Monopropellant rocket

<h2 id="chemical-reaction-based-monopropellant-rockets">Chemical-reaction based monopropellant rockets</h2>
The simplest monopropellant rockets depend on the <a href="/facts/Chemical_decomposition/4X3oxvhb">chemical decomposition</a> of a storable propellant after passing it over a catalyst bed.<a class="footnote-ref" id="fnref:3" href="#fn:3">3</a> The power for the thruster comes from the high pressure gas created during the decomposition reaction that allows a <a href="/facts/Rocket_engine_nozzle/K4kHCmFX">rocket nozzle</a> to speed up the gas to create thrust.
The most commonly used monopropellant is <a href="/facts/Hydrazine/G7P5ITzU">hydrazine</a> (N2H4, or H2N−NH2), a compound unstable in the presence of a <a href="/facts/Catalysis/LPBS7TQC">catalyst</a> and which is also a strong <a href="/facts/Reducing_agent/CtfSGVXC">reducing agent</a>. The most common catalyst is granular <a href="/facts/Alumina/wXM9P6pI">alumina</a> (aluminum oxide, Al2O3) coated with <a href="/facts/Iridium/TFQutoj1">iridium</a>. These coated granules are usually under the commercial labels Aerojet S-405 (previously made by <a href="/facts/Shell_plc/2etvCXCf">Shell</a>)<a class="footnote-ref" id="fnref:4" href="#fn:4">4</a> or <a href="/facts/Heraeus/4DVrV5WN">W.C. Heraeus</a> H-KC 12 GA (previously made by Kali Chemie).<a class="footnote-ref" id="fnref:5" href="#fn:5">5</a> There is no <a href="/facts/Igniter/BfUDd0PM">igniter</a> with hydrazine. Aerojet S-405 is a spontaneous catalyst, that is, hydrazine decomposes on contact with the catalyst. The <a href="/facts/Chemical_decomposition/4X3oxvhb">decomposition</a> is highly <a href="/facts/Exothermic/gCuSvpa4">exothermic</a> and produces a 1,000 °C (1,830 °F) gas that is a mixture of <a href="/facts/Nitrogen/Nf1QpGDz">nitrogen</a>, <a href="/facts/Hydrogen/BoYHjl0J">hydrogen</a> and <a href="/facts/Ammonia/MtLtJFtz">ammonia</a>. The main limiting factor of the monopropellant rocket is its life, which mainly depends on the life of the catalyst. The catalyst may be subject to catalytic poisoning and catalytic attrition which results in the catalyst failure. Another monopropellant is <a href="/facts/Hydrogen_peroxide/vju6HBIc">hydrogen peroxide</a>, which, when purified to 90% or higher concentration, is self-decomposing at high temperatures or when a catalyst is present.
Most chemical-reaction monopropellant rocket systems consist of a <a href="/facts/Fuel_tank/kJhnSSAc">fuel tank</a>, usually a <a href="/facts/Titanium/53ArnDoy">titanium</a> or <a href="/facts/Aluminium/7wmR8jYE">aluminium</a> sphere, with an <a href="/facts/Ethylene_propylene_rubber/kFlXh8Y2">ethylene-propylene rubber</a> container or a <a href="/facts/Surface_tension/EuluYmSM">surface tension</a> <a href="/facts/Propellant_management_device/bcP9Y8HU">propellant management device</a> filled with the fuel. The tank is then pressurized with <a href="/facts/Helium/yRul93TG">helium</a> or <a href="/facts/Nitrogen/Nf1QpGDz">nitrogen</a>, which pushes the fuel out to the motors. A <a href="/facts/Pipe_(fluid_conveyance)/dgX5uQjj">pipe</a> leads from the tank to a <a href="/facts/Poppet_valve/ADRB6Evc">poppet valve</a>, and then to the decomposition chamber of the rocket motor. Typically, a <a href="/facts/Satellite/PTX8c68t">satellite</a> will have not just one motor, but two to twelve, each with its own valve.
The <a href="/facts/Spacecraft_attitude_control/hE6aMu26">attitude control</a> rocket motors for satellites and <a href="/facts/Space_probe/AeWRBITP">space probes</a> are often very small, 25 mm (0.98 in) or so in <a href="/facts/Diameter/6uNn4VmU">diameter</a>, and mounted in groups that point in four directions (within a plane).
