Low-Cost Rapid-Cadence Hypersonic Launch

During Longshot’s Phase 2 SBIR effort, we built and tested a supersonic multi-injection gun which uses three injections of gas over a 75’ long system with an inner diameter of 8’ to drive a 500-gram projectile to Mach 2.5. By breaking up the injection of rapidly expanding gas from one event (a conventional gun or artillery system) into many precisely timed injections, we can drive massive projectiles to hypersonic speeds while imposing much lower G forces on the payload. This low-pressure architecture also allows us to build the system from inexpensive materials (steel pipe) and consists of many repeating identical (aka modular) injection units.Via this TACFI effort, Longshot proposes scaling our accelerator to push 100 kilograms to Mach 5, or 20 kilograms to Mach 7. This new accelerator will be able to accommodate payloads up to 30” in diameter, be over 1000’ long, and be built of used pipeline material. The payload will be released into the atmosphere and travel for ~1km parallel to the ground before striking a berm. This system will be built at the Tonopah Airport in central Nevada in cooperation with Nye County.The end-result would be a hypersonic testbed able to perform one launch per week into the atmosphere open to government and commercial customers. The cost of these services would be $250,000 per launch. Depending on customer demand, a Phase III effort could result in up to a ton of payload capacity; lower G forces during acceleration of the payload; a top speed of Mach 15; the ability to launch to substantially higher altitudes; and an increased daily launch cadence. The accelerator and kick stage produced by this effort would be a minimum viable product designed to prove capability, economics, and be extensible to future DoD needs.The costs associated with the proposed TACFI effort largely lie with the design labor and materials needed to scale up the hypersonic accelerator system. Longshot is in a position to leverage a robust workforce for construction and components development from the oil and gas industry. This industrial base offers many off the shelf construction labor and material suppliers across the continental U.S. of which Longshot is uniquely positioned to leverage. The fundamental output of this TACFI will be a device for releasing 100kgs to Mach 5 flight, for a $250,000 cost to the Government end user. The criteria for success should be our ultimate performance on these metrics as compared to other options in hypersonic ground and flight testing.