Storyboards for GP-B Animations - Gravity Probe...

July 6, 2007 GP-B Animation Storyboards Page 1

Storyboards for GP-B AnimationsBob Kahn & James Overduin

July 6, 2007

Changes in this Version:• Scene 4 - Slide 5b Corrected; See page 24.


Seven GP-B Animation Scenes

1. Newton’s view of space & time; Action at a distance — Gravity inNewton’s universe

2. Einstein’s view of spacetime; Following a geodesic — Gravity inEinstein’s universe

3. A “Simple” Experiment: A star, a telescope & a spinning ball4. Using Superconductivity to monitor gyro spin-axis orientation5. From gyro to payload to spacecraft to orbit (assembling the parts,

launching the spacecraft, acquiring the guide star, and orbiting fora year.)

6. The Drag-Free Satellite7. How big is a milli-arcsecond in human terms?Note: Some animation scenes are based on earlier animations

created by Norbert Bartel and Adam Jeziak for the movie, TestingEinstein’s Universe.


Scene 1 - Slide 1: Newton’s space & time• Start with full-screen

portrait of Newton onstarfield (include nameand dates ofbirth/death)

• Shrink head &shoulders vignette tocorner of scene

• Bring up earth, rotatingon radial grid, shallowview, suggesting infiniteexpanse of space

• Bring up caption


Scene 1 - Slide 2: Action at a Distance• To previous image, add

spinning gyro ball, orbiting earthin the path shown by the yelloworbit line (Q: Should yellow orbitpath line be visible or fade out?)

• Grid lines on ball indicate that itis spinning counter-clockwisealong an axis tangent to theorbit at starting point.

• The force arrows orbit with theball.

• The “Action at a distance?”caption appears, the scenefreezes for a few seconds, andthen the animation resumes as“Action at a distance?” captionfades out.


Scene 1 - Slide 3: Spin axis fixed• A spin axis arrow appears

through the “poles” of thegyro, as the gyro rotates andorbits the earth

• At the same time the arrowappears, a caption appearson screen saying that a gyrospin axis remains fixed withrespect to absolute space.

• The spin axis arrow alwayspoints in the same direction,consistent with the grid lineson the rotating sphere.

• The attractive force arrowscontinue to orbit with theball.


Scene 2 - Slide 1: Einstein’s Spacetime• Use color image of Einstein• Start with full-screen portrait

on starfield• Shrink head & shoulders

vignette to corner of scene• Bring up earth, static (not

rotating) on radial grid,shallow view, suggestinginfinite expanse

• Animate warping ofspacetime grid, with earthsinking slightly into grid

• Add caption about spaceand time being relative &interwoven into a fabriccalled spacetime.


Scene 2- Slide 2: Einstein’s Spacetime• Zoom “scene camera” out slightly

and tilt up to show higher view ofearth’s gravity well

• Start the earth rotatingcounterclockwise

• Add caption about spacetime tellingmatter how to move…

• Note: Move grid and earth higher onpage to make room for caption.

• Animate the counterclockwisetwisting of the spacetime grid. Thetwisting is most prominent at thecenter of the grid and falls off quicklyas you move further out (proportionalto the radius cubed)

• Change caption: Massive rotatingbodies, like the Earth, warp and twisttheir local spacetime.


Scene 2-Slide 3: Traveling on a Geodesic• Trac out out an equatorial geodesic

path around one of the circles in thespacetime grid.

• If possible, have the path appear asif someone took a pen and tracedaround the circular geodesic gridline.

• Bring up caption about objectsorbiting in curved geodesic paths.

• Animate the geodesic path, tippingup on a horizontal axis through thecenter of the Earth, so that the pathchanges from equatorial to polarorientation.

• Display the gyro ball, rotatingcounter-clockwise on its own spin-axis which is tipped up a bit, as itorbits the Earth on the polargeodesic path.