The rocket is fired when the <a href="/facts/Computer/SQe1aK05">computer</a> sends <a href="/facts/Direct_current/r9MNUx84">direct current</a> through a small <a href="/facts/Electromagnet/3YMYtSMX">electromagnet</a> that opens the poppet valve. The firing is often very brief, a few <a href="/facts/Millisecond/xHCyv235">milliseconds</a>, and — if operated in air — would sound like a pebble thrown against a metal trash can; if on for long, it would make a piercing hiss.
Chemical-reaction monopropellants are not as efficient as some other propulsion technologies. Engineers choose monopropellant systems when the need for simplicity and reliability outweigh the need for high delivered impulse. If the propulsion system must produce large amounts of thrust, or have a high <a href="/facts/Specific_impulse/JKGgw2I4">specific impulse</a>, as on the main motor of an interplanetary spacecraft, other technologies are used.

<h2 id="solar-thermal-based-monopropellant-thrusters">Solar-thermal based monopropellant thrusters</h2>
A concept to provide <a href="/facts/Low_Earth_orbit/rq1TwayJ">low Earth orbit</a> (LEO) <a href="/facts/Propellant_depot/srD0zEyR">propellant depots</a> that could be used as way-stations for other spacecraft to stop and refuel on the way to beyond-LEO missions has proposed that waste gaseous <a href="/facts/Hydrogen/BoYHjl0J">hydrogen</a>—an inevitable byproduct of long-term <a href="/facts/Liquid_hydrogen/Vpk3Gb8P">liquid hydrogen</a> storage in the <a href="/facts/Radiative_heat_transfer/1PD9jtCv">radiative heat</a> environment of <a href="/facts/Outer_space/R3LRKyFs">space</a>—would be usable as a monopropellant in a <a href="/facts/Solar_thermal_rocket/bXWbqTxo">solar-thermal</a> propulsion system. The waste hydrogen would be productively utilized for both <a href="/facts/Orbital_stationkeeping/tNNee2Dm">orbital station-keeping</a> and attitude control, as well as providing limited propellant and thrust to use for <a href="/facts/Orbital_maneuver/HAlEFRSJ">orbital maneuvers</a> to better <a href="/facts/Space_rendezvous/8KlcQyyf">rendezvous</a> with other spacecraft that would be inbound to receive fuel from the depot.<a class="footnote-ref" id="fnref:6" href="#fn:6">6</a>
Solar-thermal monopropellant thrusters are also integral to the design of a next-generation cryogenic <a href="/facts/Upper_stage/WNrmgztj">upper stage</a> <a href="/facts/Rocket/b6j4keIl">rocket</a> proposed by U.S. company <a href="/facts/United_Launch_Alliance/yWev1ndb">United Launch Alliance</a> (ULA). The <a href="/facts/Advanced_Common_Evolved_Stage/JJuqn6Tq">Advanced Common Evolved Stage</a> (ACES) is intended as a lower-cost, more-capable and more-flexible upper stage that would supplement, and perhaps replace, the existing ULA <a href="/facts/Centaur_(rocket_stage)/ryg96uIF">Centaur</a> and ULA <a href="/facts/Delta_IV/QWun0yHh">Delta Cryogenic Second Stage</a> (DCSS) upper stage vehicles. The ACES <a href="/facts/Integrated_Vehicle_Fluids/JJuqn6Tq">Integrated Vehicle Fluids</a> option eliminates all <a href="/facts/Hydrazine/G7P5ITzU">hydrazine</a> and <a href="/facts/Helium/yRul93TG">helium</a> from the space vehicle—normally used for attitude control and station keeping—and depends instead on solar-thermal monopropellant thrusters using waste hydrogen.<a class="footnote-ref" id="fnref:7" href="#fn:7">7</a>

<h2 id="history">History</h2>

Soviet designers had begun experimenting with monopropellant rockets as early as 1933.<a class="footnote-ref" id="fnref:8" href="#fn:8">8</a> They believed their monopropellant mixes of <a href="/facts/Dinitrogen_tetroxide/01WfnHJh">nitrogen tetroxide</a> with gasoline, or toluene, and kerosene would lead to an overall simpler system; however, they ran into problems with violent explosions with pre-mixed fuel and oxidizer serving as a monopropellant that led the designers to abandon this approach.<a class="footnote-ref" id="fnref:9" href="#fn:9">9</a>
