Release Date
August 23rd, 2023
Open Date
September 20th, 2023
Due Date(s)
October 18th, 2023
Close Date
October 18th, 2023
Topic No.


Rapid ASCENT propellant loading operations


Department of DefenseN/A


Type: SBIRPhase: BOTHYear: 2023


The Department of Defense (DoD) is seeking proposals for the topic of "Rapid ASCENT propellant loading operations" as part of the SBIR 23.3 BAA. The Air Force branch is specifically interested in this technology. The objective is to develop and demonstrate a repeatable capability to perform ASCENT propellant loading into spacecraft at the launch site. The current hydrazine-based propellant infrastructure poses challenges, including the need to halt all other ground operations due to the high risk to personnel. The development of green monopropellants, such as ASCENT, offers an opportunity to overcome these challenges and achieve responsive space access. The proposal aims to leverage previous experience to build a responsive, robust ASCENT loading capability and develop a ground CONOPS (including SOPs, Checklists, and other procedures) with stakeholder input. The project will be conducted in three phases: Phase I involves developing initial CONOPS and a business plan, Phase II includes refining the strategy and conducting a refueling demonstration, and Phase III focuses on validation with an actual mission. The project duration and funding specifics are not provided in the document. For more information, refer to the DoD SBIR 23.3 BAA on or the solicitation agency's website.


OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Space Technology;Human-Machine Interfaces

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop and demonstrate repeatable capability to perform ASCENT propellant loading into spacecraft at launch site in

DESCRIPTION: While commercial launch providers have dramatically enhanced US spacelift capability and decreased cost per pound to orbit, there remains a clear military necessity for responsive space access (as little as 24 hrs from notification to on-orbit capability) to support time-critical activities during contested space operations [1]. There are many challenges to achieving this capability, but two major challenges arise from the current hydrazine-based propellant infrastructure – due to the high risk to personnel, during both spacecraft/launch vehicle integration and fueling operations, all other ground operations must be halted. The development of green monopropellants, including the high-performance ASCENT green monopropellant propulsion systems [2], offers a potential opportunity to avoid the challenges posed by hydrazine toxicity to responsive space timelines. The NASA GPIM mission pioneered the development of new ground equipment and CONOPS for ASCENT [3,4]; however, the hardware developed was not transitioned to industry and CONOPS development did not result in clear, robust, widely accepted ground procedures. This proposal seeks to leverage this experience to build a responsive, robust ASCENT loading capability to support Responsive Space Access. Propellant ground support equipment (PGSE) should be capable of loading up to 200 kg of ASCENT propellant in the timeframe specified. A robust ground CONOPS (including SOPs, Checklists, and other procedures; potentially captured in digital tools) should be developed with stakeholder input from the entire Responsive Space team (launch vehicle, spacecraft – primary and secondary, range and ground safety). Particular range safety documents of concern include, but are not limited, to AFSPC Manual 91-710 [5].

PHASE I: Develop initial CONOPS and tools/communications strategy to satisfy AFSPC Manual 91-710 and other relevant documents. Interact with multiple range equities; range safety, LV provider, potentially primary payload integrators to identify timeline, interfaces, operational requirement to meet refueling timeline. Develop a business plan for potential future commercial applications.

PHASE II: Refine Phase 1 strategy, perform PGSE hardware build, and conduct refueling demonstration on non-operational system (either mockup or GFE provided hardware).

PHASE III DUAL USE APPLICATIONS: Validation with actual mission with rapid refueling of a satellite such as PUMA or TacRS-3.


  1. Erwin, Sandra. (2002, May 12). Space Force to select small rocket for ‘responsive space’ mission. SpaceNews;
  2. Kilcoin, Mackenzie, et al, "Development of ASCENT propellant thrusters and propulsion systems." Small Satellite Conference, Logan, UT, Aug 2022. ;
  3. Leitz, Amanda, et al, “Propellant Loading, Pre-Flight Testing, and Launch Integration of the Green Propellant Infusion Mission” AIAA Propulsion and Energy Forum, Aug 2020, AIAA-2020-3811.;
  4. Zuttarelli, Anthony, et al, “Progress in Red vs. Green Propellant Operations: ASCENT Load Operations Lessons Learned” AIAA Propulsion and Energy Forum, Aug 2020, AIAA-2020-3829.;
  5. (check for for latest update)

KEYWORDS: ASCENT; propellant loading; launch operations; PGSE; Responsive Space Access