Ligado Networks passes 3GPP review for 5G plan

Ligado Networks is a step closer toward using its L-band satellite spectrum for terrestrial wireless services in the U.S., after getting clearance from the 3GPP consortium that sets global communications standards for 5G. The company said June 21 that 3GPP approved technical specifications that enable vendors to build 5G-compatible products on its spectrum. It comes after the Federal Communications Commission granted Ligado a modification to its L-band license in April 2020, despite opposition from the Pentagon and other government agencies over GPS interference concerns. The FCC unanimously approved Ligado’s plan to use L-band for a 5G network, following a four-year proceeding, with conditions including reduced power limits and a requirement that part of it be used as a “guard band” near adjacent operations such as GPS. In October, Ligado said it had raised nearly $4 billion in new capital to develop a private network solution for energy, manufacturing, health care, transportation and other infrastructure sectors. “The final major step for Ligado will involve getting chipset and radio vendors to incorporate the L-Band into their designs, paving the way for a carrier to deploy the L-Band on towers and small cells and to sell devices that contain L-Band-supporting chipsets,” New Street Research analyst Jonathan Chaplin wrote in a report to investors. “This final leg of the process is likely to take some time, but could be accelerated by the support of a large industry player (one of the carriers), who can more easily encourage their vendors to integrate the spectrum into their equipment.”

Ligado announced an agreement June 22 with Nokia to develop 5G base station radios that will be compatible with its spectrum in North America.

“Our partnership with an industry leader like Nokia is a significant milestone for our company and brings the deployment of L-Band spectrum in 5G mobile networks one step closer to reality,” Ligado chief technology officer Maqbool Aliani said in a statement.

“Nokia is a key partner in Ligado’s commercial efforts to develop the vendor ecosystem around this lower mid-band spectrum, and we look forward to advancing our collaboration activities to ready the L-Band for 5G network deployments.”

Ligado is also collaborating with Japan-based network operator Rakuten Mobile on its private network plans, aiming to deploy field trials over the next 12 months.

U.S.-based satellite operator Globalstar achieved 3GPP approval in March 2020 amid global ambitions to use some of its S-band spectrum for terrestrial wireless services.

Announcing financial results May 6, 2021, Globalstar executive chair Jay Monroe said the company was reviewing “several private networking opportunities of varying sizes” for the frequencies.

“We will soon be at the point where the only impediment to terrestrial deployments will be commercial negotiations,” Monroe said.

Xplore wins USAF award for innovative Cislunar commercial capabilities

Xplore Inc., a commercial space company has announced they have won an Air Force award to study positioning, navigation and timing (PNT) solutions for cislunar space. The award category, for commercial and technical innovations between the Earth and the Moon - is entirely new for the Air Force, which is investigating the capabilities necessary to extend operations beyond geosynchronous orbit to now include cislunar space. Today, Earth-orbiting satellites rely on the Global Positioning System (GPS) satellite constellation circling the Earth at an altitude of about 20,000 km (12,427 miles) - to know where they are and how to navigate to a destination. This GPS infrastructure, a public service provided by the U.S. Government, is essential to satellite operations and separately has become an integral part of our daily lives. Smartphones receive GPS signals that allow us to seamlessly perform a wide range of tasks such as planning travel itineraries, hailing a rideshare, viewing local weather or ordering a pizza and tracking its delivery in real-time. Beyond Earth orbit an equivalent positioning and navigation system does not exist. Given this, it can be extremely difficult for spacecraft, landers or rovers on the Moon or on Mars to identify their exact position. Navigation considerations have been an integral part of Xplore's development strategy since the company started rigorously developing its platform and multi-mission Xcraft - an ESPA-class space vehicle that will fly missions at destinations from Earth to the Moon, Mars, Venus, Lagrange points, near-Earth asteroids (NEAs) and other locations across the inner solar system.

Beyond the more obvious hardware requirements for operating in extreme environments, Xplore will maximize the full value of its orbital assets by designing a PNT architecture that mirrors the accessibility and reliability of GPS for cislunar space. The Xcraft's ability to operate across these vast distances provides tremendous value to customers in academia, industry, civil space and national security agencies.

Xplore Founder Lisa Rich said, "We understood the need to build navigation architectures beyond Earth orbit early in our development and are proud that our thought-leadership has been recognized. Xplore is among the first to win an Air Force award in this groundbreaking new category for missions and services around the Moon. We are uniquely qualified to provide innovative commercial solutions to the Air Force and rapidly advance space domain awareness now that cislunar space operations is a focal point."

She added, "Xplore is honored to respond to the growing and dynamic needs of our national security architecture beyond Earth orbit. We are poised to set new standards across the industry and our exceptional team is excited to provide these foundational capabilities and work with the USAF to ensure mission success."

Xplore's ability to design, built and test new PNT architectures beyond Earth orbit will expand the deep space ecosystem and will provide new opportunities for civilian space agencies, national security agencies, sovereign space agencies and commercial space companies to navigate in this challenging environment. Xplore can supply navigation capabilities for Highly Elliptical Orbit (HEO) regimes where typical GPS receivers fail to pick up a signal.

Dr. Clive R. Neal, professor in the Department of Civil and Environmental Engineering and Earth Sciences at the University of Notre Dame, who has over 30 years of experience in advancing our understanding of the Moon said: "Xplore's solution has strong technical and programmatic merit, and it supports USAF objectives.