<a href="/facts/Hellmuth_Walter/UmWlIwoA">Helmuth Walter</a> was a German engineer an early pioneer of monopropellant rockets using hydrogen peroxide as fuel.<a class="footnote-ref" id="fnref:10" href="#fn:10">10</a> Although his initial work was on submarine propulsion the same jets of oxygen produced by for combustion in gas turbines could be directed through a nozzle to generate thrust.<a class="footnote-ref" id="fnref:11" href="#fn:11">11</a> The rocket Walter developed was used in the German <a href="/facts/Messerschmitt_Me_163_Komet/S7cFXmjV">ME-163</a> fighter aircraft in 1944, the first aircraft to break the 1000 km/h (635 mph).<a class="footnote-ref" id="fnref:12" href="#fn:12">12</a>  
After World War Two the British would continue to experiment with hydrogen peroxide monopropellants.<a class="footnote-ref" id="fnref:13" href="#fn:13">13</a> They would develop the <a href="/facts/De_Havilland_Sprite/0uhSqHgT">de Havilland Sprite</a> a hydrogen peroxide rocket that could produce 5000lbf of thrust over 16 seconds. Not intended for space flight the rocket would provide hot and high takeoff capability to the <a href="/facts/De_Havilland_Comet/4QKGYkFq">de Havilland Comet 1</a> the first commercial jet airliner.<a class="footnote-ref" id="fnref:14" href="#fn:14">14</a> 
In the United States, when NASA began studying monopropellants at the Jet Propulsion Laboratory (JPL) the properties of the existing propellants demanded that the thrusters be impractically large.<a class="footnote-ref" id="fnref:15" href="#fn:15">15</a> The addition of a catalyst and pre-heating propellant made them more efficient, but raised concerns over safety and handling of hazardous propellants like anhydrous <a href="/facts/Hydrazine/G7P5ITzU">hydrazine</a>.<a class="footnote-ref" id="fnref:16" href="#fn:16">16</a> However the simplicity of the thrusters designed around early monopropellants offered many simplicities and were first tested in 1959 on the <a href="/facts/Pioneer_P-3/eIe4tDJ0">Able-4</a> mission.<a class="footnote-ref" id="fnref:17" href="#fn:17">17</a> This test allowed for the <a href="/facts/Ranger_program/u9Ju9AdQ">Ranger</a> and <a href="/facts/Mariner_program/r8WmLtgy">Mariner</a> missions to use a similar thruster for correction maneuvers<a class="footnote-ref" id="fnref:18" href="#fn:18">18</a> and in the orbital insertion of <a href="/facts/Telstar/JMCJHF9w">Telstar</a>, considered by the National Air and Space Museum to be the most significant communications satellite in the beginning of the space race.<a class="footnote-ref" id="fnref:19" href="#fn:19">19</a>

In 1964, NASA began use of the <a href="/facts/Lunar_Landing_Research_Vehicle/e0b3VI3w">Lunar Landing Research Vehicle</a> to train Apollo astronauts in piloting the <a href="/facts/Apollo_Lunar_Module/XtvQS5K5">Lunar Excursion Module</a> (LEM) using an attitude control system consisting of 16 hydrogen peroxide monopropellant thrusters to steer the LEM to the lunar surface.<a class="footnote-ref" id="fnref:20" href="#fn:20">20</a>
Upper stage vehicles began using monopropellant thrusters as a convenient control device in the early 1960s when General Dynamics proposed the Centaur upper stage to the United States Airforce<a class="footnote-ref" id="fnref:21" href="#fn:21">21</a> of which versions are still in use in <a href="/facts/United_Launch_Alliance/yWev1ndb">United Launch Alliance</a>'s <a href="/facts/Atlas-Centaur/whhCjn12">Atlas</a> and <a href="/facts/Vulcan_Centaur/ItQaJHkk">Vulcan</a> rockets.<a class="footnote-ref" id="fnref:22" href="#fn:22">22</a>

<h2 id="new-developments">New developments</h2>
