+-----------------------------+----------------------------------------+
| ### PP \# 1 Energy Slate    | \[Technical Director makes connection. |
|                             | Host gathers data.\]                   |
+-----------------------------+----------------------------------------+
| 2:00                        | **Intro**                              |
|                             |                                        |
| **Energy Open**             |                                        |
|                             |                                        |
| **TBF**                     |                                        |
+-----------------------------+----------------------------------------+
| 4:00                        | **WELCOME**                            |
|                             |                                        |
| **PRESENTER ON CAMERA**     | Welcome to NASA's Digital Learning     |
|                             | Network. My name is                    |
| CG: Host Name               | {[Name}]{.underline} and I will be     |
|                             | your Host today.                       |
| **BX2BK3-01**               |                                        |
|                             | -   We are located at the Johnson      |
| **Building 9 Tour**         |     Space Center in Houston, Texas. We |
|                             |     are one of ten NASA Centers across |
|                             |     the United States.                 |
|                             |                                        |
|                             | ```{=html}                             |
|                             | <!-- -->                               |
|                             | ```                                    |
|                             | -   For first time connection to JSC   |
|                             |     continue with We are:              |
|                             |                                        |
|                             | 1.  Home of the Astronaut Corps        |
|                             |                                        |
|                             | 2.  Home of the Space Shuttle Program  |
|                             |                                        |
|                             | > Highlight Shuttle size and use       |
|                             |                                        |
|                             | 3.  Home of the International Space    |
|                             |     Station                            |
|                             |                                        |
|                             | > Highlight modules and international  |
|                             | > participants                         |
+-----------------------------+----------------------------------------+
| :30                         | > **ENERGY OVERVIEW**                  |
|                             | >                                      |
| **PRESENTER ON CAMERA**     | > **What are the different sources of  |
|                             | > energy that we use on** **earth?**   |
| #                           |                                        |
|                             | **What is our primary source of Solar  |
| #                           | Energy?**                              |
|                             |                                        |
| #                           | -   SUN                                |
|                             |                                        |
| #                           | -   Energy is the strength or power to |
|                             |     work or be active; force; vigor;   |
| #                           |     the power of certain forces of     |
|                             |     nature to do work                  |
| #                           |                                        |
|                             | **Do humans need solar energy and      |
| #                           | why?**                                 |
|                             |                                        |
| PP #2 Sun                   | -   Sun helps to regulate our climate  |
|                             |     and weather                        |
|                             |                                        |
|                             | -   The food we eat exists because of  |
|                             |     sunlight falling on green plants,  |
|                             |     and the fuel we burn comes either  |
|                             |     from such plants, or was           |
|                             |     accumulated by them (in the forms  |
|                             |     of coal, oil and natural gas) long |
|                             |     ago.                               |
|                             |                                        |
|                             | -   The Earth would not be fit for     |
|                             |     life. Life as we know it needs     |
|                             |     liquid water, and Earth is the     |
|                             |     only planet to have it: without    |
|                             |     the Sun, Earth would be an icy     |
|                             |     rock in space.                     |
+-----------------------------+----------------------------------------+
| **PRESENTER ON CAMERA**     | **HISTORY**                            |
|                             |                                        |
| PP #3 Ancient Civilizations | **Do you think the energy from the sun |
|                             | was important to ancient               |
| PP #4 Newton                | civilizations? Where do we find the    |
|                             | first traces of Sun used in history?** |
| PP \# 5 Huygens             |                                        |
|                             | -   **Ancient Civilizations**          |
| PP \# 6 Two Groups          |                                        |
|                             |     -   The sun was the integral part  |
| PP \# 7 Einstein            |         in many ancient civilizations  |
|                             |                                        |
|                             |         -   Egyptians portrayed the    |
|                             |             god Horus as a winged sun  |
|                             |                                        |
|                             |         -   Grecians believed the god  |
|                             |             Helios drove a fiery       |
|                             |             chariot across the sky     |
|                             |                                        |
|                             |         -   Chinese thought that a     |
|                             |             solar eclipse was caused   |
|                             |             by a dog taking a bite out |
|                             |             the sun                    |
|                             |                                        |
|                             |         -   The Aztec Calendar charted |
|                             |             365 days, based on the     |
|                             |             Earth's revolution around  |
|                             |             the sun.                   |
|                             |                                        |
|                             | -   **Scientific Revolution (1600s)**  |
|                             |                                        |
|                             |     -   Light and its characteristics  |
|                             |         was a much debated topic       |
|                             |         during the Scientific          |
|                             |         Revolution                     |
|                             |                                        |
|                             |     -   There were 2 groups of         |
|                             |         thinking:                      |
|                             |                                        |
|                             |         -   Particles: Sir Isaac       |
|                             |             Newton and light through a |
|                             |             prism                      |
|                             |                                        |
|                             |         -   Waves: Christiaan Huygens  |
|                             |             and *Treatise on Light     |
|                             |             (1690)*                    |
|                             |                                        |
|                             | -   **19^th^ and 20^th^ C.             |
|                             |     Discoveries**                      |
|                             |                                        |
|                             |     -   This debate continued through  |
|                             |         the centuries.                 |
|                             |                                        |
|                             |     -   Major discoveries in the       |
|                             |         19^th^ and 20^th^ centuries    |
|                             |         finally solved the problem     |
|                             |                                        |
|                             |         -   Bohr's Atomic Theory       |
|                             |             proposed that matter       |
|                             |             traveled in waves          |
|                             |                                        |
|                             |         -   Hertz and other scientists |
|                             |             established the            |
|                             |             Photoelectric Effect,      |
|                             |             where light followed       |
|                             |             particle-like              |
|                             |             characteristics            |
|                             |                                        |
|                             |         -   Albert Einstein's studies, |
|                             |             among others, further      |
|                             |             proved Wave-Particle       |
|                             |             Duality, but it was not    |
|                             |             finalized until he helped  |
|                             |             develop Quantum Mechanics, |
|                             |             which explained that all   |
|                             |             matter can have wave and   |
|                             |             particle properties.       |
|                             |                                        |
|                             |         -   SO ... Newton and Huygens  |
|                             |             were right!                |
+-----------------------------+----------------------------------------+
| **Use only with (K-4) if    | **K-4 Reinventing the** **Wheel**      |
| appropriate**               |                                        |
|                             | **Flywheel**                           |
|                             |                                        |
|                             | **Distinguish between potential and    |
|                             | kinetic energy**                       |
|                             |                                        |
|                             | **Can you identify which of these      |
|                             | images uses kinetic energy or          |
|                             | potential energy?**                    |
+-----------------------------+----------------------------------------+
| **PRESENTER ON CAMERA**     | **UNDERSTANDING ENERGY**               |
|                             |                                        |
|                             | Two types: Kinetic and Potential       |
|                             |                                        |
|                             | **[Kinetic]{.underline}** -- energy of |
|                             | motion (always positive)               |
|                             |                                        |
|                             | **K = 1/2 m V^2\ ^** (1/2              |
|                             | mass)(velocity)squared                 |
|                             |                                        |
|                             | **[Potential]{.underline}** -- energy  |
|                             | available, but not currently used, due |
|                             | to gravity (always negative); other    |
|                             | forms of potential energy include      |
|                             | elastic, electric and chemical         |
|                             |                                        |
|                             | **U = -G m M / d** (gravity)(mass      |
|                             | object 1)(mass object 2)/ distance     |
+-----------------------------+----------------------------------------+

