The Variable Pitch Screw Launcher requires a long evacuated tube so that the launch train and vehicle can travel at very high speed without incurring prohibitive aerodynamic drag, heating, or acoustic disturbance. In the currently analyzed embodiment, the evacuated tube system spans roughly 979 km, including an 857 km ground-level section and a 122 km elevated section. The primary evacuated volume is approximately $5.9 \times 10^7 \space \mathrm{m^3}$ and is maintained at an internal pressure of approximately 5 Pa. This is an unusually large vacuum system by scientific-vacuum standards, but the required pressure is modest compared with ultra-high-vacuum scientific systems such as LIGO.

The key engineering question is not whether a long tube can physically hold vacuum, but whether the tube, pumps, airlocks, and operating procedures can be implemented at a cost that remains small relative to the full launcher. Existing precedent strongly supports the technical side of this claim. LIGO’s beam tubes provide a particularly relevant example because they are long, stainless-steel, spiral-welded vacuum tubes. Each LIGO observatory uses 8 km of evacuated beam tubes, and the VPSL paper cited in the Concept's description notes that the LIGO tubes have maintained a vacuum of approximately one trillionth of an atmosphere for roughly 25 years. The VPSL tube is far longer, but its target pressure of 5 Pa is far less demanding than LIGO’s ultra-high-vacuum requirement.

The proposed VPSL tube also benefits from construction and operating features that distinguish it from passenger vacuum-tube concepts such as Hyperloop. Much of the VPSL tube would be submerged, underground, or elevated at high altitude, reducing exposure to accidental damage. The tube can also be manufactured using controlled industrial processes, such as continuous spiral welding, rather than relying primarily on many field-welded joints. The EML paper explicitly argues that this manufacturing approach makes reliable, leak-resistant construction more practical, and notes that similar large-scale production methods are already used in wind turbine tower manufacturing.

The pump-down requirement also appears economically manageable. In the EML paper’s cost model, the total evacuated volume is about 61.6 million m³. The assumed pumping system uses 10,000 vacuum pumps, each rated at 3.7 kW with a pumping speed of 108 m³/h and an ultimate pressure of 0.375 Pa. Under these assumptions, the model estimates that the system can be pumped down to the target pressure in about 36 days. The estimated capital cost of the pump system is about $121 million, and the energy cost of an initial pump-down is about $1 million. Even allowing for substantial uncertainty, these values are small compared with the full system capital cost, which the same model places in the tens of billions of dollars.

The airlock problem is also bounded. The main evacuated tube is not expected to be vented and re-evacuated for every launch. Instead, vehicles enter and exit through airlocks. The draft vacuum-system paper assumes a 250 m entrance airlock with a volume of 15,904 m³ and an exit airlock of about 18,374 m³. The exit airlock must be re-evacuated after each launch from the ambient pressure at 15 km altitude, approximately 12,000 Pa, back down to 5 Pa. The same draft states that the airlock systems require a pumping speed of about 60,000 L/s and can be re-evacuated on the order of 10 to 20 minutes, with a modeled pump-down cost of about $312 per cycle.

The scale of the VPSL vacuum system is unusual, but it is not outside the broader range of industrial gas-handling experience. A vacuum-system paper (currently in draft state) compares the VPSL evacuated volume with large gas storage, compressed-air energy storage, and CO₂ sequestration projects. These examples are not direct vacuum analogues, since they generally involve pumping gas into large volumes rather than removing gas from them, but they demonstrate that infrastructure for moving and controlling very large gas volumes is commercially familiar. The paper’s comparison table lists the proposed VPSL evacuated volume as 59 million m³, while several existing gas storage and sequestration systems operate at volumes ranging from hundreds of millions to billions of cubic meters.

Therefore, the claim is plausible at the first-order engineering level. Long vacuum tubes have already been demonstrated by LIGO at much more demanding pressures, and large-scale gas-handling infrastructure exists in other industries. The VPSL vacuum requirement is large in volume but modest in pressure, and the modeled pump capital cost, pump-down energy cost, and airlock cycling cost are small compared with the estimated total launcher cost. Further engineering work is still needed to refine leak-rate assumptions, joint design, airlock reliability, maintenance procedures, and pump placement, but the available evidence supports the conclusion that the required vacuum level can be achieved cost-effectively.