, FCC Chairman Ajit Pai backed off a plan that would have completely prevented SpaceX and other LEO companies from applying for rural-broadband funding as low-latency providers. But the FCC's full order was released today and suggests that SpaceX will have a tough time convincing the commission that its service will deliver latencies below the FCC standard of 100ms. The final version of the FCC order acknowledges that LEO satellites have "intrinsic advantages" over geostationary satellites that operate at much higher altitudes. "Satellites in low-Earth orbit are not subject to the same propagation latency limitations as higher orbiting satellites," the FCC order said. But the order goes on to say the FCC has "serious doubts that any low-Earth orbit networks will be able to meet the short-form application requirements for bidding in the low-latency tier" and that companies like SpaceX thus face a high chance of being rejected when they apply for funding as low-latency providers: Service providers that intend to use low-Earth orbit satellites claim that the latency of their technology is "dictated by the laws of physics" due to the altitude of the satellite's orbit. We remain skeptical that the altitude of a satellite's orbit is the sole determinant of a satellite applicant's ability to meet the Commission's low-latency performance requirements. As commenters have explained, the latency experienced by customers of a specific technology is not merely a matter of the physics of one link in the transmission. Propagation delay in a satellite network does not alone account for latency in other parts of the network such as processing, routing, and transporting traffic to its destination. Short-form applicants seeking to bid as a low-latency provider using low-Earth orbit satellite networks will face a substantial challenge demonstrating to Commission staff that their networks can deliver real-world performance to consumers below the Commission's 100ms low-latency threshold. $16 billion at stake If SpaceX and similar companies are rejected from the low-latency category, they will be at a disadvantage in a reverse auction that will distribute $16 billion—$1.6 billion yearly, over ten years—from the Rural Digital Opportunity Fund (RDOF). The auction, scheduled to begin on October 29, will give ISPs funding to deploy broadband in census blocks where no provider offers home-Internet speeds of at least 25Mbps downstream and 3Mbps upstream. The FCC will prioritize low-latency networks when awarding funding, so SpaceX and other LEO providers could come up short against terrestrial networks. Even DSL providers would have an advantage over LEO networks in funding battles if the satellite companies are placed in the FCC's high-latency category. SpaceX has argued that the FCC's skepticism is unwarranted, telling agency officials that its Starlink broadband system "easily clears the commission's 100ms threshold for low-latency services, even including its 'processing time' during unrealistic worst-case scenarios." While altitude isn't the only factor in latency, SpaceX's altitudes, ranging from 540km to 570km, are a fraction of the 35,000km used with geostationary satellites. SpaceX CEO Elon Musk has said the company is aiming for latency below 20ms, similar to cable Internet and low enough to support competitive online gaming. SpaceX will have a chance to make its case in detail to the FCC during the application stage. The timing is part of the problem for SpaceX. The company has launched about 480 satellites but isn't offering commercial service yet, and companies have to submit applications for the auction by July 15. Having a commercial service available would make it easier for SpaceX to convince the FCC that its service is low-latency. Getting placed in the high-latency category wouldn't completely shut SpaceX and other LEO providers out of funding, but it would likely at least reduce the amount they get. Starlink's website says the SpaceX-operated ISP plans to deploy "service in the Northern US and Canada in 2020, rapidly expanding to near global coverage of the populated world by 2021." DSL, fixed-wireless get shot at gigabit tier Separately, LEO satellite providers are forbidden from applying as gigabit providers in the FCC auction, even though DSL and fixed-wireless ISPs will be given a chance to demonstrate that they can provide gigabit speeds. While gigabit speeds "are not commercially available on a widespread basis using these technologies, service providers using these technologies have increasingly reported deploying networks capable" of providing them, the FCC order said. Like SpaceX in the low-latency category, DSL and fixed-wireless providers will face a high bar in attempts to enter the gigabit category: While an applicant will be permitted to select the Gigabit performance tier in its application if it intends to use fixed wireless or DSL technologies for meeting its Auction 904 public interest obligations, such