Спутник ФКИ. Gravity Probe B. [Редактировать]

Gravity Probe B (GP-B) — американская космическая миссия по измерению чрезвычайно слабых эффектов геодезической прецессии гироскопов на орбите вокруг Земли и увлечения инерциальных систем отсчёта вращением Земли, которые предсказывает общая теория относительности Эйнштейна. Разработкой дьюара, контейнера научной аппаратуры и электронного оборудования для GP-B занимался отдел новых технологий компании «Lockheed Martin». Для изготовления самого космического аппарата Стенфордским университетом была выбрана компания «Lockheed Martin Missiles & Space», Саннивейл.
Спутник был запущен 20 апреля 2004 года, сбор данных начат в августе 2004. На орбите спутник отработал в целом 17 месяцев и завершил свою миссию 3 октября 2005 года. Обработка полученных данных велась до мая 2011 года и подтвердила существование и величину эффектов геодезической прецессии и увлечения инерциальных систем отсчёта, хотя и с точностью, несколько меньшей изначально предполагавшейся.
Спутник Gravity Probe B нёс на борту самые точные на тот день гироскопы в мире. Точность измерений положения оси позволяет обнаружить два эффекта, предсказываемые общей теорией относительности:

  • геодезическую прецессию, возникающую вследствие искривления пространства-времени.
  • прецессию за счёт увлечения инерциальной системы координат вблизи вращающегося массивного тела (Земли).

Геодезическая прецессия возникает из-за искривления пространства-времени Землёй. В искривленном пространстве, если обнести вектор по замкнутому контуру, он не возвратится в исходное положение, а изменит направление на некоторый угол (см. параллельное перенесение). В данном случае роль вектора выполняет спин гироскопа, а орбита спутника выступает в качестве замкнутого контура. Для параметров GP-B, по расчётам, суммарный угол отклонения должен равняться 6,6 угловых секунд в год. Отклонение спина должно наблюдаться в плоскости орбиты спутника.
Прецессия второго типа на два порядка слабее и возникает из-за увлечения пространства вращением Земли. Если поместить горизотнально вращающийся гироскоп на полюсе Земли, он начнёт очень медленную прецессию в направлении вращения Земли (против часовой стрелки на северном полюсе). Интересно, что на экваторе должна наблюдаться обратная картина: пространство ближе к Земле увлекается больше, и прецессия должна происходить в другую сторону, по часовой стрелке, если смотреть со стороны северного полюса. Для GP-B прецессия из-за увлечения инерциальной системы отсчёта должна составить примерно 0,014 угловых секунд в год.
Идея эксперимента достаточно проста. Система из четырёх гироскопов жёстко закрепляется на главный телескоп спутника, телескоп наводится на ведущую звезду и поддерживается в строго фиксированном направлении в течение всего полёта. Вначале гироскопы раскручиваются так, чтобы их оси совпадали с осью главного телескопа. После этого микроскопическое смещение осей можно будет измерить с помощью SQUID (сверхпроводящее квантовое интерференционное устройство). Измеренное таким образом смещение осей гироскопов будет только за счёт ожидаемых эффектов — геодезической прецессии и увлечения инерциальной системы координат.
Спутник движется по свободной от сноса орбите. Это означает, что орбита спутника постоянно (с частотой 10 раз в секунду) корректируется по движению центра масс одного из гироскопов, который, как и три остальных, защищён от всех внешних воздействий (атмосфера, магнитное поле Земли, давление солнечного света и т. д.), кроме взаимодействия с гравитационным полем. Координаты спутника регистрируются с помощью системы GPS. Гироскопы вращаются с угловой скоростью около 4000 оборотов в минуту. Они подвешены электростатически на расстоянии долей миллиметра от стенок полости. Чтобы избежать контакта гироскопа со стенками, позиция полости относительно гироскопа корректируется 220 раз в секунду.
Роторы гироскопов GP-B изготовлены настолько совершенными, что можно исключить из рассмотрения вероятность прецессии из-за механических дефектов или электрических сил. Прибор способен зафиксировать смещение осей вплоть до 0,5 миллисекунд угловой дуги в год. Для сравнения, этот угол будет примерно равен углу, под которым виден человеческий волос с расстояния 32 км. Согласно ньютоновской механике, совершенный сферический гироскоп в отсутствие внешних сил не испытывает прецессии, то есть если вначале его ось была направлена на определённую звезду, она будет оставаться в таком положении всегда. В 1960 году доктор Леонард Шифф из Стенфордского университета на основании уравнений Эйнштейна и уравнений движения частицы со спином, выведенных Папапетру (уравнения Папапетру-Диксона (англ.)), вычислил величину прецессии осей гироскопов и предложил произвести эксперимент, либо в лаборатории на Земле, либо в космосе. Из его расчётов следовало, что эффект в лаборатории будет на несколько порядков меньше, поэтому орбитальный эксперимент более предпочтителен.
Основная научная аппаратура спутника:

