TrustPoint has transmitted its first Low-Earth Orbit Navigation System (LEONS) time-transfer and tracking signals from a ground node to spacecraft in orbit. The milestone advances the development of commercial navigation infrastructure independent of GPS.
GNSS satellites require knowledge of their own time and orbital position to provide accurate data to Earth-based users. Most LEO spacecraft currently rely on GPS or medium-Earth orbit (MEO) signals for that information. Interference and jamming are increasingly affecting these LEO connections, degrading or blocking signals.
LEONS provides GPS-independent time transfer and orbit tracking. Initially developed for TrustPoint’s planned constellation, the system can be adapted for other LEO operators requiring timing and navigation for their spacecraft. The ground-to-space infrastructure is designed to support a GPS-independent PNT layer in orbit.
“With the pace of modern threats accelerating, the difference between concepts and capabilities matters,” said Nicole Hilliard, director of government programs at TrustPoint. “This milestone demonstrates that commercial partners can field resilient, GPS-independent PNT capabilities that strengthen national security architectures and justify continued investment in companies that deliver.”
The demonstration supports TrustPoint’s participation in the SpaceWERX AltPNT Challenge, which awarded the company two contracts to develop alternative PNT capabilities. The program seeks to deploy new options for precise, dual-use PNT systems.
China has launched two satellites into medium-Earth orbits (MEO) for its BeiDou Navigation Satellite System, reported the China Satellite Navigation Office.
The satellites were carried by a Long March 3B rocket from the Xichang Satellite Launch Center in Sichuan province and are the 13th group of third-generation BeiDou satellites operating in MEO.
The two spacecraft will start formal operation after a period of in-orbit technical verification, according to the China Satellite Navigation Office.
BeiDou is China’s largest civilian satellite system and one of four global navigation networks, along with the United States GPS, Russia’s GLONASS and the European Union’s Galileo.
Since 2000, a total of 62 BeiDou satellites, including the first four experimental ones, have been lifted on 46 Long March 3 series rockets from Xichang.
In June 2020, the final satellite to complete Beidou’s third-generation network was lifted by a Long March 3B rocket launched from the Xichang center. The following month, the system was declared complete and began providing full-scale global services.
Nearly 50 Beidou satellites in active service, including the latest pair.
19% of tracked space objects threaten GPS and other GNSS satellites. While there are many fewer objects in MEO than in LEO, the risk in the former is arguably greater because GPS is so critical to almost all of our technology.
The Risk
GNSS satellites, especially GPS satellites, are critical to the well-being and smooth functioning of economies and national security. This is especially true in Europe and the United States, which do not have complementary terrestrial systems able to provide vital positioning, navigation and timing (PNT) services when signals from space are not available.
While the probability of debris damage to GNSS in medium Earth orbit (MEO) is much less than for satellites in low Earth orbit (LEO), the consequences of such an event would be much, much higher. The loss of one satellite would be a concern; that of multiple satellites, a major problem. The unthinkable chaos, national security damage, and severe economic impacts to the $21 trillion U.S. GDP make the risk unacceptable.
For those who think we need not worry about the low probability of collisions at MEO, the Galileo collision avoidance maneuver in March 2021 should be a wakeup call. The problem is here. We need to act now.
Background
Much like a nuclear fission reaction, the problem of space debris starts small then grows exponentially, as each collision creates more pieces that, in turn, can collide with other objects.
The MEO debris environment is 100 times less dense than the LEO. The spatial density of orbital debris in LEO (up to 2,000 km), shown in Figure 1, suggests that LEO is the likely location where a runaway chain reaction will initiate. This could easily result in a region of space so dangerous that it would effectively deny access to MEO, where the GPS constellation resides.
While the debris situation at MEO is much better, there are still 4,021 tracked debris objects that could impact GPS and other GNSS satellites. Because future orbital debris collisions in LEO will be responsible for more debris in MEO, the situation is guaranteed to get worse. The dead and debris objects in highly elliptical, or Molniya, orbits, shown in Figure 2, could be responsible for such collisions pushing LEO debris into MEO.
Contributions to the general MEO debris population come from launch systems and other factors. Early GPS satellites (Block II/IIA/IIR) used internal orbital-insertion motors to avoid leaving uncontrolled stages in the operational orbit range when moving from transfer orbit to MEO. For survivability reasons, they were also deployed with sufficient fuel to make several major orbital moves. Unfortunately, later versions used separate orbital-insertion stages, which were left drifting in the orbital neighborhood and carried less fuel, resulting in fewer possible maneuvers to avoid collisions.
