Sentinel-6A (Michael Freilich) – Falcon 9 (B1063.1) – Vandenberg SLC-4E – 21.11.2020 17:17 UTC

Автор zandr, 21.07.2020 00:29:54

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zandr

https://vk.com/spacex?w=wall-41152133_233917
ЦитироватьНовая полезная нагрузка для запуска SpaceX, спутник для наблюдения Земли Sentinel-6 проходит заключительные испытания
Команда инженеров из США и Европы провела ряд заключительных испытаний космического аппарата Sentinel-6, носящего имя Michael Freilich, чтобы подготовить его к запуску на ракете Falcon 9 в ноябре этого года. Спутник назван в честь бывшего директора научного отдела NASA по изучении Земли, Майкла Фрейлича (Michael Freilich). Новый космический аппарат отправится на орбиту вслед за спутником наблюдения за уровнем моря Jason-3, который был запущен в 2016 году, также на ракете Falcon 9.

Научный спутник Sentinel-6 будет собирать самые точные данные об уровне моря - ключевом показателе того, как глобальное потепление влияет на океаны, погоду и береговые линии. Но сначала инженеры должны убедиться, что космический корабль сможет выдержать нагрузки во время запуска и суровые условия космоса. Специально для этого аппарат подвергли тщательному тестированию.

"Если он сможет выдержать всё, чему мы намеренно подвергаем его на земле, значит он готов и к космосу", - сказал Джон Освальд (John Oswald), заместитель проектного руководителя миссии в Лаборатории Реактивного Движения (JPL) в NASA.

Тестирование включало в себя:
Вибротест, в котором спутник Sentinel-6 подвергался вибрационным нагрузкам, аналогичным тем, что он испытает при полёте на ракете Falcon 9.
Затем инженеры провели испытания в большой вакуумной камере и подвергли его воздействию экстремальных температур, с которыми он столкнётся в космосе, в диапазоне от +65℃ до -180℃.
Тест на акустические нагрузки помог удостовериться, что спутник может выдержать подъём на орбиту. Инженеры поместили спутник в специальную комнату, оснащенную огромными динамиками. Затем они направили на спутник четыре 60-секундных звуковых сигнала, с максимальным значением громкости ~140 дБ. Это всё равно что стоять рядом с реактивным двигателем во время взлёта самолёта.
Электромагнитный тест был проведён, чтобы убедиться, что датчики и электроника на спутнике не будут мешать друг другу и давать правильные данные.
В конце мая инженеры завершили серию испытаний космического аппарата, который строится в Германии.

"Испытания завершены, и предварительные результаты выглядят хорошо", - сказал Освальд. В течение следующих нескольких недель будет проведён анализ результатов, а затем спутник отправят на базу Ванденберг в Калифорнии для запуска этой осенью. Он станет первой полезной нагрузкой для запуска с Западного побережья США c декабря 2019, когда SpaceX запустили миссию RADARSAT с 3-мя канадскими спутниками.

Sentinel-6 является частью миссии Copernicus Sentinel-6 / Jason-CS, совместного американо-европейского проекта, в котором два одинаковых спутника будут запущены с интервалом в пять лет. Спутник создаётся сразу несколькими организациями: ESA, NASA, EUMETSAT (Европейская организация спутниковой метеорологии), NOAA (Национальное управление океанических и атмосферных исследований, США) и CNES (Национальный центр космических исследований, Франция).
Спойлер
Космический аппарат присоединится к группировке Copernicus, которая является частью Программы Европейского Союза по Наблюдению Земли (European Union's Earth Observation Programme). Находясь на орбите, каждый спутник будет собирать измерения уровня моря с точностью до сантиметра и покроет наблюдениями 90% мирового океана. Эти данные дополнят почти 30-летние исследования американских и европейских спутников, создав беспрецедентный набор данных по уровню моря за 40 лет наблюдений! Он также будет измерять температуру и влажность атмосферы Земли. Эти данные могут быть использованы для улучшения прогнозов погоды и предсказания ураганов.

