Nuclear Thermal Propulsion (NTP) and Power National Aeronautics and Space Administration A New Capability for Outer Planet Science and Exploration

• Imagine Cassini class missions to the outer solar system • Curiosity class rover possible on Triton • Shortened trip times • NTP enables approximately 5X the payload capability to the outer planets than SLS only or SLS with solid motor upperstage Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune • No gravity assist required • Allows orbit capture in the outer solar system

NTP for Departure to Outer Planets (S, U, N, P) with SLS 30 6000 Why NTP? Fission products produced in one week Faster 25 5000 at a LEU university research reactor = 107 Current NTP systems can 1 entire Roundtrip Mars mission using NTP Sails Unproven Technology (TRL 1–3) 20 Pluto Trip Time 4000 Demonstrated Technology (TRL 4–6) Neptune Trip Time be designed to use Low 106 Uranus Trip Time Operational Systems (TRL 7–9) Saturn Trip Time Antimatter Pluto Payload Enriched Uranium (LEU) Continuous Fusion 15 Neptune Payload 3000 5 Uranus Payload

10 (yrs) Time Trip Saturn Payload Pulsed Fusion Neptune w/Var. C3 with minimal (or no) SLS-ony cases 10 2000 (kg) Approximate Payload Ultra-high SLS w/Star 63F 4 Electro- αPlasma Pulsed Fission/Fusion 10 static impact on performance. Electro- Pulsed Fission Speci c Impulse (sec) magnetic 5 1000 Nuclear Thermal Past NTP systems used 103 Electrothermal Laser Solar Thermal Propulsion (NTP) Farther Fission Chemical Rockets 0 0 Highly Enriched Uranium 100 105 110 115 120 125 130 135 140 145 150 155 102 10-5 10-4 10-3 10-2 10-1 1 10 102 Departure C3 (km2/s2) (HEU) requiring Vehicle Acceleration or T/W Ratio (g’s) S U N P maximum security. The use of LEU reduces cost, The robustness supported by NTP’s higher performance enables NTP SLS Combination Provides New Capability programmatic exibility and increases probability of mission success. lowers the risk and should dramatically for Science at the Ice Giants and Beyond decrease the regulatory burden. How Best to Use NTP Ground Rules & Assumptions 7.5 m 20 • Direct ight to target planets Space Launch System Configurations 19 18 • NTP engine (3.5 mT engine mass, 850 sec Isp, 25,000 lbf thrust, LH propellant) 2 !"#$%& ',,*+& '(.*+& ',-*+& '()*+& • All Earth Departures take place from a C3 = –10 km2/s2 6 m 2 2 !"#$%&'()*+,'-./,01 • SLS to C3 = –10 km /s : 42.8 mt B$8<0+/">' 9"+7*'F"8+8$7 9"+7*'F"8+8$7 C+8*$ -,"70'(;"A,0+ 6@A>*+",8*$' 6@A>*+",8*$' :$,0+81'9+.*70$8% BAA0+'-,"70 BAA0+'-,"70 2.7 m • Length in 62.7ft SLS fairing for S/C: 17.8 m E+*A#>/8*$'-,"70 !"#$%&'D0&8%>0 :$,0+/,"70 :$,0+/,"70 19.1 m 2 2 -,"70'(;"A,0+ + • Falcon Heavy to C3 = –10 km /s : 15 mt 9*+0'-,"70 9*+0'-,"70 9*+0'-,"70 4.2 m • Length in 13.1m FH fairing for S/C: <13 m • NTP is dropped off after departure burn 2.7 m -*>8; -*>8; 2*%?0, 2*%?0, (;<"$%0; • Captures at outer planets are into elliptical orbits with apoapses at moons’ distances =**/,0+/ =**/,0+/ =**/,0+/ Payload Envelope 2 m 2-345'6$78$0/ • Capture is done with storable prop (Isp = 320 sec) 5 4 3 2 1 0 -1 -2 -3 -4 -5 /0/*12345*9 /0/*12345*91*68": /0/*12345*91*678$3 /0/*12345*,*678$3 !!!"#$%$"&'()%*% Con guration – SLS 1B (8.4-m fairing) • SLS + SRM comparison case done with a STAR 63F-derived motor (Isp = 295 sec)

Current NTP Project Partners On-going Work FY16 FY17 FY18 FY19 AMA, Inc. NASA Glenn Research Center System The goal of the current Feasibility Idaho National Lab Analysis NTP project is to Aerojet BWXT Rocketdyne determine the feasibility Technologies Oak Ridge and affordability of a Fuel Element National Lab Development The University of Low Enriched Uranium and Testing Alabama in Huntsville NASA Marshall Los Alamos Space Flight Center (LEU)-based NTP engine National Lab Project Lead with solid cost and NASA Stennis Space Center Exhaust Capture Dynetics schedule con dence. NASA Center Analysis and Aerojet Testing Rocketdyne Academia

Industry

Other Gov’t Agency

Other Future Possibilities “Speci c investments include development of… • Using NTP for braking at mission destination using advancements rapid transit nuclear thermal propulsion technology in Cryogenic Fluid Management utilizing low-enriched uranium that could potentially • NTP reactor providing multiple kWe electric power for entire mission provide 20 percent shorter travel time to Mars while • Other potential users showing interest substantially improving mission exibility.”

G-366385 www.nasa.gov