Using the CelesTrak visualization interface to extract space situational awareness data captured by the Combined Force Space Component Command’s 18th Space Control Squadron (18 SPCS) reveals a much more dire image of MEO. Of the 21,266 total tracked objects in Earth’s orbit, 157 are active GNSS satellites, as shown in Figure 3.
Figure 3. Active GNSS satellites. (Image: Celestrak)
However, a total of 4,021 objects reside or pass through MEO, which are either active (331), dead (668), debris (1,761), rocket bodies (1,100) or unknown (161) objects, as shown in this video.
These 4,021 objects represent 19% of the total number of tracked objects from the 18 SPCS space catalog. While the total 21,266 tracked objects is a far cry from the 100 million objects NASA’s Orbital Debris Program Office represents, one can imagine that a significant portion of untracked debris objects, under 10 cm in size, reside or pass through MEO as well. This is significant, according to NASA, which says that objects with a diameter of 1 cm to 10 cm are the most dangerous due to the lack of tracking data, which essentially makes them invisible.
False Sense of Security
The growing orbital-debris concern is a threat too big to ignore. Unfortunately, to date attempts to manage space traffic have amounted to passive measures, such as establishing policy, characterizing the environment, and creating orbital protection guidelines. Even the highly touted, $6 billion U.S. “Space Fence” is a passive measure that contributes nothing active to solve the problem. Not at all a “fence,” it is merely a way to detect the larger and more dangerous debris.
These efforts may, in all actuality, be counterproductive if they instill a false sense of security in the public and government leaders that the problem is being adequately addressed.
A Proactive Solution
Since 1978, the orbital debris population has been touted as our biggest space problem. It is important to do as much as we can with policies and procedures to keep the problem from getting worse faster. However, even if we humans were to completely resist our seemingly natural impulse to pollute everywhere we go, collisions with existing debris would continue to increase the number of dangerous objects in orbit.
Active debris removal (ADR) is the only solution. The sooner it begins, the safer we will all be. Like the oceans and cyberspace, orbital space suffers from the tragedy of the commons. Everyone wants to use it, but no one owns it. No one is responsible for ensuring it is cared for and maintained. As a result, user behavior is difficult to control, and the environment often suffers. Government action, presumably supporting the best interests of all users, is the default answer.
The proposed Space Debris Act of 2021 is a great start. It paves the way for persistent funding and creates an industry responsible for safeguarding humanity’s orbital infrastructure. It would introduce tax credits to incentivize non-government funding contributions and reduce the price of debris removal, so that satellite operators and the emerging space tourism industry can afford to clean up space where they plan to operate.
The bill is currently being presented by OrbitGuardians to members of Congress for sponsorship. Organizations wishing to support these efforts should contact Ken Eppens at OrbitGuardians at [email protected].
GPS/GNSS and other critical space assets are at an unacceptable level of risk from debris. It is time to safeguard orbital infrastructure to protect the interests of the United States and humanity’s future in space.
China sends two BeiDou satellites into space a Nov. 23. (Photo: Guo Wenbin/Xinhua)
China launched two satellites of the BeiDou Navigation Satellite System (BDS) into space from the Xichang Satellite Launch Center in Sichuan Province at 8:55 a.m. Saturday, Nov. 23.
Launched on a Long March-3B carrier rocket and the Yuanzheng-1 (Expedition-1) upper stage attached to the carrier rocket, the two satellites have entered their planned orbits. They are the 50th and 51st satellites of the BDS satellite family.
The two medium earth orbit (MEO) satellites are also network satellites of the BeiDou-3 system.
The two new satellites, the carrier rocket and Yuanzheng-1 were all developed by the Innovation Academy for Microsatellites of the Chinese Academy of Sciences and the China Academy of Launch Vehicle Technology under the China Aerospace Science and Technology Corporation.
The launch was the 319th mission for the Long March series carrier rockets.
China has launched two more BeiDou III satellites. The launch took place on Sunday, Sept. 22, using a Long March 3B rocket which lifted off from the Xichang space center at 2110 GMT (5:10 p.m. EDT), according to the Xinhua News Agency.
About four hours after liftoff, the upper stage delivered the Beidou satellites into a nearly circular orbit with an average altitude of 13,500 miles (21,800 kilometers) and an inclination of 55 degrees.
The satellites were produced by the China Academy of Space Technology, a government-owned satellite builder.
With Sunday’s launch, China has added five new satellites to the Beidou network this year, halfway to its stated goal of 10 Beidou satellites this year.