+-----------------------------+----------------------------------------+
| **Use only with (5-8) if    | **5-8 Beaming Down Energy Activity**   |
| appropriate**               | **Results**                            |
|                             |                                        |
|                             | **Angles**                             |
|                             |                                        |
|                             | **Electricity**                        |
+-----------------------------+----------------------------------------+
| **PRESENTER ON CAMERA**     | **SOLAR ENERGY AND LIGHT SPECTRUM**    |
|                             |                                        |
| # **Demonstration??**       | -   Solar energy is usable power       |
|                             |     derived from the Sun               |
| PP #8 Light Spectrum        |                                        |
|                             | > Light Spectrum - a band of color     |
|                             | > formed when a beam of white light is |
|                             | > spread (as by passage through a      |
|                             | > prism) so that its different         |
|                             | > wavelengths are arranged in order    |
|                             |                                        |
|                             | -   The light we see with our eyes     |
|                             |     only represents a small portion of |
|                             |     the electromagnetic spectrum.      |
|                             |                                        |
|                             | -   Herschel proved the existence of   |
|                             |     infrared light and measured the    |
|                             |     amount of heat in each color. It   |
|                             |     increased as you moved from blue   |
|                             |     to red and even higher where there |
|                             |     was no visible light.              |
|                             |                                        |
|                             | > **What is the electromagnetic        |
|                             | > spectrum?**                          |
|                             |                                        |
|                             | -   Astronomers use light to learn     |
|                             |     about properties of celestial      |
|                             |     objects in space that are too far  |
|                             |     away to visit. Helps us to learn   |
|                             |     about temperatures, composition,   |
|                             |     density, and motion.               |
|                             |                                        |
|                             | -   Our atmosphere blocks X-rays,      |
|                             |     gamma, and most ultraviolet rays   |
|                             |     and infrared. By placing           |
|                             |     telescopes in space we get clearer |
|                             |     pictures.                          |
|                             |                                        |
|                             | > How can we convert light to          |
|                             | > electricity?                         |
|                             | >                                      |
|                             | > **Photovoltaic -** capable of        |
|                             | > producing a voltage when exposed to  |
|                             | > radiant energy, especially light     |
+-----------------------------+----------------------------------------+
| PP# 9 House\                | **How is solar energy used here on     |
| PP# 10 Pumping Stations     | Earth?**                               |
|                             |                                        |
| **VIDEO:** **Final Truss    | Power homes, cars, buildings, etc.     |
| Segment**                   |                                        |
|                             | Movement towards renewable energy uses |
|                             |                                        |
|                             | **Why would solar energy be important  |
|                             | for NASA?**                            |
|                             |                                        |
|                             | > In space we must use the sun for     |
|                             | > energy, however as we continue       |
|                             | > further into our solar system, we    |
|                             | > need to look at alternate ways since |
|                             | > fuel is an expensive payload         |
|                             |                                        |
|                             | -   Power rovers on Mars               |
|                             |                                        |
|                             | -   Alternate energy sources such as   |
|                             |     New Horizons                       |
|                             |                                        |
|                             | -   Longer stays -- humans need energy |
|                             |     to survive                         |
+-----------------------------+----------------------------------------+
| 35:00                       | **NASA ENERGY ABOARD ISS**             |
|                             |                                        |
| #                           | **What is a solar cell?**              |
|                             |                                        |
| **PROP: SOLAR CELL**        | -   Each cell is .013 in thick; 3.2 in |
|                             |     x 3.2 in. made from purified       |
| PP #11 Diagram of solar     |     crystal ingots of silicon that     |
| cell                        |     converts light (photons) to        |
|                             |     electricity.                       |
| PP #12 From Cell to Array   |                                        |
|                             | ```{=html}                             |
| #                           | <!-- -->                               |
|                             | ```                                    |
| #### PRESENTER ON CAMERA    | -   The solar cells are usually made   |
|                             |     of silicon. A common material for  |
| #                           |     both space and ground solar cells. |
|                             |                                        |
| PP #13 Panel Close Up w/    | -   They measure 3.1 inch by 3.1 inch  |
| Inset                       |     by 0.008 inch thick (thickness of  |
|                             |     4 sheets of paper). They are \~15% |
| []{.mark}                   |     efficient and produce about 1 Watt |
|                             |     of electricity.                    |
| []{.mark}                   |                                        |
|                             | -   These solar cells were made by     |
| []{.mark}                   |     SpectroLab in Sylmar, CA.          |
|                             |                                        |
| []{.mark}                   | **Solar cell alignment and use**       |
|                             |                                        |
| []{.mark}                   | -   Each wing consists of articulated  |
|                             |     **mast --**                        |
| []{.mark}                   |                                        |
|                             | -   Contained in a canister and two    |
| []{.mark}                   |     blanket boxes.                     |
|                             |                                        |
| []{.mark}                   | -   Each box has 84 panels so one      |
|                             |     blanket has16, 400 solar cells.    |
| []{.mark}                   |                                        |
|                             | -   Two panels comprise a single       |
| PP #14 Extended Solar       |     electrical circuit                 |
| Panels []{.mark}            |                                        |
|                             | -   41 electrical circuits per         |
|                             |     blanket.                           |
|                             |                                        |
|                             | **What is a solar array and how does   |
|                             | it work?**                             |
