Icy moons

Spacecraft images of icy moons, (a) Voyager 2 image of Triton, showing complex "cantaloupe" terrain and a polar cap of nitrogen ice smooth areas near the equator may be frozen lakes. 

There is recent spectral data on the icy moons of Jupiter that is not yet understood and the spectral data base wUl continue to increase with new data... 

In the Jovian system, the namre of the putative subsurface oceans of the icy satellites, particularly Europa, needs intensive future study. Issues include the thickness of liquid layers and ice crusts, the history of communication between liquid layers and the surface, and the brine composition of the liquid. The next mission planned to address these issues is the Jupiter Icy Moons Orbiter, which is designed to orbit each of the icy satellites and explore their surfaces and subsurfaces in detail. 

In the upper atmosphere today, a small amount of O2 is produced through photolysis of water vapor. This process is the sole source of O2 to the atmospheres on the icy moons of Jupiter (Ganymede and Europa), where trace concentrations of O2 have been detected (Vidal et ai, 1997). Water vapor photolysis may also have been the source of O2 to the early Earth before the evolution of oxygenic photosynthesis. However, the oxygen formed by photolysis would have been through reactions with methane and carbon monoxide, preventing any accumulation in the atmosphere (Kasting et al., 2001). 

On Callisto, a cold, icy moon of Jupiter, lives a race of intelligent worms called infinity worms. The number of years they are permitted to live is based on mathematical formulas that they are free to select early in their lives. (The government uses this approach to prevent overpopulation.)... 

Venus shows that too much gas on the surface of a planet could doom its prospects for Earth-like conditions and the liquid flow of water. The four gas giants, from Jupiter to Neptune, are swollen spheres of hydrogen and helium. These gas giants have so much of the first two elements that they lost the chance for interesting chemistry with any of the next hundred. Gas giants are chemically simple, with few of the elements we need for simple Ufe, much less complex life. (Their icy moons are another story in a later section.)... 

This paper summarizes the work completed and future work recommendations of the Naval Reactors Prime Contractor Team (NRPCT) as part of the NASA Prometheus space reactor development project. The majority of the work undertaken was focused on a reactor system suitable to a deep space nuclear electric propulsion (NEP) system, with the Jupiter Icy Moons Orbiter (JIMO) as the first mission. 

NRPCT has been working on design of a nuclear reactor for the NASA Jupiter Icy Moons Orbiter (JIMO). 

FIGURE 24 Typical 13-cm echo spectra for the terrestrial planets are compared to echo spectra for Jupiter s icy moon Europe. The abscissa has units of half the echo bandwidth. 

In order to explain the surface structures on Europa, cryovolcanism plays an important role. A cryovolcano is an icy volcano erupting erupt volatiles such as water, ammonia or methane. Cryovolcanoes form on low temperature objects in the solar system such as on the icy moons. 

On Tethys, a striking surface feature can be seen, a tremendous rift called Ithaca Chasma (see Fig. 4.14), which is 100 kilometers and runs nearly three-fourths of the way around the icy moon (Elder et al., 2007 [116]). One theory to explain the formation of this phenomenon is that Ithaca Chasma formed as Tethys internal liquid water solidified, causing the moon to expand and cracking its surface to accommodate the extra volume within (because water ice is less dense than liquid water). 

Project Prometheus was established in 2003 and included the goal of developing the first reactor-powered spaceship and demonstrating that it can be operated safely and reliably on long duration, deep-space missions for civilian space exploration. NASA s Jet Propulsion Laboratory (JPL) had overall lead for the project. The initial application of space fission power being evaluated was for the Jupiter Icy Moons Orbiter (JIMO), a nuclear electric propulsion spaceship intended to perform deep-space scientific research. 

JPL Document 982-00098, Revision 0, Jupiter Icy Moons Orbiter Deep Space Vehicle Level 3 Key Driving Requirements", dated July 12, 2005... 

Mission Duration Jupiter Icy Moons Orbiter (JIMO) mission duration is 12 years. The mulh-mission duiation is 20 years, and applies to subsequent missions. To meet these NASA requirements, the reactor should designed to support an initial operating life of 12-15 years, with subsequent missions of inaeasing duration, up to 20 years. Based on JPL document 982-00116. revision 2, Prometheus Project JIMO Project Derived Requirements, dated July 15,2005 and JPL document 982-00115, revision 2, Prometheus Project Multi-mission Project Derived Requirements, dated July 15, 2005. 

NGST Report 04.1F102.JM.006, Task 2 Conceptual Design Summary Report, Jupiter icy Moons Orbiter (JiMO) Phase A Study, JPL Contract N. 120530" dated 8/13/04. 

Prometheus Baseline 1 - Li/Brayton Concept, Northrop Grumman Space Technologies 10- 2 Jupiter Icy Moons Orbiter (JIMO) Environmental Requirements Document - Preliminary , 982-00029, Rev. 0, July 6, 2005... 

B-SE(SPS)FMS-008, Technical Documentation in Support of Project Prometheus Plant Pre-Conceptual Design Report," November 11, 2005 10-4 Haley, V.F., Insulation forTEM Pump , General Electric Corporation, Sept. 23, 1987 10- 5 Cooke, Bill. Jupiter Icy Moons Orbiter Meteoroids/Orbital Debris and JIMO" Presentation. MSFC/UNITeS. July 27, 2004. 

Chemical Engineer s Handbook, Fifth Edition, Perry and Chilton 12-14 Bettis Letter B-SE(RE)-0001, "Fuel Type Recommendation for the Project Prometheus Space Nuclear Reactors, For Naval Reactors Approval," 7/28/2005 12-15 Los Alamos Letter LA-CP-04-0341, Jupitor Icy Moons Orbitor Reactor Module Design and Development," Rev.1, April 2004... 

Siamidis, John, Glenn Research Center report - Jupiter Icy Moons Orbiter Heat Rejection System DRAFT Sept. 22, 2004... 

The Naval Reactors program was specifically chartered to work on a deep space nuclear power system for the Jupiter Icy Moons Orbiter (JIMO) mission. The requirements for the Deep Space Vehicle (which includes the Reactor Module) included multi-mission capability for other civilian deep space exploration missions. The high level requirements of the Prometheus project also included that the nuclear power technologies developed be extensible to Moon/Mars surface exploration missions. This requirement of extensibility was implemented by NASA through Level 1 and Level 2 requirements as discussed below. 

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