NASA is developing a new monopropellant propulsion system for small, cost-driven spacecraft with <a href="/facts/Delta-v/eM4TaG9d">delta-v</a> requirements in the range of 10–150 m/s. This system is based on a <a href="/facts/Hydroxylammonium_nitrate/EyIxSyFK">hydroxylammonium nitrate</a> (HAN)/water/fuel monopropellant blend which is extremely dense, environmentally benign, and promises good performance and simplicity.<a class="footnote-ref" id="fnref:23" href="#fn:23">23</a>
The EURENCO Bofors company produced LMP-103S as a 1-to-1 substitute for hydrazine by dissolving 65% <a href="/facts/Ammonium_dinitramide/WxDvmXuq">ammonium dinitramide</a>, NH4N(NO2)2, in 35% water solution of <a href="/facts/Methanol/EIfpoNCg">methanol</a> and ammonia. LMP-103S has 6% higher specific impulse and 30% higher impulse density than hydrazine monopropellant. Additionally, hydrazine is highly toxic and carcinogenic, while LMP-103S is only moderately toxic. LMP-103S is UN Class 1.4S allowing for transport on commercial aircraft, and was demonstrated on the <a href="/facts/Prisma_(satellite_project)/EQdRpFjw">Prisma</a> satellite in 2010. Special handling is not required. LMP-103S could replace hydrazine as the most commonly used monopropellant.<a class="footnote-ref" id="fnref:24" href="#fn:24">24</a><a class="footnote-ref" id="fnref:25" href="#fn:25">25</a>

<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Monopropellant/nf8KGzDj">Monopropellant</a></li>
<li><a href="/facts/Hypergolic_propellant/p0Goa3rn">Hypergolic propellant</a></li>
<li><a href="/facts/Liquid-propellant_rocket/TAonrVDn">Liquid-propellant rocket</a></li>
<li><a href="/facts/Mars_Reconnaissance_Orbiter/7odg7YfX">Mars Reconnaissance Orbiter</a></li>
<li><a href="/facts/Reaction_wheel/m3M5RKGF">Reaction wheel</a></li>
<li><a href="/facts/Nitrous_oxide_fuel_blend/sd1T9EBc">Nitrous oxide fuel blend</a></li>
<li>Rocket propulsion technologies (disambiguation)</li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="http://www.hydrogen-peroxide.us/uses.htm">Technical Reports on Hydrogen Peroxide as a Monopropellant for Rockets</a></li>
<li><a href="http://www.google.com/patents/US20090133788.pdf">USPAT 20090133788 Nitrous oxide fuel blend monopropellants</a>[dead link]</li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">United States Army: Elements of Aircraft and Missile Propulsion. Department of Defense. United States Army Material Command. July 1969. pp. 1–11. Retrieved March 1, 2024. <a href="https://app.knovel.com/web/view/khtml/show.v/rcid:kpEDHEAMPH/cid:kt008MK1A8/viewerType:khtml//root_slug:engineering-design-handbook/url_slug:liquid-monopropellant?kpromoter=federation&view=collapsed&zoom=1&page=11" target="_blank">https://app.knovel.com/web/view/khtml/show.v/rcid:kpEDHEAMPH/cid:kt008MK1A8/viewerType:khtml//root_slug:engineering-design-handbook/url_slug:liquid-monopropellant?kpromoter=federation&view=collapsed&zoom=1&page=11</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">Sutton, George; Biblarz, Oscar. Rocket Propulsion Elements (7th ed.). Wiley-Interscience. p. 259. ISBN 0-471-32642-9. <a href="0-471-32642-9" target="_blank">0-471-32642-9</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Price, T; Evans, D (February 15, 1968). The Status of Monopropellant Hydrazine Technology. TR 32-1227. Pasadena, California: National Aeronautics and Space Administration. pp. 1–2. <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Aerojet Rocketdyne (12 Jun 2003). "Aerojet Announces Licensing and Manufacture of Spontaneous Monopropellant Catalyst S-405". aerojetrocketdyne.com. Archived from the original on 5 December 2017. Retrieved 9 Jul 2015. <a href="https://web.archive.org/web/20171205194721/http://ir.aerojetrocketdyne.com/releasedetail.cfm?releaseid=708514" target="_blank">https://web.archive.org/web/20171205194721/http://ir.aerojetrocketdyne.com/releasedetail.cfm?releaseid=708514</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">Wilfried Ley; Klaus Wittmann; Willi Hallmann (2009). Handbook of Space Technology. John Wiley & Sons. p. 317. ISBN 978-0-470-74241-9. <a