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pierredv : constellations   10

APOD: 2019 January 23 - Orion over the Austrian Alps
Explanation: Do you recognize this constellation? Through the icicles and past the mountains is Orion, one of the most identifiable star groupings on the sky and an icon familiar to humanity for over 30,000 years. Orion has looked pretty much the same during the past 50,000 years and should continue to look the same for many thousands of years into the future. Orion is quite prominent in the sky this time of year, a recurring sign of (modern) winter in Earth's northern hemisphere and summer in the south. Pictured, Orion was captured recently above the Austrian Alps in a composite of seven images taken by the same camera in the same location during the same night. Below and slightly to the right of Orion's three-star belt is the Orion Nebula, while the four bright stars surrounding the belt are, clockwise from the upper left, Betelgeuse, Bellatrix, Rigel, and Saiph.
APOD  astronomy  photography  constellations  mythology 
january 2019 by pierredv
Here Are the Odds That One of SpaceX’s Internet Satellites Will Hit Someone - IEEE Spectrum Dec 2018
"The chance that SpaceX’s planned Starlink satellite constellation will cause an injury or death is 45 percent every six years, according to an IEEE Spectrum analysis of figures submitted by the company to the U.S. Federal Communications Commission."

"When that fuel runs low, after around six years, the satellites will use the remainder to nudge themselves into the denser atmosphere below. Each satellite, just a little smaller in size than a Tesla Model 3, will then swiftly burn up. Except that some of it won’t. "

"When SpaceX plugged the numbers into NASA’s Debris Assessment Software, the package calculated that there was, at most, a 1 in 18,200 chance that an individual satellite in its LEO orbital shells would hurt or kill someone. VLEO satellites were generally slightly riskier, with up to a 1 in 17,400 chance. All figures are handily less than the 1 in 10,000 figure that NASA has adopted as a standard, and that U.S. and European space agencies require for space missions."
IEEE-Spectrum  SpaceX  orbital-debris  risk-assessment  satellite  constellations 
december 2018 by pierredv
OneWeb scales back baseline constellation by 300 satellites -, Dec 2018
"Greg Wyler, OneWeb’s founder, said the company will need only 600 satellites or so instead of 900 after ground tests of the first satellites demonstrated better than expected performance."

"OneWeb had been under increased scrutiny within the satellite industry amid speculation that its satellite costs had grown well beyond their initial $500,000 target. Wyler confirmed the satellites had passed $500,000 a unit, but said the exceedance was minimal. "

"Wyler said 600 is the minimum needed for global coverage. Beyond that, OneWeb is deciding whether it will add 300 first-generation satellites or shift to a second-generation constellation designed to layer on more capacity. "
SpaceNews  OneWeb  NGSO  constellations  satellite  business  Greg-Wyler 
december 2018 by pierredv
Viasat shrinks MEO constellation plans - Nov 2018
"... another satellite operator is reducing the size of its proposed constellation. Viasat of Carlsbad, California, modified its design for a medium-Earth-orbit constellation that would consist of 20 telecom satellites instead of 24 as originally envisioned, the FCC said Nov. 2."

The smaller constellation would orbit in four orbital pathways in 8,200-kilometer orbits, with five satellites per pathway"

"Viasat is one of several operators to have modified its constellation plans since 2016. The new approvals SpaceX is seeking cover an additional 7,518 satellites in V-band, a rarely used spectrum.

Telesat wants to double its approval, adding another 117 satellites that, like SpaceX, would use V-band spectrum.

OneWeb also asked the FCC to OK 1,200 more satellites in March, although its new request has not yet been scheduled for a vote. "
Viasat  NGSO  satellite  MEO  FCC  constellations 
november 2018 by pierredv
Does the satellite industry have antenna deficit disorder? - Oct 2018
"To connect the masses, megaconstellations will need mega antennas mega cheap. Antenna makers need mega orders to make that happen."

David Hartshorn: “There are business plans, big ones, hanging out there that depend if not entirely then at least to a very large extent on the availability of high-performance, low-cost, high-volume, low-profile antennas,”

"Northern Sky Research expects companies to ship 1.8 million flat panel antennas between now and 2027 with revenues topping $8 billion for the decade."

"For years, antenna manufacturers have produced high-performance alternatives to gimbaled parabolic antennas pointed at geostationary communications satellites. Price tags range from a few thousand dollars to $250,000 depending on the application."

"To work with low Earth orbit constellations, the antennas need to track two or more satellites simultaneously — something parabolic dishes can’t do. They also need to be small and durable, prevent signal interference, instantly find satellites and secure links, degrade gracefully and have great signal efficiency.

“It turns out that according to the laws of physics, you cannot do all those things at the same time,” said Ralph Brooker, president of SatProf"

John Finney, Isotropic: “What OneWeb wants in terms of target price is in the very low hundreds of dollars. We see a way to get there.”
satellite  constellations  antennas  NGSO  SpaceNews  business  NSR 
october 2018 by pierredv
Analysts see demand for two or three megaconstellations - Oct 2018
"While there may be enough customer demand for two or three megaconstellations, it will be difficult for the ventures to attract enough financing, according to analysts speaking at the Satellite Innovation conference here."

