A long time ago in a NASA far, far away….

Noam R. Izenberg, Ralph L. McNutt JHUAPL, Laurel, MD, USA

International Venus Conference 2016 Oxford UK 4-8 April, 2016

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Age of EMPIRE: Origins

•  1956 paper by Gaetano Crocco, 7th Int’; Astronautical Foundation Congress in Rome. Earth-Mars-Venus-Earth flyby mission to save fuel.

•  Beginning of over 2 decades of human spaceflight studies looking beyond the moon.

•  EMPIRE - Early Manned Planetary-Interplanetary Roundtrip Expeditions

•  Human space flight was assumed in an age before capable robotic craft.

Age of EMPIRE: 60’s – 70’s

•  AEC-NASA nuclear rocket program, established in 1960; Nova rocket program.

•  Explore advanced operational concepts necessary for flyby and orbiter missions.

•  Other studies leveraged Apollo instead.

Opposition vs. Conjunction class missions: Short vs. long stay

(Drake & Watts Eds DRA Appdx2 2014, & others)

(Time/Life)

Age of EMPIRE: 60’s – 70’s

Aerojet-General Coorp – Westinghouse Astronuclear Laboratory Aeronutronic Division of Ford Motor Company General Dynamics/Astronautics Lockheed Missiles and Space Co. Belcomm Inc. Univelt Inc.

Opposition vs. Conjunction class missions: Short vs. long stay

(Drake & Watts Eds DRA Appdx2 2014, & others)

(Time/Life)

Age of EMPIRE: 60’s – 70’s Planetary JAG Phase 1, 1966 •  ‘Feasible’ Piloted Mars/Venus Flybys (1975-80)

–  Piloted Mars flyby leave Earth-orbit in Sept 1975. –  Mars flyby launch opportunities in Oct 1977 and Nov 1979. –  Multiple flyby missions were possible

•  Venus/Mars mission Dec 1978, •  Venus/Mars/ Venus mission Feb1977. •  Dispense automated probes based on Mariner and Voyager

technology.

•  Piloted Mars Landing and piloted Venus Capture (orbiter) missions (post-1980) would see introduction of AEC-NASA nuclear-thermal rockets.

•  EMPIRE study mandate assumed nuclear propulsion was coming, and Planetary JAG deemed nuclear propulsion “essential for a flexible Mars landing program” capable of reaching Mars in any launch opportunity regardless of the energy required.

Age of EMPIRE: 60’s – 70’s •  Piloted Venus Flybys •  Triple Planet Flybys (with abort option) •  Multiple planet flybys to Venus and Mars.

•  Piloted Venus Orbting Mission (1967) •  Buoyant Venus station (1972-1973 launch)

(1969)

•  Nuclear rocket programs did not survive the 60’s –  Final NERVA cancellation 1972)

Fallen EMPIRE: 80’s – 90’s

•  Nuclear rocket programs long gone. •  End of Apollo was also the end of

Apollo derivative human spaceflight. •  Focus of Planetary missions on

increasingly capable robotic craft. •  Refocus of human spaceflight to LEO,

Shuttle, ISS –  Interplanetary Mission Design Handbook

(George & Kos 1998): No DRM opportunities that includs Venus.

•  Reduction, loss of US human rated heavy lift.

Ashes of EMPIRE: 21st Century •  Human spaceflight targets: Mars, Moon,

Asteroids…Venus? –  Venus competitive with MB Asteroids (Landis,

2003) •  Human spaceflight focus on pathway to Mars •  Heavy planetary payloads as part of revived

heavy lift capability (SLS) •  Venus scenarios remain in Design Reference

Architecture (DRA, 2009, through latest addendum (#2) 2014) –  But not focused upon –  Opportunity unexplored / unexploited

Ashes of EMPIRE: 21st Century

(Drake & Watts Eds, DRA Appdx2 2014)

Ashes of EMPIRE: 21st Century

•  Opposition flight opportunities where both Total ΔV and Total Mission Duration are low.

•  From near “double flyby” to Mars Mission Durations up to 100 days.

•  Multiple arguments for Piloted Venus flybys

Venus to Mars: Mars via Venus

•  Venus as possible essential waypoint to human Mars exploration.

•  Mars via Venus – Reducing ΔV cost – Shortest total mission duration for Mars

stay and reasonable ΔV •  Possibly crucial for early exploratory missions

– Variety of Opposition Class missions to Mars

Venus to Mars: Venus flyby Precursor

•  Mission opportunity cadence – Venus: 19 mo / <8

years – Mars: 26 mo / 15-18

years

•  Mission Time: Missions ~ 1 year.

•  Delta V Lower still Earth-Venus-Earth (EVE) mission (Crain et al., 2000)

Venus to Mars: Human Factors

•  Time: Shorter duration vs crew stress •  Power: plentiful. EVE more easily/

conventionally powered for long mission

•  Thermal protection •  Radiation exposure

Radiation Hazards

Crain et al., 2001

Mission radius vs Mission day (2006 and 2010 model missions)

Mission radiation vs Mission day

•  Radiation Limits EVE vs EME –  30 day max doses less for

EVE –  Total doses comparable

for both •  Solar Cycle and Solar

distance: – More active sun reduces

Cosmic Ray risk, greater reduction closer to sun

Radiation Hazards

Energy spectra of nucleons and electrons in interplanetary space near Earth orbit. Flares also shown. Miroshnischenko, 2003, Lin, 1980

•  Increased CME/SPE risk – more mitigate-

able than CR – Mitigation (e.g.

