Galileo SCIENCE KIT Presentation Guide

DISPLAY IDEAS FOR SCIENCE FAIRS, CLASSROOM USE, CLUB ACTIVITIES, PLANETARIUMS, ETC.

Instructions for the Coordinator:

Instructions grouped on this sheet as "Tasks" are building blocks of ideas for accurate and educational displays. Coordinator and Participants should modify them freely to suit individual circumstances, as well as invent new ones altogether. While this sheet was written for people working together in groups, nothing should prevent a single individual from working any or all of them alone.

Photocopy all the tasks on this sheet and cut them into individual Task-Cards. Assign two or more participants to each of the tasks, based on their preferences and abilities. Give each participant a copy of the appropriate card(s), and a copy of the Support Component diagram. Each group should also be armed with a dictionary. Have the participants thoroughly read and discuss their Task Cards before beginning work. The coordinator should assist participants by providing workspace and time, helping obtain materials, and suggesting sources of information.

The Support tasks are accomplished first. They provide components which will be used in the Demonstration Tasks to illustrate various modes of scientific space flight operations. Each group should sketch and discuss its Demonstration Task before starting work on it. Multiple displays may be set up at the same time by arranging to provide multiple support components. Alternatively, one set of support components may be rearranged repeatedly, say daily or weekly, to accomplish the demonstrations one at a time. Situations in these displays depict Galileo operations. Some of them show operations which are typical of different past and future space missions.

These tasks touch the tips of a lot of icebergs, so to speak, and provide many opportunities for curious, motivated individuals to do further research. Use public and university libraries, and NASA Educational Outreach offices, for more information.

Support Tasks

(Complete these before starting the Demonstration Tasks.)

Support Task #1: The Galileo Spacecraft.

Assemble one Galileo Space Craft SCIENCE KIT model according to the instructions provided. Fashion a moveable tabletop stand with a heavy base which will allow some adjustment in the spacecraft's attitude. See the Support Components diagram. Make an arrow labeled "DIRECTION OF FLIGHT" and tape it to the stand, pointing generally opposite the direction the antenna dish points. Plan to pin up the Galileo Spacecraft Description sheet provided with the kit.

Support Task #2: The Planet Jupiter

Obtain a globe-shaped object to represent the planet Jupiter. The object should be large enough to suggest that the spacecraft can be completely hidden behind it. Paint the sphere, if desired, with various shaded bands of brown and white, and a Great Red Spot. For details of Jupiter's appearance, see http://www.scikits.com, and choose the "Links" page. Fashion a tabletop stand to set the planet on.

Support Task #3: One of Jupiter's moons.

Obtain a ping pong ball-size object to represent one of Jupiter's giant satellites: Europa, Io, Callisto, or Ganymede. Mount it on a separate, moveable stand, with a label to identify it. Size is chosen for convenience and perspective, not scale. If the extra work is desired, paint the sphere appropriately: Io would be yellowish with black active volcanoes and lava flows; Europa with a light-colored, cracked icy surface; Callisto with a dark surface full of impact craters; or Ganymede much like our own moon with solid areas or "seas," craters, and faults.

Support Task #4: Sun, Earth, and two distant stars.

Obtain a ping pong ball-size object to represent the Sun, and a marble-size object to represent the Earth. Sizes are chosen for convenience and perspective, not scale. Color them appropriately: the sun bright yellow, the Earth blue and white. The Sun and Earth should be mounted a couple of inches apart, on one stand about a foot high, with a heavy base. Fashion two clearly visible stars which can be pinned to the display sidewalls. Optionally, make an enlargement of the solar system trajectory diagram (Figure 2) from the Spacecraft Description Sheet, to pin up.

Support Component Diagram

Note: components not to scale.

Support Components Diagram

Demonstration Tasks

(These require completion of Support Tasks #1 through 4)

Demonstration Task #5: Spacecraft Attitude Control.

This demonstration shows how the Galileo spacecraft maintains its three-axis orientation in space. The spacecraft's star tracker observes the positions of carefully selected stars as they pass across its field of view while the spacecraft spins slowly about its roll axis. The attitude control computer aboard the spacecraft uses these measurements in reference to an onboard star catalog to manage the firing of small rocket engines mounted on booms which extend from the spacecraft. Normally, the spacecraft spins continuously to maintain its assigned attitude. During relatively short periods when the Sun or star cannot be seen, such as when a nearby planet hides them, or when it is desirable to have the spacecraft turn away, the attitude control computer uses signals from a set of gyroscopes for reference.

