In the last article on The Modern Battlespace, we spoke with Robert Roy, Program Engineering Manager at Collins Aerospace, about the importance of fuel cell systems in the Department of Defense (DoD) and how this technology can improve military operations and the performance of military platforms, such as unmanned vehicles.
As hydrogen-powered fuel cell systems make their way to the battlefield, the military will need to consider how to refuel these systems with hydrogen. But hydrogen’s nature as both difficult to store and transport has long been a limiting factor for its expanded adoption across the DoD.
According to an article featured on the Modern War Institute’s Website, “The gap in hydrogen deployment for DoD has always been at the tactical level. Transporting hydrogen cylinders is less than ideal because of their bulk and weight.” But that could all be about to change.
Industry partners like Collins Aerospace are developing solutions to generate hydrogen at the tactical edge. The Collins solution, which is called the Refueling and Servicing Package (RASP), is being developed in association with the U.S. Navy and will make refueling fuel cell systems with hydrogen as quick and efficient as pumping gasoline into an automobile.
In the second part of our conversation with Robert, we explore other use cases for hydrogen at the edge and how the RASP solution can increase readiness.
The Modern Battlespace (TMB): Aside from powering fuel cells, for what other use cases would the military need hydrogen available at the edge?
Robert Roy: Hydrogen is also an alternative to helium as a lift gas for high-altitude balloons. Helium is a nonrenewable resource with dwindling supplies. Because of this, helium demand is outpacing supply and is putting tremendous cost pressures on agencies looking to complete surveillance and reconnaissance missions.
“Hydrogen can be viewed as enabling connected battlespace operations.” — Robert Roy
On the other hand, hydrogen is a renewable resource that can be produced in a number of different ways, as previously discussed; producing hydrogen via water electrolysis from renewable energy provides an environmentally sustainable source of lift gas for these types of missions.
TMB: What is the RASP, and what does it do? How does it operate, and what does it use to create hydrogen?
Robert Roy: The RASP produces compressed hydrogen and liquid oxygen from pure water and electricity. The RASP integrates a water electrolysis system to produce oxygen and hydrogen, a liquefaction system to produce liquid oxygen, and a compressor to pressurize hydrogen at up to 10,000 pounds per square inch gauge (psig) to recharge air-independent power and propulsion systems such as a fuel cell-powered unmanned undersea vehicle (UUV). The RASP also provides other utilities necessary to safely return the UUV to the water, including management of the byproduct water and backup battery system. The system only requires a source of potable water and electricity to operate.
“This ability eliminates the need to store and transport hydrogen to the edge and can provide on-demand fuel or lift gas to UUVs, UAVs, and HABs.” Robert Roy
The RASP has evolved to provide hydrogen refill capability for high-altitude balloons and fuel cell-powered unmanned aerial vehicles (UAVs). In these instances, hydrogen is stored at about 5,000 psig; it can then be delivered to the high-altitude balloon (HAB) to provide buoyancy for the balloons or to a UAV to be used as fuel in a fuel cell.
TMB: Why would the RASP be a viable solution for generating hydrogen at the edge for the military? Where could the RASP be used? Is this something that can function in any domain?
Robert Roy: The RASP uses resources that are readily available to the military – namely, potable water and electricity. This ability eliminates the need to store and transport hydrogen to the edge and can provide on-demand fuel or lift gas to UUVs, UAVs, and HABs.
The RASP can be used anywhere there is a source of potable water and electricity. Depending on the operating domain, it may be necessary to prevent water from freezing, but that is about it.
“These assets are relatively inexpensive compared to conventional surveillance aircraft and do not put our military personnel in harm’s way.” — Robert roy
Hydrogen can be viewed as enabling connected battlespace operations. HABs launched from the ground or surface ships can communicate with their host platform. UAVs similarly launched can survey areas of interest to the military and report their findings via the HAB to the host platform. These assets are relatively inexpensive compared to conventional surveillance aircraft and do not put our military personnel in harm’s way.
TMB: What is the status of the RASP today? Is this something that is still in development, or is it something that is already being used in the military?
Robert Roy: We completed the critical design review of the RASP in September and have begun the procurement of long-lead items. A Technology Readiness Level 5 (TRL5) demonstration is currently planned for the fourth quarter of 2024.