Scene 2 - Slide 4: Geodetic Precession• Animate gyro, rotating counter-

clockwise, together with whitespin-axis pointer, orbiting earth.

• Caption explains precession ofthe spin axis over time.

• A 2nd colored pointer marks thegyro’s initial direction as thewhite pointer opens anincreasing angle with eachsuccessive orbit.

• The final geodetic precessionangle, in the plane of the orbitafter a year, is 6,606 milli-arcseconds, as indicated by thefinal angle and captions.


Scene 2- Slide 5: Frame-dragging Precession• Zoom out and tilt “scene camera” up to

bird’s eye view, looking down on topview of rotating earth and surroundingspacetime grid.

• Show rotating gyro, with spin-axispointer moving forward and backward,alternating above and below earth toindicate polar orbit.

• Caption describes gyro precession fromtwisting spacetime

• Slowly animate counter-clockwisetwisting of spacetime grid.

• Use white spin-axis indicator to showinitial pointing position, and show slowprecession of red pointer relative towhite pointer, due to precession.

• Show final frame-dragging angle 0f 39milli-arcseconds/yr and caption.


Scene 2 - Slide 6: Combined Measurements• Combine scenes 4b and 4c together in a

perspective view• Zoom in so that gyro is prominent

(enlarge gyro, if necessary)• The gyro’s spin axis is pointing out of the

frame, towards you, and it is spinningcounter-clockwise as it orbits “counter-clockwise” around the earth’s poles. Theearth is also rotating counter-clockwise,and spacetime is twisting in the samedirection.

• The yellow spin-axis arrow begins on topof the white (reference) arrow.

• The spin axis arrows need to be longenough to exaggerate the effects.

• The initial (white) caption explains thatthe two effects occur at right angles toone another.

• The colored captions appear after anorbit or two, explaining the coloredarrows that are opening up.


Scene 2 (Continued) - Slides 6c & 6d• Slide 6c shows the angles from slide 6b

gradually opening further as more orbitsprogress.

• The initial caption fades out, and theanimation continues for a total of 4-5orbits—long enough for people to readthe captions and grasp the concept, butnot so long that the spin-axis deflectionangles grow larger than those shown inthese storyboards.

• As we reach the final angles, the coloredcaptions fade out.

• For Slide 6d, the final scene, we zoom inon the gyro and earth to exaggerate thefinal annual deflection angles.

• Bring up the final deflection angle values,and freeze this frame long enough forpeople to read both captions.

• Fade to black.


Scene 3 - Slide 1 — “Simple” Experiment• Earth crescent in lower right

corner rotates counter-clockwise about its axis (off-screen); stars remain fixed

• Caption begins Fairbankquote

• In slide 1b, first line ofcaption rolls up anddisappears as 2nd linebegins “It’s just a star”

• A bright star appears inupper left corner of screen(image pictured is a photo ofthe guide star IM Pegasi)corresponding with emerging2nd line of caption.


Scene 3 - Slide 1 (Cont.)• In Slide 1c, caption continues to

build “It’s just a star, a telescope”• Telescope appears,

corresponding to caption• In slide 1d, caption completes as

shown.• Gyro spinning counter-clockwise

appears, with completed caption.• Note: Gyro surface needs to be

marked somehow (e.g. grid linesor arrows) so you can tell that it’sspinning.

• Note: Star, telescope, & gyro needto be aligned, but can berepositioned along that line asneeded—I.e. they can be movedtowards the star a bit more.


Scene 3 - Slide 2• Starlight beams into

telescope• Note: It should not look like

the telescope is shooting atthe star (it’s starlight, not alaser beam); make the beamlook somewhat diffuse withparticles streaming towardsthe telescope.

• Bring up caption as shown• Note: Both Earth & gyro

continue their rotating motionthroughout this entiresequence.


Scene 3 - Slide 3• Transitioning from Slide 2, the

caption changes to explain therole of the telescope

• A spin-axis arrow appears onthe spinning gyro, initiallyaligned with the guide star.