Tasks #1, 2, 3 and 4 should be finished. Make a sign for your display showing the above title. Attach a brightly colored string to a star on the display sidewall. Run it to the star tracker on the spacecraft (see spacecraft description provided with kit) and attach. This represents the view of stars which the star tracker senses. Place another star on the display sidewall to indicate the next star the tracker will view as the spacecraft spins. Direction of spin is shown on the Spacecraft Description sheet. Attach another string to Earth and run it to the Low Gain Antenna. This represents the radio signal aimed at Earth. Arrange the spacecraft so that both strings are straight. Clear away all unused components. Write up a sign explaining the display, using information from this card and/or from outside references. Make mention of the fact that the spacecraft is slowly spinning for stabilization.

Demonstration Task #6: Remote Optical Sensing.

This demonstration shows how the Galileo spacecraft makes observations with its four pointable optical instruments and returns the data toward Earth immediately via telemetry. (Data can also be recorded for later playback to Earth, as is the case when the spacecraft maneuvers off Earth point)

Tasks #1, 2, 3 and 4 should be finished. Make a sign for your display showing the above title. For distance reference (not scale), have the spacecraft closer to the satellite than the satellite is to the planet. Refer to the Spacecraft Description provided with the kit to identify all of the optical instruments on the pointable scan platform. Arrange the components so the ISS Camera is pointing to the satellite, and the Low Gain Antenna #1 (atop the High-Gain antenna dish) is pointing to the Earth. Attach the model's Scan Platform to its stand with wire or tape, so it can anchor a string. Attach a brightly colored string to the the surface of Jupiter's satellite, and run it straight to the Solid State Imaging Camera on the spacecraft. Take a paper ribbon and write a string of ones and zeroes along its entire length to represent the binary link of computer communications. Run the ribbon from the spacecraft's Low-Gain antenna #1 straight to the Earth. Clear away all unused components. Write up a sign explaining the display, using information from this card and/or from outside references. Optionally, make an enlargement to pin up of the Jovian Orbital Tour (Figure 4) from the Spacecraft Description Sheet.

Demonstration Task #7: Tracking the Atmospheric Probe.

This demonstration shows how the spacecraft tracks the atmospheric probe which had been released one hundred fifty days prior to entering Jupiter's atmosphere. Slowed via aerobraking, it parachutes down through the clouds, while it radios data back to the orbiter above for about an hour.

Tasks #1, 2, 3 and 4 should be finished. Remove the atmospheric probe from the Galileo model and put away. Make a sign for your display showing the above title. Cut out the illustration of GalileoÕs atmospheric probe entry (or fashion a better one). Using glue or a pin, attach it to the planet Jupiter near the mid-southern latitudes. Arrange the components so the RRH Antenna on the Galileo Orbiter is pointing directly to the descending probe, and Galileo's Low Gain Antenna #1 (atop the High-Gain antenna dish) is pointing to Earth. Note that the scale of the parachuting probe is by far too large in this arrangement. It could never be seen from orbital altitude. This is intentional, to illustrate the concept, and should be mentioned in your explanation. Take a paper ribbon about a foot in length and write a string of ones and zeroes along it to represent the binary link of computer communications. Run this from the parachuting probe to the RRH antenna dish to illustrate its data link to the orbiter. Make another paper ribbon with a string of ones and zeroes to stretch from the spacecraft's Low Gain Antenna #1 (atop the High-Gain antenna dish) to the Earth to represent telemetry to Earth. Clear away all unused components. Write up a sign explaining the display, using information from this card and/or from outside references. Optionally, make an enlargement to pin up of the Probe Entry Profile (Figure 3) from the Spacecraft Description Sheet.

Demonstration Task #8: Radio Science Atmospheric Study.

This demonstration shows how radio signals coming from the spacecraft are refracted (bent) by the nearby planet's atmosphere on their way back to Earth. They are also affected in other ways. The signals captured on Earth can be studied to provide much information about atmospheric structures, pressures, temperatures, and more. During such occultations, the spacecraft is programmed to transmit only the purest and steadiest radio signals possible. This way, the signals are stronger, and the atmosphere's effects on them can be seen more clearly, than if the signals were carrying telemetry.

Tasks #1, 2, 3 and 4 should be finished. Make a sign for your display showing the above title. Attach a brightly colored string to the spacecraftÕs Low Gain Antenna #1 (atop the High-Gain antenna dish). Run the string so it touches and bends slightly around the planet, and attach it to the Earth. Arrange the centers of Earth, the ringed planet, and the spacecraft in a straight line, and aim the Low Gain Antenna #1 right at the edge of the planet where the string touches. Keeping them in line, adjust the components so that the string is fairly taut, and shows a noticeable bend around the planet. Clear away all unused components. Write up a sign explaining the display, using information from this card and/or from outside references.

Permission is granted to reproduce this Presentation Guide for use with an associated SCIENCE KIT.
SCI Space Craft International, P.O. Box 61027, Pasadena, CA 91116-7027 USA