|                             |                                        |
|                             | -   Eight flexible solar array wings.  |
|                             |                                        |
|                             | -   Each 107 by 38 ft.; when fully     |
|                             |     deployed covers 32,528 sq. ft.     |
|                             |                                        |
|                             | -                                      |
|                             |                                        |
|                             | -   Power the ISS for 15 yrs.          |
|                             |                                        |
|                             | -   1^st^ one deployed STS-97,         |
|                             |     December 2000                      |
|                             |                                        |
|                             | -   When both wings are deployed, they |
|                             |     span 240 ft, tip to tip, by 38 ft  |
|                             |     across.                            |
|                             |                                        |
|                             | -   Each wing is 107 ft by 38 ft,      |
|                             |     weighs 2500 lb, produces \~32 kW   |
|                             |                                        |
|                             | -   This solar array will be the       |
|                             |     largest and most powerful ever     |
|                             |     flown in space.                    |
|                             |                                        |
|                             | -   The wings were made by             |
|                             |     Lockheed-Martin in Sunnyvale, CA.  |
+-----------------------------+----------------------------------------+
| **DEMONSTRATION**           | **Solar Array Panel Technology**       |
|                             |                                        |
| **VIDEO: ISS Construction** | The flexible panels are made from a    |
|                             | bonded sandwich of Kapton/glass        |
|                             | cloth/Kapton. *Kapton* is a polymer    |
|                             | material similar to Mylar (commonly    |
|                             | used to make festive helium balloons). |
|                             |                                        |
|                             | Solar cells are bonded to the panel.   |
|                             | Solar cells are electrically           |
|                             | interconnected by welding to flat      |
|                             | copper conducting wires (ribbons).     |
|                             | Slightly thicker copper ribbon         |
|                             | conducting wires transfer the wing     |
|                             | power from the edges of the solar      |
|                             | array blankets to the base of the      |
|                             | solar array.                           |
|                             |                                        |
|                             | The total panel thickness is 0.022     |
|                             | inches (includes Kapton sandwich,      |
|                             | adhesives and solar cell with cover    |
|                             | glass).                                |
|                             |                                        |
|                             | **How do we deploy solar arrays?**     |
|                             |                                        |
|                             | The solar array wings will be          |
|                             | automatically deployed one at a time.  |
|                             |                                        |
|                             | -   First, solar array wing blanket    |
|                             |     storage boxes will be rotated into |
|                             |     place (like a person fully opening |
|                             |     up their straightened arms).       |
|                             |                                        |
|                             | -   Then, an electric motor will be    |
|                             |     turned on to drive a mechanism     |
|                             |     that extends a square truss        |
|                             |     structure out of a canister. The   |
|                             |     truss is 30 inches on a side and   |
|                             |     107 ft long. As the truss extends, |
|                             |     it drags out solar array wing      |
|                             |     panels from storage boxes. The     |
|                             |     panels unfold like a decorative    |
|                             |     fan (PI = Chinese fan).            |
|                             |                                        |
|                             | -   The automatic deployment takes 13  |
|                             |     minutes to complete. If the        |
|                             |     automatic deployment fails, the    |
|                             |     astronauts can perform a space     |
|                             |     walk. Using a tool like an         |
|                             |     electric hand drill, the astronaut |
|                             |     can drive the array wing           |
|                             |     deployment mechanism.              |
|                             |                                        |
|                             | The solar array wing deployable "FAST  |
|                             | Mast" was built by AEC-Able Inc. in    |
|                             | Goleta, CA.                            |
+-----------------------------+----------------------------------------+
| PROPS: Solar Cells and      | **SOLAR CELL DEMONSTRATION**           |
| powering electronics        |                                        |
|                             | **What do you think these solar cells  |
|                             | could power?**                         |
|                             |                                        |
|                             | Let us take a look at exactly what     |
|                             | will happen when we use these solar    |
|                             | cells.                                 |
|                             |                                        |
|                             | -   Variation according to the amount  |
|                             |     of light                           |
|                             |                                        |
|                             | **Why is the solar array important to  |
|                             | ISS?**                                 |
|                             |                                        |
|                             | -   This US solar array will more than |
|                             |     double the power available on ISS. |
|                             |                                        |
|                             | -   This added power is needed to run, |
|                             |     among other things, the Russian    |
|                             |     "Elecktron" oxygen generating      |
|                             |     system and to run experiments in   |
|                             |     the US "Destiny" Lab module        |
|                             |     (launched in 2001).                |
|                             |                                        |
|                             | **How are they different than the ones |
|                             | used on Earth?**                       |
|                             |                                        |
|                             | -   Compared to typical solar cells    |
|                             |     used in solar panels on the        |
|                             |     ground, the ISS solar cells: have  |
|                             |     a much larger area (by a factor of |
|                             |     5 or more)                         |
|                             |                                        |
|                             |     -   are much thinner (by a factor  |
|                             |         of 3 or 4)                     |
|                             |                                        |
|                             |     -   are lower weight (by a factor  |