The satellites are the 47th and 48th spacecraft launched in the Beidou navigation program.
China has launched its first geostationary satellite for the BeiDou constellation, according to press reports.
The successful launch of satellite G1Q took place at 15:57 UTC on Nov. 1 from the LC2 Launch Complex of the Xichang Satellite Launch Center, Sichuan province, using a Long March-3B/G2 (Chang Zheng-3B/G2) launch vehicle.
Beidou-3G satellites are the geostationary Earth orbit (GEO) component of the third phase of the Chinese Beidou satellite navigation system. The GEO satellites will be in high orbit, about 36,000 kilometers above the Earth, following the Earth’s rotation to view the same point on Earth continuously.
In addition to navigation services, the satellite will serve as a satellite-based augmentation system (SBAS) and provide short message services (Research Data Shared Service, RDSS).
The G1Q satellite is the 17th BeiDou-3 satellite and the 41st overall BeiDou satellite. Another pair of BeiDou-3 medium Earth orbit (MEO) satellites, M17 and M18, will be launched in mid-November.
The recent BeiDou launches will expand the system to global navigation coverage.
The G1Q satellite is based on the DFH-3B bus that features a phased array antenna for navigation signals and a laser retroreflector, and also is equipped with an apogee propulsion system for final orbit insertion. The satellite has a launch mass of about 4,600 kg.
The European Commission (EC) has awarded Thales Alenia Space a contract to develop and build an operational ground station on La Reunion Island to track GNSS satellites in medium Earth orbit. The ground station will be an operational part of the Galileo search-and-rescue (SAR) system.
The contract includes one Medium Orbit Local User Terminal (MEOLUT), engineering support and maintenance services for one year, and the hosting site on La Reunion Island.
Using Thales Alenia Space’s powerful and compact MEOLUT Next phased-array solution, the EC and European GNSS Agency (GSA) will improve their contribution to the Cospas-Sarsat system.
Thales Alenia Space is a joint venture between Thales (67 percent) and Leonardo (33 percent).
The ground station will receive and process 406-MHz distress beacon signals from the MEO satellites being tracked, and relay them to the SAR/Galileo network via the French Mission Control Center (FMCC) at the CNES facility in Toulouse. The contract also included the procurement of the best possible hosting site for this ground station.
Image: International Cospas-Sarsat Programme
This MEOLUT Next will enhance the EC’s contribution to the Cospas-Sarsat SAR system by extending its coverage in the South Indian ocean, contributing to worldwide coverage. It complements the three MEOLUTs that are already deployed around Europe — in Larnaca (Cyprus), Maspalomas (Grand Canaria) and Spitzbergen (Norway) — and under responsibility of the GSA.
The MEO system, which replaces the legacy LEO (low Earth orbit) system, is designed to offer a faster response and better location data in near real time for search-and-rescue authorities, using spacecraft and ground facilities to detect and locate signals from the 406-MHz distress beacons.
The MEOLUT Next will also support the second generation of Cospas-Sarsat beacons. The SAR/Galileo site on La Reunion will be fitted with reference and calibration beacons to monitor the performance of the extended SAR ground segment and precisely calibrate MEOLUT measurements.
“Using Thales Alenia Space’s powerful and compact MEOLUT Next phased array solution, the European Commission will benefit from the world’s first spaceborne search & rescue system of this type,” said Philippe Blatt, vice president, Navigation France at Thales Alenia Space. “We are very proud that our advanced technology is now recognized by many customers worldwide. The performance logged by our MEOLUT Next units in service far exceeds requirements, which not only benefits our customer countries, but also makes travel even safer. It’s worth remembering that the Cospas-Sarsat system, operational since 1988, saves some 1,500 lives a year.”
Thales Alenia Space designs, operates and delivers satellite-based systems for governments and institutions, helping them position and connect anyone or anything, everywhere. Since commissioning in 2016, MEOLUT Next has delivered unrivaled performance, detecting distress signals from more than 5,000 kilometers away. Several countries have already chosen or are interested in the technology, including Canada and Togo.
By Changfeng Yang, Chief Architect of BeiDou Navigation Satellite System
Changfeng Yang
As one of the four major GNSS providers, the establishment of BeiDou Navigation Satellite System (BDS) has been steadily developed, following a three-step strategy. By around 2020, BDS will form a nominal space constellation consisting of 30 satellites, including three satellites in geostationary Earth orbit (GEO), three satellites in inclined geosynchronous satellite orbit (IGSO) and 24 satellites in medium Earth orbit (MEO). It will provide global users with open and high-quality services free of charge, including navigation, positioning, timing, short message communication, search and rescue and so on.