  • Основные приборы — корпус гироскопа, телескоп и несущие конструкции — изготовлены из кварцевого стекла. Кварц практически не подвержен тепловому расширению в широком диапазоне температур — расширяется и сжимается очень мало и очень однородно. Кварцевые детали были изготовлены компанией Speedring из города Куллман, штат Алабама.
  • Главный телескоп имеет апертуру 14 см и направлен на двойную звезду IM Пегаса (HR 8703).
  • Техники центра Маршалла (Marshall Space Flight Center) создали совершенное полировочное оборудование, позволившее им выточить самые сферические объекты из когда-либо изготовленных человеком — роторы гироскопов спутника. Шероховатость поверхности сфер составляет всего несколько десятков атомных слоёв — если увеличить их до размера Земли, самая высокая гора или самая глубокая впадина будет всего 2,4 метра в высоту.
  • Инженеры в Стенфорде разработали технологию нанесения тонкой (всего несколько нанометров в толщину) сверхпроводящей ниобиевой плёнки на поверхность сферы.
  • Основное измерительное оборудование GP-B помещено в сигарообразную 2,7-метровую криогенную ёмкость, окружённую слоем сверхпроводящей свинцовой фольги для защиты от внешних магнитных полей. Эта ёмкость, в свою очередь, вместе со сверхпроводящей оболочкой, помещена в сосуд Дьюара, в момент запуска содержавший 2441 л жидкого гелия. Для поддержания ниобиевой плёнки в сверхпроводящем состоянии необходимо поддерживать криогенную температуру 1,8 К.
  • Направление оси вращения гироскопа детектируется по магнитному моменту (Лондоновскому моменту), который генерирует вращающийся сверхпроводник. Детекторами поля служат квантовые интерферометры (СКВИДы) с чувствительностью, позволяющей измерять магнитное поле на 10 порядков более слабое, чем поле Земли.
  • Сверхтекучий гелий в сосуде Дьюара спутника служит не только для поддержки криогенной среды, но и как рабочее тело реактивных микродвигателей для манёвров при точной наводке телескопа.
  • Более 400 электрических проводов, а также звёздный свет, который попадает в криогенную среду, нагревают сосуд Дьюара. Из-за этого тепла жидкий гелий потихоньку выкипает. Поэтому специалисты Стенфорда изобрели специальную «пористую пробку», которая отводит выкипевший газообразный гелий из сосуда Дьюара, оставляя только жидкий гелий и поддерживая необходимую криогенную температуру.
  • Газообразный гелий пропускается через несколько внешних охлаждающих слоёв сосуда Дьюара, а затем выбрасывается в космос одним из восьми микродвигателей на борту спутника. На основании данных телескопа и положения гироскопов, выходящий гелий аккуратно дозируется таким образом, чтобы поддерживать один из четырёх гироскопов строго в центре масс всей системы.

Дополнительные наименования

#НаименованияПоиск в новостяхПоиск в документах
128230НайтиНайти
22004-014AНайтиНайти

Дополнительная классификация

#Наименования
1Тип орбиты - НОО
2Страна оператор(владелец) - США
3Страна производитель - США
4Тип оператора(владельца) - государственный

Новостная лента[Найти информацию в новостях] [Найти информацию в документах]

#Новостная лента.
12005-01-21. Получены отказы от быстрых протоновТэги: Gravity Probe B

Технические характеристики

#ХарактеристикаЗначение
1Масса КА, кг3100
2Габариты, метра6.4x6.2
3Мощность, Вт606
4Мощность (платформа), Вт293
5Мощность (полезная нагрузки), Вт313

Характеристики орбиты

#ХарактеристикаЗначение
1Наклонение, градусов90
2Период, минут97.6
3Апоцентр, км645
4Дата окончания работы2010-12-08
5Перицентр, км641

Пусковые характеристики

#ХарактеристикаЗначение
1Космодром База Ванденберг
2Средство выведения 1x*Delta 2 (7920, 7925)
3Дата пуска2004-04-20
4Код NSSDC2004-014A

Экономические характеристики

#ХарактеристикаДата измеренияЗначение
1Разработчик Lockheed Martin
2Прогнозируемая стоимость (разработки), млн. долл.2000-04-01615
3Прогнозируемая стоимость (разработки), млн. долл.2001-04-01631
4Прогнозируемая стоимость (разработки), млн. долл.2002-04-01667
5Прогнозируемая стоимость (разработки), млн. долл.2003-01-01709.3
6Прогнозируемая стоимость (проекта), млн. долл.2003-01-01734.9

Информация об удачном запуске

#ХарактеристикаЗначение
1Дата пуска2004-04-20 at 16:57:26 UTC
2Полезная нагрузка 1xGravity Probe B
3Ракета-носитель 1xДельта 2

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... Universe Give Me a Boost – How Gravity Assists Aid Space Exploration Can.... ▼ Lesson 2: Give Me a Boost — How Gravity Assists Aid Space Exploration The... Universe Give Me a Boost – How Gravity Assists Aid Space Exploration Can... being compressed under its own gravity, is thought to be ultimately... Galilei in 1610. Jupiter’s immense gravity exerts strong tidal forces on... the trajectory so that the gravity of the target world continue... its mainly by the Earth’s gravity, which is pulling the engines... Sun with course correction or gravity assist maneuvers. the same as... quick “back-of-the-envelope” gravity assist trajectory, the MESSENGER spacecraft... no human method known as gravity assist where a spacecraft has been.... Often, the proposing team lower gravity to making sure the dangerous... http://discovery.nasa.gov/ NASA: Gravity Assist Primer http://www2.jpl... being compressed under its own gravity, is thought to be ultimately... Galilei in 1610. Jupiter’s immense gravity exerts strong tidal forces on... action of water, ice, wind, gravity where they are then deposited... action of wind, rain and gravity) or create new ones (e.g., a river... of water, ice, wind, and gravity, with the eroded materials often... action of wind, rain and gravity) or create new ones (e.g., a river... agents of erosion (wind, water, gravity) might have generated the alluvium... of rain, wind, ice, or gravity) [Hint: remember which planet the... agents of wind, water, and gravity. For example, sand dunes Lesson... have degraded, probably due to gravity, since wind and water are... the star-planet system that gravity can cause stars and planets... Unseen planet focused by the gravity of a foreground (“lens”) star (see... be explained best Figure 6. The gravity of a star (“lens star”) passing... Design Education Module n D es Figure 1. Gravity assists are an important part...; top left), the spacecraft performed gravity-assist maneuvers while flying by... the various ways in which gravity assists can be Version 1.1 – June..., and angular momentum. ▼ Describe how gravity can be used to modify... to modify the spacecraft’s trajectory. ▼ Gravity-assist maneuvers are used to... orbit around Mercury in 2011. Gravity assists from each flyby are... Key N Give Me a Boost GER gravity-assist maneuvers. MES SE S ta... energy vary as a planet planet’s gravity and direction of motion—and...’s reference frame. The spacecraft approaches Gravity assist is a technique used by... spacecraft flies N Give Me a Boost Gravity Assists MES SE the acceleration..., the Venus and Mercury gravity-assist flybys gravity-assist maneuvers are one... the target planet’s velocity around gravity assists as an integral part..., the received a gravity-assist boost to its velocity so gravity-assist trajectory... target planet makes the the gravity-assist maneuver, the journey would... Gravity Assists in Space Exploration Mercury in March 2011, uses a complex gravity- Gravity...; exploration. Before the concept of gravity-assist that is, to change... is through the concept of gravity assists. For example, Lesson Overview... follow the directions to explore gravity assists using the simulation Web... students the different types of gravity assists they explored using the... are behind the concept of gravity-assist maneuvers. Ask the students... works in the case of gravity assists, even though the spacecraft... the quantities between the objects. Gravity works well in this respect..., including the trajectories and any gravity-assist maneuvers used in the... of a complex trajectory involving multiple gravity assists was conceived, a mission to... so many spacecraft missions use gravity-assist maneuvers; they do so... possible at present time without gravity assists. ▼ Hand out to the... the connection between the different gravity assist scenarios and elastic collisions...://www.nap.edu/html/nses/ Gravity Assist Discussion at the MESSENGER... http://messenger.jhuapl.edu/the_mission/gravity.html Gravity Assist Simulator http://www... Propulsion Laboratory: Interplanetary Trajectories and Gravity Assists http://www2.jpl.nasa... use an online gravity assist simulator to explore how gravity assists can aid space exploration. Directions 1. Navigate to the Gravity... you predicted? Mi Student Worksheet 2: Gravity Assist Simulator ss io page... N page 2 of 5 GER Student Worksheet 2: Gravity Assist Simulator MES SE final... know? Part 3: New Horizons: Jupiter Gravity Assist The New Horizons spacecraft.... However, it still needs a boost (gravity assist) from Jupiter to reach... dwarf planet Pluto. Without the gravity assist, New Horizons spacecraft would... a N page 3 of 5 GER Student Worksheet 2: Gravity Assist Simulator MES SE result... a gravity assist from Jupiter along the way. Part 4: MESSENGER: Venus Gravity Assist...: N page 4 of 5 GER Student Worksheet 2: Gravity Assist Simulator MES SE a) In.... N page 5 of 5 GER Student Worksheet 2: Gravity Assist Simulator MES SE Answer... when a complex journey using multiple gravity assists was conceived in the... (Mission Operations Center of the Gravity Probe B spacecraft at Stanford University; bottom...



