For the last few years, SpaceX have quietly worked with the Department of the Air Force to develop rocket cargo transport, using its revolutionary Starship launch system. Many questions surround this effort: could a complex rocket like Starship be kept on continuous standby, can this cutting edge vehicle be recovered after landing – even whether delivering 100 tons of cargo in one piece is feasible, to name but a few. Perhaps, more important still, why are the US military interested in developing such a capability, when they are currently well served by USTRANSCOM – the US Transport Command? Starship capabilities are unprecedented so we have no frame of reference to judge by, hence how it will be used, and why, might seem counterintuitive which is certainly worth exploring.
How Rocket Cargo Works
The Air Force want Starship to land at austere sites, so SpaceX will probably perform flight tests from Starbase Tx to some remote location, to demonstrate this capability. For example, they could perform a complete orbit then land Starship on a commercial barge stationed in the Gulf of Mexico. No doubt SpaceX could find a way to transport it vertically on the barge, similar to how they recover Falcon 9 boosters at Vandenberg and the Cape. This should allow the vehicle to be towed to the Port of Brownsville then returned to Starbase on a Self Propelled Modular Transporter (SPMT), via the newly constructed connector road.
“The Air Force Research Laboratory is currently assessing emerging rocket capability across the commercial vendor base, and its potential use for quickly transporting DOD materiel to ports across the globe,” ~ Air Force Research Laboratory
Alternately, Kwajalein Atoll in the Marshall Islands might serve as a landing site, as it can provide the necessary operational security and a suitable port facility to return the landed vehicle. If SpaceX want to avoid the long and circuitous sea voyage they could refuel Starship at Kwajalein (using an LNG tanker converted to carry methalox propellant), then fly it back to Starbase directly.
“Add 2 to 4 more Raptor [engines] for Starship point to point on Earth. You can go surprisingly far, even with low lift/drag… Distances of ~10,000 km with decent payload seem achievable at roughly Mach 20.” ~ Elon Musk
Essentially this extreme velocity would allow Starship to skip along the upper atmosphere for great distances, without requiring a Super Heavy booster for launch. As Elon suggests, the current version Starship lacks the thrust to weight necessary to make these long sub-orbital hops possible - but Version 2 looks more than capable.
Once proven, Starship will then have to undergo field trails to various locations around the world. Suitable landing sites could be arranged at US military bases, preferably ones close to a large seaport. Alternately, SpaceX intend to operate their own floating spaceports to transport commercial passengers via Starship. If these cargo transport flights land at one of these prototype spaceports it would allow SpaceX to develop both technologies in parallel, perhaps with some financial support from the military. In this case it should be possible for Starship to return under its own steam at relatively low cost, as these floating spaceports will have an ample supply of methalox propellant to replenish passenger Starships and Super Heavy boosters. Later on military bases could be equipped with methalox storage tanks, sufficient to return these vehicles relatively quickly after offloading their vital cargo. SpaceX are currently testing an automated dispenser to deploy Starlink 2 satellites and a powered elevator platform for HLS. If these systems can be combined, it should allow cargo pallets weighing more than a tonne to be offloaded relatively quickly at the landing site, without human assistance.
“Companies selected for this [rocket transport] project will have to demonstrate autonomous cargo delivery in at least one of three modes: from Earth to a designated orbit, return from space to Earth to a precise point of recovery, and through space from one orbit to another.” ~ The Defense Innovation Unit/SpaceNews.com
How long it might take to load Starship with 100 tons of military materiel then ready it for launch is still an open question. However, the response time could be reduced to less than an hour if one or more Starships are used to store cargo in Low Earth Orbit (LEO). SpaceX are developing propellant depots for storing cryogenic propellant in orbit hence these cargo Starships could be maintained in a fully fueled condition if this storage technology can be transferred. Then, when cargo is urgently needed anywhere around the world, the fully primed Starship could execute a plane change maneuver and release cargo containers designed to reenter the atmosphere and safely parachute to the ground.
Why pursue Rocket Cargo
“The amateurs discuss tactics: the professionals discuss logistics.” ~ Napoleon Bonaparte
In some situations supplying urgently needed materiel could be crucial to the outcome of any conflict, as they say: “a stitch in time saves nine.” Say the People’s Liberation Army develops amphibious armored vehicles that can be deployed at sea, then use them to attack the Taiwanese coast en masse. Instead of a handful of transport ships to deal with, the defenders could easily be swamped with enemy vehicles, particularly if the attack was carried out at night. In response, a single Starship could deliver more than 300 Javelin missiles to a Taiwanese fallback position, significantly changing the defender’s outlook. However, this poses a problem, is the express delivery of this vitally needed materiel worth the risk of losing all the technical secrets stored in Starship, if it remains on the island? However, after all cargo was offloaded these vehicles could be destroyed using demolition charges to ensure they didn’t fall into the wrong hands; similar to how they disposed of a stealth helicopter during the Osama bin Laden raid. Alternately, Starship should have a small reserve of propellant available after landing (to avoid running the tanks dry), which could be used to launch it towards some little habited spot. Raptor engines are incredibly highly tuned hence thoroughly destroyed if they ingest any propellant fumes after the tanks run dry, likely removing any prospect of back-engineering this prized piece of technology.