BDS is aimed at developing into a world-class global navigation satellite system, with innovative and advanced technologies, extraordinary user experience, international development and worldwide presence, which can provide fundamental time and space reference for national defense and economic-social development, and advance the progress of high-tech and IT industries.
BDS has initiated several innovative attempts in the fields of both international satellite navigation and domestic aerospace for the first time, and paved a unique development path of a satellite navigation system, with an eye on the state conditions and distinctive features. On Jan. 9, 2017, the BD-2 Project won the top National Scientific and Technological Progress Award. In 2017, BDS achieved fruitful results in the aspects of system construction, integrated applications and international development.
System Construction
Through upgrading and reconstructing the ground system, the service performance, stability and availability of the BD-2 constellation have been improved. To achieve user-oriented services, the updated Interface Control Document (ICD) for B1C and B2a open service signals (Version 2.1) was released in accordance with the constellation change.
The international GNSS Monitoring and Assessment System (iGMAS) has been built, consisting of eight domestic monitoring stations and 16 overseas stations, to monitor and assess the service performances of BDS, GPS, GLONASS and Galileo at real-time worldwide. It has taken all factors into consideration, including constellation status, signal-in-space, navigation message, service performance and high-precision products, and so on. According to its analysis results, the nominal positioning accuracy of the BD-2 system in the coverage area has been optimized from 10 meters to 8 meters.
Development of the BD-3 System. On Nov. 5, the first pair of the 24 BD-3 MEO satellites were successfully launched, while another pair is planned to be launched by the end of the year.
Liftoff of the first pair of the BD-3 MEO satellites on Nov. 5, 2017. (Credit: Xinhua)
The BD-3 satellites are equipped with B1C and B2a signals with optimized performance, which are compatible and interoperable with other GNSS signals. The interface control document of B1C and B2a signals (beta version) was released in September. The BD-3 satellites also adopt the higher-performance rubidium atomic clock with stability of E-14 and hydrogen atomic clock with stability of E-15. By utilizing new technologies, the signal-in-space (SIS) accuracy will be superior to 0.5 m; the position accuracy will be doubled or quadrupled, and reach 2.5 m to 5 m.
The BD-3 system will retain the short message communication service of its predecessors, and further enhance basic positioning, navigation and timing (PNT) service capabilities. Satellite-based augmentation system (SBAS) and search-and-rescue (SAR) services will be added and developed according to international standards.
After in-orbit tests and networking validation, the BD-3 satellites will be able to provide operational services, and accelerate the global coverage of BDS.
Ground-Based Augmentation. The Phase I construction of the BDS/GNSS ground-based augmentation system has been completed, consisting of 150 framework reference stations, 1,200 reference stations of higher density network, national data processing center, six industrial data-processing centers, and manufacturing of user terminals. This system has achieved basic service capabilities, and its service performance standard (version 1.0) has been released. Through integration with the internet, a cloud platform has been established to provide high-precision space-time information services, including real-time navigation services at meter-level and decimeter-level, as well as precise positioning services at centimeter-level and millimeter-level.
Satellite-Based Augmentation. Based on the International Civil Aviation Organization (ICAO) standards, system demonstration and validation work on the BeiDou Satellite-Based Augmentation System (BDSBAS) has been completed, and the technical status of the system has been confirmed in accordance of the next-generation SBAS Dual Frequency Multiple Constellation (DFMC) standards.
Integrated Applications
Currently, a great number of independent, self-controlled intellectual property rights on the fundamental BDS products have been achieved. World-class, advanced technologies have been developed. With the release of the first Chinese in-house developed meter-level fast positioning BDS chip, BDS applications have begun to embrace the era of meter-level positioning.
In 2017, the sales volume of BDS navigation chips and modules exceeded 50 million pieces, and that of high-precision surveying boards and navigation antenna captured 30% and 90% of market shares respectively. There are more than 14,000 enterprises (including more than 50 publicly listed companies), and more than 450,000 employees in China engaging in BDS-related business.
The annual output value of the publicly listed company in 2017 is more than RMB 50 billion (US $7.53 billion). The number of terminals produced by domestic enterprises surpasses 40 million pieces/sets. BDS has gained recognition from mainstream chip producers such as Qualcomm, Trimble, Hemisphere GNSS, Huawei, Samsung, u-blox, MTK, Broadcom, NovAtel and more, and the total number of terminals is estimated to surpass 300 million pieces or sets.