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... to Jupiter on August 5. The Gravity Recovery and Interior Laboratory (GRAIL... physiological effects from radiation, reduced gravity and microgravity, and terrestrial environments... of an asteroid in low gravity. A submersible simulated a crew excursion vehicle... at the Red Planet. The probe began its 3,340th day in... of the moon by Jupiter’s gravity as Io orbited the largest...’s Dawn spacecraft became the first probe ever to enter orbit around... of eight science instruments to probe beneath the gas giant’s obscuring... 10, 2011, NASA’s twin lunar Gravity Recovery and Interior Laboratory (GRAIL... the moon to measure its gravity field. GRAIL answered long-standing...’s influence is wielded through its gravity, radiation, solar wind, and magnetic... locations. The journey required many gravity-assists from the moon and... where the moon and Earth’s gravity balance perfectly. These locations were... sky, NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) space mission concluded its... and carbon monoxide molecules to probe the chemical reactions, motions of...-years. On May 3, 2011, NASA’s Gravity Probe B (GP-B) mission confirmed two key... changes moved its center of gravity, reduced its angle of attack... the potential benefits of A e r o n a u t i c s a n d R e p o r t current probe-based metrology for mandrels. These... scale calibration of optical, scanning probe, and scanning particle beam instruments... commissioned high-resolution airborne magnetic, gravity, and radiometric (gamma-ray spectroscopy... km 87.8 min 28.5° NASA’s Gravity Recovery and Interior Laboratory (GRAIL... and Flow) mapped the moon’s gravity field to study its subsurface... R Gravity Probe B General Purpose Heat Source Radioisotope Thermoelectric Generator Global Positioning System Gravity... Survey Explorer Wilkinson Microwave Anisotropy Probe A c t i v i t i e s unmanned aircraft system; unmanned aerial...



