# US 12,180,914 B1 · Boost injection turbine exhaust cycle (BITEC) > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,180,914 B1 - Document ID: US12180914B1 - Status: Granted - Kind: B1 - Application number: 18/457,312 - Filed: 2023-08-28 - Granted: 2024-12-31 - Earliest claimed: 2023-08-28 - Assignees: Pivotal Space, Inc. - Applicants: Pivotal Space, Inc. - Inventors: Lloyd J Droppers; Landon Luick - Web page: https://patentgrep.com/patent/US12180914B1 ## CPC - F02K 9/97: Rocket nozzles (thrust or thrust vector control F02K9/80) - F02K 9/46: using pumps - F02K 9/48: driven by a gas turbine fed by propellant combustion gases {or fed by vaporized propellants or other gases} - F02K 9/50: using pressurised fluid to pressurise the propellants - F02K 9/52: Injectors - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) ## Abstract A rocket propulsion system that may include a supersonic rocket nozzle with a supersonic divergent section, and a heat transfer system configured to transfer heat from the supersonic rocket nozzle to a propellant where a portion of the propellant may be selectively injected, combusted, and expanded in the supersonic nozzle generating an additional thrust. In examples, the heated propellant may be used to power a pump system to feed the rocket engine. ## Claims ### Claim 1 A rocket propulsion system comprising: a supersonic rocket nozzle defined by a convergent section, a throat, a supersonic divergent section, and a heat transfer system configured to transfer heat from the supersonic rocket nozzle to a propellant; and a propellant pump feed system comprising: a prime pump configured to pressurize the propellant, the prime pump comprising a prime pressurizing side driven by a prime drive side; a boost pump configured to pressurize the propellant, the boost pump comprising a boost pressurizing side driven by a boost drive side; and a distribution system configured to deliver a portion of the pressurized propellant from the prime pressurizing side to the heat transfer system, from the heat transfer system to the prime drive side, from the prime drive side to the boost drive side, and from the boost drive side to the prime pressurizing side. ### Claim 2 (depends on 1) The rocket propulsion system of claim 1, the distribution system further comprising a mixing system configured to mix propellant exiting the boost drive side with propellant entering the prime pressurizing side. ### Claim 3 (depends on 2) The rocket propulsion system of claim 2, the mixing system comprising one or more of a bend, a mixing vane, or an operation configured to mix propellant exiting the boost drive side with propellant entering the prime pressurizing side. ### Claim 4 (depends on 1) The rocket propulsion system of claim 1, the distribution system further configured to selectively direct propellant from the prime drive side to a propellant injection system disposed at a region of the supersonic divergent section, the propellant injection system configured to inject propellant into the region of the supersonic divergent section. ### Claim 5 (depends on 4) The rocket propulsion system of claim 4, wherein an amount of propellant directed to the propellant injection system is based at least in part on a heat and pressure of propellant exiting the boost drive side and a heat and pressure of propellant exiting the boost pressurizing side, to avoid cavitation of the propellant in the prime pump. ### Claim 6 (depends on 1) The rocket propulsion system of claim 1, wherein the propellant is a bipropellant and the propellant pump feed system further comprises a fuel pump feed system and an oxidizer pump feed system. ### Claim 7 (depends on 5) The rocket propulsion system of claim 5, wherein the fuel pump feed system comprises a fuel prime pump and a fuel boost pump, and the oxidizer pump feed system comprises an oxidizer prime pump and an oxidizer boost pump. ### Claim 8 A method for operating a rocket engine, comprising: pressurizing a propellant with a boost pump to a boost pressure; increasing a pressure of the propellant from the boost pressure with a prime pump to a prime pressure; directing a first portion of the propellant, at the prime pressure, to a combustion chamber and passing a second portion of the propellant to a heat exchanger; transferring heat from the rocket engine to the second portion of the propellant via the heat exchanger, thereby generating a heated propellant; transferring the heated propellant to a prime drive side of the prime pump; extracting a first portion of energy from the heated propellant by the prime drive side of the prime pump; applying the first portion of energy to pressurize the propellant to the prime pressure; transferring the heated propellant from the prime drive side to a boost drive side of the boost pump; extracting a second portion of energy from the heated propellant by the boost drive side of the boost pump; applying the second portion of energy to pressurize the propellant to the boost pressure; and mixing the heated propellant from the boost