San Antonio Express-News (Sunday)
ROCKET CARGO
air defenses at less risk. That’s an increasing concern as tensions rise with adversarial countries such as China and Russia.
With 150 tons of cargo capacity, a few flight tests under its belt and early collaboration between SpaceX and the military, Starship stands at the forefront of the Pentagon’s Rocket Cargo project, which is also working with Blue Origin, Sierra Space and Rocket Lab.
Now, along with NASA’s hopes for the craft to carry out moon missions and SpaceX CEO Elon Musk’s dream of using it to colonize Mars, Starship is taking a role in national security.
New challenges
The military — which excels at moving material anywhere in the world via air, land and sea — is learning to do the same via space, a domain that presents new challenges to the military logistics system.
“This is an entirely new mode of transportation for the DOD … a fourth mode of transportation, and we haven’t explored some of the challenges of this magnitude since the invention of the airplane,” said Dan Brown, principal investigator on the Rocket Cargo project for the Air Force Research Lab at Wright-Patterson AFB, Ohio.
In 2021, the Air Force announced its research lab at Wright-Patterson would lead Rocket Cargo, designating the project as its fourth vanguard program, seeking to “rapidly advance emerging weapon systems and warfighting concepts through prototyping and experimentation.”
The Space Force’s Assured Access to Space office oversees the program, which has offices across the Air Force and the U.S. Transportation Command, the military organization responsible for moving military people and gear.
Brown sees parallels in the project with the earliest days of aviation.
Engineers are working on “some pretty pretty fundamental things that in 100 years from now will seem easy,” he said, but “right now, everything is hard, and so there’s just no shortage of challenges.”
With that in mind, the Pentagon’s vision for Starship grows each time the craft reaches a milestone.
Paradigm shift
Currently, it envisions Starships transporting what might otherwise by carried by one or two C-17 Globemasters — the DOD’s workhorses for strategic airlift around the world. Each is able to carry 170,900 pounds of cargo across 18 pallet positions, and frequently transport tanks and helicopters.
Greg Spanjers, the Rocket Cargo program manager, sees rockets someday helping the U.S. perform disaster relief missions. While crewed flight and patient transport are years off, military medical people envision transporting vaccines, medicines and blood products via rocket.
“We have the medical community talking to us often about how the speed to which you can get to a viral outbreak makes a big difference in how well you can contain it,” he said.
Spanjers said the rocket cargo concept is at least 50 years old but that until the past few years it was too expensive and not feasible. Now, the cost is less expensive than ever, thanks largely to SpaceX’s success with rocket reusability.
“It changes how you approach what you ship,” he said. “You do not have to mass optimize anymore. If anything, you volume optimize. … We have lots and lots of capacity.”
Spanjers and his team are working to determine whether rocket cargo transportation’s time is near.
“Has the technology indeed caught up with what’s always been a good idea — just impractical?” he said. “It’s determining viability,
real cost and utility of using a large liquid rocket to transport 100 tons of cargo on very fast timelines.”
That entails working through how to fuel, load and launch a rocket in an hour, as well as how to offload its cargo quickly at its destination.
Launching massive liquid rockets in an hour is a huge paradigm shift, considering that it normally takes several months or even years to prepare such craft for liftoff. Then there’s the engineering problems of reentering the atmosphere and returning so much mass to Earth.
The lab is doing thermal and wind tunnel analysis, as well as studying reentry materials.
“Eventually, we’re heading toward tests where we start bringing reentry systems down with more and more mass and see how they respond and measure it in real time,” Spanjers said.
Pallets and pulleys
After the craft survives its launch, flight, reentry and landing, it will need to be unloaded — fast.
“If you get up there in an hour and it takes you two days to unload it, you haven’t accomplished anything,” Spanjers said.
The Rocket Cargo project is working with U.S. Transportation Command to understand how the U.S. military moves cargo. It’s been a crash course on the types of shipping equipment used on military aircraft.
Standardized containers and pallets make it easy to move and store goods between modes of transportation. Engineers want to use the same concepts for space flight, eyeing specialized shipping containers that are roughly 10 feet by 10 feet by 20 feet. They’re stress testing the hardware at Wright-Patterson and working through how to pressurize and power containers depending on a given cargo’s needs.
“What we don’t want to do is to have to build unique DOD hardware because it’s going on a rocket,” Spanjers said. “We want the container to handle that interface” between the cargo and the spacecraft.
In an old Space Shuttle building at Kennedy Space Center, crews have built a full-scale replica of Starship’s cargo bay — the top 30 to 40 feet of the rocket — to figure out the best ways to load and unload the craft.
“It opens up and things come out, and boxes come out and get set on the ground,” Spanjers said. “It’s pretty cool.”
At its origin, Spanjers envisions cargo being prepackaged in containers in a warehouse “at Canaveral, ready to go.” But things get more complicated at its destination, especially if there’s no infrastructure or logistical support.
Starship’s cargo door is more than 100 feet off the ground, so the engineers have developed a system of pulleys, cables, motors and zip lines to offload the containers.
The system, which they first tested in January, is now “moving around 5-ton boxes like it’s nothing, and it’s hitting a pretty good speed right now on how fast it could unload the rocket,” he said.
Beyond Rocket Cargo
The Defense Department’s plans for Starship may go beyond the Rocket Cargo program.
In the past several weeks, the military has backtracked on comments — reported in Aviation Week — by Col. Eric Felt, director of space architecture for the Air Force’s office for Space Acquisition and Integration, suggesting that it may one day want its own fleet of Starships to respond quickly to world events.
Speaking in January at a Space Mobility Conference in Orlando, Fla., Felt said that while buying commercial transportation service is standard practice, there may be cases where a “government-owned, governmentoperated” vehicle is called for.
Later, a spokesman for the Assured Access to Space office said in an email that it “has no plans to own or operate Starship” and that it plans to use a “commercial service model” similar to what’s used for “national security space launch today.”
Nate Allen, a Transportation Command spokesman, echoed that position, saying the DOD “transports about 90% of its warfighting material and personnel on contracted lift.”
But he left open the possibility for change, saying the organization expects that current practice will support DOD logistics without the military needing its own “mobility fleets for the foreseeable future.”
Next steps
Military leaders already have visited Starbase several times to “observe and discuss emerging capabilities,” Allen said.
Spanjers said the next step — now that the Starship cargo bay mockup is operational — is having the craft achieve orbit and attempt reentry. It could take its third shot at achieving that later this week.
“That’ll give us the hard data we need on exactly what environments cargo containers need to survive during the flight,” he said. “We have good estimates and all, but we don’t have hard data.”
Once Starship reaches orbit, carrying military payloads won’t be far behind. And getting there, Spanjers said, will likely involve more Starships failing along the way.
“I would be shocked if they don’t toast a few rockets as they’re learning how to get that thermal protection system working,” he said. “If you’ve been down to Starbase, they have lots of test articles ready to go.”