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...-Venus-Earth-Jupiter Gravity Assist VVVGA . . . . . . . . . .Venus-Venus-Venus Gravity Assist WFC... experiments; e.g., solar U.V., meteoric impacts. (c) Intermediate gravity tracking for other experiments; e.g., cosmic... finish, data on center of gravity, moments of inertia, dynamic balancing... Observatory has not been started. GRAVITY PROBE-B Gravity Probe-B is designed to be a cornerstone... theory, and alternative hypotheses exist. Gravity Probe-B will measure both the distortion... processes, and to understand how gravity affects and has shaped life... mechanisms by which organisms perceive gravity and transmit the information to..., to determine the role of gravity in reproduction, development, maturation, and... interactions between planetary bodies as gravity. 6 By the early seventeenth century... intelli6. Newton’s famous work on gravity and other physical principles is... that a probe launched to Jupiter could leverage that planet’s gravity to boost it to Saturn, where it would receive another “gravity... scientists to create high-resolution gravity and surface maps of over... support itself against the Venusian gravity. Clearly a large amount of the... control and sensing systems in a gravity-free environment poses special problems... as seismic activity (3-axis seismometer), gravity and tilt, magnetic field, temperature... on Minovitch’s work by calculating gravity-propelled trajectories to the outer... method. NASA planned to use gravity-assisted trajectories as the basis... mission and renamed it Voyager. Gravity-assisted trajectories have also been... derived in this fashion, utilizing gravity perturbations from Jupiter, for reduction... the method “gravity propelled interplanetary space travel” or simply “gravity propulsion.” It is popularly known as “gravity-assist trajectories... as how and when the gravity propelled encounter sequence, Earth-Jupiter... the computer code for my gravity propelled trajectory program, or a description...–109. 5. Minovitch, M. A., “The Invention Of Gravity Propelled Interplanetary Space Travel: A Technical... Propulsion Laboratory,” Oct. 1997. 6. Reichhardt, T., “Gravity’s Overdrive,” Air and Space Smithsonian..., R. L., et al., “The Origin of Gravity-Propelled Interplanetary Space Travel,” 41st.... 90–630. 8. Dowling, R. L. et al., “Gravity Propulsion Research at UCLA and...: (1) the planetary magnetic field, (2) Uranus’ gravity field, [J2] and satellite masses... local relief, elevations, and slopes. Gravity data are required for geophysical..., the baseline mission now includes a gravity assist from Mars. This will... resources mapping mission and a lunar gravity-topography mission, both of which... a 6.7-year Venus-Venus-Earth-Jupiter-Gravity-Assist (VVEJGA) trajectory to Saturn... an 8.8-year Venus-Earth-Earth-Gravity-Assist (VEEGA) trajectory and a backup... a 10.3year Venus-Venus-Venus-Gravity-Assist (VVVGA) trajectory to Saturn... mission to Saturn requires planetary gravity-assist trajectories; and (3) the spacecraft... launch phases and the Earth-Gravity-Assist trajectories) from the primary... and before the final planetary gravity-assist, the spacecraft could eventually... employ a Venus-Venus-Earth-Jupiter-Gravity-Assist (VVEJGA) trajectory to Saturn... 2001 using a Venus-Venus-Venus-Gravity-Assist (VVVGA) trajectory. A backup opportunity... lower risks for the Earth gravity assist (EGA) swingby segment. Both... 2), late launch (Phases 3-8) and Earth Gravity Assist (EGA). The pre-launch.... There are other theories of gravity that agree with Einstein’s within... prediction more accurately led to Gravity Probe A, the first space experiment specifically..., William Fairbanks in 1964 proposed Gravity Probe B (GP-B). Although work was started... the first time. To detect gravity waves longer than those observable... be estimated. Since the surface gravity and resulting pressure decrease together... the influences of wind and gravity or from a balloon. Balloons fly... of external torques due to gravity gradients, magnetic fields, and air.... With access to the reduced gravity environment of space, scientists might... experiments, called Gravity Probes, with which NASA became involved. While Gravity Probe A flew on a sounding rocket in 1976, Gravity Probe C, proposed by the European Space Research Organization, was ultimately cancelled. Gravity Probe... the attached summary document for Gravity Probes that was prepared for... operation in zero gravity, dewar-gyroscope operation in zero gravity, and optical... Very Large Space Telescope (VLST), gravity wave experiments using laser interferometry... is the investigation of relativistic gravity effects to test gravitational theories... gravitational effects in the strong gravity field close to the Sun.... Edmund Nowinski Prof. Bradford Parkinson Gravity Probe B Hansen Experimental Physics Laboratories Stanford... cosmic rays • Measure how strong gravity operates near black holes and..., 612, 618, 621, 624 Earth Gravity Assist, EGA, 486 Earth Observing...



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NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Gravity Probe B Experiment “Testing Einstein’s Universe” Press... GENERAL RELEASE & MEDIA SERVICES INFORMATION .............................5 GRAVITY PROBE B IN A NUTSHELL ................................................................9 GENERAL RELATIVITY — A BRIEF... (400 miles) above Earth, the Gravity Probe B spacecraft will circle the globe... the general theory of relativity, Gravity Probe B will monitor any drift in... II. More information about the Gravity Probe B mission is available at: http... will be available from the Gravity Probe B Public Affairs Office at Stanford... Briefings & Launch The launch of Gravity Probe B from Vandenberg AFB, California, is....edu. In addition, there is a Gravity Probe B section on NASA’s Marshall Space.../index.htm. 8- Gravity Probe B in a Nutshell Brief Summary of the Gravity Probe B Relativity Experiment... force. The experiment aboard the Gravity Probe-B spacecraft is designed to measure... quantify these minuscule relativistic effects. Gravity Probe-B’s measurement of the geodetic effect... directly been measured before, but Gravity Probe-B is expected to determine its... order to carry out the Gravity Probe B experiment. The spherical gyroscopes have... lifespan, spin offs from the Gravity Probe B program have yielded many technological..., but perhaps most important, the Gravity Probe B program has had a profound effect... way to think about gravity. If the Gravity Probe-B experiment corroborates the two... of matter. Whatever the result, Gravity Probe B will provide us another glimpse... studies 1973 Gyroscope experiment becomes "Gravity Probe B" 1973 J.R. Nikirk designs gyro electrical... Pound-Rebka Experiment and NASA’s Gravity Probe A. In 1960, physicists Robert Pound... the redshift was conducted by Gravity Probe A in 1976, a rocket-based experiment.... Will Gravity Probe B Verify or Refute Einstein? Will the results of Gravity Probe B verify... the motion of matter. Will Gravity Probe B Reveal Where “Inertia” Comes From... creates the property of inertia. Gravity Probe B’s investigation of frame-dragging will.... This is the mission of Gravity Probe B: to experimentally measure our local... ever before. The Mechanics of Gravity Probe B The Gravity Probe B experimental design is as...-dragging effect. In other words, Gravity Probe B intends to use gyroscopes and... arcseconds, or 21.6 million milliarcseconds. Gravity Probe B must be able to measure... Space Vehicle All of the Gravity Probe B technologies are integrated into one... specifically for use in the Gravity Probe B mission. Inside the Dewar A Dewar... being readied for launch. The Gravity Probe B Space Vehicle 32- Science Instrument... vacuum chamber inside the probe and Dewar. Before Gravity Probe B was completely integrated... which a satellite is pointing. The Gravity Probe B satellite contains two star trackers... with the guide star. The Gravity Probe B on-board telescope basically performs... Overview The purpose of the Gravity Probe B Relativity Mission satellite is to... from the Gravity Probe B Mission Operations Center (MOC), located in the Gravity Probe B building... 75 minutes after launch, the Gravity Probe B Space Vehicle will separate from... and early orbit mission phase. Gravity Probe B — Launch & Early Orbit Nominal Timeline... timeline of the IOC activities. Gravity Probe B — Nominal Timeline of IOC Activities... L+22 Days) Spinning up the Gravity Probe B gyroscopes is a delicate and complex... Einstein’s theory of general relativity, Gravity Probe B must measure two minuscule angles...’s. The GP-B Science Instrument The Gravity Probe B science instrument takes the shape... and 40.9 milliarcseconds per year— Gravity Probe B needed to build a near-perfect... interfering supports. Spinning Superconductivity Each Gravity Probe B gyroscope is nearly perfectly spherical... metal. Here was the “marker” Gravity Probe B needed. GP-B scientists coated each... axis of the magnetic field, Gravity Probe B knows precisely which direction the... one readout scheme perfect for Gravity Probe B: extremely sensitive, extremely stable, applicable... the greatest technical challenges for Gravity Probe B is to keep its science... Department as an offshoot of Gravity Probe B research. Drag-free technology is... quasars separately, so that the Gravity Probe B gyroscope measurements can be related... determined with high accuracy for Gravity Probe B to be successful. IM Pegasi...” that obscures it. For the Gravity Probe-B experiments, however, that choice was... the precision of the instruments. Gravity Probe B’s four gyroscopes, housings, and telescopes...+ year lifespan, spinoffs from the Gravity Probe B program have yielded many technological... for Commercial Use Spinoffs from Gravity Probe B aren’t limited to aerospace applications... optical systems. Photo-diode Detectors Gravity Probe B engineers created a revolutionary detector mount..., but perhaps most important, the Gravity Probe B program has had a profound effect... minds. As of October, 2003, Gravity Probe B had produced 78 doctoral dissertations...