applicants face a high burden to persuade Commission staff that they are reasonably capable of meeting the public interest obligations in rural areas and thus qualified to bid for the Gigabit performance tier. Particularly for DSL services, we do not anticipate that an applicant using DSL technologies would be able to demonstrate that it is reasonably capable of offering a service that meets the Gigabit performance tier public interest obligations absent a hybrid approach that relies mostly on fiber. Fixed-wireless providers will have to account for "distance limitations, spectrum bands attributes, channel bandwidths requirements, backhaul and medium haul requirements, tower siting requirements, capacity constraints, required upstream speeds, required minimum monthly usage allowances, and other issues raised in the record," the FCC said. Ultimately, the FCC said it expects that "relatively few fixed wireless and DSL technologies will be able to meet the short-form requirements for bidding in the Gigabit performance tier." FCC has “serious doubts” that SpaceX can deliver latencies under 100ms
  2. For the first time, a spacecraft has returned an aging satellite to service It’s a big step forward for satellite servicing. Enlarge / View of IS-901 satellite from Mission Extension Vehicle-1’s “near hold” position. Northrop Grumman 85 with 47 posters participating In a triumph for the nascent industry of "satellite servicing," an aging communications satellite has returned to service in geostationary orbit. Northrop Grumman announced Friday that its Mission Extension Vehicle-1, or MEV-1, has restored the Intelsat 901 satellite and relocated it into a position to resume operations. "We see increased demand for our connectivity services around the world, and preserving our customers’ experience using innovative technology such as MEV-1 is helping us meet that need,” Intelsat Chief Services Officer Mike DeMarco said in a news release. After launching on a Proton rocket last October, Northrop Grumman's servicing vehicle used its mechanical docking system to latch onto Intelsat 901 on February 25, at an altitude of 36,000km above Earth. Prior to this, no two commercial spacecraft had ever docked in orbit before. Since then, the MEV-1 servicer has assumed navigation of the combined spacecraft stack, reducing the satellite's inclination by 1.6 degrees and relocating it to a new orbital location, at 332.5° east. Intelsat then transitioned about 30 of its commercial and government customers to the satellite two weeks ago. The transition of service took approximately six hours and was successful. Based on the agreement between Northrop and Intelsat, MEV-1 will provide five years of life extension services to the satellite before moving it into a graveyard orbit. MEV-1 will then be available to provide additional mission extension services, Northrop said, including orbit raising, inclination corrections, and inspections. Northrop is already building a second MEV to service another Intelsat satellite, 1002, later this year. This satellite servicing milestone comes as both low-Earth orbit as well as geostationary space—where large, expensive communications satellites are often placed high above the planet to hold their position over the ground—are becoming more crowded. The availability of a service such as that offered by MEV-1 offers satellite providers both the ability to extend the lifetime of aging assets, but also to potentially remove those they have lost control of from the ground. These kinds of services are generally seen in the space community as important to keeping orbit as decluttered as possible in the coming decades, so it is good that this demonstration case worked out well. Source: For the first time, a spacecraft has returned an aging satellite to service (Ars Technica)
  3. Report: Apple is developing satellites so the iPhone can skip wireless carriers The company hopes to deploy something within five years, according to Bloomberg. Enlarge / The iPhone 11. Samuel Axon Bloomberg has cited sources familiar with Apple plans saying that the iPhone-maker has a "top-secret" team dedicated to developing satellite technology that could, among other things, allow Apple's mobile devices to communicate with each other without relying on wireless carriers like Verizon, Deutsche Telekom, or China Mobile. The report claims that Apple CEO Tim Cook has said it is a high priority and that the team is made up of "about a dozen" engineers from industries like aerospace and satellite design. While the long-term outcome of the work is not fully decided, it could allow iPhones to directly communicate with one another without using carrier networks, or it could improve location services and other key features of the devices. Former Google satellite and aerospace engineers Michael Trela and John Fenwick lead the team, Bloomberg's sources say. They left Google in 2017 to join Apple. They report to Apple's iPhone engineering lead. The