Part of the DoW SBIR/STTR FY27 Release 2 topic list. Browse all 83 topics by industry or service.
Topic DAF27TX02-DV502 from the DoW STTR 2027 BAA, Release 2. Pre-release now; proposals due January 6, 2027, 12:00 PM ET.
Quick answer
The Department of the Air Force, through the DoW STTR 2027 CSO, wants a low-power feed system that converts green liquid monopropellants such as ASCENT into a controlled vapor stream for electric propulsion thrusters, with real-time composition feedback. This is a Direct-to-Phase II STTR topic, and Phase I proposals will be rejected. Proposals are due January 6, 2027, 12:00 PM ET.
Solicitation at a glance
- Topic number: DAF27TX02-DV502
- Official title: Next-generation Green Monopropellant Gas Generation
- Agency: Department of the Air Force
- Program: STTR (DoW STTR 2027 CSO, Release 2)
- Award type: Direct to Phase II (no Phase I awards)
- Award amount: Up to $1,900,000. Source: Department of the Air Force Release 2 instructions in DSIP.
- CMMC level: Level 2 (Self)
- ITAR: Yes. Export-controlled (ITAR/EAR); see topic text
- Technology areas: Space Platforms
- Pre-release (direct TPOC contact allowed): November 4 to December 2, 2026, 8:00 AM ET
- Opens in DSIP: December 2, 2026, 8:00 AM ET
- Proposals due: January 6, 2027, 12:00 PM ET
- Official source: DSIP Topics app (search DAF27TX02-DV502)
BW&CO's take
What the Department of the Air Force wants
USSF multimode propulsion would use one liquid monopropellant for both chemical and electric thrusters, but green propellants such as ASCENT have near-zero vapor pressure and are hard to combust at low temperature and pressure. The Air Force wants a low-SWaP liquid-to-gas feed system that reports mass flow, species composition, and temperature in real time and actively holds target species fractions, in steady-state and pulsed operation above 5 Hz, with warmup under 10 minutes. Phase II delivers a flight-like engineering development unit for thrusters such as Hall effect or MPD, demonstrated across part of the sub-kW to 100 kW range with a physics-based scaling path.
Who is a good fit
- Prior thermal, catalytic, or other vaporization work on ASCENT, LMP-103S, or similar green monopropellants, backed by test data.
- In-line sensing of vapor species composition with closed-loop control of the vaporization process.
- Materials experience with long-term exposure to green monopropellants and their breakdown products, including condensation and freezing risks.
- Working relationships with plasma thruster manufacturers that can inform interfaces and integration.
Watch-outs
- Direct-to-Phase II: Phase I proposals will be rejected as nonresponsive. You need prior work, such as IRAD or other funded efforts, with technical reports, test data, and prototype designs.
- This is an STTR topic. The topic text does not describe partnering requirements, so confirm research institution partner rules in the DoW STTR 2027 CSO instructions.
- Phase II must produce flight-like EDUs and demonstrate actual performance across a subset of the sub-kW to 100 kW range. Teaming with established thruster manufacturers is highly encouraged.
- The topic metadata marks this topic as ITAR-restricted, so plan for export-control handling. It also lists CMMC Level 2 (Self).
Think your company fits DAF27TX02-DV502? Talk with BW&CO before the January 6 deadline.
Plan Your DAF27TX02-DV502 Submission
Official topic text (verbatim from DSIP)
The text in this section is copied word for word from the official DSIP topic as published on November 4, 2026. DSIP is the official source and topics can be amended. Always confirm the current version at dodsbirsttr.mil before you submit. Our commentary above is BW&CO's interpretation, not Government guidance.
Title
Next-generation Green Monopropellant Gas Generation
Objective
Develop a low-power, real-time precision liquid-to-gas phase-change feed system featuring active molecular feedback control to enable the seamless integration of liquid propellants (including next-generation green liquid propellants such as ASCENT and LMP-103S) with high-efficiency in-space plasma propulsion systems. While legacy propellants like hydrazine vaporize with relative ease, next-generation green propellants possess near-zero vapor pressures that streamline ground operations but make efficient vaporization and stable gas-phase molecular composition extremely difficult to control. Proposed solutions must actively monitor and modulate the vaporization process in real time to deliver precise molecular species fractions under tight power constraints, ultimately establishing a versatile, fuel-agnostic propellant conditioning capability to support dynamic space operations and emerging in-space refueling architectures.