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... activities continue on the Relativity (Gravity Probe-B) mission, which is now scheduled... space, and the effects of gravity on plant photosynthesis and respiration...-outs, weight and center of gravity measurement, and rack/component to... for studying the role of gravity on biological, physical and chemical... in diameter will provide artificial gravity, generating forces ranging from 0.01... 2.0 g (i.e., from 1/100 to twice the gravity on Earth). Specially developed "holding... without the complications introduced by gravity and perform high-resolution tests...: solution crystal growth in low gravity; organic fiber optic sensors; hydrology... of life forms to reduced gravity. Dryden Flight Research Center (DFRC... DSN antenna distortions due to gravity and wind buffeting. Development of... Relativity Mission (also known as Gravity Probe-B) is to verify Einstein's theory... integration and test of the Gravity Probe-B science payload with the spacecraft.... SAT 1-13 ACCOMPLISHMENTS AND PLANS Gravity Probe-B was proceeding toward a September 2001... will initiate a termination review for Gravity Probe-B. Accomplishments in FY 2000 included... again in November 2000 and Gravity Probe-B is now proceeding toward an..., the satellite will be given gravity assist maneuvers once by Mars... its moons, studying surface properties, gravity fields and magnetic fields, and..., examining the ultimate limits of gravity and energy in the universe... high-resolution studies of atmospheric gravity waves, calibration of the TIMED... continue leading the Relativity Mission (Gravity Probe-B) and will continue to manage... effects of returning to Earth’s gravity after space flight. BR&C: 1) provides... understanding of the role of gravity in biological processes and provide... determining the combined effects of gravity and other space environmental factors... investigations of: the effects of gravity on plant growth and physiology... space, and the effects of gravity on plant photosynthesis and respiration... for the development of low-gravity technology required to SAT 2-18... ESSP missions have been selected, Gravity Recovery and Climate Experiment (GRACE... (2001) – time variations of Earth’s gravity field ICEsat (2001/02) - ice... is TBD. The second mission, Gravity Recovery and Climate Experiment (GRACE... resulted in TBD launch date. Gravity Recovery and Climate Experiment Plan... understand variations in the Earth’s gravity field related to partitioning of... mass flux estimation from temporal gravity field observations in preparation for... cannot support themselves in Earth gravity. To obtain the maximum structural..., and flight operations of the Gravity Probe– B (GP– B) flight experiment. The GP... opportunity to use the low gravity environment of space as a catalyst... of life forms to reduced gravity and the biotechnology which supports... continues into the effects of gravity on living systems using spaceflight... hypergravity facilities to understand how gravity affects the development, structure, and... may initiate a termination review for Gravity Probe-B. The estimates provided below include..., “Explore the ultimate limits of gravity and energy in the Universe...; explore the ultimate limits of gravity and energy in the universe...: Explore the ultimate limits of gravity and energy in the Universe... and determine the role of gravity in this process. • Establish how... of the forward pressure bulkhead. • Gravity Probe-B (GP-B) Development: Initiate flight vehicle... integration and test of the Gravity Probe-B science payload with the spacecraft..., conduct planning for the Jupiter gravity-assist flyby, and explore early... and determine the role of gravity in this process. (2) Establish how... ice mass changes based on Gravity Recovery And Climate Experiment (GRACE... mass flux estimation from temporal gravity field observations in preparation for...). launch in September time-varying gravity 1999. (Y6). observations for the... flight exposes humans to low gravity and radiation environments never before... scientists study the role of gravity in important industrial processes. Physicists... researchers investigate the role of gravity in life processes and how... understanding of the role of gravity in complex chemical, biological, and... when space travelers return to gravity. NASA research will identify methods... partnership with the scientific community. Gravity’s influence is everywhere. From the..., gravity plays a role. Researchers can only eliminate the effects of gravity in space. In space, we can study how gravity has... materials and combustion science using gravity as a theoretical and experimental revealing... area: • Understand the role of gravity in biological processes at all... study transit, orbital, and of gravity on the nervous surface radiation... area: • Understand the role of gravity in biological processes at all... open symposium relaying (ITEA), for gravity related the results of spaceeducational... area: Understand the role of gravity in biological processes at all... materials and combustion sciences using gravity as a theoretical and experimental revealing...



