Space Force Seeks Market Answers on In-Orbit Refueling

United States - Ekhbary News Agency

Space Force Seeks Market Answers on In-Orbit Refueling

The U.S. Space Force is charting a course toward a future where satellites can be refueled while in orbit, a capability that promises to extend mission life and enhance operational flexibility. In a move signaling intent without yet committing to a full-scale logistics network, the service recently solicited industry input via a request for information (RFI). This endeavor is a crucial first step in cultivating a commercial market for space-based refueling services, with expectations that initial solutions could be operational by 2030.

The RFI was issued by the Servicing, Mobility and Logistics program office within Space Systems Command. It specifically asks for "technical concepts and approaches to refueling services for prepared clients in orbit," inviting companies to propose innovative solutions for this burgeoning need. Clare Martin, senior vice president of Astroscale U.S., described the RFI as "a very positive step," highlighting its significance in advancing the concept.

Astroscale is actively involved in this domain, developing its own refueling vehicle, the Provisioner, partially funded by the Space Force. The company is preparing for its inaugural mission in geostationary orbit, where the Provisioner will attempt hydrazine refueling operations on a U.S. military satellite. This mission represents a significant technical milestone in demonstrating the feasibility of such operations.

Beyond soliciting new ideas, the Space Force took concrete steps in 2024 by selecting two preferred hardware interfaces for refueling ports: RAFTI (Rapidly Attachable Fluid Transfer Interface) and PRM (Passive Refueling Module). These selections provide clearer guidance for satellite manufacturers and servicing companies, enabling them to design spacecraft capable of connecting and interacting in orbit for fueling purposes. This standardization is seen as vital for interoperability.

However, the selection of these ports is merely the beginning. The existence of an interface standard does not guarantee the availability of sufficient numbers of "tanker" vehicles, nor does it ensure propellant compatibility across different programs or competitive pricing compared to simply replacing a satellite. Furthermore, critical questions remain about how refueling vehicles would operate in a contested or denied environment. The Space Force still lacks visibility into whether a commercial refueling market will mature organically or require sustained government underwriting to develop.

Astroscale's Provisioner is equipped with the RAFTI interface, developed by Orbit Fab. The PRM interface was developed by Northrop Grumman. Martin explained that the Space Force's selection of two interfaces acknowledges that multiple technical approaches may coexist. The goal is to foster competition and avoid vendor lock-in while promoting standardization. Although Provisioner utilizes RAFTI, Astroscale emphasizes its "interface agnostic" approach, focusing on delivering the service rather than being tied to a specific technical implementation.

Martin further noted that the Space Force "put a lot of time and work into assessing them and their capability," deeming RAFTI and PRM the most mature options. "They’ve specified those interfaces, but they’ve left the rest up to industry to determine how you would interact with them." From an acquisition perspective, this selection is intended to facilitate future service contracts. If multiple national security satellite programs adopt compatible ports, the government could procure refueling "as a service," streamlining procurement and potentially reducing costs compared to bespoke solutions for each mission.

The RFI suggests the Space Force is looking beyond initial demonstration missions toward a broader operational architecture. "It is a good sign that the work they’re doing now is going to move beyond this initial phase and into the future," Martin commented. This future phase involves complex questions that extend far beyond the physical docking port.

Companies like Astroscale, Northrop Grumman, and others are developing the necessary "shuttles" or "tankers" that would ferry propellant between depots and client satellites. Northrop Grumman has developed an Active Refueling Module for PRM-equipped spacecraft, while Orbit Fab has created the GRIP nozzle system for RAFTI interfaces. The overall architecture remains fluid, with various concepts for how these elements might interact: a client vehicle might travel to a depot, a depot could be brought to the client, or a dedicated service shuttle could move between them.

Building this complex ecosystem requires significant coordination among suppliers. "In order to give us the building blocks from which we can build our services, we’ll need to look at how we actually source the fuel. Where do you get the hydrazine from? We’ll need to work with the actual launch providers themselves, understand whether you need to go direct, whether you can do geostationary transfer, availability of launches, size of launch vehicle," Martin explained. "So it’s a whole industry solution that would be required."

While Astroscale's launch timeline for Provisioner is still being finalized, integration and testing are underway, with the company stating, "We’ll be ready to launch this year." Space Force officials have indicated that an upcoming mission will deploy two small satellites equipped with the RAFTI port to further test the concept, with one satellite attempting to dock with an Orbit Fab propellant depot and the second with Astroscale's fuel shuttle.

Ekhbary News Agency