Важность этих измерений объясняется крайне тесной связью между океаном и атмосферой. Более 90% тепла парниковых газов уходит в океан. Повышение температуры заставляет морскую воду расширяться, на что приходится примерно одна треть среднего глобального повышения уровня моря. Учёным важно знать уровень моря не только сегодня, но и, для сравнения, 20 лет назад. Необходимы более длительные наблюдения для понимания происходящих изменений, и запуск таких спутников поможет науке в этом.
[свернуть]

zandr

Оттуда же:
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Акустические испытания спутника Sentinel-6  Credit: Airbus

Вы не можете просматривать это вложение.
Спутник Sentinel-6 перед помещением в испытательную камеру  Credit: Airbus

tnt22

Цитировать NASA's Launch Services Program @NASA_LSP 3 ч. назад

Launch Alert 🚀 We are targeting Nov. 10 for the launch of the newest ocean-observer, Sentinel-6 Michael Freilich, aboard a @SpaceX Falcon 9 rocket from Vandenberg Air Force Base in California

tnt22

Цитировать Stephen Clark @StephenClark1 33 мин. назад

This launch is set for 11:45 a.m. PDST, and will include a first stage return to LZ-4 at Vandenberg.

Цитироватьhttps://twitter.com/NASA_LSP/status/1300827174602256384
10 ноября 2020 г. в 19:45 UTC / 22:45 ДМВ

tnt22

#4
https://blogs.nasa.gov/sentinel-6/2020/09/21/nasa-prepares-for-upcoming-launch-of-sentinel-6-michael-freilich-satellite/

ЦитироватьNASA Prepares for Upcoming Launch of Sentinel-6 Michael Freilich Satellite

Anna Heiney
Posted Sep 21, 2020 at 12:56 pm


Illustration of the Sentinel-6/Michael Freilich satellite in orbit. Image credit: ESA

NASA is preparing for the launch of the Sentinel-6 Michael Freilich satellite, an international partnership that is the first launch of a constellation of two identical satellites launched sequentially. Together, they will continue observations of sea level change for at least the next decade. The mission is targeted for launch Nov. 10 at 2:31 p.m. EDT (11:31 a.m. PDT) from Vandenberg Air Force Base (VAFB) in California. Sentinel-6 will launch on a SpaceX Falcon 9 rocket from Space Launch Complex 4, and the launch is managed by NASA's Launch Services Program, based at the agency's Kennedy Space Center in Florida.

Named in honor of the former director of NASA's Earth Science Division, Dr. Michael Freilich, who was instrumental in advancing ocean altimetry, Sentinel-6 Michael Freilich follows the most recent U.S.-European sea level observation satellite, Jason-3, which launched in 2016 and currently is providing high-precision and timely observations of the topography of the global ocean.

Sentinel-6 is part of Copernicus, the European Union's Earth observation program managed by the European Commission. The Copernicus Sentinel-6 missions are being jointly developed by ESA (European Space Agency), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), NASA, and the National Oceanic and Atmospheric Administration (NOAA), with funding support from the European Commission (EC) and support from France's National Centre for Space Studies (CNES).

NASA's contributions to the Sentinel-6/Jason-CS missions are three science instruments for each of the two Sentinel-6 satellites: the Advanced Microwave Radiometer, the GNSS-RO, and the Laser Retroreflector Array. NASA is also contributing launch services, ground systems supporting operation of the NASA science instruments, the science data processors for two of these instruments, and support for the international Ocean Surface Topography Science Team.

Прим.
https://dateandtime.info/ru/country.php?code=US
Цитата: undefinedПереход на зимнее время в США в 2020 году ожидается 1 ноября 2020 года в 2 часа ночи по местному времени. Стрелки часов будут переведены на час назад.

tnt22

https://www.nasa.gov/feature/jpl/new-sea-level-satellite-arrives-at-california-launch-site

ЦитироватьSept. 25, 2020

New Sea Level Satellite Arrives at California Launch Site


A shipping container containing the Sentinel-6 Michael Freilich satellite is transported on a truck to the SpaceX payload processing facility at Vandenberg Air Force Base after landing in California on Sept. 24, 2020.
Credits: 30th Space Wing

The Sentinel-6 Michael Freilich spacecraft will launch from the U.S. West Coast aboard a SpaceX Falcon 9 rocket in November.

The world's latest ocean-monitoring satellite has arrived at Vandenberg Air Force Base in Central California to be prepared for its Nov. 10 launch. The product of a historic U.S.-European partnership, the Sentinel-6 Michael Freilich spacecraft touched down at Vandenberg in an Antonov 124 aircraft at around 10:40 a.m. PDT (1:40 p.m. EDT) on Sept. 24 after a two-day journey from an IABG engineering facility near Munich, Germany.