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... only through the pull of gravity? INTRODUCTION 5 Could there be particles... force? Perhaps their portraits of gravity, like unfinished masterpieces, require extra... together through the force of gravity. Examining the Coma Cluster (in... signs its name only with gravity’s mark? Early on, scientists supposed... charging full speed ahead. Ordinary gravity cannot account for such acceleration... demonstrated that the strength of gravity varies in inverse proportion to... going in a straight line, but gravity continuously pulls it toward Earth... an essentially circular path. Though gravity is a force, inertia is not... two critical omissions: acceleration and gravity. An avid reader of Mach... same rate? Clearly, he surmised, gravity’s pull cannot just depend on... fashion to his earlier theory, gravity came to Einstein’s attention in... terrestrial gravity, for example; a piece near Jupiter would describe Jovian gravity. All... from other possible theories of gravity. Determining that the Sun’s gravitational... description of the workings of gravity. Nevertheless, many theorists take issue... known as quantum chromodynamics. Yet gravity, the fourth force, remains the... items, but not so for gravity. Gravity, considered on its most miniscule... the correct pathway to quantum gravity. Such theories predict that for... to measurably different results. Thus, gravity would have two different faces... first instants of the universe, gravity could scarcely be distinguished from... another. In those turbulent moments, gravity and the other forces could... centers of collapsed stars, where gravity wears titan’s boots, the conventional... different jobs? General relativity describes gravity as a geometric effect in four... at the same rate under gravity. Refining Eötvös’s concept even further.... An orbiting satellite called GP-B (Gravity Probe B) is currently engaged in a far... him with compelling accounts of gravity’s actions in the universe. “My... experts in highprecision measurements of gravity. The capstone of Weiss’s career... symmetry, or sameness. Then, somehow gravity separated from the other three... inflation (where a field interacts with gravity, causing it to eventually put... constant term. The attraction of gravity overpowered the repulsion of lambda... for the outermost orbits, where gravity tugs weakly. For example, distant.... What are their secret identities? GRAVITY’S LENS One prominent category of.... Using the Einsteinian result that gravity bends light, he developed the... could unite other interactions with gravity into a single model. Meanwhile, Wess... through Earth. Only extremely sensitive gravity wave detectors, well beyond current... and garden variety materials; only gravity could provide a connection. Thus, a particle...” that enables spacecraft to overcome gravity and effortlessly lift off from... (including Randall-Sundrum) postulate that gravity takes a different form on various..., which would naturally explain why gravity seems strictly attractive on the... from the standard law of gravity. Nevertheless, theorists have pressed on... of repulsive force. Over time, gravity would increasingly cower before its... Newton’s inverse-square law of gravity. It too contains a seemingly enduring... ticked, gravity would become slightly weaker. Consequently, by 1040 ticks, gravity would... supporters over the decades. CHANGING GRAVITY Spurred by Dirac’s curious notion... relativity. Another model of changing gravity was developed several years later... dark-energy conundrum. A diminution in gravity’s strength would offer a natural way... Chandrasekhar limiting mass, depend on gravity’s strength. Subsequently, if G varies, the... spin, are sensitive measures of gravity’s strength. Hence, geophysics provides us... a prize-winning essay in the Gravity Research Foundation competition. ATLAS UNBOUND... According to these arguments, if gravity’s strength has decreased with time... test of theories of changing gravity has been whether geophysical evidence.... Kaluza’s theory thus showed how gravity and electromagnetism as four-dimensional... dimensions were required to merge gravity with the other interactions. This... field theory. Attempts to quantize gravity in a similar manner to electromagnetism... this situation by proposing that gravity, at ultrahigh energies, forms part... brane designed to replicate precisely gravity’s distinctive behavior. BRANE BENDERS In... the long-established law of gravity. Such a minute difference could be.... Given the essential relationship between gravity and mass, one might presume... of gravity as a force. Even after Einstein informed us that gravity is... would generate regions of strong gravity. These would serve as spawning... dimensions, Smolin delving into quantum gravity, Linde speaking about inflation, and... arranged by Francis Everitt at Gravity Probe B, at Stanford. His views were... Classical Tests in Kaluza-Klein Gravity,” Astrophysical Journal, vol. 439, p. 548... and Constraints on Higher-Dimensional Gravity,” Physical Review D, vol. 62, p. 102001... Gravity Probe B (GP-B) satellite, 64, 65, 66, 67–68 Gravity Research Foundation, 158 Gravity...



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... Operatl Environ Satellite B use GOES 2 Gravity Probe B HEAO B X-258Y- use HEAO 2 Helios... gravitropism gravity use gravitation artificial gravity center of gravity low gravity use microgravity reduced gravity use microgravity specific gravity... gravity use weightlessness high gravity (acceleration) use high gravity environments gravity anomalies gravity use high gravity gravity gravity low gravity gravity use gravity Gravity Gravity... perception Probe B Recovery and Climate Experiment mission use GRACE mission Gravity Recovery... probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe... probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe lunar probe... distribution functions probability theory probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe) use Microwave Anisotropy Probe probe probe probe probe probe probe probe probe probe probe Mariner 11 space... plasma pneumatic probe probe Probe probe probe probe probe use Pioneer 4 space probe probe probe probe probe probe probe probe probe probe use Pioneer Venus spacecraft probe use Pioneer 10 space probe probe use Pioneer 11 space probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe probe Probe B probe method... probe) use Microwave Anisotropy Probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe... space probe space probe space probe space probe space probe space probe space probe space probe space probe space probe...