Description
The USSF has a desire to use liquid monopropellants for high thrust propulsion (natively in chemical thrusters) and for low-thrust, very energetic missions (in electric propulsion thrusters) - so called Multimode Propulsion (MMP) capabilities - to support Dynamic Space Operations. Such MMP capabilities have a number of very favorable characteristics including high propellant density, reduced need for high pressure storage systems, continued need for chemical propulsion on DoW assets for high thrust prompt maneuver, and compatibility with future on-orbit liquid propellant refueling capabilities.
One critical capability gap is an energy efficient, precision propellant feed system which efficiently converts next-generation liquid monopropellant into non-reactive vapor phase products which can be fed into the electric propulsion (EP) thruster. Key challenges arise from the fact that next-generation monopropellants have negligible vapor pressure and are extremely difficult to combust at low temperature and pressure.
The desired technology should present a solution for a feed system capable of supporting sub-kW to 100 kW class EP systems:
- Operation at minimum on ASCENT propellant (T) or on ASCENT and other monopropellant formulations (O)
- Realtime telemetry, including mass flow rate, species composition, and temperature as inputs to the EP device
- Maintain consistently characterized molecular composition (T) and extremely stable molecular composition (O) of the output vapor and support both steady-state and pulsed operation at frequencies greater than 5 Hz
- Minimal SWaP with particular focus on low power consumption
- Incorporate fluid/vapor facing materials that can reliably withstand long-term exposure to green monopropellants and their breakdown products over the required lifespan. Potential issues also include condensation or freezing for long-duration propellant storage in ullage and plenums if these or similar components are used
- Demonstrate rapid warmup/gas generation in less than 10 minutes (T) or on-demand (O)
- Ensure lifetime design consideration for future multiple refueling opportunities
This work directly supports the Contested Logistics Technologies (LOG) Critical Technology Area with respect to space mobility operations.
Phase I
As this is a Direct-to-Phase-II (D2)2) topic, no Phase I proposals will be accepted and no Phase I awards will be made under this topic. Offerors responding to this topic shall demonstrate “Phase I-type” technical feasibility through prior research, development, laboratory validation, commercial development, or operational demonstrations performed outside of the SBIR/STTR program. Phase I proposals will not be evaluated and will be rejected as nonresponsive.
For this D2P2 topic, the Government expects that the small business would have accomplished the following in a “Phase I-type” effort via some other means (e.g. IRAD, or other funded work). It must have developed a concept for a workable prototype or design to address at a minimum the basic capabilities of the stated objective above. Proposal must show, as appropriate to the proposed effort, a demonstrated technical feasibility or nascent capability to meet the capabilities of the stated objective. Proposal may provide example cases of this new capability on a specific application. The documentation provided must substantiate that the proposer has developed a preliminary understanding of the technology to be applied in their Phase II proposal to meet the objectives of this topic. Documentation should include all relevant information including, but not limited to, technical reports, test data, prototype designs/models, and performance goals/results.
Phase II
The rapid advancement of plasma thruster operation on next-generation molecular propellants is currently bottlenecked by the lack of an energy-efficient, precise, real-time vaporization solution. While previous research has explored thermal and catalytic vaporization strategies, existing options suffer from high power consumption, ill-defined operational lifetimes, inconsistent vapor-phase molecular output, and a total lack of real-time compositional feedback to the thruster. To bridge this critical technology gap and enable commercial transition, Phase II efforts must focus on developing a robust, energy-efficient liquid-to-gas propellant conditioning system when operating on both legacy and next-generation green monopropellants.