drive side with propellant exiting the boost pump directed to the prime pump. ### Claim 9 (depends on 8) The method of claim 8, wherein the mixing comprises sending the propellant through a bend, a mixing vane, or a venturi prior to the propellant entering the prime pump. ### Claim 10 (depends on 8) The method of claim 8, further comprising: directing an amount of propellant from the prime drive side to a propellant injection system disposed at a region of a supersonic divergent section of a nozzle; and injecting the amount of propellant into the supersonic divergent section of the nozzle. ### Claim 11 (depends on 10) The method of claim 10, wherein the amount of propellant directed to the propellant injection system is based at least in part on a heat and pressure of propellant exiting the boost drive side and a heat and pressure of propellant exiting the boost pressurizing side, to avoid cavitation of the propellant in the prime pump. ### Claim 12 (depends on 8) The method of claim 8, wherein the propellant is a bipropellant, and bipropellants are moved via a fuel pump feed system and an oxidizer pump feed system. ### Claim 13 (depends on 12) The method of claim 12, wherein the boost pump comprises a fuel boost pump and an oxidizer boost pump, and wherein the prime pump comprises a fuel prime pump and an oxidizer prime pump. ### Claim 14 (depends on 8) The method of claim 8, wherein the boost pump comprises a turbopump having a turbine on the boost drive side. ### Claim 15 (depends on 8) The method of claim 8, wherein the transferring heat from the rocket engine to the second portion of the propellant causes a phase change of the second portion of the propellant based on an amount of energy transferred to the second portion of the propellant from a supersonic rocket nozzle or a combustion chamber. ### Claim 16 (depends on 15) The method of claim 15, wherein extracting the first portion of energy from the heated propellant causes a phase change of the propellant based on an amount of energy transferred from the heated propellant through the prime drive side of the prime pump. ### Claim 17 (depends on 15) The method of claim 15, wherein extracting the second portion of energy from the heated propellant causes a phase change of the propellant based on an amount of energy transferred from the heated propellant through the boost drive side of the boost pump. ### Claim 18 A rocket propulsion system comprising: a supersonic rocket nozzle defined by a convergent section, a throat, a supersonic divergent section, and a heat transfer system configured to transfer heat from the supersonic rocket nozzle to a propellant; and a bipropellant pump feed system comprising: a fuel prime pump configured to pressurize fuel, the fuel prime pump comprising a fuel prime pressurizing side driven by a fuel prime drive side; a fuel boost pump configured to pressurize the fuel, the fuel boost pump comprising a fuel boost pressurizing side driven by a fuel boost drive side; an oxidizer prime pump configured to pressurize oxidizer, the oxidizer prime pump comprising an oxidizer prime pressurizing side driven by an oxidizer prime drive side; an oxidizer boost pump configured to pressurize the oxidizer, the oxidizer boost pump comprising an oxidizer boost pressurizing side driven by an oxidizer boost drive side; and a distribution system configured to deliver a portion of the pressurized fuel from the fuel prime pressurizing side to the heat transfer system, from the heat transfer system to the fuel prime drive side, from the fuel prime drive side to the fuel boost drive side, and from the fuel boost drive side to the fuel boost pressurizing side, and configured to deliver a portion of the pressurized oxidizer from the oxidizer prime pressurizing side to the heat transfer system, from the heat transfer system to the oxidizer prime drive side, from the oxidizer prime drive side to the oxidizer boost drive side, and from the oxidizer boost drive side to the oxidizer boost pressurizing side. ### Claim 19 (depends on 18) The rocket propulsion system of claim 18, the distribution system further comprising a mixing system configured to mix fuel exiting the fuel boost drive side with fuel entering the fuel prime pressurizing side, and configured to mix oxidizer exiting the oxidizer boost drive side with oxidizer entering the oxidizer prime pressurizing side. ### Claim 20 (depends on 18) The rocket propulsion system of claim 18, the distribution system further configured to selectively direct fuel from the fuel prime drive side to a fuel injection system disposed at a region of the supersonic divergent section, the fuel injection system configured to inject fuel into the region of the supersonic divergent section, and the distribution system further configured to selectively direct oxidizer from the oxidizer prime drive side to an oxidizer injection system disposed at the region of the supersonic divergent section, the oxidizer injection system configured to inject oxidizer into the region of the supersonic divergent section.