• As we progress from Slide 3a toSlide 3b, the spin axisorientation changes, movingboth towards the viewer slightly(frame-dragging precession)and down from the guide starreference line (geodeticprecession).

• Use same technique forshowing gyro spin-axisprecession as in Scene 4b,since this is basically the sameview.


Scene 3 - Slide 4• Fade away the spin-

axis arrows from Slide3, and transition captionto “Simple in concept…”

• Begin shrinking bothtelescope and gyro, andthen add 3 more gyros;the telescope and gyrosshould end up in theirproper position insidethe spacecraft, acutaway of which willnow begin to fade intoview.


Scene 3 - Slide 4 (Cont.)• As the Simple in concept

caption completes, fade in acutaway side view of thespacecraft, so that thetelescope and gyros end upproperly positioned at centerand towards the bottom of thedewar.

• Note: the cutaway of thespacecraft can be much lesscomplete than the one shown.The idea is to show the relativepositions of telescope and gyrosinside the spacecraft, which isoriented towards the guide staras it orbits the Earth.

• In the final slide, the cutawaycloses up, showing only thespacecraft.


Scene 4- Slide 1 — Gyro Readout• Show a spinning glass

(quartz) gyro ball.• The ball is spinning fast,

counter-clockwise about anaxis pointing towards 9:00

• At top of screen, bring upcaption 1: “How can onemonitor the spin axisorientation of a near-perfectspherical quartz gyro with nomarkings?

• Fade in caption 2 at bottomof screen: “The answer liesin superconductivity.


Scene 4 - Slide 2• Fade out original captions and fade

in new top caption: “Coat the gyrowith a thin film of superconductingniobium.

• Animate a color/texture change ofthe gyro surface from translucentglass to shiny metallic (niobiumcoated), with grid lines or arrows toindicate the fast spinning ball.

• Fade in magnetic field lines aroundgyro and the spin-axis arrow.

• Bring up lower caption: “A spinningsuperconductor develops amagnetic “London moment” exactlyaligned with its spin axis.


Scene 4 - Slide 3 — SQUID Readout

• Fly in pick-up loop around gyroequator, connected to a readout.

• The pick-up loop rotates around thegyro’s spin-axis, in the samedirection as the gyro, but it rotatesmuch more slowly.

• The rotation collar of the pick-uploop is connected to a SQUIDreadout display, which looks like anoscilloscope.

• Top Caption appears: “The Londonmoment is used to measure thespin-axis precession of the gyros.

• The pick-up loop rotates about thespinning gyro, but until the spin-axisand magnetic field begin to deflectdownward, the readout remains aflat line.


Scene 4 - Slide 4• Transitioning from Slide 3b, the

gyro, spin axis line andmagnetic field lines all nowbegin to rotate slightly counter-clockwise.

• The amplitude of the readoutsignal begins to increaseproportional to the increasingdeflection of the gyro spin axis.

• Note: The period of the readoutsignal corresponds to rotationrate of the pick-up loop. Thesine wave starts when the loopis horizontal, and one completesine wave corresponds to onecomplete rotation of the loop.


Scene 4 - Slide 5• Zoom out from Scene 4b and dissolve to scene

with all 4 gyros lined up, each with its own pick-up loop and readout.

• If possible, show the quartz block, whichhouses the gyros in the background. This canbe done in wireframe or using transparency toshow that the gyros are lined up along thecentral axis. If it’s too hard to model this, youcan omit the quartz block from Slides 5a & 5b.

• Show that the pick-up loops for gyros 3 and 4are offset 90 degrees from the pick-up loops forgyros 1 and 2, due to the way the 2 pairs ofgyro housings are mounted in the block.

• Note that the spin directions of the gyrosalternate: gyros 1 and 3 spin counter-clockwise; gyros 2 and 4 spin clockwise (righthand rule applies to their spin axes.)

