In April 2020, Lockheed Martin was awarded a $5.8m contract for the first phase of satellite integration on DARPA’s Blackjack programme. Lockheed Martin will manage interfacing between Blackjack’s bus, payload and Pit Boss in the run-up to the launch of a demonstration constellation in 2021-22.

As traditional military satellites are expensive to replace, DARPA is betting on low earth orbit constellations as a means to get military hardware into orbit at a lower cost with the Blackjack programme. Such a system would remove single points of failure both in space and on the ground. It would also mean a shift towards on-orbit processing, where the Blackjack constellation can shoulder the processing burden of ground-based systems.

“The advantage of on-orbit processing is that it brings resilience in a proliferated LEO constellation, DARPA Blackjack programme manager Paul "Rusty" Thomas told us. “Putting distributed processing in space eliminates a single point of failure in space or on the ground.”

The US is looking to achieve a number of goals with a military low earth orbit constellation, ranging from cost to latency, says Lockheed Martin programme director for advanced missile defence Julie Pecson.

“There are advantages and disadvantages of all orbital regimes,” she tells us. “For LEO constellations, data latency is reduced because the satellites are closer to the earth compared to geosynchronous earth orbit (GEO) where traditional military satellites fly. Also, LEO satellites are generally smaller in size because they require less propulsion and less power.”

However, due to operating at a higher altitude, one GEO satellite can cover the same area as several LEO satellites. This means that more LEO satellites are needed to provide the same level of service to the military. This disadvantage can be somewhat an advantage in itself, though.

“Due to their proximity to earth, more LEO satellites are required to perform similar GEO missions,” Pecson explains. “However, the numerous spacecraft required in LEO provide an inherent constellation-level resiliency advantage over traditional military constellations relying on a small number of spacecraft. Lockheed Martin Space performs mission analysis to determine the best orbit and constellation architecture to support the mission.”

“The lower unit size and mass also enables faster design and deployment cycles because the design/build complexity of a 200kg LEO satellite is so much lower than a GEO satellite.”

Commenting on the need for more LEO satellites to do the job of one GEO satellite, Blackjack lead Paul Thomas said: “The trade-off is that you need more satellites in LEO for regional or global coverage, but the same rocket can put two to three times as much mass into LEO as it can into GEO, and the LEO satellites are ten to 25 times lower in mass. That means you have proliferated constellations in LEO that can either do similar missions as in GEO, or augment GEO missions.”

Thomas explains that LEO constellations offer a number of advantages over traditional GEO satellites. The components of a LEO system, such as sensors, communications and ISR equipment, are smaller and lighter – as are the power systems and bus components needed to run a LEO satellite. This means several LEO satellites can be put into space in one single launch.

“The lower unit size and mass also enables faster design and deployment cycles because the design/build complexity of a 200kg LEO satellite is so much lower than a GEO satellite that weighs in at two metric tons,” Thomas adds.

Project Blackjack was partly inspired by the proliferation of LEO constellations and the development of the technology in the commercial space. Plans for Blackjack were originally built around the concept of leveraging commercial developments, such as those recently highlighted by the Starlink constellation.

“Blackjack was founded on the concept of leveraging the commercial communications mega-constellations' global datalink and the capability of their commoditised production line buses to produce a satellite a day, which would enable LEO constellations where you have these smaller satellites,” Thomas explains. “Mega-constellations are in the early phases of showing these lower cost, and individual satellites can add up to highly capable global broadband networks.

“Commercial LEO constellations have shown that LEO satellites can be developed and manufactured on a large scale.”

“Even with the success of Starlink getting to 420 satellites to orbit we recognise that complete reliance on any commercial system for DoD/IC use is not ideal and the Blackjack demo will be built with appropriate communication subsystems to ensure military utility with or without operational commercial constellations.”

Commercial LEO constellations have shown that LEO satellites can be developed and manufactured on a large scale, and have proven to excel in tasks such as providing broadband access over a large area. Blackjack is building on this by bringing the capabilities to military use, allowing for low-cost upgrades and a faster design cycle than those offered by existing satellite options.

DARPA is currently working with the US Space Force and US Space Development Agency to demonstrate ‘small-risk’ satellites that will take flight towards the end of this year and later in 2021.

“The first demonstration, Mandrake 1, is a cubesat that will carry supercomputer processing chips to LEO,” Thomas says of the planned timeline. “Mandrake 2, with SDA, is a pair of small satellites that will carry optical inter-satellite links for broadband data on laser links and could form the basis of future optical mesh networks in LEO. We're also targeting a risk reduction payload called Wildcard, a software-defined radio that will experiment with links from LEO to tactical radios.

“A data fusion experiment with ability to host massless payloads – that is, advanced 3rd party algorithms – for on-orbit target data fusion will go on a Loft Orbital mission. All of these risk reduction satellites will be launched on rideshares starting this summer and progressing through next spring and summer.”

“We anticipate we'll begin integrating the first two payloads next summer with launch via rideshare in late 2021, followed by the remainder of the Blackjack demonstration sub-constellation in 2022.”

DARPA is working to ensure the design is mature enough as it moves forward on the various aspects of the LEO constellation. As Thomas explains, the current focus is on the buses used by the satellite, before moving onto the Pit Boss autonomous mission management system.

“We anticipate we'll begin integrating the first two payloads next summer with launch via rideshare in late 2021, followed by the remainder of the Blackjack demonstration sub-constellation in 2022,” he adds.

For DARPA’s partner Lockheed Martin, one challenge to overcome for Blackjack is the complexity of integration. “Lockheed Martin Space constantly looks for innovative ways to assure delivery of mission capabilities to our partners,” Pecson explains. “Integrating different bus types from multiple performers adds a level of complexity to the Blackjack program.

“However, we are working with our associate contractors to maximise the use of existing, proven and open interface standards to achieve the greatest amount of synergy. Lockheed Martin’s performance on Blackjack will further demonstrate our commitment and expertise as a proven integrator for rapid mission schedules.”