Enlarge /. Mission Shakti anti-satellite weapons are on display during the Republic Day parade in New Delhi, India on January 26, 2020.
Ramesh Pathania / Mint via Getty Images
The creation of the US Space Force has generated all sorts of imaginative ideas about combat in space. Will military satellites like X-Wings and Tie Fighters act, whiz around and shoot at each other? Or will larger ships similar to the USS Enterprise fire photon torpedoes at enemy birds of war?
Barely. But even those with more realistic expectations of what might happen if nations go to war in space – perhaps satellites that use orbital kinetic weapons to attack other satellites? – may not be able to fully appreciate the physics of space combat. This is the result of a new report that examines what is physically and practically possible in space combat.
Edited by The Aerospace Corporation, The Physics of Space War: How Orbital Dynamics Restricts Space-Space Engagements, contains several fundamental concepts that are likely to govern any space combat for the foreseeable future. Any physical constraints suggest that battles must be planned well in advance.
In contrast to a war on Earth, in which opposing forces usually try to dominate a physical location, satellites in orbit do not occupy a single location. Hence, report authors Rebecca Reesman and James Wilson write that controlling space does not necessarily mean physically conquering sectors of space.
Rather, control of the highlands involves reducing or eliminating enemy satellite capabilities while ensuring that one retains the ability to use their own space capabilities for communication, navigation, observation and all of the other increasingly important ways in which the military rely on space free to operate.
In considering how space should be controlled, the authors point out how space battles are counter-intuitive for policy makers and strategists.
- Satellites move quickly but predictably: Satellites in frequently used circular orbits move at speeds between 3 km / s and 8 km / s, depending on their altitude. In contrast, the average bullet only moves about 0.75 km / s. You are here and then gone.
- The room is big: The volume of space between near-Earth orbit and geostationary orbit is about 200 trillion cubic kilometers. That is 190 times larger than the volume of the earth.
- Timing is everything: Within the atmosphere, planes, tanks and ships can nominally move in any direction. Satellites do not have this freedom. Due to the gravitational pull of the earth, satellites always move on either a circular or an elliptical path, constantly in free fall around the earth. It is not intuitive to place two satellites in the same place. Hence, it requires careful planning and perfect timing.
- Satellites maneuver slowly: While satellites move quickly, the space is large and that makes targeted maneuvers appear relatively slow. Once a satellite is in orbit, it takes time and a large amount of Delta-V to perform phase maneuvers.
Given all of this, maneuvers and actions for engagements in space need to be planned well in advance, Reesman said in an interview. "Any conflict in space will be much slower and more conscious than a Star Wars scene," she said. "It takes a lot more long-term thinking and strategic asset placement."
In a perfect world, space can be seen as a haven. But since the mid-1970s and the advent of anti-satellite weapons in the Soviet Union and the United States, outer space has been treated as a disputed domain by the United States, the Soviet Union, and other emerging powers. While gun warfare has not broken out in space, the ability to degrade space weapons has been viewed by new powers such as China (2007) and India (2019) as a means of demonstrating their capabilities.