|                             |         of 3 or 4)                     |
|                             |                                        |
|                             |     -   have higher efficiency (\~15%  |
|                             |         of ISS cells,                  |
|                             |                                        |
|                             |     -   \~10% for typical ground       |
|                             |         cells)                         |
|                             |                                        |
|                             |     -   have higher cost (by more than |
|                             |         a factor of                    |
|                             |                                        |
|                             |     -   10\)                           |
|                             |                                        |
|                             | -   The biggest difference between     |
|                             |     solar cells for space and solar    |
|                             |     cells for use on the ground is:    |
|                             |                                        |
|                             |     -   space solar cells must be      |
|                             |         tolerant of radiation damage   |
|                             |         caused by high-energy          |
|                             |         electrons and protons in space |
+-----------------------------+----------------------------------------+
| PP #16 Futuristic           | **What does this mean for our          |
| Spacecraft                  | future?**                              |
|                             |                                        |
| PP #17 Stardust             | **In space Uses:**                     |
|                             |                                        |
| PP #18 Solar Array Tower    | -   Landis and his colleagues at       |
|                             |     Glenn\'s Photovoltaics and Space   |
| PP #19 Tower Example #2     |     Environment Branch are exploring   |
|                             |     new ways to harness the Sun\'s     |
|                             |     power \-- including more efficient |
|                             |     solar cells, laser-beaming energy  |
|                             |     to distant spacecraft, and solar   |
|                             |     power systems for the Moon and     |
|                             |     Mars.                              |
|                             |                                        |
|                             | ```{=html}                             |
|                             | <!-- -->                               |
|                             | ```                                    |
|                             | -   \"Using today\'s technologies,\"   |
|                             |     he says, \"the \'edge\' of         |
|                             |     sunshine we can use is about four  |
|                             |     astronomical units away from the   |
|                             |     Sun, where the sunlight is about   |
|                             |     one-sixteenth as bright as it is   |
|                             |     near the Earth.\" That\'s beyond   |
|                             |     the orbit of Mars (1.5 AU), but    |
|                             |     closer to the Sun than Jupiter     |
|                             |     (5.2 AU).                          |
|                             |                                        |
|                             | -   To date, the farthest any          |
|                             |     solar-powered spacecraft has       |
|                             |     ventured from the Sun is 2.72 AU   |
|                             |     by Stardust. Stardust\'s solar     |
|                             |     arrays are actually producing more |
|                             |     energy than expected, perhaps      |
|                             |     because its photovoltaic cells     |
|                             |     operate more efficiently in the    |
|                             |     cold of deep space than in Earth   |
|                             |     labs. No one is certain; this is   |
|                             |     unexplored territory.              |
|                             |                                        |
|                             | -   \"We\'re investigating the concept |
|                             |     of using lasers to beam photons to |
|                             |     solar arrays. So distance from the |
|                             |     Sun will no longer matter.         |
|                             |                                        |
|                             | > *For more information*               |
|                             | > <http://science.nasa.g               |
|                             | ov/headlines/y2002/08jan_sunshine.htm> |
|                             |                                        |
|                             | **On Earth Uses:**                     |
|                             |                                        |
|                             | -   Solar power collected in space and |
|                             |     beamed to Earth could be an        |
|                             |     environmentally friendly solution  |
|                             |     to our planet\'s growing energy    |
|                             |     problems.                          |
|                             |                                        |
|                             | -   Giant structures consisting of row |
|                             |     after row of photovoltaic (PV)     |
|                             |     arrays could be placed either in a |
|                             |     geostationary Earth orbit or on    |
|                             |     the Moon. A complete system would  |
|                             |     collect solar energy in space,     |
|                             |     convert it to microwaves, and      |
|                             |     transmit the microwave radiation   |
|                             |     to Earth where it would be         |
|                             |     captured by a ground antenna and   |
|                             |     transformed to usable electricity. |
|                             |                                        |
|                             | -   Photovoltaic arrays in a           |
|                             |     geostationary Earth orbit (at an   |
|                             |     altitude of 22,300 miles) would    |
|                             |     receive, on average, eight times   |
|                             |     as much sunlight as they would on  |
|                             |     Earth\'s surface.                  |
|                             |                                        |
|                             | <http://science.na                     |
|                             | sa.gov/headlines/y2001/ast23mar_1.htm> |
|                             |                                        |
|                             | <http://www.msfc.nasa.go               |
|                             | v/news/news/releases/1999/99-096.html> |
+-----------------------------+----------------------------------------+
| PP #20 Process of Fission   | **What are some other ways that we can |
|                             | convert energy to electricity when the |
|                             | solar technology is not available --   |
|                             | or we are out of the sun's reach?**    |
|                             |                                        |
|                             | **[Fission:]{.underline}** the         |
|                             | splitting of an atomic nucleus         |
|                             | resulting in the release of large      |
|                             | amounts of energy                      |
|                             |                                        |
|                             | **[Fusion:]{.underline}** the joining  |
|                             | together of atomic nuclei to form      |
|                             | heavier nuclei resulting in the        |
|                             | release of enormous quantities of      |
|                             | energy                                 |
+-----------------------------+----------------------------------------+
