The Pentagon is taking a victory lap after President Donald Trump signed off on $700 billion in defense spending.
Touting the bill as a "matter of national security," Trump noted big-ticket defense procurements as well as the significant increase in spending for missile defense.
However, even that massive amount of spending may not be enough to full modernize U.S. missile defense systems.
The military's massive funding hike allocates $11.5 billion for the Missile Defense Agency, the largest amount ever. But there are brewing threats even greater than North Korea, particularly from other countries' outer space capabilities.
"North Korea is deploying lots of new things, but it's not just about North Korea and it's not just about ballistic missiles anymore. There is a missile-rich threat environment that is getting more powerful and it will hold U.S. forces at risk," Thomas Karako, director of the Missile Defense Project at the Center for Strategic and International Studies, told CNBC.
Karako explained that missile threats posed to the U.S. include everything from rocket artillery to cruise missiles to ballistic missiles to hypersonic weapons.
"It's that whole spectrum of things that unfortunately kind of snuck up on us when we were focused on the counterterrorism mission," he said.
And while Karako said the record $11.5 billion was a step in the right direction, he noted that the U.S. is still "playing catch up" in building a robust missile defense program.
"We are playing catch up, above all, because of the risk that we have been taking for, I would say the last decade," Karako said. "The dip in funding for MDA and the services over the past six to 10 years is the reason why that number is where it is."
Karako emphasized that aside from funding, the U.S. must field systems in space and integrate them with land- and sea-based platforms in order to counter the full spectrum of missile threats. The U.S. currently fields four components of ballistic missile defense, none of which are space-based: Patriot, Terminal High Altitude Area Defense (THAAD), AEGIS, and Ground-based Midcourse Defense (GMD).
"The thing that is missing from the FY18 omnibus and the FY19 request is space sensors," Karko said. "So tick tock, people, time is running out. The time for studies is over. Where is the plan to actually field some space sensors?"
An animation of a space-based sensor tracking a missile. Source: AGI
While the U.S. military is already tracking more than 23,000 objects in space around the Earth, space-based missile sensors would be fundamentally different in function, according to AGI, a company which provides software to commercial and government entities to analyze and track objects. Missile defense sensors in space would look down at the Earth, instead of up at space, AGI vice president Travis Langster told CNBC.
"From a missile defense perspective, the reason why you'd need sensors in space is because you'd need to be able to – the moment a ballistic missile is launched – detect it from anywhere on the Earth," Langster said. "If you know it's already in space, headed toward its target, then it's too late."
Tracking objects in space is no simple feat either. These new missile defense sensors, like the thousands of satellites set to launch in the next few years, would need to avoid the constantly-growing field of objects and debris.
An animation of the history of space debris around the Earth. Source: AGI
"Today's public catalogs, by AGI's estimates, only account for about 4 percent of the objects in space around the Earth," Langster said.
Catalyzed by incidents in the late 2000s, both commercial and military entities are working to solve the growing space debris problem. The military was first put on high alert that space debris must be combated after a Chinese military test in 2007.
"China conducted an anti-satellite weapons test on one of their own defunct weather satellites. It created thousands of pieces of debris."
Today's technology can track objects in space "on the order of 10 centimeters," Langster said. But, moving at thousands of miles per hour in orbit, objects 2 centimeters or larger "could cause catastrophic damage." While an anti-satellite weapon is a direct threat, the thousands of pieces of debris from such destruction creates an invisible menace.
Commercial entities were put on notice when, in 2009, a dead Russian military satellite shattered a $50 million Iridium telecommunications satellite. With near-misses becoming increasingly common, companies focused on space debris now makeup 2 percent of the $350 billion space industry.
An animation of the collision in 2009 between an Iridium satellite and a dead Russian military satellite. Source: AGI
"Inevitably there are situations where space debris, dead or inoperable satellites could get too close to a functioning satellite, and then a satellite operator must make the decision of whether to maneuver or not," Langster said.
The government is seeking to regulate space debris, with Commerce Secretary Wilbur Ross recently declaring there must be more "rules to the road" in space.
"There need to be means for policing, if you will, the debris in space," Ross said. "That's one of the big problems. And as more and more launches occur, more and more satellites reach the end of their life, that's going to be a problem we have to deal with."
Regardless of space debris, Karako said the four existing U.S. missile defense systems would "be better and more effective and lethal with space sensors."