• All four pick-up loops rotate counter-clockwise,in unison along with the quartz block (if shown).The collars on the pick-up loops allow them torotate, while the readout boxes remain fixed.

• As long as the gyro spin axes are horizontal,there is only a flat signal on the readoutscreens.


Scene 4 - Slide 5 (Cont)• After a couple of complete rotations

of the pick-up loops (and quartzblock, if shown), slowly begin todeflect the gyro orientations, alongwith their spin axis pointers andmagnetic field lines, as shown.

• As the gyro spin axes deflect,signals appear on the readoutdisplays.

• As in Slide 4, the amplitude of thereadout signals grows in proportionto the spin-axis deflection angles.

• Note that the sinusoidal readoutsignals are in different phases fromeach other, due to the differences inspin directions and pick-up looporientations.


Scene 4 - Slide 6• Zoom out , while enclosing

the quartz block and gyros ina cutaway or wireframe ofthe spacecraft, showing thelocation of the gyros inside.

• Roll the spacecraft along itscentral axis (which is whatcauses the pick-up loops torotate).

• As the cutaway region rollsout of view, fade in thespacecraft skin, and zoomout further to show thespacecraft rolling next to acorner of the Earth (like inScene 5) and pointingtowards the guide star.


Scene 5 — From Gyro to Orbit• Re-create, in reverse, Norbert Bartel’s

animation “zooming” from the outside ofthe spacecraft inside, layer by layer,down to the four gyros. (A reversedcopy of this sequence is available forviewing in the Storyboards folder on ourGP-B Web server.)

• In other words, re-create this sequencein reverse, starting with a gyro andbuilding up to the completespacecraft…and then summarize thewhole mission, as described below.

– Show the spacecraft launch (real video)– Show separation & orbit acquisition– Show guide star capture and rolling

spacecraft orbiting earth– Show earth and spacecraft orbiting the

sun for a year (use animated calendaretc. to show time passage.)


Scene 6: Drag-free Flight—Slide 1• Earth is rotating

counterclockwise• GP-B spacecraft orbits Earth

counterclockwise• The spacecraft’s body axis is

tilted up 23 degrees fromhorizontal, and it maintainsthis attitude throughout itsorbit

• The spacecraft rolls slowly,counterclockwise along itsbody axis as it orbits.


Scene 6 — Slide 2a• Zoom in on spacecraft in orbit to a

camera vantage point parallel to thespacecraft.

• The spacecraft is continually rolling alongits axis and moving “downwards”,following the golden geodesic orbit line.

• The camera is moving next to thespacecraft, so the spacecraft remainsfixed in the field of view.

• Perhaps the orbit line can be made of“particles” that appear to be movingupward.

• The Earth appears to be rotating both onits axis and “upwards,”opposite thespacecraft’s motion.

• The stars may also appear to be slowlymoving upwards if this doesn’t make theviewer seasick.


Scene 6 — Slides 2b & 2c• The spacecraft is suddenly

bombarded with solar radiation,causing it to recoil slightly oppositethe direction of the radiation hit.

• Earth’s atmosphere (wisps of cloud)also jostles the spacecraft, causingit to recoil opposite to the directionthat the cloud strikes the vehicle.

• The concept to get across is that thespacecraft does not enjoy a smoothride along the geodesic path —rather, it gets buffeted around by thesolar radiation and Earth’satmosphere.

• Note: If the spacecraft’s rolling inorbit is confusing or distracting, wecan turn it off until the last slide.


Scene 6 — Slide 2d• Solar radiation and

atmosphericdisturbances continueto strike the spacecraftat random intervals,slightly jostling thespacecraft’s position onthe geodesic orbit line

• The text caption sets upthe next series of slides.


Scene 6 — Slide 3a• The outside shell of the spacecraft

dissolves to a cutaway, showing theinside of the dewar, a single gyro, andfour sensors.

• Note 1: This is a very simplified andstylized, rather than a realistic view of theinterior of the spacecraft; it is designed toclearly demonstrate the drag-freeconcept.