| **Use only with (9-12) if   | **9-12 Chain Reaction**                |
| appropriate**               |                                        |
|                             | **Which is better? Why?**              |
| PP #21 New Horizons         |                                        |
|                             | **[Fission vs. Fusion:]{.underline}**  |
|                             |                                        |
|                             | Nuclear fusion can occur in the core   |
|                             | of the sun because the core is         |
|                             | tremendously hot and dense. Because    |
|                             | nuclei have a positive charge, they    |
|                             | tend to repel one another. But the     |
|                             | core\'s temperature and density are    |
|                             | high enough to force nuclei together.  |
|                             |                                        |
|                             | The most common fusion process in the  |
|                             | sun is called the proton-proton chain. |
|                             | This process begins when nuclei of the |
|                             | simplest form of hydrogen \-- single   |
|                             | protons \-- are forced together one at |
|                             | a time. First, a nucleus with two      |
|                             | particles forms, then a nucleus with   |
|                             | three particles, and finally a nucleus |
|                             | with four particles. The process also  |
|                             | produces an electrically neutral       |
|                             | particle called a neutrino.            |
|                             |                                        |
|                             | The final nucleus consists of two      |
|                             | protons and two neutrons, a nucleus of |
|                             | the most common form of helium. The    |
|                             | mass of this nucleus is slightly less  |
|                             | than the mass of the four protons from |
|                             | which it forms. The lost mass is       |
|                             | converted into energy. The amount of   |
|                             | energy can be calculated from the      |
|                             | German-born physicist Albert           |
|                             | Einstein\'s famous equation E =        |
|                             | mc-squared (E=mc2). In this equation,  |
|                             | the symbol E represents the energy, m  |
|                             | the mass that is covered, and          |
|                             | c-squared (c2) the speed of light      |
|                             | multiplied by itself.                  |
|                             |                                        |
|                             | **How do you think NASA is using       |
|                             | this?**                                |
|                             |                                        |
|                             | To power satellites and vehicles into  |
|                             | outer space that is out of suns reach  |
|                             | for solar cells.                       |
|                             |                                        |
|                             | > **New Horizons use of plutonium**    |
|                             | >                                      |
|                             | > Radioscope Thermoelectric Generators |
|                             | > are compact and extraordinarily      |
|                             | > reliable spacecraft power systems.   |
|                             | >                                      |
|                             | > RTGs convert the heat generated from |
|                             | > the natural decay of the radioactive |
|                             | > fuel into electricity. RTGs consist  |
|                             | > of two major elements: a heat source |
|                             | > that contains plutonium dioxide in   |
|                             | > the form of ceramic pellets and a    |
|                             | > set of solid-state thermocouples     |
|                             | > that convert the plutonium's heat    |
|                             | > energy to electricity.               |
|                             | >                                      |
|                             | > **<http://pl                         |
|                             | uto.jhuapl.edu/mission/whereis_nh.php> |
|                             | > to show where it is and where it     |
|                             | > still has to go**                    |
+-----------------------------+----------------------------------------+
| #### PRESENTER ON CAMERA    | **CAREERS**                            |
|                             |                                        |
|                             | **What types of jobs do you think you  |
|                             | could have that deal with energy?**    |
|                             |                                        |
|                             | There are a wide variety of            |
|                             | professions available in the renewable |
|                             | energy industry. This fact can make it |
|                             | challenging to find the right          |
|                             | professional niche, but it also        |
|                             | provides the opportunity for           |
|                             | individuals with many different types  |
|                             | and degrees of training to get         |
|                             | involved with renewable energy.        |
|                             |                                        |
|                             | Some jobs---such as those in           |
|                             | communications, community outreach,    |
|                             | sales/marketing, and business support  |
|                             | (e.g., corporate planning and finance, |
|                             | accounting, human resources, law, and  |
|                             | information technology)---can be found |
|                             | in almost every renewable energy       |
|                             | field. Other jobs are specific to      |
|                             | individual renewable energy            |
|                             | technologies, as shown in the          |
|                             | following discussion of the five main  |
|                             | renewable energy power sources: wind,  |
|                             | solar, bioenergy, geothermal, and      |
|                             | hydropower.                            |
|                             |                                        |
|                             | <http://www1.eere.energy.gov/ed        |
|                             | ucation/careers_renewable_energy.html> |
|                             | jobs & info.                           |
|                             |                                        |
|                             | -   Research                           |
|                             |                                        |
|                             | -   Science                            |
|                             |                                        |
|                             | -   Biological and environment         |
|                             |                                        |
|                             | -   Physics                            |
|                             |                                        |
|                             | -   Nuclear science                    |
+-----------------------------+----------------------------------------+
| **PERESENTER ON CAMERA**    | **CONCLUSION**                         |
|                             |                                        |
| **PERESENTER ON CAMERA**    | -   **TEACHING MOMENTS**- ASK STUDENTS |
|                             |     FOR QUESTIONS OR PREWORK           |
| PP \# NASA Meatball         |     ACTIVITIES DONE                    |
|                             |                                        |
|                             | **CLOSING**                            |
+-----------------------------+----------------------------------------+