href="978-0-470-74241-9" target="_blank">978-0-470-74241-9</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">Zegler, Frank; Bernard Kutter (2010-09-02). "Evolving to a Depot-Based Space Transportation Architecture" (PDF). AIAA SPACE 2010 Conference & Exposition. AIAA. p. 3. Archived from the original (PDF) on 2011-10-20. Retrieved 2011-01-25. the waste hydrogen that has boiled off happens to be the best known propellant (as a monopropellant in a basic solar-thermal propulsion system) for this task. A practical depot must evolve hydrogen at a minimum rate that matches the station keeping demands. <a href="https://web.archive.org/web/20111020010301/http://www.ulalaunch.com/site/docs/publications/DepotBasedTransportationArchitecture2010.pdf" target="_blank">https://web.archive.org/web/20111020010301/http://www.ulalaunch.com/site/docs/publications/DepotBasedTransportationArchitecture2010.pdf</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">Zegler and Kutter, 2010, p. 5. <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">Sutton, George (2006). History of Liquid Propellant Rocket Engines. Reston, Virginia: American Institute of Aeronautics and Astronautics. pp. 533–534. ISBN 1563476495. <a href="1563476495" target="_blank">1563476495</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">Sutton, George (2006). History of Liquid Propellant Rocket Engines. Reston, Virginia: American Institute of Aeronautics and Astronautics. pp. 533–534. ISBN 1563476495. <a href="1563476495" target="_blank">1563476495</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">Stokes, P. R. (14 January 1998). "Hydrogen Peroxide for Power and Propulsion" (PDF). Archived from the original (PDF) on 15 February 2006. Retrieved 24 January 2024. <a href="https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf" target="_blank">https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">Stokes, P. R. (14 January 1998). "Hydrogen Peroxide for Power and Propulsion" (PDF). Archived from the original (PDF) on 15 February 2006. Retrieved 24 January 2024. <a href="https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf" target="_blank">https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
<li id="fn:12">Stokes, P. R. (14 January 1998). "Hydrogen Peroxide for Power and Propulsion" (PDF). Archived from the original (PDF) on 15 February 2006. Retrieved 24 January 2024. <a href="https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf" target="_blank">https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></li>
<li id="fn:13">Stokes, P. R. (14 January 1998). "Hydrogen Peroxide for Power and Propulsion" (PDF). Archived from the original (PDF) on 15 February 2006. Retrieved 24 January 2024. <a href="https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf" target="_blank">https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></li>
<li id="fn:14">Stokes, P. R. (14 January 1998). "Hydrogen Peroxide for Power and Propulsion" (PDF). Archived from the original (PDF) on 15 February 2006. Retrieved 24 January 2024. <a href="https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf" target="_blank">https://web.archive.org/web/20060215104117/http://www.cue-dih.co.uk/aerospace/aeropdfs/htp_for_prop.pdf</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></li>
<li id="fn:15">Price, T.W.; Evans, D. D. (February 15, 1968). "The Status of Monopropellant Hydrazine Technologies" (PDF). TR 32-1227. National Aeronautics and Space Administration. pp. 1–2. Retrieved March 21, 2024. <a href="https://ntrs.nasa.gov/api/citations/19680006875/downloads/19680006875.pdf" target="_blank">https://ntrs.nasa.gov/api/citations/19680006875/downloads/19680006875.pdf</a> <a href="#fnref:15" class="footnote-back-ref">↩</a></li>
