Thirty Years of Outer Solar System Exploration Planning and Execution True Cost in Technology Projected Cost in Millions Millions $ - True Cost Base Drivers FY75$ Development Year for Fixed $ Only New Frontiers Space Science Space Science Resolution NASA Space System Solar System SSES Disposition Remarks Required to in the Solar Science "Vision Project Number Name (1975) Exploration Division Recommendations Enterprise Enterprise Implemented Type Transportation Illustrative Implemented Implemented ers Total Total Notes (September System RTG Core Strategic Plan Strategic Plan Mission Flight Dates Launch Vehicle Launch Total (October 2001) Enable Mission" Prometheus Return (1975) Lander Strategic Plan (1991) (1994) Sample Program Requires Requires (1997) (2000) 2003) ("Decadal and Core 1991-2000 1986-1990 1981-1985 Advanced 1976-1980 Propulsion Penetromet (October 2001) Survey") Studies 1081 Jupiter Galileo in transit to <COMPLETED> Galileo Probe Strategic Titan IIIE/Centaur 1980 Shuttle / PAM D 1989 100 55 50 205 Galileo Probe Atmospheric Jupiter; Measure- w/Galileo Orbiter completed; impact Probes Jupiter Jupiter Probe Galileo (approve 1082 Saturn Saturn Probe - Shuttle/IIUS 1984 150 20 5 175 Saturn Atmospheric Discovery 2 candidate Atmospheric complement Cassini Probes Probes robe - Saturn Flyby/P 1083 Titan Orbiter Titan Organic Titan Explorer Shuttle/Tug 1991 200 100 300 Titan Explorer - Nuclear Thermal Planning requires Titan Explorer - Study w/Penetrometer Explorer post-2005 post-2007 Huygens followon Rocket and/or successful completion Case 16 aerocapture of Huygens mission 1 and advanced propulsion and/or aerocapture 1084 Uranus Uranus Orbiter/Probe - Shuttle/Tug 1984 200 35 235 Uranus Atmospheric Nuclear Thermal "Reasonable" (<~15 Atmospheric candidate for FY99- Probe Rocket and/or yr) flight times require Probe 1 FY03 aerocapture Jupiter flyby obe - Uranus Flyby/Pr 1091 Jupiter Orbiters, Galileo in transit to Galileo in Galileo Europa Galileo Strategic Shuttle/US or Titan 1985 Shuttle / PAM D 1989 135 45 180 1401 1992 Galileo Europa spinning/3-axis Jupiter operation in Jupiter Mission (Galileo III/Centaur Mission (Galileo orbit Extended Mission) Extended Mission) - Orbiter Galileo (approve completed Jupiter Grand Tour - Measure- Jupiter Jupiter Polar INSIDE Jupiter - Discovery INSIDE Jupiter - Solar System Medium Jupiter Icy Moons candidate for FY99- Orbiter post-2007 Phase II Phase II Discovery 3. Jupiter Polar Orbiter Orbiter (JIMO) FY03 Discovery competition - not with Probes competition selected Europa Orbiter - Europa Orbiter Europa Orbiter - Payload competition Solar System Large 1. derived from cancelled awaiting selection; Europa Geophysical Galileo price estimate over Orbiter magnetometry $1B results Europa Lander - Europa Lander Europa Lander Nuclear Thermal follow Europa Rocket needed; Orbiter post-2005 extreme radiation environment; RTG Europa Europa Subsurface needed for power; subsurface Explorer specialized, major Explorer post- ATD needed 2007; follow Europa Lander Io Volcanic Io Orbiter Observer - derived ? from Galileo and ?????? Measure-Jupiter 1092 Titan Lander Huygens in Huygensconcept in transit Huygens in transit Huygens/ESA Strategic Shuttle/Tug 2000 Titan IV 1997 700 700 ESA Huygens in transit with development with Cassini with Cassini SRMU/Centaur Cassini 1 adar w/Cassini Titan Probe/R 1093 Uranus Orbiter Shuttle/Tug 1995 350 350 Uranus Orbiter Nuclear Thermal Decreased interest Rocket and/or following Voyager 2 aerocapture flyby of Neptune and Triton; 98 deg 1 inclination restricts equatorial plane capture to equinox arrivals 1096 Saturn Orbiter Cassini Orbiter in Cassini in transit Cassini in transit Cassini Strategic Shuttle/Tug 1986 Titan IV 1997 200 100 300 1457 1992 Cassini in transit with Solar System Small 2. development with Huygens with Huygens SRMU/Centaur Huygens Cassini Extended w/Huygens Saturn Orbiter - Supplement mission Saturn Ring Saturn Ring Observer Nuclear Thermal Multiple maneuvering Observer post- Rocket and/or Nuclear capabilities seen as 2007 Electric Propulsio0n driver for NEP development 1097 Neptune Orbiter Pluto Flyby/Neptune Neptune Orbiter Shuttle/Tug/SEP 2000 450 450 Neptune Orbiter Nuclear Thermal "Reasonable" (<~15 Neptune Orbiter with Orbiter - recommended post-2007 Rocket and/or yr) flight times require Probes - Study Case for 1996 aerocapture Jupiter flyby; capture 17 requires nuclear stage 1 or aerocapture ballute in unknown environment Pluto Fast Flyby Pluto/Kuiper Pluto-Kuiper Pluto Kuiper Belt Discovery II New Horizons now in Solar System Express Express competition prototype development Medium 1. Kuiper- Belt Pluto Explorer; New Horizons selected for flight 1107 Jupiter-Saturn <COMPLETED> Voyager 1 and Strategic Titan IIIE/Centaur x 2 