company has also hired prominent wireless engineer Matt Ettus and established executives Ashley Moore Williams (Aerospace Corp) and Daniel Ellis (Netflix). While it's uncertain that the final outcome of this project will be freedom from carriers, it's not surprising that Apple would at least explore that possibility. It has struggled against and with carriers throughout the history of the iPhone, and Apple's philosophy of seeking end-to-end integration of all aspects of a product is well-known. The company is also rumored to be developing silicon that would replace Intel CPUs in its Mac products, for example, and it is attempting to develop its own cellular modems to include future iPhones. Apple is not the only tech company to explore launching satellites. Amazon plans to launch thousands in the near future, and other tech companies have made attempts to build satellite-based networks (though many have failed). Bloomberg's sources did not clarify whether Apple plans to build and deploy these satellites itself or if it plans to instead work with an established player in that space. Source: Report: Apple is developing satellites so the iPhone can skip wireless carriers (Ars Technica)
  4. Satellites play chase to measure gravity, achieve picometer accuracy Satellites tracked to the picometer, test tech for gravitational wave detector. Enlarge NASA/JPL-Caltech The spinoffs from gravitational wave detectors are not just new scientific discoveries. The technology also has other uses. A good example of this is the gravity-measuring mission, GRACE Follow On, which was launched last year. The first reports on its laser rangefinder's performance have been released, and it makes for impressive reading. Gravitational wave detectors work by measuring tiny changes in the distance between two mirrors. Ripples in space-time cause a tiny oscillation in that distance, which is then detected by comparing the phase shift between light that has traveled between the two mirrors and light that has traveled along a path that was unaffected by the gravitational wave. To put it in perspective, a gravitational wave detector measures changes that are far smaller than the diameter of an atom and are more like the diameter of a single proton. The gravity of GRACE Similar technology found its way into space to increase the sensitivity of Earth-monitoring instruments. On Earth, we have stationary detectors that wait for gravitational waves to pass through them. In orbit, the detector is moving and can measure subtle changes in the Earth's gravitational field. That brings us to GRACE—a backronym for gravity recovery and climate experiment—a pair of satellites that orbited the Earth at a fixed distance from each other. Or they would be fixed if the Earth’s gravity didn’t change in time and space. GRACE used a radar system to measure the distance between the two satellites to track those changes, providing information about the gravitational field it was traveling through. Changes in that distance could be translated into local measurements of the acceleration due to gravity. This, in turn, is used to measure things like the volume of water in aquifers. GRACE turned out to be hugely useful but, like all satellite missions, eventually died. In this case, the battery on GRACE-2 failed, and the pair was cremated in the Earth’s atmosphere. The follow-up to GRACE, called GRACE-FO (follow on), was launched in 2018. GRACE-FO is mostly a copy of GRACE, but scientists took the opportunity to include a new distance-measuring tool that would outperform the old GRACE radar system. This, if successful, would mean that the measurement data would not put a limit on how we interpreted the data. Instead, models of the tides would need to be improved. It also just happens that the technology required to do this sort of station-keeping measurement is exactly the technology required for LISA (a proposed space-based gravitational wave observatory). The LISA pathfinder mission was hugely successful but, being a single satellite, could not test station-keeping technologies. So, in many ways, the GRACE-FO satellites are also a lightweight LISA pathfinder mission. Smooth running Since June 14, when contact was established with the satellites, scientists have been testing the laser range-finder system. And, to put it simply, it absolutely smashes the design specifications. Over a time period between 5 and 1,000 seconds, the system should be able to detect distance changes of 2 to 40 billionths of a meter between two satellites that are separated by 220km. However, the team reports sensitivity as low as 300 trillionths of a meter. To put this in perspective, the radar system on the original GRACE was sensitive to changes at about the 10 micrometer level. How do you achieve this sort of accuracy? In short, with lasers. More seriously, a laser beam on the master satellite is stabilized to have a very precise frequency. That laser is shot at the slave satellite. This in