##### 

##### 

##### PROPS

######## PROPS NEEDED

1.  Solar cells and voltmeter

2.  Items to run

3.  ISS model

> **MPEGs**

#### MPEG #1 NASA Vision Open TRT 2:11 VOT

**MPEG #2 Final Truss Segment TRT 0:30 MOS**

**MPEG #3** **International Space Station Assembly TRT 1:53 MOS**

**Background information**

> [Heat transfer -]{.mark} [The transfer or exchange of heat by
> radiation, conduction, or convection within a substance and between
> the substance and its]{.mark} [surroundings.]{.mark}

**Nuclear Power, Fission, & Chain Reaction**

**<http://www-spof.gsfc.nasa.gov/stargaze/Snuclear.htm>**

Uranium nuclei in nature are unstable. Each of their 92 protons repels
the rest, and sooner or later (half of them within 4.5 billion years)
they eject a positive fragment, an \"alpha particle\" which is another
term for a rapidly moving nucleus of helium. Almost all the helium atoms
we extract from natural gas and from rocks\--for filling balloons and
for other uses\--were originally created as alpha particles.

    But there exists a way of **speeding up** this break-up, by exposing
the material to **free neutrons.**

![](media/image1.png){width="3.1354166666666665in"
height="2.4166666666666665in"}

>     Free neutrons are not found in nature (they would decay into
> protons and electrons), but they can be released from atoms of
> beryllium by bombarding them with alpha particles from radioactive
> materials, or by other methods. Since they are only attracted by
> nuclei (while protons are repelled before they get close enough for
> the nuclear attraction to do its job), they can easily enter a nucleus
> and stick to it\--a bit like small magnets clicking onto a chunk of
> steel.
>
>     Such an attraction releases energy. If the nucleus is heavy and
> unstable, like that of uranium, adding energy destabilizes it even
> more, to where it may break up **immediately**. The interesting thing
> about such a break-up is the spectacular way in which it sometimes
> happens, as was discovered by Hahn and Meitner in 1939. Instead of
> breaking off a little chip, a helium nucleus containing less than 2%
> of the mass, the **entire nucleus splits** into 2 comparable
> fragments, typically containing 1/3 and 2/3 of the mass.
>
>     This process is called **nuclear fission** and besides the speed
> with which it can take place, it has at least two other remarkable
> features:

1.    It releases **much more energy** then the chipping-off of a helium
    nucleus (\"alpha radioactivity\").

2.    The **fragments themselves are unstable.** If you break up a
    nucleus which has (say) 40 protons for every 60 neutrons, into
    fragments whose optimal ratio is only (say) 45 to 55, there is bound
    to be some adjustment.