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... of lab-based tests of gravity” The workshop will take place... inquiry based lessons on spectroscopy, gravity and stellar evolution. In addition... of the Acceleration Due to Gravity Bill Crummett1 1 Centre College. 068....11 NASA’s Gravity Probe B Mission: Was Einstein Right? Shannon K. Range1 1 NASA’s Gravity Probe B at... Univ.. 230.02 StarSpotz: A Sensitive Probe of the Differential Rotation Profile....04 Measurement of the Surface Gravity of ␩ Boo Gerard van Belle1... in 3-year Wilkinson Microwave Anisotropy Probe Data Kevin M. Huffenberger1, H. K. Eriksen2, F. K. Hansen2... necessarily enhanced by the self-gravity. Their growth may be deteriorated... at the longest wavelengths, which probe the largest redshifts. Analysis of... widely exploited as a radio jet probe. To determine CP variability properties... follow different evolutionary tracks. A principal probe of this evolution are metal... observations are just beginning to probe the detailed chemistry of the... planet formation, we need to probe the physical conditions of protoplanetary... which the signature of inflationary gravity waves ͑or “B-modes”͒ is expected... search for the signal from gravity waves excited during an inflationary... include NASA’s Wilkinson Microwave Anisotropy Probe and the Sloan Digital Sky... phenomena and serve as a sensitive probe of the structure and composition... describes a design concept for such a probe under study at Ball Aerospace... to an operational orientation. Each probe accommodates a payload of several kilograms... excitation or cratering experiments. The probe provides a standard suite of services... the surface of a micro-gravity body. Such a basic probe could become a low... Keck II 10-meter telescope probe deeper atmospheric levels and show... be. Formaldehyde is a proven molecular probe for this purpose. Measurements of... line ratio may become a sensitive probe of physical conditions in Class... needed to make this potential probe a quantitative one. This project was... gravitational lensing. The velocity with gravity alone is calculated in a variety... strength about 0.4 0.8 times that of gravity would provide the needed additional... projections within a looser group. We probe the evolution of galaxies in... rich in absorption features that probe the characteristics of galactic outflows... detailed parameters ͑effective temperature, surface gravity and composition͒ for nearly 1,000... that flew aboard NASA’s zero gravity airplane last May. 043.03... NASA’s Beyond Einstein Program, would probe the physical mechanism responsible for... detector development. Black Hole Finder Probe to EXIST:Surveying Black Holes..., studied as a Black Hole Finder Probe within NASA’s Beyond Einstein Program..., implying that the X-factor can probe sub-cloud structure. While this... AAPT, APS and NASA’s Reduced Gravity Program. My Top Ten List... required to reproduce the trajectory: gravity, buoyancy, the drag force and... of the Acceleration Due to Gravity Inservice Preparation of High School... holes, gravitational lensing, dark energy, gravity waves--are rooted in the... matter, the quarks and leptons. Gravity and particle physics, long separate....gov. NASA’s Gravity Probe B Mission: Was Einstein Right? Shannon K. Range1 1 NASA’s Gravity Probe B at...’s theory of general relativity -the Gravity Probe B mission based at Stanford University... of physics and engineering innovations, Gravity Probe B was ready to go. In... cluster environments feature full 3D gravity and realistic temperature and density... demographics and the behavior of gravity in the strong, non-linear... under the balance between central gravity, centrifugal force and the pressure... it cannot balance against the gravity, making a dense part of the..., Italy. 1 The COMPLETE ͑COordinated Molecular Probe Line Extinction and Thermal Emission... Attitudes about Science Survey to probe students’ beliefs at different stages... full spectral range, important to probe the nature of extrasolar giant... such as composition and surface gravity. All of this recent scrutiny... a massive young star and provide a probe of the stellar environment on... host galaxies offer a powerful, direct probe of the AGNgalaxy connection. We... 21 cm line offer a promising probe of early radiation backgrounds. Anisotropies..., thus providing the needed independent probe of the gigaparsecscale Universe. In... analyzing smaller-scale surveys to probe the late integrated Sachs-Wolfe... Sachs-Wolfe ͑ISW͒ effect to probe the evolution of the gravitational... identified through radio observations which probe relativistic material. Motivated by SN... distance from the center of gravity of NGC 346 will indicate... optical spectropolarimetry as a tool to probe the three-dimensional structure of... the Surface Gravity of ␩ Boo 230.02 StarSpotz: A Sensitive Probe of the... from the MOST investigation, a surface gravity of log gϭ3.817 Ϯ 0.016 ͓cm... equilibristic skills to demonstrate gyroscopics, gravity, inertia and other topics in... differential MIR photometry allows to probe the cool atmospheres of the... in 3-year Wilkinson Microwave Anisotropy Probe Data We discuss the Atacama...



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... "clumpy" as it collapses under gravity. Mapping dark matter's distribution in... such as Jason and the Gravity Recovery and Climate Experiment (GRACE... Aquarius) and three operating missions (Gravity Recovery and Climate Experiment [GRACE... Decadal Survey. Gravity Recovery and Climate Experiment (GRACE) The Gravity Recovery and... ESSP mission. GRACE measures Earth's gravity field and its variations with... Dev Ops Res OCO Aquarius Gravity Recovery and Climate Experiment (GRACE...; Institut fur Umweltphysik, Bremen, Germany. Gravity Recovery and Climate Experiment (GRACE... Resource Identification and Security (OSIRIS), Gravity Recovery and Interior Laboratory (GRAIL... Lunar Reconnaisance Orbiter (LRO) and Gravity Recovery and Interior Laboratory (GRAIL... will be cruising toward a Mars gravity assist in March 2009. ASPERA...-1 payload, will collect science measurements. Gravity Recovery and Interior Laboratory (GRAIL... 2007 to use that planet's gravity to move the spacecraft's trajectory...'s atmospheric composition and dynamics; and Gravity Recovery and Interior Laboratory (GRAIL... The Gravity Recovery and Interior Laboratory (GRAIL) will perform high-quality gravity... Tech Form Dev Ops Res Gravity Recovery and Interior Laboratory (GRAIL... Principal Investigator and leads the Gravity Recovery and Interior Laboratory (GRAIL... Formulation: Science Planetary Science Discovery Gravity Recovery and Interior Laboratory FY... have declined. Project Purpose The Gravity Recovery and Interior Laboratory (GRAIL... origin and of masons (i.e., high-gravity areas); - study the temporal evolution...-precision measurements of the lunar gravity. GRAIL will ultimately provide a global... on the successful Earth orbiting Gravity Recovery and Climate Experiment mission... Science Discovery Gravity Recovery and Interior Laboratory Project Management The Gravity Recovery... make global maps of the gravity, magnetic fields, and atmospheric composition..., high-sensitivity radiometers, magnetometers, and gravity science systems. Juno's 32 orbits..., ion & electron sensors Same Same Gravity Science Jet Propulsion Lab (JPL... MSFC/New Frontiers Magnetometer, and Gravity Program Office Science Experiment Jet... holes, and the nature of gravity. APG 9AS1 Demonstrate progress in..., Programs and the nature of gravity. Progress will be evaluated by...'s prediction that a repulsive form of gravity emanates from empty space. Data... 9AC5 Validate a ground analog fractional-gravity test Human methodology to assess... suit weight, pressure, center of gravity and kinematics. None APG 9AC4... analog fractional-gravity methodology to assess whether lunar gravity is protective of... suit weight, pressure, center of gravity, and kinematics. Exp-60 Mission... exploration, the effects of gravity transitions, low gravity environments, and limited communications... protocols, integrated physiological countermeasures, partial gravity human performance predictions and requirements... on joint flight proposals, reduced gravity studies, and collaborative bed rest.... This research focuses on reduced gravity investigations in the life and... vehicle, LCROSS will use a lunar gravity assist to achieve a highly inclined... the unique environment of reduced gravity in two broad categories – Exploration... from prolonged exposure to reduced gravity, space radiation and isolation during... Program will investigate the underlying gravity-dependent phenomena in the following... holes, and the nature of gravity. APG 8AS01 Demonstrate progress in... holes, and the nature of gravity. Progress will be evaluated by... holes, and the nature of gravity. APG 9AS1 Demonstrate progress in... holes, and the nature of gravity. Progress will be evaluated by... weight, pressure, center of Research gravity and kinematics. Program Advanced Capabilities....4 Yellow FY 2007 Green NASA's Gravity Recovery and Climate Experiment (GRACE... relies on observations of Earth's gravity field to infer oceanic and... matter and that the Newtonian gravity familiar on Earth and in... have proposed alternative theories for gravity where it is stronger on... itself or the gas through gravity, was not slowed. This produced... clusters, as proposed by alternative gravity theories, the data would not... clusters by observing how its gravity bends the light of more... pulled back and flattened by gravity. The findings rely on a special...'s prediction that a repulsive form of gravity emanates from empty space. Data... holes, and the nature of gravity. Progress will be evaluated by... collapse under its own huge gravity. After the violent collapse, runaway... demonstrations in a zero- or reduced-gravity environment, maturing technologies needed by... announced the selection of the Gravity Recovery and Interior Laboratory (GRAIL... of baryons, dark matter, and gravity shapes galaxies and systems of... of baryons, dark matter, and gravity in the evolution of galaxies... Monitoring Experiment-2 Hy-BoLT GP–B Gravity Probe–B Hypersonic Boundary Layer Transition Flight... GRACE Gravity Recovery and Climate Experiment IBEX Interstellar Boundary Explorer GRAIL Gravity...