<li id="fn:16">Price, T.W.; Evans, D. D. (February 15, 1968). "The Status of Monopropellant Hydrazine Technologies" (PDF). TR 32-1227. National Aeronautics and Space Administration. pp. 1–2. Retrieved March 21, 2024. <a href="https://ntrs.nasa.gov/api/citations/19680006875/downloads/19680006875.pdf" target="_blank">https://ntrs.nasa.gov/api/citations/19680006875/downloads/19680006875.pdf</a> <a href="#fnref:16" class="footnote-back-ref">↩</a></li>
<li id="fn:17">Price, T.W.; Evans, D. D. (February 15, 1968). "The Status of Monopropellant Hydrazine Technologies" (PDF). TR 32-1227. National Aeronautics and Space Administration. pp. 1–2. Retrieved March 21, 2024. <a href="https://ntrs.nasa.gov/api/citations/19680006875/downloads/19680006875.pdf" target="_blank">https://ntrs.nasa.gov/api/citations/19680006875/downloads/19680006875.pdf</a> <a href="#fnref:17" class="footnote-back-ref">↩</a></li>
<li id="fn:18">Price, T.W.; Evans, D. D. (February 15, 1968). "The Status of Monopropellant Hydrazine Technologies" (PDF). TR 32-1227. National Aeronautics and Space Administration. pp. 1–2. Retrieved March 21, 2024. <a href="https://ntrs.nasa.gov/api/citations/19680006875/downloads/19680006875.pdf" target="_blank">https://ntrs.nasa.gov/api/citations/19680006875/downloads/19680006875.pdf</a> <a href="#fnref:18" class="footnote-back-ref">↩</a></li>
<li id="fn:19">"Telstar". National Air and Space Museum. Retrieved March 8, 2024. <a href="https://airandspace.si.edu/collection-objects/communications-satellite-telstar/nasm_A20070113000" target="_blank">https://airandspace.si.edu/collection-objects/communications-satellite-telstar/nasm_A20070113000</a> <a href="#fnref:19" class="footnote-back-ref">↩</a></li>
<li id="fn:20">"55 Years Ago: The First Flight of the Lunar Landing Research Vehicle". National Aeronautics and Space Administration. October 30, 2019. Retrieved March 8, 2024. <a href="https://www.nasa.gov/history/55-years-ago-the-first-flight-of-the-lunar-landing-research-vehicle/" target="_blank">https://www.nasa.gov/history/55-years-ago-the-first-flight-of-the-lunar-landing-research-vehicle/</a> <a href="#fnref:20" class="footnote-back-ref">↩</a></li>
<li id="fn:21">Arrighi, Robert (December 12, 2012). "Centaur: America's Workhorse in Space". National Aeronautics and Space Administration. Retrieved April 19, 2024. <a href="https://www.nasa.gov/history/centaur-americas-workhorse-in-space/" target="_blank">https://www.nasa.gov/history/centaur-americas-workhorse-in-space/</a> <a href="#fnref:21" class="footnote-back-ref">↩</a></li>
<li id="fn:22">"Atlas V Users Guide" (PDF). United Launch Alliance. 2010. Retrieved April 19, 2024. <a href="https://www.ulalaunch.com/docs/default-source/rockets/atlasvusersguide2010a.pdf?sfvrsn=f84bb59e_2" target="_blank">https://www.ulalaunch.com/docs/default-source/rockets/atlasvusersguide2010a.pdf?sfvrsn=f84bb59e_2</a> <a href="#fnref:22" class="footnote-back-ref">↩</a></li>
<li id="fn:23">Jankovsky, Robert S. (July 1–3, 1996). HAN-Based Monopropellant Assessment for Spacecraft. 32nd Joint Propulsion Conference. Lake Buena Vista, Florida: NASA. NASA Technical Memorandum 107287; AIAA-96-2863. <a href="https://ntrs.nasa.gov/citations/19960048008" target="_blank">https://ntrs.nasa.gov/citations/19960048008</a> <a href="#fnref:23" class="footnote-back-ref">↩</a></li>
<li id="fn:24">"Green propellant LMP 103S". ecaps.se. Archived from the original on April 25, 2024. Retrieved April 25, 2024. <a href="https://www.ecaps.se/rocket-fuel-1" target="_blank">https://www.ecaps.se/rocket-fuel-1</a> <a href="#fnref:24" class="footnote-back-ref">↩</a></li>
<li id="fn:25">"High Performance Green Propulsion (LMP-103S)". ecaps.space. Archived from the original on June 7, 2023. Retrieved February 3, 2023. <a href="https://web.archive.org/web/20230607062315/https://www.ecaps.space/hpgp-performance.php" target="_blank">https://web.archive.org/web/20230607062315/https://www.ecaps.space/hpgp-performance.php</a> <a href="#fnref:25" class="footnote-back-ref">↩</a></li>
</ol>

Monopropellant rocket open-in-new

Monopropellant rocket