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Earth from Space

ORBITGUARD 1 Explained!

[Toulouse, France]

Imagine this scene: hundreds of thousands of faster-than-a-speeding-bullet objects zooming by, threatening the life of multi-million dollar assets in orbit. All it takes is one collision to generate hundreds or more pieces and potentially triggering a catastrophic Kessler syndrome effect. In another thought experiment, an enemy spy satellite is approaching a satellite of our own. While it remains untracked, inconspicuous, completely unnoticeable, it could, at the end of its mission, take the plunge and easily destroy its target. In yet another scenario, our GEO telecom satellite is receiving less and less energy as time passes due to unidentified reasons. If only we could go there, at a 36000 km altitude, inspect it visually and determine what the issue really is.

As satellite operators, we are constantly bombarded with reminders of how cold and hostile space is to human activity. We shield our satellites from radiation, we develop parts that can withstand extreme environmental conditions, we design redundancy into our fault-tolerant systems; solutions which are driving up the costs of our missions. And yet, we take close to no action in order to safeguard our satellites from the above threats.

We at Infinite Orbits have taken many of the lessons learned from the mission design of Endurance, our life extension vehicle, and applied them to our newest offering, Orbit Guard. Orbit Guard is a cost-effective GEO-capable smallsat that can safely provide in-orbit Space Situational Awareness (SSA), Satellite Inspection and defensive capabilities against space weapons and other threats. It is built around our patented OrbSight vision-based navigation system, with an end-to-end NewSpace approach in the supply chain. Orbit Guard enables a plethora of services, but I would like to focus on the three most useful ones: SSA, Satellite Inspection and Space Defense.

Space situational awareness

The United States Space Surveillance Network (SSN) and the EU Space Programme are focusing their efforts for Collision Avoidance on ground-based solutions. Optical telescopes and RADAR provide accurate positioning of space debris and satellites but fall short in other respects:

  1. In-orbit sensors can directly observe and measure the characteristics of objects in space, such as their size, shape, and composition, which can be difficult or impossible to determine using ground-based sensors alone. Estimating an object’s tumbling rate can also aid the development of future removal missions.

  2. In-orbit sensors can operate continuously, providing a continuous stream of data on the movements of objects in space. Ground-based sensors, on the other hand, are typically limited by the Earth’s rotation and the location of the sensor, so they can only observe objects for a limited time each day. Since our Orbit Guard satellites directly monitor the space environment, they can detect potential threats, such as debris or hostile spacecraft, in real time.

  3. In-orbit sensors can operate closer to the objects they are observing, which allows for higher resolution and more accurate measurements.

In order to protect the space environment from all threats, we need to combine all of our available tools; ground-based and in-orbit. The US Space Force is aware of this and this is why they are extending SSN with the Space Based Space Surveillance (SBSS) system, a constellation of 6 currently operational satellites in “near-geosynchronous orbits”. Orbit Guard will be another constellation of satellites available to the commercial and defense worlds to meet SSA needs.

Satellite inspection & Defense against space weapons

Orbit Guard’s strongest suit is the ability to safely rendezvous with another satellite. Inheriting from Endurance, the only thing Orbit Guard is not capable of is docking. It can get close but cannot touch. It is able to perform rendezvous with a known or unknown target at different levels of cooperation and autonomy. A side effect of the rendezvous GNC subsystem is the relative state estimation—namely the target’s angular velocity (tumbling rate), its trajectory and location. This together with information on the target’s shape and size allows us to assess the risk of an active debris removal mission and to determine what type of docking system will be most suitable for capturing the target.

We can also include other instruments and sensors such as multispectral imagers in order to observe defects and monitor known Client satellites or to identify parts in enemy satellites. Such information is invaluable to satellite and subsystem manufacturers, as well as mission planners and insurance companies. The exact effects of the orbital environment on long life missions is not fully understood yet; the damage from micrometeorites and dust, the impact of ionizing radiation on satellite buses and payloads, the changes in the material properties and shape of telecom satellites reaching end-of-life. We can answer a lot of these questions with careful planned inspection missions using one of many Orbit Guard satellites.

Orbit Guard-1 is launching in GEO in March 2023, and it will serve as an in-orbit demonstration mission for the aforementioned capabilities. The second generation Orbit Guard-2 with even higher performance is slated for launch in Q1 2024 and two more Orbit Guard satellites will be operable by 2025. Infinite Orbits could not be more excited to offer this state-of-the-art service and advance the field of space robotics. Stay tuned for news on Orbit Guard, Endurance and our future servicers!

Manos Koumantakis,

Chief Architect and Co-founder of Infinite Orbits


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