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..., as well as various micro-gravity experiments for several academic institutions... surveys: measuring parameters of Earth's gravity field, creating a highly accurate geodetic... Mach 1.2 under the influence of gravity. During the descent phase, the... to the programme. ESA’s GOCE gravity mission achieved another major milestone..., ILA 2010, to extend the Gravity Recovery and Climate Experiment - 23... towards Earth for its final gravity-assist swingby, scheduled for 13... the orbit of Europe's GOCE gravity-measuring - 44 - satellite in a successful... AND ADVANCES VI.1 Propulsion ESA’s gravity mission GOCE released its first... that the gravity measurements taken by GOCE are of true gravity, the... km could potentially drown the gravity data. This posed a technological challenge... success of GOCE´s ultra-sensitive gravity measurements depends on finely controlling... explore the extreme Universe. >> ESA’s gravity mission GOCE issued its first... gravitational potential defined by the gravity field - crucial for deriving accurate... a robot using a tether under a micro-gravity environment. >> VI.7 Space Research Facilities... dedicated to measuring the Earth’s gravity field and modelling the geoid... mission objectives are to determine gravity-field anomalies with an accuracy... 1-2 cm. Data from this advanced gravity mission will improve our knowledge... calculations, validated with gravity observations from the Gravity Recovery and Climate Experiment..., terrain camera, radar sounder), for gravity studies (VLBI and data relay... for launch in 2012. GRAIL (Gravity Recovery and Interior Laboratory) was... is to map the lunar gravity field with unprecedented precision, using... UT on 6 October 2008, gaining a gravity assist that tightened its orbit... combination of electric propulsion and gravity assists, the planned cruise duration... and, along with high precision gravity data, revolutionized studies and understanding... of the nominal mission (including gravity measurements and seasonal coverage), to... Jupiter in early 2008 for a gravity assist and scientific studies (see... variation, albedo, spectrum, mineral composition, gravity, and the main chemical composition.... After a successful commissioning phase, a Mars gravity assist was successfully performed in... that the cratering process was gravity-dominated, lending to the notion... to reach the cometary target, gravity assists (and accompanying science studies... in late 2005. A third Earth-gravity assist occurred in November 2009... study of the magnetic and gravity fields with unprecedented precision, and... in another. Observations of Titan’s gravity field and spin state are... important ingredient in geospace variability. Gravity waves generated by hurricanes or... frequencies and scales, such as gravity waves, tides, and planetary waves... X-ray sky monitoring and survey. gravity waves sub-mm LISA Pathfinder... Biology Here, we focus on gravity perception, genetic and physiological modifications... response to microgravity or simulated gravity. Genetic studies are typically paired...-based low-G simulation; gravity perception and orientation; gravity scale effects; centrifuge high... plants are light and gravity. With regard to gravity, this is quite... increasing evidence, that changes in gravity are sensed as environmental stress... the involvement of phytohormone transport (gravity-induced changes in the localization... effect in early phases of gravity reception, but can optimize statolithreceptor... (e.g. selfsustained oscillations without impact of gravity), gene expression studies prevail, but... further examine specific steps of gravity sensing and signal transduction, genetically... and Cologne in which artificial gravity, exercises and nutritional measures will... usually negligible with respect to gravity, can dominate fluid behaviour and... reported in the following paragraphs. Gravity Probe-B (US with some data analysis... fields of geopotential modelling (Earth’s gravity and magnetic fields), oceanography (altimeter... strongly supporting mission operations and gravity field determination from a complement of... field of precise orbit and gravity field determinations from Lunar and... improved gravity field models for Mars and a better observation of temporal gravity... NASA for more advanced future gravity field satellites, relying on very... (Category III due to a Mars gravity assist) continues on course, using...’s next Discovery-class mission, the Gravity Recovery and Interior Laboratory (GRAIL... 2016. Juno will map the gravity field, magnetic field and atmospheric... (Category II due to Venus gravity assist), is a joint mission between... Explorer (NASA) fiscal year Earth gravity Global Assimilation of Ionospheric Measurements... Plasma Model Geospace Environment Modelling Gravity and Extreme Magnetism SMEX Geostationary... Model Global Navigation Satellite System Gravity field and steady-state Ocean... Spacecraft Gravity Probe B Global Plasmasphere Ionosphere Density Global Positioning System General Relativity Gravity Recovery and Climate Experiment Gravity Recovery and Interior...