Challenges of providing STM
Despite an impressive infrastructure of sensors used for STM and the capabilities of the various actors, there are still significant challenges in creating a full understanding of the space environment that can be used to ensure minimal risk to space assets. And while some of these challenges may seem intractable, recognizing them allows for an assessment of capability gaps that could be proactively addressed. While this would be beneficial to all actors, it could also provide those either wishing to establish relationships with mature STM providers or looking to increase their standing within existing partnerships with a valuable contribution.
Within the group encompassing the US and its allies, intelligence capabilities in determining the intent and capability of others, specifically Russia and China, is dominated by the US, in part because of its longer history in military space operations and its technical capabilities in classifying non-allied space assets.
The first set of challenges to STM (and, indeed, wider SSA) are political, particularly around the concept of information sharing. As mentioned above, much of STM is carried out by militaries, who are understandably unwilling to share data beyond allies under existing agreements. The US and the UK have an agreement covering the sharing of data gathered through their partnership, which is further shared with other members of the CSpOC. Another type of political challenge relates to space environment intelligence, specifically that referring to the capabilities and actions of potential adversaries. Within the group encompassing the US and its allies, intelligence capabilities in determining the intent and capability of others, specifically Russia and China, is dominated by the US, in part because of its longer history in military space operations and its technical capabilities in classifying non-allied space assets.
The second set of challenges are technical and may be those that are most open to exploitation by STM providers hoping to establish or increase their contribution. Despite the number of sensors and actors, there are still significant difficulties in understanding and predicting the movements of pieces of orbital debris. One of these is related to the size of debris that can be tracked, although the US Air Force will have greater capability in detecting smaller objects following the completion of the Space Fence in 2021. Many of the models used to predict debris movements do not take into account the effects of solar radiation and internal dynamics, such as residual radiation pressure from power sources or whether the object is tumbling. As a result, while it is possible to detect objects over a certain size, it is not always possible to track them. Research is required to further understand the behaviour of certain materials when they are subjected to radiation and to how internal radiation and tumbling affect the orbit of a piece of debris. Technical challenges also relate to the sharing of information. Although more data sources used to create positional information increases reliability, there can be difficulty in incorporating data from these sources if they use different methodologies, lexicons and ways of characterizing objects.
These challenges lead to a range of capability gaps that can be exploited, including:
- Detecting and tracking smaller debris in orbit, due to the threat that they pose to operational space systems. This is expected to lead to a requirement to maintain a far larger catalogue.
- Tracking objects with higher accuracy, to reduce the prediction errors associated with each object and allow conjunction warnings to be calculated with greater precision.
- Tracking objects more frequently, to help maintain custody of specific objects, and to ensure that their error ellipsoids do not increase unacceptably over time.
- Measuring a greater number of parameters associated with a space object, such as ballistic coefficient, albedo and attitude, to correctly predict its orbit in advance.