The company has created a strong plan to use its Xcraft asset to facilitate a precision positioning, navigation and timing architecture to service our growing civil and national security needs. Not only is it a step in obtaining security in the cislunar domain, it provides vital infrastructure for expanding humanity to the Moon, and for creation of a vibrant cislunar economy. This first opportunity for Xplore has good potential."

Xplore plans to accelerate innovation and commercialize deep space via higher cadence, low-cost missions to the inner solar system. The highly capable Xcraft, a modular next-generation spacecraft, is uniquely designed to service the needs of multiple customers on a single mission, and operate in Low Earth Orbit (LEO), Geostationary Earth Orbit (GEO), cislunar space and deep space.

Dr. Lou Friedman, founder of The Planetary Society and Advisor to Xplore said, "Xplore demonstrated tremendous foresight in their plans for deep space exploration as they build architectures to achieve positioning, navigation and timing between the Earth and the Moon. They understood early on that GPS doesn't work beyond the Earth, and to navigate beyond Earth, we must develop new technologies to perform in deep space environments."

Positioning, navigation and timing systems will directly benefit existing and future operations in cislunar and interplanetary space. As Xplore ventures beyond Earth orbit, their new infrastructure will support our nation's strategy and form essential building blocks for a sustainable cislunar economy.

Russian scientists develop high-precision laser for satellite navigation

Scientists from ITMO University developed a laser for precise measurement of the distance between the Moon and Earth. Short pulse duration and high power of this laser help to reduce error in determining the distance to the Moon to just a few millimeters. This data can be used to specify the coordinates of artificial satellites in accordance with the lunar mass influence to make navigation systems more accurate. The study was published in Optics Letters. Both GPS and GLONASS systems are based on accurate measurement of the distance between a terrestrial object and several artificial satellites. Satellite coordinates must be as accurate as possible to ensure precise object location. On top of that, the Moon's mass affects satellite trajectories, therefore lunar coordinates must be taken into account when calculating satellites position.The lunar coordinates are obtained by measuring the distance to the Moon with laser locators. The accuracy of such locators depends on the laser features. For example, the shorter is the impulse and the smaller is laser's beam divergence, the easier it will be to measure the distance between the laser and the Moon. Scientists from ITMO University's Research Institute of Laser Physics have developed a laser for a lunar locator capable of measuring the distance to the Moon with a margin of error of a few millimeters. The laser boasts a relatively small size, low radiation divergence and a unique combination of short pulse duration, high pulse energy and high pulse repetition rate.

The laser pulse duration is 64 picoseconds, which is almost 16 billion times less than one second. The laser's beam divergence, which determines radiation brightness at large distances, is close to the theoretical limit; it is several times lower than the indicators described for similar devices.

"Actually, creating a laser with a pulse duration of tens of picoseconds is no longer technically difficult," says Roman Balmashnov, engineer at the Research Institute of Laser Physics and PhD student at ITMO University School of Photonics.

"However, our laser's output pulse energy is at least twice higher than that of its analogs. It is 250 millijoules at the "green" wavelength and 430 millijoules at the "infrared" wavelength. We managed to achieve high pulse repetition rate of 200 Hz and energy stability, so the pulse energy does not vary from pulse to pulse."

The new laser will be used in a lunar laser locator of the GLONASS navigation system. This will make it possible to correct satellite coordinates calculating in real-time, making the Russian navigational system more accurate. The margin of error when locating users may be reduced to 10 cm.

"The laser we've developed is a cutting-edge by several criteria. According to our data, it is the most powerful pulse-periodic picosecond source of laser radiation in the world. In addition to strictly ranging applications, lasers of this class can be used for imaging of orbital objects: for example, satellites or space debris," notes Andrey Mak, the head of ITMO University's Research Institute of Laser Physics.

Ariane 5 rocket takes off with European GPS satellites

An Ariane 5 rocket put four GPS satellites into orbit on Tuesday for Europe's Galileo navigation project, Arianespace said. The European space workhorse took off at 1836 GMT and deployed the satellites four hours after launch. The Galileo programme, when complete, will have 30 satellites in three orbital planes by 2020. If all goes according to plan the system will be able to pinpoint a location on Earth to within a metre -- compared to several metres for the United States' GPS and the Russian GLONASS systems. The civilian-controlled Galileo system, seen as strategically important to Europe, went live in December last year, providing initial services with a weak signal, having taken 17 years at more than triple the original budget to get there. "With this sixth successful launch of an Ariane 5 in 2017, marking the second mission of the year for the benefit of the European Commission and the European Space Agency (ESA), Arianespace is proud to guarantee Europe reliable and independent access to space," said Stephane Israel, Arianespace's executive chairman. The satellites launched Tuesday, each one weighing 715 kilogrammes (1,590 pounds), were placed into orbit 23,000 kilometres (14,000 miles) from Earth.

The Galileo programme is funded and owned by the EU.

The European Commission has overall responsibility for the programme, managing and overseeing the implementation of all activities, but the deployment, design and development of the infrastructure is entrusted to the ESA.

The European Commission announced in July that investigators had uncovered the problems behind the failure of atomic clocks onboard satellites already launched as part of the Galileo satnav system.

For months, the ESA had been investigating the reasons behind failing clocks onboard some of the 18 navigation satellites it had already launched for Galileo.

The ESA found after an investigation that its rubidium clocks had a faulty component that could cause a short circuit, according to European sources.