“For whosoever commands the sea commands the trade; whosoever commands the trade of the world commands the riches of the world, and consequently the world itself.” - Sir Walter Raleigh

The ocean and space are remarkably similar environments. Both are vast, isolated, and only navigable with specialized equipment. Both contain tremendous wealth: trillion-dollar fish, oil, gas, and mining markets in the ocean; and the promise of space mining, abundant energy, exotic zero-gravity products, and electromagnetic resources above our atmosphere. Oceans have supported the most expansive and valuable trade routes for millennia, while space is emerging as a venue for point-to-point transport for people and goods, potentially connecting any two locations on Earth with a 45-minute journey. But their shared qualities are most consequential from a military perspective. 

Navies seek “Sea Control.” Sea control is what it sounds like. To “control” the sea is to have the freedom to operate without enemy interference, and the ability to interfere with those enemies. To obtain Sea Control, nations must cultivate Sea Power — in the form of superior naval vessels and strategy. Nations seek Sea Control to protect their sovereign economic activity, their territorial integrity, and their ability to wage war in far-away places: places beyond the seas.

In March 2025, General Chance “Salty” Saltzman, Chief of Space Operations, gave remarks redefining the mission of the United States Space Force: Space Control.

“It is now our job to contest and control the space domain. To fight and win so that we assure freedom of action for our forces while denying the same to our adversaries.” 

General Chance Saltzman, Chief of Space of Operations 

For the U.S. Navy, Sea Control includes blockading enemy fleets in their ports while protecting supply lines and providing services for ground forces. Space Control will include maintaining communications, sensing, and power constellations to support terrestrial forces, and blockading spaceports (i.e., intercepting adversary launch vehicles in their boost stage) when vehicles that seek to challenge that constellation.