‘storm cellars’) Necessary for all interplanetary targets regardless (French, 1967)

The Case for, and Opportunity of Venus

•  Multiple arguments for human spaceflight to include Venus as flyby destination alone and/or on way to Mars.

•  Significant opportunity for Venus planetary community (science)

•  Significant opportunity for diverse NASA communities (e.g. HEOMD, SMD)to advocate for common goal.

A New EMPIRE •  Large Probes Enabled by SLS carrying

capacity –  Power, Data volume, Capability –  SLS leverage-able without piloted flyby.

•  Real-Time Telemetry –  No light speed delay –  Tele-operated probes –  Human decision making in the loop

•  Guided aerial and landers (flight/descent control) •  Optimized sampling

•  Sample Return (Upper atmosphere) •  Beyond (HAVOC)

…Or the rise of VAMPIRE •  Bringing a version of EMPIRE back from the

dead as Venus And Mars Piloted Interplanetary Roundtrip Expeditions

•  Requires revival of certain ambitions and ways of thinking, with application of current tech

•  Requires new generation to be aware of the work that has been done before

•  Requires advocates in Path to Mars and planetary community.

“Humans to Mars Via Venus” is logical, smart, and should be the path we take. And with that comes unprecedented opportunity for Venus science.

References 1 •  Crocco, Gaetano A. “One-Year Exploration-Trip Earth-Mars-Venus-Earth,”

Rendiconti del VII Congresso Internanzionale Astronautico, Associazione Italiana Razzi, 1956, presented at the Seventh Congress of the International Astronautical Federation, Rome, Italy, 1956, pp. 227-52.

•  Harry Ruppe, Manned Planetary Reconnaissance Mission Study: Venus/Mars Flyby (Huntsville, AL: NASA/TM X-53205, 1965).

•  Gillespie, R.W., and Ross, S. "Venus-swingby mission mode and its role in the manned exploration of Mars." Journal of Spacecraft and Rockets 4, no. 2 (1967): 170-175.

•  Feldman, M. S. et al. "Manned Venus Flyby." Belcomm, Inc., TR-67-600-1-1, Performed for NASA Manned Space Flight Center under Contract NASw-417 (1967).

•  Gray, Edward, and Franklin Dixon. “Manned Expeditions to Mars and Venus,” Eric Burgess, editor, Voyage to the Planets. San Diego: Univelt, Inc., 1967, pp. 107-35.

•  Spacecraft Engineering Branch, Apollo-based Venus/Mars Flybys (Houston: NASA MSC, September 1967).

•  Contracting Officer to Prospective Contractors, “Planetary Surface Sample Return Probe Study for Manned Mars/Venus Reconnaissance/Retrieval Missions,” Request for Proposal No. BG721-28-7-528P, 3 August 1967.

•  Ordway, F. I. III et al. “EMPIRE: Early Manned Planetary-Interplanetary Roundtrip Expeditions Part I: Aeronutronic and General Dynamics Studies.” J. Brit. Interplanet. Soc. 46 (1993): 179-190

•  Ordway, F. I. III et al. “EMPIRE: Early Manned Planetary-Interplanetary Roundtrip Expeditions Part II: Lockheed Missiles and Space Studies.” J. Brit. Interplanet. Soc. 47 (1994): 181-190

References 2 •  Dewar, J. A. “Atomic Energy: The Rosetta Stone of Space Flight.” J. Brit. Interplanet.

Soc. 47 (1994): 199-206 •  George, L.E. and Kos, L. D. “Interplanetary Mission Design Handbook: •  Earth-to-Mars Mission Opportunities and Mars-to-Earth Return Opportunities 2009–

2024.” NASA TM-1998-208533 (1998), 162 pp. •  Crain, T. et al. "Interplanetary flyby mission optimization using a hybrid global-local

search method." Journal of Spacecraft and Rockets 37, no. 4 (2000): 468-474. •  Crain, T. et al. "Radiation Exposure Comparison of Venus and Mars Flyby

Trajectories." Journal of Spacecraft and Rockets 38, no. 2 (2001): 289-291. •  Landis, G.A. "Colonization of Venus." Expanding the Frontiers of Space 654 (2003):

1193-1198. •  Portree D.S.F. Humans to Mars, Fifty Years of Mission Planning, 1950-2000, NASA

SP-2001-4521, 2001, 151 pp. •  McNutt R.L. et al. “Propulsion for Manned Mars Missions: Roundtable 3” 10-IWCP •  Lafleur, J.M., and Saleh, J.H. "Survey of intra-and inter-mission flexibility in space

exploration systems." Acta Astronautica 67, no. 1 (2010): 97-107. •  Foster, C. and Daniels, M. “Mission Opportunities for Human Exploration of Nearby

Planetary Bodies.” AIAA Space 2010 Conf. & Expo. 30-Aug-2-Sept, 2010. AIAA 2010-8609.

•  Design Reference Architecture (DRA) for Mars: –  DRA Mars 5.0: Drake B.G., Ed. “Human Exploration of Mars Design Reference Architecture

5.0.” NASA/SP-2009-566 2009, 100 pp. •  Summary paper – same title IEEEAC paper #1205 does not mention Venus.

–  DRA Addendum #1, Drake B.G., Ed., NASA/SP-2009-566-ADD, 2009, 406 pp. –  DRA Addendum #2, Drake B.G. and Watts, K.D., Eds., NASA/SP-2009-566-ADD, 2014, 598 pp.