by Dave Nordling, President, Reaction Research Society

RELEASE DATE: December 31, 2023

The Reaction Research Society (RRS) is pleased to announce an annual competition for university project teams to compete for an annual prize for the longest steady-state impulse duration of a regeneratively cooled bi-propellant liquid propellant rocket engine in static fire at the RRS MTA.  

All rules are explained below.  Rules are subject to change solely by the RRS and updates shall be provided on our website, RRS.ORG, whenever they arise.  The newest release date shall replace and void all prior copies.  In event of conflict, federal, state and local laws, the RRS Constitution and by-laws shall take precedence.

  1. Engines shall be designed and operated with liquid propellants.  Only bi-propellant engines are permitted.  Engines shall be safely tested in static fire conditions at the RRS MTA.  Only testing conducted at the RRS MTA after the start of the annual competition period will be considered for the prize.
  2. This will be an annual competition that will begin July 1, 2024.  Each annual competition period will begin on July 1st and close on June 30th of the following calendar year.  The RRS shall determine how long the competition will continue and may terminate this competition at any time.  A prize winner, if any, shall be announced no earlier than July 31st after that competition year closes.  Announcements shall be made on the RRS.ORG website.
  3. The RRS executive council shall appoint a three-person committee with the task of judging this competition and determining which team, if any, will be awarded the prize in accordance with the rules herein.  Committee members shall be technically proficient in liquid rocket engines and be neutral observers.  Committee members shall not have any influence over or be any part of any university team.  University teams are encouraged to ask questions of the committee at any time.  The committee’s decisions are final and not subject to repeal by the RRS.  All data and information regarding the engine testing must be recorded and submitted to the RRS for judging.
  4. Any missing information, deception or lack of clarity in the submitted information provided to the judging committee may result in disqualification of the testing attempt or barring the team from future competitions.
  5. Engines shall be designed and constructed by the student team and not be derived from pre-existing commercial or surplus hardware.  Teams shall provide a full description of all material suppliers and machining service providers used to the RRS judging committee.
  6. All teams shall provide a distinctive name for their team and must provide an accurate listing of all participating members and a single point of contact to serve as the advisor for the project.  The advisor must be a current university faculty member.  All teams must submit their membership list and full point of contact information for their advisor to the RRS.  
  7. Only university-funded projects consisting solely of students shall be allowed to participate. Sponsor-donated funds are acceptable, but for a team to be eligible for this competition they must represent a specific university.  All teams must provide a full description of their budget and all sources of funding to the RRS judging committee. All teams must provide sufficient financial information for the transfer of prize money or for the payment of fees or damages to the RRS.  
  8. Competition is open only to teams comprised entirely of US Persons and all teams must remain in full compliance with US ITAR laws.  US Persons are defined by being a natural person who is a lawful permanent resident as defined in 8 U.S.C 1101(a)(20) or who is a protected individual as defined by 8 U.S.C. 1324b(a)(3).  All teams shall provide a full listing of all participants and the universities shall issue statements to the RRS certifying compliance.  Failure to comply with ITAR laws shall result in disqualification from this competition.  This competition shall also be compliant to all US federal, state of California and local jurisdictional laws.  Additional requirements for eligibility may also apply.
  9. All participants in this competition shall list the RRS and its assignees as listed insured by their university insurance policy.  Consult the RRS executive council on these matters.
  10. All engines in this competition shall use a regenerative cooling scheme. The regenerative cooling flow path of the engine must cover the entire chamber length from injector face to throat line and to the nozzle exit plane.  There is no specific requirement on the direction of the regenerative cooling path in engine designs, but the coolant path geometry and design must be fully described in the submittals to the RRS judging committee.  All engine designs must have a diverging nozzle with a minimum expansion ratio of 4.0.  Local elevation of the RRS MTA is 2,300 feet above sea level.
  11. Ablative liners, graphite inserts or throats or the use of ceramic coatings are not permitted in engine designs in this competition.  
  12. All regenerative cooling paths must be demonstrated not to leak both before and after the valid test attempt.  This shall be confirmed by the RRS pyro-op in charge and the RRS judging committee.
