Micro- and nanosatellites have emerged as a highly versatile and economical resource for the satellite community, becoming one of the major areas of development and growth. They find application in scientific research, communication, navigation and mapping, power, reconnaissance, and others including Earth observation, biological experiments, and remote sensing.
There is growing utilization of miniaturized satellites for military and defense applications. Defense organizations have been launching communication nanosatellites and microsatellites to provide communication signals to soldiers stationed in remote locations or in dense forests. The military needs more data bandwidth and reliable communications infrastructure for its UAVs, which can be fulfilled using constellations of nano and microsatellites.
Large networks of small, cheap satellites derived from commercial technology would be harder for China or Russia to kill than a handful of expensive, exquisite large military satellites. “The larger numbers of satellites complicates an adversary’s decision-making calculus and increases the uncertainty of outcomes. Smaller, lower-cost satellites, built and launched on frequent schedules could also make it much easier to reconstitute space capabilities, and introduce new technologies and capabilities. New countermeasures could also be added as the corresponding threat systems are developed and fielded.”
DARPA had launched a program called Blackjack and invited companies to pitch ideas on:, “How to leverage the commercial sector at LEO, how we leverage the manufacturing of smaller cheaper satellite buses, and looking at how we put our payloads into those more affordable buses,” Walker said.
DARPA Director Walker said it’s time for DoD to shift future spending to constellations in low earth orbit made up of dozens or hundreds of small satellites. Both DoD and the commercial sector have “very exquisite satellites,” he said. They are high-performance systems but cost too much, and take too long to build and launch, Walker added. “We have been saying this for 10 years: We want to see a shift to LEO, get capabilities in larger constellations.” The more satellites in the system, the harder it will be for the enemy to take it down, the thinking goes.
Larger constellations can be used for multiple missions, Walker said, and they could even “enable a battle management system for tactical war fighting on the ground,” he said. “We’ve been talking about this for a while” but only recently have these ideas been taken more seriously. Under Blackjack, DARPA hopes to have successfully launched 20 demonstration satellites with a variety of experimental payloads based on a ‘standardized’ commercially-provided satellite bus by the end of fiscal 2022, according to the agency’s website. DARPA asked for $25 million for the project in FY2020, up from $16.4 million the previous year.
Both the Air Force’s Space and Missile Systems Center (SMC) and the Pentagon’s brand-new Space Development Agency (SDA) are laying plans to transition Blackjack’s technology into their own acquisition programs. “SMC is currently partnered with DARPA and providing funding for Blackjack. When Blackjack is proven successful, SMC is planning a transition of the architecture to a program called CASINO [Commercially Augmented Space Inter Networked Operations].”
“SMC is currently partnered with DARPA and providing funding for Blackjack. When Blackjack is proven successful, SMC is planning a transition of the architecture to a program called CASINO [Commercially Augmented Space Inter Networked Operations],” Col. Dennis Bythewood, Program Executive Officer for Space Development at SMC, told me in a Friday evening email statement. “SMC is also working with the newly created SDA to define roles and responsibilities and how our respective efforts will complement each other. SMC is committed to continued partnership with DARPA and SDA to provide future capabilities to the warfighter.”
Lt. Gen. Jim Dickinson, head of the Army’s Space and Missile Defense Command explained the technology in Colorado Springs, Colo., on the final day of the 34th annual Space Symposium. Currently, the average Army combat brigade takes 3,000 pieces of satellite gear into battle, he said. And the reliance is only growing. One of the key concerns for the Army is potential enemies’ greater likelihood of being able to jam US satellite signals, Dickinson said. Often, Dickinson said, soldiers will encounter technical problems on the ground not knowing that the problems originate from space.
So the US Army Space and Missile Defense Command is developing a series of “nano-satellites” designed to compensate for damage done to larger satellites, the Gazette reported. Unlike the larger satellites, which are designed to stay in orbit for decades, the “nano-satellites” will stay in orbit for months or weeks. “We envision a constellation of nano-satellites,” Dickinson said.