BDS continues to:
promote integrated applications and development of related industries;
bring GNSS high-precision services in combination with cloud computing, Internet of Things, big data and other technologies;
push forward the integration between BDS-related industries and high-end manufacturing, software, and integrated data industries.
BDS has been applied in the transportation, logistics, emergency rescue, marine fishing and other fields, which has greatly improved production efficiency, reduced resource consumption, and lowered pollution. For example, benefiting from the BDS applications in traffic management industry, the number of major accidents has decreased by 46.7%, and the death toll has been reduced by 48.9%. With BDS-based maritime applications, more than 10,000 lives have been saved.
BDS/GNSS augmentation services have been applied to precision agriculture, land mapping, monitoring on deformation and displacement of large-scale public facilities, and earthquake and geological hazard measurement and survey; the latter has provided important monitoring for public safety. As a result, the production of precision agriculture has increased by 5%, and the oil consumption by agricultural machinery has decreased by 10%. The time for surveying and mapping of national land is shortened from a few days to several seconds.
BDS has been fully put into mass applications. BDS-based navigation services have been adopted by various enterprises, such as Huawei, ZTE, Baidu, Autonavi, Alibaba, JD and others in the fields of manufacturing of mobile and smart terminals, location-based services (LBS), e-commerce, and so on. BDS-based LBS have been widely applied in the mass consumption sector and people’s livelihood, and many innovative applications have emerged, such as caring for seniors and children, shared vehicles, BDS-based logistics, and so on, which have been changing people’s lives and providing more convenience for the public.
International Development
At present, BDS has covered more than 50 countries and more than 3 billion people. BDS-related products have gained access to the markets of more than 70 countries and regions, more than 30 of which are along the (land-based) Belt and (maritime) Road (in line with the Belt and Road Initiative). Through joint applications with other compatible navigation satellite systems, BDS provides global users with diversified choices for better application experience.
Meanwhile, the iGMAS has contributed to the implementation of the Asia-Pacific Space Cooperation Organization project, iGMAS-International GNSS Service Pilot experimental project, and Sino-Russian monitoring and assessment cooperation, and has provided GNSS users with authentic third-party assessment results. China continuously pushes forward BDS to be recognized by the ICAO, International Maritime Organization (IMO), mobile communication standard Partnership Project and other organizations, to serve the world in line with international conventions.
In October, three PRN codes which are essential to the development of BDSBAS were assigned; the SBAS service provider identifier and UTC standard identifier have been assigned to BDSBAS by ICAO, which marks BDSBAS an official SBAS provider in the ICAO family, and lays the foundation for the follow-up construction of BDSBAS, as well as its provision of standard navigation services for the civil aviation sector.
In March, a multi-system (including GPS, BDS and GLONASS) ship-borne receiver standard was approved by the IMO. BDS has also been included in the PNT guidelines of maritime applications.
In the field of mobile communication, 26 technical standards that support the BDS positioning function have been adopted by the third- and fourth-generation mobile communication standard Partnership Projects.
Future Plans
BDS will keep improving its continuous stability and service accuracy. Two more BD-2 replacement satellites will be launched in 2018, ensuring its regional service performance will be remain stable and be enhanced.
Eighteen BD-3 MEO satellites and one BD-3 GEO satellite will be launched by around the end of 2018. Upon the deployment of those 19 satellites, BD-3 will possess the initial operational capability and serve the countries along the Belt and Road. The official version of ICD for B1C and B2a open service signals, as well as other system documents, will be released, in line with the operational status of BD-3 satellites, for the convenience of public applications.
In regard to augmentation systems, China plans to complete the construction of Phase II BDS/GNSS ground-based augmentation system in 2018, and advance the recognition of BDS-based high-precision services as public goods. In 2018, the first BDSBAS GEO satellite with the BDSBAS payload will be launched to start the deployment of the BDSBAS system.
In terms of applications and international development, China will give full play to the role of BDS in the integration procedure between industrialization and IT applications, to promote the development of information industry, adjustment and upgrading of industrial structure.
China will also strengthen the cooperation and communication with other navigation satellite system providers, carry out coordination under the framework of international organizations and multilateral platforms, improve the international development of BDS, provide better services for users along the Belt and Road, and expand BDS services to serve users worldwide.
Web chatter indicates that the launch of a pair of BeiDou-2/Compass medium Earth orbit (MEO) satellites from the Xichang Satellite Launch Center will take place around April 23. This will be the first time that a pair of BeiDou-2/Compass satellites is launched on a single rocket. The satellites are designated M3 and M4. M1 is already in orbit, and M2 and M5 are expected to be launched in June.
