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Category: satellites – Page 104

5 january 2020.

This paper proposes the use of Flower Constellation (FC) theory to facilitate the design of a Low Earth Orbit (LEO) slotting system to avoid collisions between compliant satellites and optimize the available space. Specifically, it proposes the use of concentric orbital shells of admissible “slots” with stacked intersecting orbits that preserve a minimum separation distance between satellites at all times. The problem is formulated in mathematical terms and three approaches are explored: random constellations, single 2D Lattice Flower Constellations (2D-LFCs), and unions of 2D-LFCs. Each approach is evaluated in terms of several metrics including capacity, Earth coverage, orbits per shell, and symmetries. In particular, capacity is evaluated for various inclinations and other parameters. Next, a rough estimate for the capacity of LEO is generated subject to certain minimum separation and station-keeping assumptions and several trade-offs are identified to guide policy-makers interested in the adoption of a LEO slotting scheme for space traffic management.

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Japan’s space agency wants to keep the satellite’s cameras out of military hands.

An unusual geopolitical situation is brewing aboard the International Space Station. Prior to the military coup in Myanmar earlier this year, Japan’s space agency JAXA had been collaborating with the country to build microsatellites that it planned to deploy in partnership with Myanmar’s government.

Now, JAXA has no idea what to do with the pair of 50-kilogram satellites, according to SlashGear. And while Japanese scientists hope to bring the agriculture and fishery-monitoring satellites to life, they’re currently holding them on the ISS instead of deploying them out of fear they might be misused for military purposes — a striking example of real-world geopolitics spilling over into space.

After the military coup in Myanmar, Teppei Kasai, the Asia program director for the group Human Rights Watch noted that it would be relatively straightforward to use the satellites’ Earth-facing cameras for military or surveillance purposes, according to SlashGear.

Continue reading “Satellites Are Stranded on the ISS Because of a Military Coup” | >

WASHINGTON — A Falcon 9 launched another set of Starlink satellites March 14, with the rocket’s first stage setting a record with its ninth launch and landing.

The Falcon 9 lifted off from Launch Complex 39A at the Kennedy Space Center at 6:01 a.m. Eastern. The upper stage deployed its payload of 60 Starlink satellites into orbit 65 minutes later, bringing the size of the broadband internet constellation to 1260 satellites.

The launch was the eighth for the Falcon 9 this year, and took place a little more than 72 hours after another Falcon 9 launch of Starlink satellites. Six of the eight Falcon 9 launches this year have been dedicated to Starlink, and one of the other two, the Transporter-1 dedicated rideshare flight, also carried 10 Starlink satellites.

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Elon Musk’s SpaceX is preparing to further expand testing of its Starlink satellite internet in a test for the U.S. Air Force, an FCC request revealed.

Elon Musk’s SpaceX is preparing to further test its Starlink satellite internet in a demonstration for the U.S. Air Force, the company revealed in a recent request to the Federal Communications Commission.

“SpaceX seeks to make minor modifications to its experimental authorization for additional test activities undertaken with the federal government,” the company wrote to the FCC in a filing on Thursday.

“The tests are designed to demonstrate the ability to transmit to and receive information from two stationary ground sites and one airborne aircraft at one location, and would add to these limited testing from a moving vehicle on the ground,” SpaceX said.

Continue reading “SpaceX prepares for Air Force test connecting an aircraft to its Starlink satellite internet” | >

Primordial magnetic fields (PMFs), being present before the epoch of cosmic recombination, induce small-scale baryonic density fluctuations. These inhomogeneities lead to an inhomogeneous recombination process that alters the peaks and heights of the large-scale anisotropies of the cosmic microwave background (CMB) radiation. Utilizing numerical compressible MHD calculations and a Monte Carlo Markov chain analysis, which compares calculated CMB anisotropies with those observed by the WMAP and Planck satellites, we derive limits on the magnitude of putative PMFs. We find that the total remaining present day field, integrated over all scales, cannot exceed 47 pG for scale-invariant PMFs and 8.9 pG for PMFs with a violet Batchelor spectrum at 95% confidence level.

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SpaceX wants to begin connecting moving vehicles – from cars and trucks to jets and ships – to its Starlink satellite internet network, according to a request the company filed with the Federal Communications Commission.

“This application would serve the public interest by authorizing a new class of ground-based components for SpaceX’s satellite system that will expand the range of broadband capabilities available to moving vehicles throughout the United States and to moving vessels and aircraft worldwide,” SpaceX director of satellite policy David Goldman wrote in a letter to the FCC filed on Friday.

Starlink is the company’s capital-intensive project to build an interconnected internet network with thousands of satellites, known in the space industry as a constellation, designed to deliver high-speed internet to consumers anywhere on the planet.

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SpaceX has launched another batch of its Starlink satellites — the usual complement of 60 of the low Earth orbit spacecraft, which will join the more than 1000 already making up the existing constellation. This is the fifth launch of Starlink satellites for SpaceX this year, and the twentieth overall.

Earlier this year, SpaceX opened up Starlink access to anyone in a current or planned service area via a pre-order reservation system with a refundable up-front deposit. The company aims to continue launches like this one apace throughout 2021 in order to get the constellation to the point where it can serve customers over a much larger portion of the globe. SpaceX COO and President Gwynne Shotwell has previously said that the company expects it should have coverage over much of the globe at a constellation size of around 1200 satellites, but the company has plans to launch more than 30000 to fully build out its network capacity and speed.

While SpaceX is making good progress on Starlink with its Falcon 9 launcher, it’s also looking ahead to Starship as a key driver of the constellation’s growth. Starship, SpaceX’s next-generation launch vehicle currently under development in South Texas, will be able to deliver to orbit 400 Starlink satellites at a time, and it’s also being designed with full reusability and fast turnaround in mind.

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