Military use of Microsatellites : Disaggregated Architecture for more resilient space architectures
According to US army, there are many benefits of Smallsats in LEO: the first is low per-unit cost that enables affordable satellite constellations with minimal personnel and logistics tail and opportunity of frequent technology refresh. The second is high survivability as they fly far above common threats and crowded airspace. The constellations also degrade gracefully and lost capability can be rapidly augmented and reconstituted. The ASAT attack is also difficult as microsatellites provide very very small target. ASAT attack also becomes less economical with ASAT engagement cost ratio in our favor. The Responsiveness is also enhanced due to rapid design and built, can be tasked from theater and also better adapt to the threat.
Senior leaders and policy makers in the US government have been calling for a disaggregated National Security Space architecture in response to the rapidly changing nature of the space domain. The Air Force Space Command (AFSC) defines disaggregation as: “The dispersion of space-based missions, functions or sensors across multiple systems spanning one or more orbital plane, platform, host or domain.”
“A disaggregated system design offers a means to avoid threats, ensure survivable capabilities despite hostile action, and develop the capacity to reconstitute, recover or operate through adverse events should robustness fail. Carefully pursued, disaggregation can lead to less costly and more resilient space architectures in the face of a rapidly evolving security environment.”
“The larger numbers of satellites complicates an adversary’s decision-making calculus and increases the uncertainty of outcomes. Smaller, lower-cost satellites, built and launched on frequent schedules could also make it much easier to reconstitute space capabilities, and introduce new technologies and capabilities. New countermeasures could also be added as the corresponding threat systems are developed and fielded.”
SMC Commander Lt. Gen. John Thompson testified to the SASC Strategic Forces subcommittee in March 2019 that CASINO, which would move Blackjack into the Air Force, is now one of nine key “pacesetter” programs under SMC’s initiative to speed acquisitions (known as SMC 2.0). “The SMC pacesetter effort, known as CASINO will expand the efforts” of Blackjack, “to increase resilience by disaggregating various mission capabilities using large, Low Earth Orbit constellations,” he said.
Microsatellites could also be adapted as weapons. They can stealthily inspect and monitor a large satellite to determine its capabilities Microsatellites carrying hard-kill or soft-kill payloads can permanently or temporarily disable a large satellite. There are reports of plans to use microsatellite technology to develop and deploy long-duration orbital ASAT interceptors. The Sing Tao newspaper recently quoted Chinese sources as indicating that China is secretly developing a nanosatellite ASAT weapon called “parasitic satellite.” The sources claim this ASAT recently completed ground testing and that planning was underway to conduct testing in space.
The USAF Scientific Advisory Board’s (SAB) Microsatellite Mission Applications (MMA)
Study was chartered to review the potential mission utility of satellites with weight less than 300 kilograms (i.e., microsats). Satellite design approaches considered the ability of microsats to achieve mission utility by delivering: (1) complete mission capability, (2) disaggregated mission requirements, (3) augmentation of current capabilities, (4) fractionation of satellite functions, or (5) reconstitution of capability.
The Study was motivated by the rapidly changing strategic setting of space as a result of evolving threats, diminishing budgets, increasing space activity, increasing technology miniaturization, and emerging launch options. The Study found that microsatellites have significant near-term (2-5 years) mission capability. Specific findings include : (1) microsats can address all Category A weather requirements, (2) microsats can address some critical space situational awareness (SSA) requirements, (3) other potential near- and mid-term microsat missions exist in space-to-surface intelligence, surveillance, and reconnaissance (ISR) and position, navigation, and timing (PNT), (4) potential far-term microsat missions exist in missile warning, PNT, and communications.
