SSA and SDA: What's the Difference?

There is a lot of talk about the need for SSA (Space Situational Awareness) and SDA (Space Domain Awareness), and sometimes these terms are used interchangeably. However, there is an important difference, and the distinction matters. As this is key to our mission, we thought we’d take the time to break it down. 

SSA is the knowledge and characterization of objects in space, and is part of SDA (Space Domain Awareness) which is a more comprehensive understanding of these resident space objects and is predictive in nature - where are these objects going to be? SSA focuses on cataloging the many objects in space and creating databases of these objects. 

The term “Space Domain Awareness” came into use in 2019, when the Air Force Space Command introduced it in a memo authored by Air Force Space Command’s deputy commander Maj. Gen. John Shaw. It replaced the term SSA, and added another layer of knowledge. SDA is a better and improved SSA, though the term SSA still comes up often. This was important because as space became more congested and rival nations began to develop weapons to target U.S. satellites, the U.S. military changed its position regarding outer space and now considers it a domain of warfare, like air, sea or land. 


The new term recognized the importance of the assets on orbit, and their vulnerability. Our country needs the network in space for so many day-to-day uses, from GPS information to economic networks. Currently, most of the crucial assets are in LEO, but as we expand further beyond, there needs to be a robust network that can service this area. 

This is why we’re developing the space infrastructure to utilize cislunar space. We envision a future where we can service space, from space. Think about the monitoring of on-orbit assets: currently, most are monitored from Earth, with large dishes that can pinpoint locations of objects on orbit. By monitoring from orbits beyond LEO, we get another view. By making these objects more visible, we can ensure space is a safe operating environment for commercial and government space assets. We are building a network of sensing vehicles that will bring a new layer of security and knowledge that will keep us safer and more productive on Earth. As human spaceflight progresses, the need for this infrastructure only grows. 

At Quantum Space, we’re aware of the critical importance of the military and commercial assets in space. Too often, people take systems that rely on space for granted. We cannot allow these assets to be compromised, whether by adversaries or space debris. We’re proud to be building the infrastructure that will make us all safer.