itself is an achievement because the laser has to be continuously aimed in the right direction (the radar system manages this with a fixed antenna). The slave satellite uses the incoming light (all 25nW of it) to do two things. First it uses a tiny amount to check that the laser is pointing in the right direction. The remainder of the light is used to set the phase of its own laser, which is sent back to the master satellite—the received laser light is too weak to just be reflected back. The light that is received at the master acquires a phase shift relative to the transmitted light that is proportional to the distance between the two satellites. Since the distance is continuously changing, this is measured as an additional frequency in the received laser spectrum. Hence, a frequency measurement of the incoming laser spectrum becomes a measurement of distance, which, in turn, becomes a measurement of acceleration due to gravity. In the short term, this means that GRACE-FO data will be even better than expected, and the modelers are going to have to get back to work. In the long term, it means that more of the technology for LISA will be validated with the additional benefit of a long-term robustness study. In the very short term, it gave me some good weekend reading. Source: Satellites play chase to measure gravity, achieve picometer accuracy (Ars Technica)
  5. Are Russian space satellites failing? It’s now harder to find out Information about satellite health will now be "For Official Use Only." Enlarge / Roscosmos Head Dmitry Rogozin before Russian-Chinese talks at the Moscow Kremlin in June. Mikhail Metzel/TASS via Getty Images One of the key themes of HBO's new Chernobyl miniseries is the Soviet Union's control of information. As the television series shows, the state's warping of reality had very real consequences in terms of lives lost. The control of information has continued into the modern Russian era, as the nation's state television network is now planning its own series to recount the Chernobyl incident. Reportedly, a central theme of the series to be shown to Russian viewers is that American operatives infiltrated the nuclear facility and orchestrated the disaster. (There appears to be no credible evidence that this actually happened.) This predisposition to avoid or obfuscate information that could be embarrassing to the Russian state also evidently applies to the aerospace industry, with fresh reports from the country saying the leader of Russia's space corporation, Roscosmos, is limiting the flow of news about spaceflight activities. According to a report in RIA Novosti, Roscosmos head Dmitry Rogozin recently issued a directive classifying information about the condition of Russia’s orbital satellites as "For Official Use Only." One source told the publication, "The directive covers technical information including launches and functional condition of satellite constellations." (A translation of this article was provided to Ars by Robinson Mitchell). No more faxes The order requires that any of the press offices of the various companies that comprise the Roscosmos enterprise must receive approval from Roscosmos itself before sharing any information about satellite launches or failures. "Transmission and distribution of any such information using wireless technology, email, faxes, by mobile or landline telephone, or social networking is now banned," according to a second source. It's not entirely clear what may have prompted the missive from Rogozin, who has had a controversial tenure as head of the Russian space agency and has recently resorted to making wild promises, such as human landings on the Moon by 2030. The decision may have come down to some recent problems with Russian space satellites and GLONASS, Russia's version of the Global Positioning System. Two GLONASS-M satellites reportedly failed in 2018, bringing the network perilously close to not having enough coverage for the entire Russian territory. Roscosmos oversees civilian and dual-use spacecraft for Russia, including its Soyuz program that currently transports Russian and US astronauts to the International Space Station. Russia’s Air and Space forces control military satellites. In his annual report earlier this year, Rogozin said Russia currently has 156 civilian and military satellites in orbit, of which 91 are for civilian purposes. Source: Are Russian space satellites failing? It’s now harder to find out (Ars Technica)