The report recommended “Initiate Science and Technology (S&T) Investments to Enable Far-Term Employment of Microsats”. S&T investments by the Air Force should address both hardware (i.e., infrared focal plane arrays, cryocoolers, radio frequency amplifiers, on-board digital processing, etc.) and processes (open/modular architectures, constellations, rapid design/prototype manufacture, automation and autonomy, etc.). Advances in these areas will reduce the size, weight, and power requirements of microsat payloads and help optimize design, performance, cost, and constellation size to best meet Air Force Requirements
Army nanosatellites mission
Three U.S. Army Space and Missile Defense Command/Army Forces Strategic Command nanosatellites were on board an Atlas V rocket launched from Vandenberg Air Force Base, Calif., in Oct 2015. Each SNaP nanosatellie consists of three approximately 10 centimeter cubes stacked for a length a little more than 30 centimeters and a weight of 5.5 kilograms. Each nanosatellite has four deployable solar panels and four deployable RF antennas.
The mission objectives for the nanosatellites are to successfully demonstrate beyond-line-of-sight voice and data relay, and data exfiltration of unattended ground sensors. Other supporting technologies such as encryption and propulsion will also be demonstrated. The nanosatellites are part of the USASMDC/ARSTRAT Nanosatellite Program (SNaP), a Joint Capabilities Technology Demonstration
The SNaP program is part of a continuing evolution of Army nanosatellite capabilities that started with the first SMDC-ONE nanosatellite launch in December 2010, followed by the launch of additional SMDC-ONE nanosatellites in September 2012 and December 2013.
US Army’s SMDC Program
In many remote areas where Soldiers operate, Army radio over-the-horizon communication from the field to higher headquarters like the brigade is nonexistent. SMDC-ONE was a technology demonstration that showed nanosatellites in low Earth orbit could be used for beyond-line-of-sight communications and data exfiltration. The ONE stands for Orbital Nanosatellite Effect.
Army SMDC focus is on demonstrating the utility of nanosatellites and microsatellites for the warfighter. SNaP – SMDC Nanosatellite was launched in August 2015 consisting of 5kg mass cube satellite, $500K each, 5 times the data rate of SMDC-One, 3 Axis Stabilization and Propulsion. “This is a Joint Capabilities Technology Demonstration that will focus on voice and data communications beyond line of sight and improved access to high value information.”
“Nanosatellites in low-Earth orbit are traveling approximately 17,000 mph and are about the size of a football which makes them very survivable,” Thomas E. Webber, director, SMDC Technical Center Space and Strategic Systems Directorate said. “Providing the ability for our warfighter to communicate in an environment where traditional SATCOM is unavailable can literally be the difference between life and death.”
Another difference from previous satellites is that this is the first cubesat launch with propulsion capability and SMDC’s first with deployable solar arrays for battery charging. “The benefit of propulsion is to prove we can accomplish the technological challenge of having propulsion capability in a small package and to allow us to maintain proper satellite spacing within the constellation to maximize contact availability,” said Jeff Stewart, technical manager, Space Superiority Division, USASMDC/ARSTRAT. “The benefit of deployable solar arrays is to maximize power generation. On previous satellites the solar panels were attached to the sides of the satellite. At any one time, a maximum of only two panels would be pointed at the sun. With deployable arrays, we can orient all four toward the sun.”
“SNaP is designed for UHF communication with existing Army and some coalition radios,” Webber said. “The advantage low-Earth orbit provides is the fact that satellites are so much closer to the Earth, which allows much lower signal levels to be received and processed.”
The Army is also developing tactically controlled imagery satellites like Kestrel Eye, which will provide soldiers with improved battle space awareness. These small (40 lbs) satellites can perform tactical imaging achieving 1.5 GSD from 450 km and 1.7 from 600 km; can be tasked by forward forces to take images of designated points, can take individual or strip images (5.8 km x 3.8 km frames), returns imagery to user within seconds, can Roll ±30° (swath width ≈300 miles), Max roll rate ≈3°/sec in Roll, 1.2°/sec in Pitch. A constellation (5 planes, 8 SC/plane) can provide high persistence coverage of broad latitudinal swath.