1977 Titan 1977 350 350 776 1992 Voyager planetary Flyby Voyager 2 IIIE/Centaur x 2 encounters completed r 1 and 2 flybys Voyage 1108 Uranus Flyby <COMPLETED> Voyager 2 Strategic Titan IIIE/Centaur 1979 Titan IIIE / 1977 165 15 180 Centaur Voyager 2 flyby completed 1109 Neptune Flyby Voyager 2 flyby <COMPLETED> Voyager 2 Strategic Titan IIIE/Centaur 1992 Titan IIIE / 1977 50 175 225 completed Centaur Genesis in transit Genesis Discovery Delta II 2001 Genesis Cost Genesis in transit Total Cost in 615 755 500 1780 3650 Millions of FY75$ Mission in Possible Discovery 11 February 2005 Mission OPAG Meeting #1 Bethesda, MD Required technology 1 development or Possible Discovery candidate with larger completed or in launched but not not currently mission candidate mission lifecycle completion phase available Sample landing yet at target cost cap handling, capability propulsion associated Radioactive acquisition, power supply Automomous Non-chemical Colors denote Penetration of regolith, sample manipulation, in technologies are ??????? Denotes questionable as enabling versus enhancing Science Goals Help Drive NASA Exploration Space Exploration has historically been aligned with an outward …with the idea look …. that humans would follow 11 February 2005 OPAG Meeting #1 Bethesda, MD 2 How Good Is Our Crystal Ball For Space Technology? Large-scale projects were predicted in the late 1940s and early 1950s Space stations were staging grounds for multiple-vehicle voyages to the Moon and Mars BUT … Reality lay in small instrumented probes - and then in the “Moon race” Following Apollo, the Shuttle held promise for “easy access to space.” Fiscal realities and the end of the cold war have led to slower gains 11 February 2005 OPAG Meeting #1 Bethesda, MD 3 Future Predictions Can be Misleading… [Cartoon from 1907] IN 1950. “Why, there’s an automobile! How funny it looks!” “Yes.11 February That’s 2005old fossil JonesOPAG - Meetingsays he #1 can Bethesda,’t stand MD these newfangled notions.4 ” …Or Fullfilling But not as easily as we had thought 11 February 2005 OPAG Meeting #1 Bethesda, MD 5 The Devil is ALWAYS in the Details Say, I think I see where we went off. Isn’t eight times seven fifty-six? 11 February 2005 OPAG Meeting #1 Bethesda, MD 6 For Any Mission There Are Four Key Elements • Science the case for going • Technology the means to go • Strategy all agree to go • Programmatics money in place A well-thought-out systems approach incorporating all key elements is required to promote and accomplish a successful exploration plan 11 February 2005 OPAG Meeting #1 Bethesda, MD 7 The Robotic Probe Vision (or “Do we need Astronauts?”) Launch a probe to a target Probe returns knowledge - not data BUT without return of all data, how is the knowledge to be validated? Return of all data requires large bandwidth Drives receiver and transmitter sizes and transmitter power “Compression” leaves doubts of data fidelity Luna 24 Data return drives power and, hence, mass Mass drives propulsion …Did we REALLY think EVERYTHING Apollo 17 through ahead of time, though? 11 February 2005 OPAG Meeting #1 Bethesda, MD 8 The Technology Element • Propulsion Systems • Power Systems • Communications Systems • Spacecraft Architecture • Instrumentation – mass – power – data downlink 11 February 2005 OPAG Meeting #1 Bethesda, MD 9 Propulsion Issues for Robotic Missions Equatorial Object escape speed (km/s) Earth 11.18 Venus 10.36 Mars 5.02 Mercury 4.25 Moon 2.38 • Going to the outer solar system and into orbit • Landing on any solid planet (Mercury through Pluto + minor bodies) - high thrust required • Sample returns to Earth - high thrust required 11 February 2005 OPAG Meeting #1 Bethesda, MD 10 High Thrust Requires Thermal Rockets For a chemical biprop system Isp ~ 320s --> vexhaust = 3.1 km/s For a cryogenic biprop Isp ~ 420s --> vexhaust = 4.1 km/s For a nuclear thermal system Isp ~ 900s --> vexhaust = 8.8 km/s LH2 storage is an issue LOX and hydrazine is a possibility Integrated systems studies are required All targets are also effectively vacuum environments - notable exception of Titan What works for the Moon can work for all cases - most stressing is Ganymede of 2.74 km/s (versus 2.38 km/s for the Moon) 11 February 2005 OPAG Meeting #1 Bethesda, MD 11 Propulsion Systems Status Chemical propulsion remains the primary propulsive means and is the only current high- thrust option Large ΔV at low thrust in the inner solar system now seen as “enabling” for multiple advanced exploration missions BUT… Solar Electric Propulsion tested (DS-1) but currently limited by specific mass (~65 kg/kW) of power plant Nuclear Electric Propulsion has similar limitations and requires extensive (reactor) development (min. size?) Aerocapture - braking into planetary orbits -