  6. SpaceX launched two new Earth science satellites for NASA and five Iridium Next communications satellites into orbit on May 22 The ride-share mission lifted off on a pre-flown Falcon 9 rocket from Vandenberg Air Force Base in California at 3:47 p.m. EDT (12:47 p.m. PDT, 1947 GMT). "Liftoff for GRACE Follow-On, continuing the legacy of the GRACE mission of tracking the movement of water across our planet," NASA TV's launch commentator Gay Yee Hill announced as the Falcon 9 rocket soared into the sky. "That's a beautiful launch," replied her fellow commentator Sammy Kayali, director for the Office of Mission Safety and Success at NASA's Jet Propulsion Laboratory (JPL) and former deputy manager for GRACE-FO. A SpaceX Falcon 9 rocket launches NASA's twin GRACE-FO satellites and five Iridium Next communications satellites from Vandenberg Air Force Base in California on May 22, 2018. Credit: NASA TV For the launch, SpaceX used the same Falcon 9 rocket booster that launched the classified Zuma mission for the U.S. Air Force in January. Zuma ended up crashing into the ocean instead of reaching orbit, but investigators determined that the Falcon 9 rocket did not cause the accident. After launching Zuma, the booster returned to Cape Canaveral to stick a vertical landing, and SpaceX refurbished it before today's flight. SpaceX did not attempt to land the rocket this time, though. However, SpaceX did attempt to recover the valuable payload fairing, or nose cone, that covered the GRACE-FO and Iridium satellites during launch. The clamshell-like fairing halves were expected to glide back to Earth under a parafoil and be caught by Mr. Steven, a SpaceX recovery boat equipped with a huge net suspended between giant metal arms. But Mr. Steven didn't succeed at catching the payload fairing today. "We came very close. We're going to keep working on that," John Insprucker, a principal integration engineer at SpaceX, said during a live webcast of today's mission. About 12 minutes after liftoff, the rocket's second stage deployed twin satellites for NASA's Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission into a near-polar orbit. The second stage then ignited its engines once more and headed to a higher orbit to drop off the five Iridium Next satellites. NASA confirmed contact with both GRACE-FO satellites shortly after launch via the McMurdo tracking station in Antarctica. SpaceX confirmed that the five Iridium satellites also deployed successfully about an hour after liftoff. These satellites will join a constellation of 50 satellites owned by a company called Iridium Communications, bringing the total number of Iridium satellites to 55. By the time Iridium Communications completes the constellation, there will be 75 satellites in orbit. The other payload, GRACE-FO, is a follow-on to the original GRACE mission, which mapped Earth's water and ice by measuring changes in Earth's gravity field from 2002 to 2017. GRACE-FO will pick up where GRACE left off to continue studying rising sea levels, the melting of glaciers and polar ice caps and other changes in the distribution of water around the globe. NASA is spending $430 million on the GRACE-FO mission, which is a joint project with the German Research Center for Geosciences (GFZ). The GFZ has invested another 77 million Euros (nearly $91 million) in the mission, said Frank Flechtner, GRACE-FO's project manager at GFZ in Potsdam, Germany, at a news conference Monday (May 21). "GRACE was really a revolutionary mission for understanding the water cycle, how the climate behaves and the trends taking place over the last 10 or 15 years, and it did this in a very unique way by making measurements of how the mass gets redistributed on the surface of the earth," said Frank Webb, GRACE-FO project scientist at JPL, at the news conference. "We're able to see how water has moved from different parts of the earth by actually measuring its mass, which is not something you see with your eyes. It's something you have to feel with the satellite system," Webb said. To measure Earth's gravity, the two spacecraft will orbit Earth together, with one trailing behind the other at a distance of 137 miles (220 kilometers). Because Earth isn't a perfect sphere and has different features, like mountains and oceans, across its surface, the gravitational pull exerted on the spacecraft is not consistent. When the gravity field changes, the separation between the two satellites changes slightly. The measurement of that change in separation can reveal information about what kinds of features the spacecraft are flying over. The spacecraft measure that change with a microwave tracking system, beaming signals back and forth between the two. GRACE-FO's instruments are so sensitive that they can detect changes "with a precision of about 1 micrometer. That is about one-tenth of a human hair over the distance between Los Angeles and San Diego," Flechtner said. The twin satellites that launched are almost identical to the two original GRACE satellites, with the exception of one new tool: the Laser Ranging Interferometer. This experimental device serves the same purpose as the microwave instrument, but it's designed to take measurements up to 10 times as precise as the microwave instrument. If the new instrument works out, NASA plans to use it on subsequent GRACE follow-on missions. GRACE-FO is expected to spend the next five years mapping Earth's water. Source
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