SpaceX’s Starlink satellites could make US Army navigation hard to jam
SpaceX has already launched more than 700 Starlink satellites, with thousands more due to come online in the years ahead. Their prime mission is to provide high-speed internet virtually worldwide, extending it to many remote locations that have lacked reliable service to date. Now, research funded by the US Army has concluded that the growing mega-constellation could have a secondary purpose: doubling as a low-cost, highly accurate, and almost unjammable alternative to GPS. The new method would use existing Starlink satellites in low Earth orbit (LEO) to provide near-global navigation services.
In a non-peer-reviewed paper, Todd Humphreys and Peter Iannucci of the Radionavigation Laboratory at the University of Texas at Austin claim to have devised a system that uses the same satellites, piggybacking on traditional GPS signals, to deliver location precision up to 10 times as good as GPS, in a system much less prone to interference.
The US military relies heavily on GPS. The problem with GPS is that those signals are extremely weak by the time they reach Earth, and are easily overwhelmed by either accidental interference or electronic warfare. In China, mysterious GPS attacks have successfully “spoofed” ships in fake locations, while GPS signals are regularly jammed in the eastern Mediterranean.
Building a whole new network of LEO satellites with ultra-accurate clocks would be an expensive undertaking. Bay Area startup Xona Space Systems plans to do just that, aiming to launch a constellation of at least 300 Pulsar satellites over the next six years. Humphreys and Iannucci’s idea is different: they would use a simple software upgrade to modify Starlink’s satellites so their communications abilities and existing GPS signals could provide position and navigation services . They claim their new system can even, counterintuitively, deliver better accuracy for most users than the GPS technology it relies upon. That is because the GPS receiver on each Starlink satellite uses algorithms that are rarely found in consumer products, to pinpoint its location within just a few centimeters. These technologies exploit physical properties of the GPS radio signal, and its encoding, to improve the accuracy of location calculations. Essentially, the Starlink satellites can do the heavy computational lifting for their users below.
The new system, which Humphreys calls fused LEO navigation, will use instant orbit and clock calculations to locate users to within 70 centimeters, he estimates. Most GPS systems in smartphones, watches, and cars, for comparison, are only accurate to a few meters. But the key advantage for the Pentagon is that fused LEO navigation should be significantly more difficult to jam or spoof. Not only are its signals much stronger at ground level, but the antennas for its microwave frequencies are about 10 times more directional than GPS antennas. That means it should be easier to pick up the true satellite signals rather than those from a jammer. “At least that’s the hope,” says Humphreys.
According to Humphreys and Iannucci’s calculations, their fused LEO navigation system could provide continuous navigation service to 99.8% of the world’s population, using less than 1% of Starlink’s downlink capacity and less than 0.5% of its energy capacity. Fused LEO navigation does have its drawbacks, however. The initial Starlink mega-constellation is not expected to operate above 60 degrees latitude, meaning that residents of Helsinki might miss out on its benefits, as would soldiers in any future disputed Arctic or Antarctic regions.
DARPA’s call for Intersatellite Microsatellite links
The Defense Advanced Research Projects Agency has awarded a contract to speed development of technologies that could improve communications amongst its growing fleet of very small satellites. Under the two-year, $5 million contract, LGS Innovations of Herndon, Virginia, will prototype a lightweight, low-power optical communication terminal system that will enable light-based communications between micro-satellites in low-earth orbit.
The desire for rapid revisit rates or persistence from low-earth-orbit (LEO) satellites is also driving the development of large constellations of small satellites, potentially with ~100-400 satellites. In addition to performing their core sensing mission, such satellites also have the potential to provide inter-satellite data relay, providing a highly survivable mesh of nodes capable of relaying data before downlink to ground stations.