    Ordinarily, such an adjustment calls for the conversion of some
neutrons into protons (plus emitted electrons, \"beta rays\"), a process
known as \"beta radioactivity.\" Such an adjustment does in fact occur,
making such fragments fiercely radioactive, and turning their disposal
into a major issue for the nuclear power industry.

![](media/image2.png){width="1.9375in" height="2.3125in"}    But at
first, when the nucleus breaks up, the fragments are too unstable for
such a gradual process. A quicker adjustment is needed, and the
fragments achieve it by each **emitting** one or sometimes more **free
neutrons.**

## *The Chain Reaction* 

    On the average, about **two** neutrons are released this way per
fission event. But it takes only **one** neutron to initiate another
fission! Thus if fissionable nuclei are so densely packed that each
neutron is bound to produce a new fission, the number of fission events
quickly multiplies: 2, 4, 8, 16, 32, 64, 128\... Since the energy
release is proportional to the rate of fission, it also grows\--very
quickly!

    This **chain reaction** is what makes a **nuclear bomb** (or
\"atomic bomb\") function. The material with nuclei prone for
fission\--usually plutonium, an artificial heavy elements with 94
protons\--must be compressed tightly and at the appropriate moment,
exposed to a blast of neutrons. A variety of tricks, all of them top
secret, is used to make sure that at least an appreciable fraction of
its atoms undergoes fission before the whole thing blows apart.

    **Commercial nuclear power** is produced somewhat differently, in a
more controlled fashion. The fuel is uranium 235 (U-235)\--a variant
(\"isotope\") with 92 protons but only 143 neutrons, not 146, an odd
number which makes it less stable. Natural uranium consists mostly of
U-238, and it can absorb a neutron without undergoing fission (it
ultimately turns into plutonium). U-238 therefore will not support a
chain reaction. However, 0.7% of uranium is U-235, which can fission as
soon as it absorbs a neutron.

>     By using a clever design, one can actually build a reactor fueled
> by natural uranium. The trick is to form the fuel into rods, and put
> between them some material (\"moderator\") which slows down neutrons
> but does not absorb them, e.g. pure carbon or \"heavy water\"
> containing the heavy isotope of hydrogen. Neutrons produced in a rod
> generally escape into the moderator, and by the time they hit another
> rod, they are moving very slowly: such slow neutrons are gobbled up
> much more avidly by U-235 than by U-238, so that even in a rod
> containing only 0.7% U-235, the U-235 atoms make most of the
> \"catches. \"

**Part of article on Fusion (scroll towards bottom)**

<http://helios.gsfc.nasa.gov/ed-acecosmo.html>

**FUSION AND NUCLEOSYNTHESIS**

The elements we see all around us in the universe were created by
nucleosynthesis. In this process, nuclear fusion occurs in stars. As
fusion proceeds, lighter elements combine to produce heavier elements.
Fusion also generates large amounts of energy (such as visible light) as
matter is converted into energy. Einstein's famous E = mc^2^ equation
can be used to calculate the amount of energy released when a given mass
is converted. The *m*in the equation represents the nuclear mass defect.
This mass defect is the difference between the mass of the stable
nucleus that was produced during the process and the sum of the masses
of its parent particles.

According to the theory, the light elements (hydrogen, helium, and
lithium) were produced during the first few minutes. During the first
three minutes after the Big Bang, the universe cooled from 10 E 32 K to
10 E 9 K. After this cooling took place, protons and neutrons that
formed right after the Big Bang collided to produce deuterium (one
proton combined with one neutron). The deuterium then either combined
with an additional proton to create helium-3 and energy (gamma rays,
which are high frequency electromagnetic radiation) or it combined with
another deuterium to create helium-3 and a free neutron. A tritium
(hydrogen-3, the heaviest isotope of hydrogen) and a free neutron are
formed from the combination of two deuterium nuclei. The helium-3 would
have combined with deuterium to form helium-4 and a proton, while the
tritium would have combined with a deuterium to form helium-4 and a free
neutron. The lithium -7 isotope could also have been created from the
combination of a helium-3 and a helium-4.\
\
This theory is collectively called Big Bang nucleosynthesis and makes
the prediction that approximately 25% of the mass of the primordial
universe (shortly after Big Bang nucleosynthesis) should have been
helium, mainly helium-4. The abundance of helium-4 is slowly increasing
as the universe ages due to its production in stars. ACE instruments are
collecting data to test scientists' theories concerning the abundance of
helium isotopes and other elements.\
\
Current theory suggests that the production of the heavier elements
(from oxygen up through iron) only occurs on stars where temperatures
are very much hotter than our Sun. These stars have temperatures above
one billion degrees because they contain masses at least ten times that
of our Sun.

NASA Fact Sheet

February 2005

*Spacecraft Power for New Horizons*

NASA's planned New Horizons mission

would be the first-ever spacecraft exploration

of Pluto and the Kuiper Belt.

If approved, a radioisotope thermoelectric

generator (RTG) will provide the electrical

power to operate the New Horizons

spacecraft's mechanical and electronic

systems in the cold darkness of deep space.

The Johns Hopkins University Applied

Physics Laboratory (APL) will build the

spacecraft.

