Manned Space Goals: Science and AdventureTO MARS VIA ITS MOON DEIMOS

NASA-JSC Gilruth Center Clear Lake, TX June 21, 2012

S. Fred Singer, PhD Professor Emeritus, University of Virginia

President, Science & Environmental Policy ProjectFormer director of US Weather Satellite Service

Arlington, Virginia<singer@sepp.org>

 

Fundamental Science Goals• How do planets develop? Comparative Planetology• What happened to Mars oceans?• What happened to Mars magnetic field?• Mars volcanism and mountain building

• Climate history• Was Mars wet and warm?• Climate change as spin axis moved• Do climate cycles exist as on Earth?• Can models explain climate changes? • Origin of Life• Existence of fossil life forms?• Existence of hidden life –– beneath surface or near ice caps?• Biochemistry and morphology --- similar to terrestrial life forms?

Manned Mission to the Moons of Mars (MMMM)

• Phobos and Deimos -- discovered in Washington, DC in 1870in near-circular equatorial orbits -- at 2.8 and 7.2 Martian radii.

• Rocks about size of Manhattan

• Mystery of Origin• Captured asteroids? Co-formation?• Phobos orbit shrinking• Deimos in near-synchronous orbit

• Deimos is an ideal base• low gravity and escape velocity• shelter from environmental hazards

National space program needs a single overarching goal

• Manned exploration, with unique scientific content -- -- not a publicity stunt

• • First step: Ph-D Project, with a base on Deimos• • Faster: 10 - 15 years -- right time-frame

• Better: than a series of unmanned probesthan a base on Mars surface

• Cheaper: than either alternative within current NASA budget

FASTER………………………..

• Orbit transfer from Earth orbit to Mars orbit • Deimos provides shielding and shelter against meteor

streams, cosmic rays, solar flares

• Builds on ISS experience

• Uses ongoing NASA developments

• No showstoppers • Project attainable in 10-15 years

BETTER…………………

• Unmanned rovers controlled in real time – no delay • Tele-robots return data/samples to Deimos

• Immediate evaluation permits sequential exploration• --- with results in hours instead of years

• Complete scientific laboratory setup• --- natural vacuum – for instruments • Sortie to Phobos for sample collection • **Manned sortie to Mars surface --- for follow-up science?• **et up prototype automatic propellant factory?

CHEAPER……………………….

• Assemble gradually in Earth orbit ---30 tons, mostly propellants • Pre-position “Slow Freight “ on Deimos ---Investigate cheapest route – via L-1? • Test Manned Habitat and crew in LEO; • We need further life-support studies in ISS

• When ready, send by fastest route --- propulsion vs. transit time trade-offs• Minimizing transit time vs. additional del-vee • Desirable technology developments ---(now in pipeline)• ---Heavy-lift vehicle (“Space Truck”)• ---Nuclear reactor electric power supply (“Prometheus”)

• Cost Estimate: $30 billion over 15 years ---within present NASA budget

PhD Mission (Manned-Robotic) vs   a Manned Planetary Base

• Ph-D incurs no delta-vee penalty (2 x 2.38 km/sec _Moon) (2 x 5.0 km/sec_Mars)

• Hence: Less Need for Propellants (and for their transport)• No Need for High-Thrust Engine -- since del-vee = thrust x time• No Landings—only Orbit Maneuvers. • Use existing engine (smaller, less weight, better mass ratio)• *******************************************************• Problems with Mars Base:• Safety issues: Landing and take-off; Difficult Mars sfc terrain• Envir hazards: Dust storms; Solar flares ; GCR; Asteroid impacts• Biological Contamination • Limited Mobility, Control problems for Rovers,• No vacuum for instruments

Futuristic follow-ons:

• Mars base:• Habitation & colonization• Propellant production• Detailed exploration & experiments• Terraforming & agriculture******************************** • Phobos / Deimos are cheapest sources for materials for space construction

-- compared to Moon or asteroids********************************

Origin of Martian Moons• Captured asteroids -- 1968• Co-formation with Mars – 1971• New hypothesis: Capture of large Mars-Moon (M-M), now

disappeared -- with Ph and D as remnants

• Tidal energy dissipated within Mars’ interior following capture is quite sufficient to cause melting and core formation

• Differential tidal effects on the core and mantle create and maintain a temporary magnetic field and magnetosphere. As a result, oceans and an atmosphere may be maintained long enough against exospheric escape and the eroding effects of the solar wind to permit the evolution of life forms on Mars.

Observational tests of hypothesis• Existence of tiny moonlets in circular, equatorial orbits between Phobos and

Deimos

• Dust clouds around Mars

• Evidence for ancient impacts in Mars’ equatorial zone

• Ph &D: Close relationships (composition, petrology, cosmic-ray ages, impact histories)-------------------------------------------------------------------------------------------

• Date of formation of Mars core (Hf-W dating)

• Decay of magnetic field, followed by evaporation of surface oceans

• Discovery of paleo-life or krypto-life

Martian meteorites• There is little doubt that certain classes of meteorites, called the 

SNC group (Shergottites, Nakhlites, Chassignites) originated on the surface of Mars [1].  They were ejected by some kind of impact with sufficient velocity to leave the gravitational field of Mars and then enter a transfer trajectory to Earth.  The necessary ejection velocity from the surface would have to be on the order of [(5.0)^2 + (24.14/1.52)^2]^0.5 or 16.6 km/sec. 

 • The puzzle has always been (at least for me) how they could survive 

the required acceleration of ejection, on the order of 1660 km/sec^2 (with an assumed ejection time of 0.01 sec) which involved forces that approach the “crushing strength” of the rocks, assumed as 10 tons per square inch (granite).  How could they remain whole in spite of being subject to such forces?  What is needed is an extended period of lower acceleration, more like a rocket rather than a gun.

Linear accelerator on Mars?

• http://www.esa.int/SPECIALS/Mars_Express/SEMTK5VTLKG_0.html

Orcus Patera on Mars