Proposals must deliver a low Size, Weight, and Power (SWaP) vaporization solution capable of providing a well-quantified, repeatable vapor stream to high-efficiency plasma thrusters, such as Hall Effect Thrusters (HETs) or Magnetoplasmadynamic (MPD) thrusters. Key technical requirements include the ability to deliver real-time feedback on the actual molecular composition being provided, and the capacity to actively modulate operation to target and maintain specific molecular species fractions. While the target operational envelope spans plasma propulsion systems from <1 kW to 100 kW, a single hardware unit is not expected to cover the entire spectrum; rather, performers must demonstrate actual performance across a subset of this range alongside a credible, physics-based pathway for modular scalability.
To maximize commercial transition and support the emerging in-space refueling architecture, Phase II projects must focus on developing flight-like engineering development units (EDUs) designed for integration into existing and future plasma propulsion systems. While formal spaceflight qualification (e.g., strict shock, vibration, and radiation acceptance testing) is not required during this phase, performers are highly encouraged to team with established thruster manufacturers. This collaboration will ensure that relevant aerospace engineering best practices, interfaces, and integration protocols are incorporated into the design, positioning the technology for rapid transition.
Phase III Dual Use Applications
This technology is directly applicable to both defense and civil spacecraft, delivering a hybrid propulsion capability that enables both prompt, high-thrust maneuvers (e.g., threat and debris avoidance) and high-efficiency, low-thrust orbital transfers. In the near term, the primary market is centered on Department of War (DoW) applications to meet critical requirements for Dynamic Space Operations (DSO), enhanced space warfighting maneuverability, and the rapid emergence of tactical in-space refueling architectures. The primary Phase II deliverable-an Engineering Development Unit (EDU) gas generator-is optimized for direct integration into various molecular plasma thrusters currently under development by commercial space partners. Although final flight qualification must be accomplished on the integrated, combined propulsion system (thruster and gas generator), the Phase II EDU serves as the critical hardware stepping stone. Depending on future government and commercial funding profiles, this technology is well-positioned for independent maturation as a standalone, platform-agnostic product through a follow-on Phase III contract or Tactical Funding Increases (TACFI) effort.
References
Hauck, Curtis, Caleb Medchill, Boxin Zhang, Yu Yun Wang, Mariano Rubio, and Stephen B. Cronin. "Ionic Liquid-Based Gas Generators Using High Voltage Nanosecond Pulse Discharge." ACS omega 10, no. 37 (2025): 42651-42659. https://pubs.acs.org/acsodf/article/10/37/42651/3656097/Ionic-Liquid-Based-Gas-Generators-Using-High.
Rovey, Joshua, Christopher T. Lyne, Alex J. Mundahl, Nicolas Rasmont, Matthew S. Glascock, Mitchell J. Wainwright, and Steven P. Berg. "Review of chemical-electric multimode space propulsion." In AIAA Propulsion and Energy 2019 Forum, p. 4169. 2019. https://arc.aiaa.org/doi/10.2514/6.2019-4169.
Keywords
Green monopropellant; electric propulsion; propulsion feed system; ASCENT propellant; multimode propulsion; high thrust; low thrust; space mobility
Frequently asked questions
What is DAF27TX02-DV502?
The Next-generation Green Monopropellant Gas Generation topic from the Department of the Air Force in the DoW STTR 2027 CSO. It seeks a precision liquid-to-gas feed system with active molecular feedback control so green monopropellants can feed in-space plasma propulsion.
When is DAF27TX02-DV502 due?
Proposals are due January 6, 2027, 12:00 PM ET. DSIP pre-release began November 4, 2026, and direct contact with the topic authors (TPOCs) is allowed only until the topic opens on December 2, 2026, 8:00 AM ET.
Is DAF27TX02-DV502 Phase I or Direct-to-Phase II?
Direct-to-Phase II STTR. No Phase I proposals will be accepted and no Phase I awards will be made. Offerors must show Phase I-type feasibility from work performed outside the SBIR/STTR program.
Does one unit need to cover the full sub-kW to 100 kW range?
No. The topic states that a single hardware unit is not expected to cover the entire spectrum. Performers must demonstrate actual performance across a subset of the range and present a credible, physics-based pathway for modular scalability.