The U.S. Space Force is looking for advanced technologies for space-based interceptors that can intercept ballistic missiles during their boost phase inside the atmosphere, according to a Small Business Innovation Research solicitation.
“The desired outcome is to develop and integrate high-G propulsion systems, advanced seekers, and low-SWaP [size, weight and power] interceptors integrated into space vehicles for … SBI [space-based interceptor] architectures that support fast detection-to-intercept timelines,” stated the SBIR solicitation, which opens Jan. 7 and closes Jan. 28.
Space-based interceptors are a key component of the Trump administration’s massive Golden Dome program for missile defense of the United States. Earlier this month, the Space Force released a Request for Proposal for space-based midcourse interceptors that would target missiles as they coast in space in between launch and reentering the atmosphere. Boost-phase interceptors seek to destroy missiles during their slower, more vulnerable ascent as the rockets gathers speed after launch.
The Space Force recently awarded a few small contracts for prototype space-based boost-phase interceptors. But the SBIR suggests that the service is also eager for research into advanced interceptors. The problem with existing antimissile interceptors is that they are too big and expensive, according to the SBIR.
“Current state-of-the-art interceptors demonstrate high performance but are significantly larger and not optimized for rapid deployment or distributed constellations,” the SBIR said. “Proposed solutions should demonstrate how comparable or greater performance can be achieved in a significantly smaller package.”
The Space Force envisions boost-phase interceptors that can hit missiles at an altitude of less than 120 kilometers, or about 75 miles or less, above the Earth’s surface. Intercept time should be less than 180 seconds.
Propulsion for the new interceptor should enable high thrust, plus rapid acceleration of at least 6 kilometers, or at least nearly 4 miles, per second.
“Desired characteristics include dual-pulse or throttleable motors, high-grain solid or hybrid propellants, and thrust vector control,” the SBIR specified.
Other features include fast shutdown and reignition of the rocket motors, and improved specific impulse for more efficient thrust.
The service also wants to increase the probability of a kill by fitting the interceptors with multiple sensors.
The interceptors should also be small, easy to manufacture at scale and capable of being fired from constellations of orbital launch platforms that would allow continuous coverage over specific terrestrial regions below. Because they will be descending rapidly from space into the atmosphere, they will also need strong thermal protection.
“Successful solutions will also consider survivability under extreme conditions experienced during atmospheric re-entry including the extreme temperatures from aero-thermal heating,” the Space Force noted.
These are formidable requirements, according to Patrycja Bazylczyk, associate director of the Missile Defense Project at the Center for Strategic and International Studies think tank.
“Taking out a missile as it boosts is a tall order,” Bazylczyk told Defense News. “The compressed timeline for detection, tracking, decision-making and interception makes boost-phase defense one of the toughest technical challenges in missile defense.”
Nonetheless, Bazylczyk believes the concept is feasible.
“The technology for space-based intercept exists — the primary challenges are cost, the operational concept and the ability to scale,” she said. “Significant reductions in satellite launch expenses, coupled with advances in electronic miniaturization, have the potential to substantially lower the overall cost of fielding a constellation.”
Phase I of the project calls for companies to submit concepts, followed by Phase II prototypes. Phase III includes adapting the technology to support the other military services with missile defense or high-speed intercept needs.
In addition, the Space Force sees the project leading to “commercial applications for high-performance propulsion, compact sensor suites, or integrated aerospace systems in areas such as hypersonics testing, responsive launch, atmospheric sensing, or high-speed autonomous systems,” according to the SBIR.