  13. Transpiration cooling schemes from the chamber walls, throat, or nozzle are not permitted in engine designs in this competition.  Only transpiration cooling of the injector face is permitted.
  14. Dump cooling schemes are not permitted in engine designs in this competition.
  15. Boundary layer coolant holes from the injector face are acceptable but must not exceed 5% of the total injector mass flow as determined by analysis submitted and approved by the RRS judging committee.
  16. All participants will conduct their qualifying hot fires exclusively at the Reaction Research Society’s Mojave Test Area (MTA).  All scheduling shall be by the RRS president.  Testing conducted outside of the RRS MTA or conducted before the start of the annual competition period shall not be considered.
  17. All participants shall be subject to society rules on safety and operations and federal, state and local regulations.  A licensed CALFIRE Rockets Class 1 pyrotechnic operator is required to be present for each test attempt. The RRS president shall appoint the licensed pyrotechnic operator in charge for any operation at the MTA including each valid test attempt.
  18. Prize for the winning team will be $1.20 USD for every 1.0 lbf-seconds of verified steady state impulse operation meeting all requirements as determined by the RRS judging committee.  Longest steady-state duration shall be verified through submitted test data and information submitted by a competition team.  Team demonstrating the longest steady-state duration of a valid engine design shall be the winner in each annual period of competition only if it exceeds the prior record by the minimum impulse amount.   Prize will be awarded based on fully demonstrated and confirmed compliance with each of the following: (A) Minimum impulse to qualify for the prize at the start of the competition shall be 3,000 lbf-seconds in the steady-state condition.  (B) Prize money is based on the adjusted impulse value generated in test subtracting away this minimum qualifying impulse value. Example: a 1000 lbf engine fired for a steady-state duration of 25 seconds that meets all requirements has a total impulse of 25,000 lbf-sec, but will have an adjusted impulse of only 22,000 lbf-sec when subtracting the minimum impulse value.  The prize awarded, if this is the winning team, would be $26,400 USD in that annual competition period. Bonuses are considered separately. (C) Minimum chamber pressure throughout the entire steady-state period shall be 300 psig.  Chamber pressure values shall be rounded down to the nearest whole number value. (D) Minimum thrust throughout the entire steady state period shall be 300 lbf.  Thrust values shall be rounded down to the nearest whole number value. (E) Steady state conditions are defined as reaching and holding the declared nominal chamber pressure (psig) within +/~10% for the steady-state period. (F) Minimum steady-state period shall be for a minimum of 5.0 seconds.  Hot-fire durations shall be rounded down to the nearest tenth of a second. (G) Each annual competition winner must exceed the prior record by a minimum steady-state impulse of 300 lbf-seconds.  Otherwise, the prior record stands and no winner is awarded in that annual period of competition. (H)  If no team is successful in surpassing the initial minimum impulse (in part a) or surpasses previous record from the past annual competition periods by the minimum amount (in part g), no award will be given.  (I) No more than one team will be awarded the prize in any annual competition period. (J) Maximum prize is capped at $50,000 USD.  Any bonuses may be awarded on top of the prize money if the RRS judging committee can confirm full compliance to the requirements for the bonuses.  Bonuses are awarded only to the annual competition winner if there is one.
  19. A $1,500 fixed bonus shall be awarded only to the annual competition winner if their engine design entirely avoids the use of 3-D printing or any additively manufactured parts as confirmed by the RRS judging committee.  This bonus is to reward those teams demonstrating more desirable skills in traditional manufacturing.
  20. Each winning team shall be required to fully describe their engine design with their hot-fire results in a 20-minute presentation to be given at the next annual RRS symposium.  The purpose of this competition is to aid the development of the technology by sharing best practices.
  21. All qualifying test attempts for the annual competition prize shall measure thrust, chamber pressure and all propellant flow rates by data files submitted to and by techniques validated by the judging committee.  All valid attempts to claim the prize will include the minimum amount of functioning instrumentation during the entire hot-fire period being evaluated.  All teams shall declare their targeted performance parameters in advance of their testing attempt for valid comparison and qualification for the prize.  Failure to meet any of these requirements shall invalidate the testing attempt.
  22. Instrumentation shall include a direct measurement of chamber pressure, engine thrust, and the propellant mass flow rates of all fuels and oxidizers. Measurements of fuel and oxidizer supply manifold pressures may be included but neither shall be a valid substitute for direct chamber pressure measurement. Microsoft Excel CSV files are the only allowed file format.  