Fortunately Starship should prove extremely difficult to intercept due to its highly energetic flight profile. During transit to the war zone its trajectory would be difficult to predict as it skipped along the exosphere at mach 20; like trying to hit a hypersonic skimming stone with a bullet. No doubt too it would use a combat approach, i.e. heading nose-down into the combat zone until pulling up just before landing. The ship would be surrounded by ionized plasma during reentry which should reduce its radar cross section, similar to how a stealth coating works. Of course everyone would be aware of its arrival due to the supersonic boom but hopefully this should occur relatively close to the ground, allowing little time for any interceptors to be launched. Of course Starship could be used to transport more than just cargo, in which case these defense features become even more important…
The war in Ukraine has demonstrated that drones change everything about the order of battle. Large force concentrations are almost impossible now because they are immediately spotted by surveillance drones then easily interdicted by their big brothers. Small unit tactics are now the rule and have proved surprisingly effective throughout this conflict. The US is particularly well furnished with Special Forces, with their Special Operation Command (SOCOM) numbering over 70,000 personnel. Special Forces punch well above their weight, particularly against an unprepared enemy. If trouble is brewing, a SOCOM unit and support personnel could be shipped to an allied base in a couple of hours, with no-one the wiser if their flight was reported as a rocket cargo test. Essentially they could resolve the local situation with a surprise strike – then disappear before anyone (living) knew they were in country. For example: any group of armed servicemen can hose down a building full of terrorists but it takes a team of Tier-1 special forces to neutralize the terrorists and safely release any hostages. Unfortunately Tier-1 are rare as hen’s teeth so can’t be everywhere at once but Starship could certainly make it seem that way by significantly reducing their reaction time.
Next Step After Rocket Cargo
The US Space Force (USSF) are still finding their feet and gaining the necessary allies to expand their budget and reach. However, at some point in the future, they plan to go much farther than Earth orbit and become the Guardians of cislunar space. Hence rocket cargo transport could be seen as the gateway to a much larger field of operation, demonstrating they are capable of handling this kind of complex launch mission. They are already investigating the feasibility of operating a military space station, possibly stationed in geostationary space to guard vital US assets. From a legal perspective, the Outer Space Treaty allows military personnel to be deployed in space (many astronauts, cosmonauts and taikonauts are servicemen) and only states weapons of mass destruction not be used there.
With a cargo capacity of 200 tons, Starship would seem the ideal candidate to build such a station, then continue to service it with combined passenger/cargo missions. Of course once such capability is established, USSF could use the station as a base for manned space patrols utilizing specialized Starship carriers, equipped with all manner of mission specific drones. As cislunar space becomes busier due to the expanding space economy, USSF will likely be called upon to maintain the peace, perform rescue missions and remove space hazards (spent stages, failed satellites, even rogue asteroids).
But all this begins with rocket cargo, a valuable market in its own right with great prospects for the future, which only SpaceX seem able to field at the moment due to their finesse with stage recovery.
In Conclusion
Whether rocket cargo transport is a practical solution for military logistics has yet to be discovered. However, it should be feasible, at least from a commercial perspective, if Space Force are willing to pay for it. While this appears a shot in the dark for the DoD much could certainly come of it, including increased space utilization and a safer world.
Admittedly, Starship would present a large target during final descent into a war zone but the opposition would need to be on their toes and posses a sophisticated air defense system to intercept it with any certainty. It’s arrival should literally come out of the blue and be completely silent until it passes the sound barrier relatively close to the ground. Yet assuming one is shot down, in the final analysis the vehicle is unmanned hence the outcome is just bent metal. SpaceX can turn them out one-a-day if called upon, so they are easily replaceable. People are unique and irreplaceable, the lives of allied servicemen and innocent civilians far outweigh any material loss.
Hmmm ... military cargo is the one application that makes Earth point-to-point look reasonable in comparison. The key may be to develop a low cost re-entry pod that can be dropped out of the cargo bay. That pod can later be recovered for reuse as time and resources permit. When this first came up a couple years ago I suggested they carry up an end-of-line Cargo Dragon and release that from the payload bay to see if they could hard land that at some point to demo it to the SF.