Chris Quilty, president of Quilty Analytics, a financial services firm based in St. Petersburg, Florida, sees demand for two or three constellations serving distinct markets like broadband and machine-to-machine communications."

"Nick Flitterman, co-founder and telecommunications head for Portland Advisers, a financial advisory firm based in the United Kingdom and Hong Kong, sees global demand for two or three megaconstellations but said it will be difficult to finance that many."
SpaceNews  satellite  NGSO  constellations  investing  finance  business 
october 2018 by pierredv
Satellite Constellations: Too Much of a Good Thing? - Northern Sky Research, Aug 2018
"LEO constellations, theoretically, benefit from economies of scale [but] it is crucial to recognize the point where the variable costs start to outweigh the fixed cost benefits, and the cost save turns into cost disadvantages, also known as diseconomies of scale."

"To support the production of satellite constellations ... will most definitely result in bottlenecks within the industry with further increase in internal diseconomies of scale for operators as well as for the suppliers."

"At a certain point, the additional satellites for the larger constellation continue to increase the costs but are unable to produce revenues at the same rate, resulting in a lower ROI for the 4,425-satellite [SpaceX] constellation."
NSR  space  satellite  constellations  economics  business  SpaceX 
august 2018 by pierredv
Enabling a GEO-NGEO Hybrid System - Northern Sky Research, Jul 2018
"The Military segment has, historically, primarily been served by GEO satellites for execution of critical applications, including intelligence gathering, navigation and communication. GEO systems, by nature, offer the advantage of significant coverage via a single satellite, especially with the advent of GEO-HTS satellites. On the other hand, latency and significant CAPEX have always been limitations of the GEO architecture. These drawbacks have given rise to the emerging trend of LEO and MEO constellations (NGEO) that can offer low latency and lower cost per satellite. However, constellations have their own set of constraints, with system complexity, ground infrastructure costs and frequency spectrum coordination, to name a few. Considering both, the shortcomings as well as the strengths of each system, could this perhaps be the start of an integration between GEO and LEO/MEO operators with a hybrid GEO-NGEO system on the rise? "

"Keeping the overall system costs low, however, is where it gets complex for NGEO framework. Although the manufacturing and launch costs per satellite are relatively lower, the need for a considerable number of satellites, the associated replenishment costs and the ground infrastructure expenses – all intensify the overall system cost."

"NSR estimates just over 1% of total revenues for gov/military will come from Non-GEO constellations by 2027."

"[TCO] is a key driver for NGEO constellations, military and otherwise, and is as well one of the biggest challenges for the operators presently. Simply put, either the expenses, mostly CAPEX, need to drop or the revenues need to grow for the business case to sustain. This is where a GEO-NGEO Hybrid architecture could prove pragmatic."

"Intelsat’s and OneWeb’s unsuccessful attempt towards a strategic alliance was one example of this hybrid system. GEO operators JSAT and Hispasat have similarly announced strategic investment in LEO constellations including LeoSat."

"Another level of integration, perhaps more technically innovative, and therefore challenging, is a system where GEO satellites can handle the TT&C operations for LEO constellations and act as the base station control system of the network."
NSR  GEO  NGSO  Intelsat  OneWeb  LeoSat  SES  O3b  satellite  constellations  military  DARPA  business  market-research 
july 2018 by pierredv
Russia to create orbital Internet satellite cluster by 2025 - TASS: Science & Space, May 2018
"Russian Space Systems Company (part of the State Space Corporation Roscosmos) plans to implement a project to create a global satellite communications network, which will require 288 satellites operating in the 870 km orbit by 2025"

"We plan [to embrace] 10,000 mobile transport objects, 10,000 outlets of collective access to the Internet, 10 million personal communication subscribers and provide for about a billion transactions a day via secure channels"
Russia  Tass  satellite  constellations  Communications 
may 2018 by pierredv
Satellite Constellations: A Critical Assessment - Northern Sky Research Apr 2018
From the email, "LEO-HTS Constellations Present Great Promise but Challenging Business Cases"

From graphic, studied following constellations:
SES mPower (aka O3b)

"NSR predicts two, out of the five Non-GEO HTS constellations analyzed, do not have a viable business case and will not be sustainable, if launched. The remaining three will generate 12% of overall satcom market revenues over the next decade. Costly systems and replenishment cycles, matched against funding challenges, demand questions, and extraordinary technical and regulatory complexity, will separate contenders from pretenders in the high stakes constellations market."

"The associated CAPEX, including replenishment costs, is one the biggest hurdles to HTS, EO, and IoT constellation business plans"

"Vertical integration trends – such as in-house manufacturing and, in the case of SpaceX, incorporating that with its own launch services - aimed at lowering costs further actually add another layer of complexity that is greatly underestimated. Supply chain management is a momentous challenge, ..."

"There is a compelling level of optimism towards Non-GEO constellations, ... However, financial success for LEO constellations depends on their ability to bring pricing down to a level competitive with terrestrial networks and make the services affordable to target markets"
satellite  constellations  LEO  HTS  research  NSR  reports  consulting  market-analysis  market-research  business 
may 2018 by pierredv

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