Many applications of these satellites will benefit from jam-resistant, high-data-rate, low-latency communications between satellites, whether for cooperative sensing applications or for data relay back to ground stations. Since ground stations may be unavailable in many locations, relaying data between satellites to reach one with a connection to a ground station is an attractive option when low data latency is needed.
DARPA had solicited proposals to develop and demonstrate lightweight, low-power, and low-cost inter-satellite communications links (ISCLs) suitable for use on a wide range of small LEO satellites. Specifically, this program seeks to develop ISCLs with high communication data rates (>1 Mbps) while having a per-link average weight of less than 2 pounds and an orbit-average power dissipation of less than 3 watts. Both optical and radio frequency (RF) links will be considered.
Lockheed Martin’s Smart Satellites will test swarming formations
Satellites that launched one, ten or even fifteen years ago largely have the same capability they had when they lifted off. That’s changing with new architecture that will let users add capability and assign new missions with a software push, just like adding an app on a smartphone. This new tech, called SmartSat™, is a software-defined satellite architecture that will boost capability for payloads on several pioneering nanosats ready for launch this year.
“Imagine a new type of satellite that acts more like a smartphone. Add a SmartSat app to your satellite in-orbit, and you’ve changed the mission,” said Rick Ambrose, executive vice president of Lockheed Martin Space. “We are the first to deploy this groundbreaking technology on multiple missions. SmartSat will give our customers unparalleled resiliency and flexibility for changing mission needs and technology, and it unlocks even greater processing power in space.”
Lockheed Martin is integrating SmartSat technology on ten programs and counting, including the Linus and Pony Express nanosats, which will be the first to launch. These are rapid-prototype, testbed satellites using internal research and development funding, ready for 2019 launches on the first LM 50 nanosatellite buses:
- The Linus project delivers two 12U cubesats performing a technology demonstration mission, validating SmartSat capabilities as well as 3D-printed spacecraft components.
- Pony Express builds multiple 6U satellites destined for a low earth orbit and will space qualify state-of-the-art networking technologies. Pony Express 1 is a pathfinder for a software-defined payload that will test cloud computing infrastructure and was developed in nine months. Follow-on Pony Express missions will prove out RF-enabled swarming formations and space-to-space networking.
LM launched the Pony Express 1 mission as a hosted payload on Tyvak-0129, a next-generation Tyvak 6U spacecraft. Lockheed Martin (LM) is testing a new space-based computing method now being tested in-orbit, enabling artificial intelligence, data analytics, cloud networking, and advanced satellite communications in a new software-defined architecture.
Cyber security is at the core of this new technology. SmartSat-enabled satellites can reset themselves faster, diagnose issues with greater precision and back each other up when needed, significantly enhancing resiliency. Satellites can also better detect and defend against cyber threats autonomously, and on-board cyber defenses can be updated regularly to address new threats.
SmartSat uses a hypervisor to securely containerize virtual machines. It’s a technology that lets a single computer operate multiple servers virtually to maximize memory, on-board processing and network bandwidth. It takes advantage of multi-core processing, something new to space. That lets satellites process more data in orbit so they can beam down just the most critical and relevant information—saving bandwidth costs and reducing the burden on ground station analysts, and ultimately opening the door for tomorrow’s data centers in space.
SmartSat uses a high-power, radiation-hardened computer developed by the National Science Foundation’s Center for Space, High-performance, and Resilient Computing, or SHREC. Lockheed Martin helps fund SHREC research, and in turn gains access to world-class technologies and student researchers.
“SmartSat is a major step forward in our journey to completely transform the way we design, build and deliver satellites,” said Ambrose. “The LM 50 bus is the perfect platform for testing this new, groundbreaking technology. We’re self-funding these missions to demonstrate a number of new capabilities that can plug into any satellite in our fleet, from the LM 50 nanosat to our flagship LM 2100. And the same technology not only plugs into ground stations, improving space-ground integration, it will one day connect directly with planes, ships and ground vehicles, connecting front-line users to the power of space like never before.”
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