  23. Minimum data sampling resolution for all instrumentation shall be 0.1 seconds (10 Hz) with the exception of temperature measurements which shall be (0.25 Hz) if temperature measurements are used.
  24. Minimum accuracy of all pressure, thrust and mass flow rate measurements shall be no more than 5% of declared nominal values as stated by the team prior to the test attempt.  Error analysis and instrumentation accuracy information shall be supplied to and confirmed by the RRS judging committee with the test data.
  25. All participants including visitors and spectators shall have signed and submitted the indemnification waivers in advance of their arrival to the MTA on any day of operation. All participants including visitors and spectators shall fully comply with the instructions of the pyrotechnic operator in charge.  The pyrotechnic operator in charge or the RRS reserves the right to limit the number of people in attendance at any particular MTA event.
  26. RRS shall approve all test plans, hardware, engine designs and operations well in advance of testing before allowing the test to be scheduled.  A minimum of 4 weeks advance notice with all final materials submitted is recommended.  Review of all testing equipment, test plans, procedures, safety features and equipment must be conducted by a Class 1 licensed pyro-op or an expert appointed by the RRS president.
  27. The pyrotechnic operator in charge has full authority to stop any operation or disqualify any team for any reason.  All participants, attendees, visitors and spectators shall fully and immediately comply with all RRS appointed pyrotechnic operator instructions at all times.
  28. All resources used in this competition shall be coordinated and approved by the RRS president.  The RRS is not obligated to provide any financial or material support to any team in this competition.
  29. All hot-fire attempts for this competition shall be subject to a minimum daily fee of $500 USD paid to the RRS within 30 calendar days of the test attempt. Universities may have multiple teams in the competition but each team shall be required to pay their own $500 USD minimum daily fee for that specific team.  The RRS standard fee policy shall apply to any operations outside of this competition.  Failure to pay fees can result in disqualification or exclusion from future competition of the university. Fees are not refundable, but attempts may be rescheduled with sufficient advance notice.
  30. All teams shall be responsible for providing adequate and suitable fire suppression measures and the protection of RRS assets.  
  31. All teams shall be responsible for the repair of damage to RRS assets sustained in events related to testing or paying for the costs of repairs as determined by the RRS.
  32. All teams shall make safety their highest priority.  All teams shall be responsible for designing safe and reliable pressure relief and venting systems, propellant filling and draining operations, prevention of cryogenic hazards including exposure, fire and trapped fluid volumes, and incorporate adequate spill and contamination prevention and mitigation measures.  All systems including but not limited to instrumentation, remote actuation, ignition, propellant and pressurization management shall be fully described for a full review by the RRS and the pyrotechnic operator in charge prior well in advance of any testing day.  Changes to the designs after review are not permitted without subsequent review and approval by the RRS and pyrotechnic operator in charge. Teams are strongly encouraged to consult with the RRS in all phases of their design and development processes including the early conceptual periods.
  33. All teams shall abide by the stored energy limitations (10,000 Joules) for all attended operations at the RRS MTA.  Otherwise, only remotely controlled operations are permitted.  All teams shall fully and immediately comply with the instructions given by the pyrotechnic operator in charge as appointed by the RRS president.
  34. All teams shall abide by the flaring stack rules on the venting of volatile fuels as imposed by the RRS.
  35. The wearing and proper use of suitable personnel protective equipment in all operations at the RRS MTA is mandatory and shall be the sole responsibility of every individual.
  36. All teams participating in this competition are required to specifically mention the “Reaction Research Society” in their related public announcements or social media postings.  Contact the RRS secretary and vice-president for details.

For any questions regarding this competition or its rules, contact the RRS president or the RRS director of research.  Questions shall be relayed from the executive council to the judging committee for their consideration.  Please use the official RRS emails as individual officers are elected to annual terms and offices may change ownership in each calendar year.



Other important points of contact include:





Updates and new releases on this competition will be announced by postings on the Reaction Research Society website,


For US Mail correspondence, write to:

Reaction Research Society

8821 Aviation Blvd.

P.O. Box 90933

Los Angeles, CA, 90009-0933