New Horizons' journey is planned to take it

more than 4 billion miles from Earth, where

the Sun is just a bright star in the dark sky.

Besides taking longer than 4 hours to reach

Pluto and nearby Kuiper Belt objects, light

from the Sun is 1,000 times fainter there than

at Earth.

What Are RTGs?

![](media/image3.wmf){width="2.8645833333333335in" height="1.5in"}

RTGs are compact and extraordinarily

reliable spacecraft power systems.

RTGs convert the heat generated from the

natural decay of the radioactive fuel into

electricity. RTGs consist of two major

elements: a heat source that contains

plutonium dioxide in the form of ceramic

pellets and a set of solid-state thermocouples

that convert the plutonium's heat energy to

electricity.

In 1821, Thomas Johann Seebeck discovered

how to convert heat directly into electricity

using a simple and robust device. He found

that an electrical current is generated when

two dissimilar electrically conductive

materials are connected in a closed circuit

and their junctions are kept at different

temperatures. Thermoelectric couples (or

thermocouples) in various forms are in

common use today, with proven long-term

reliability and no moving parts they are well

suited to the space environment.

The RTG thermocouples use heat generated

by the radioactive decay of plutonium to heat

the hot junction of the thermocouple, and

exposure to the cold of outer space to

maintain the temperature of the cold junction.

The electrical output is a function of the

temperature difference between the hot and

cold sides of the thermocouple. A number of

these thermocouples are arranged in a

converter assembly and the electricity

generated by the converter is then available

to power the spacecraft instruments.

RTGs can provide continuous power in

regions of space where the use of solar power

is not feasible. Over the past 40 years, RTGs

have been used safely and reliably on 25

missions, including six Apollo flights to the

moon, two Pioneer spacecraft to Jupiter and

Saturn, two Mars Viking landers, two

Voyager missions to the outer planets, the

Galileo mission to Jupiter, the Ulysses

mission to the Sun's poles, and the Cassini-

Huygens mission to Saturn.

Designed for Safety

More than 40 years have been invested in the

engineering, analysis and testing of RTGs.

As described below, safety features of an

RTG include the use of a specific type of fuel

material, a modular design and construction

and the use of multiple physical barriers.

The plutonium dioxide fuel contained in

RTGs is a specially formulated fire-resistant

ceramic that is manufactured as pellets to

reduce the possibility of fuel dispersion in a

launch or reentry accident. This ceramic form

resists dissolution in water and reacts little

with other chemicals. If fractured, the

ceramic tends to break into relatively large

particles and chunks that pose fewer hazards

than small, microscopic particles.

Multiple layers of protective materials,

including iridium capsules and high-strength

graphite blocks, protect and contain the fuel

and reduce the chance of release of the

plutonium dioxide. Iridium, a strong, ductile,

corrosion-resistant metal with a very high

melting temperature, encases each fuel pellet.

Impact shells made of lightweight and highly

heat-resistant graphite provide additional

protection.

Each RTG contains 18 heat source modules

with four plutonium dioxide pellets in each

module. There are two plutonium dioxide

pellets in each graphite impact shell, and two

graphite impact shells go into each heat

source module. The figure below shows part

of a heat source stack within the RTG.

![](media/image4.wmf){width="2.8743055555555554in"
height="2.1284722222222223in"}

Risk Assessment and Launch Approval

Any mission that plans to use an RTG as a

power source undergoes a safety analysis

carried out by the Department of Energy

(DoE). The safety analysis report provides a

comprehensive assessment of the potential

consequences of a broad range of possible

launch accidents. In addition to the DOE

review, an ad hoc Interagency Nuclear Safety

Review Panel (INSRP), which is supported

by experts from government, industry and

academia, is established as part of a

Presidential nuclear safety launch approval

process to evaluate the safety analysis report

prepared by DOE. Based upon the INSRP

evaluation and recommendations by DOE

and other Federal agencies, NASA may then

submit a request for nuclear safety launch

approval to the White House Office of

Science and Technology Policy (OSTP). The

OSTP Director (i.e., the President's science

adviser) may make the nuclear safety launch

decision or refer the matter to the President.

In either case, the launch cannot proceed

until nuclear safety launch approval has been

granted.

SUMMARY

RTGs enable spacecraft to operate on

missions where solar power systems would

not be feasible. The Department of Energy is

responsible for all aspects of RTG production

and delivery to NASA, including safety

analysis of the mission. RTGs can be used on

NASA spacecraft only after this detailed

safety analysis has been completed, reviewed

by safety experts, and launch approval

obtained from OSTP. RTGs have a proven

record of safety and remain unmatched for

reliability and durability over any other

power technology for outer solar system

missions.

For New Horizons, an RTG is uniquely

capable of powering this reconnaissance

mission to distant Pluto and the Kuiper Belt,

where the Sun is no more than a bright point

of light in the sky.

For more information, please contact:

Michael Braukus, NASA Headquarters

\(202\) 358-1979,

Alice Caponiti, Department of Energy

\(301\) 903-6062, or

Mike Buckley, Applied Physics Laboratory

\(240\) 228-7536