• Note 2: For all of the “cutaway” slides, thegeodesic orbit line is shown runningthrough the center of the spacecraft andthe gyro inside. This clearly shows thatthe gyro remains centered on thegeodesic, while the whole spacecraftmoves around it.

• The gyro and sensors are scaled up insize so that together, they fill the dewar’scavity. Again, this is a conceptual, ratherthan realistic depiction.

• The spacecraft should not be rotatingalong its axis in these cutaway slides.


Scene 6 — Slides 3b & 3c• Solar radiation is shown striking the

spacecraft, which moves the vehicle inthe opposite direction.

• This vehicle motion causes two of thesensors to move close to the gyro.

• We show these sensors changing colorto emphasize that they are responding tothe vehicle motion—that is, they havemoved too close to the gyro, and they aresignaling the guidance system to movethe spacecraft back to a centered gyroposition.

• In response to the sensor signals, theappropriate micro-thrusters increase theirflow of helium. Again, this is highlyexaggerated to make the concept clear.

• As the thrusters fire, the spacecraftbegins moving back towards its originalcentered position.

• Throughout all of this motion, the gyroclearly remains centered on the geodesicorbit line.


Scene 6 — Slides 3d & 4a• These two slides are

identical and should actuallybe just one slide.

• When the thrusters finishfiring following slide 3c, thespacecraft and sensorsmove until they are onceagain centered around thegyro.

• The spacecraft remains inthis position until the nextsolar radiation oratomospheric disturbanceevent.


Scene 6 — Slides 4b & 4c• These two slides are just like

Slides 3b & 3c, only this time,the spacecraft movement is dueto atmospheric disturbance,rather than solar radiation.

• The atmospheric strikeoriginates on the Earth side ofthe spacecraft, rather than theSun side.

• Thus, the spacecraft movescloser to the bottom sensor,rather than the top sensor.

• Activation of these two sensorscauses the guidance system tofire a different set of thrusters tomove the spacecraft back to acentered position.


Scene 6 — Slide 4d• As in Slide 3d, after the

thrusters finish firing, thespacecraft and sensors moveback to their correct position,centered around the gyro.

• The solar radiation/atmosphericdisturbance strikes andcorresponding spacecraftmotion, sensor alerts, thrusterfirings and spacecraft re-centering can now be shown acouple more times, as peopleread the caption in Slide 4dabout GP-B’s unique drag-freequalities.


Scene 6 — Slide 5• In Slide 5, we close up the cutaway,

once again showing the outside ofthe spacecraft.

• We send the geodesic orbit lineback behind the spacecraft.

• We re-start the spacecraft’s rotation,(if we decide to have it rotating atthe beginning in Slides 2a, 2b, 2c &2d.

• Perhaps show a final solar radiationstrike, with correspondingspacecraft motion, now with theviewer knowing what is going oninside.

• We end this scene here—orperhaps zoom back out to theoriginal orbiting depiction in Slides1a & 1b.


Scene 7 —How Big is a Milli-Arcsecond?• This animation will be a replacement for Norbert

Bartel’s NY to Paris clip that showed the size of1/10 of a milli-arcsecond.

• Note that this clip will show an angle 10 timeslarger than the NY to Paris clip.

• Two visual analogies hold the most promise forthis clip:

– An astronaut in a spacesuit (7’ tall),standing on the moon as viewed fromEarth, measured to an accuracy of a button

– The width of a strand of human hair viewedfrom 10-15 miles

• If possible, we should also indicate the accuracylevel of the measurement (e.g. a button on theastronaut’s spacesuit)

• One possible approach is to come up with aseries angular measurements of, say a 7’ tallsuited astronaut, starting at a distancerepresenting an angle of 45 degrees, and thendecreasing the angle and correspondingdistance of the astronaut, until we reach 0.001arcseconds at the distance of the moon.

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Storyboards for GP-B Animations - Gravity Probe...

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