The National Aeronautics and Space Administration (NASA) intends to modify the existing Hydrogen Electrical Power System (HEPS) contract to include a heat exchanger trade study for the tipping point rocket locker hardware. This modification will be executed as a sole source contract with Teledyne Energy Systems, Inc., as they are deemed the only responsible source capable of fulfilling the agency's requirements under FAR 6.302-1. Interested organizations are invited to submit their capabilities and qualifications by November 13, 2024, at 12:00 PM PST, to determine if the acquisition can be conducted competitively. For further inquiries, interested parties may contact Roxana Romero at roxana.l.romero@nasa.gov or Lonna Rumsey at lonna.rumsey@nasa.gov.