"The spacecraft had a smooth trip from Europe and is in good shape," said Parag Vaze, the mission's project manager at NASA's Jet Propulsion Laboratory in Southern California. "Final preparations are under way to see the satellite safely into Earth orbit in a little under seven weeks."

The satellite is named after Dr. Michael Freilich, the former director of NASA's Earth Science Division and an instrumental figure in advancing ocean observations from space. Sentinel-6 Michael Freilich is one of two identical spacecraft that compose the Sentinel-6/Jason-CS (Continuity of Service) mission developed in partnership with ESA (the European Space Agency). ESA is developing the new Sentinel family of missions to support the operational needs of the European Union's Copernicus program, the EU's Earth observation program managed by the European Commission. The spacecraft's twin, Sentinel-6B, will launch in 2025.

"It has been a long journey of planning, development, and testing for the mission team," said Pierrik Vuilleumier, the mission's project manager at ESA. "We are proud to work with our international partners on such a critical mission for sea level studies and are looking forward to many years of Sentinel-6 Michael Freilich taking critical sea level and atmospheric data from orbit."


A shipping container containing the Sentinel-6 Michael Freilich satellite is removed from an Antonov 124 aircraft at Vandenberg Air Force Base in California on Sept. 24, 2020, after its two-day journey from an IABG engineering facility near Munich, Germany.
Credits: 30th Space Wing

Once in orbit, each satellite will collect sea surface height measurements down to the centimeter for more than 90% of the world's oceans. They'll be contributing to a nearly 30-year-long dataset built by an uninterrupted series of spacecraft that started with the TOPEX/Poseidon mission in the early 1990s and that continues today with Jason-3. Instruments aboard the spacecraft will also provide atmospheric data that will improve weather forecasts, help to track hurricanes, and bolster climate models.

Although Sentinel-6 Michael Freilich has already undergone rigorous testing, it will go through a final checkout at the SpaceX payload processing facility at Vandenberg to verify that the satellite is healthy and ready for launch.

Once tests are complete, Sentinel-6 Michael Freilich will be mounted atop a SpaceX Falcon 9 rocket at Vandenberg Air Force Base's Space Launch Complex 4E. The launch is scheduled for 11:31 a.m. PST (2:31 p.m. EST) on Nov. 10.

"The Sentinel-6 Michael Freilich satellite will extend our observation record of global sea level, advance our understanding of the Earth as a system, and inform decision-makers, from federal to local levels, who must manage the risks associated with rising sea level," said Karen St. Germain, director of NASA's Earth Science Division in Washington.

Sentinel-6/Jason-CS is being jointly developed by ESA, the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), NASA, and the National Oceanic and Atmospheric Administration, with funding support from the European Commission and technical support from France's National Centre for Space Studies (CNES).

JPL, a division of Caltech in Pasadena, is contributing three science instruments for each Sentinel-6 satellite: the Advanced Microwave Radiometer, the Global Navigation Satellite System - Radio Occultation, and the Laser Retroreflector Array. NASA is also contributing launch services, ground systems supporting operation of the NASA science instruments, the science data processors for two of these instruments, and support for the international Ocean Surface Topography Science Team.

2020-186

Last Updated: Sept. 25, 2020
Editor: Tony Greicius

tnt22

https://blogs.nasa.gov/sentinel-6/2020/10/01/sentinel-6-satellite-arrives-at-vandenberg-for-preflight-checkout/

ЦитироватьSentinel-6 Satellite Arrives at Vandenberg for Preflight Checkout

Linda Herridge
Posted Oct 1, 2020 at 11:14 am


A shipping container containing the Sentinel-6 Michael Freilich satellite is transported on a truck to the SpaceX payload processing facility at Vandenberg Air Force Base after arriving in California on Sept. 24, 2020. Photo credit: NASA/JPL

The Sentinel-6 Michael Freilich satellite, secured inside a shipping container, arrived at Vandenberg Air Force Base in California on Thursday, Sept. 24, aboard an Antonov cargo aircraft. It was offloaded from the aircraft and moved to the SpaceX Payload Processing Facility for checkout and preflight processing.

The mission is an international partnership and the first launch of a constellation of two satellites that will observe changes in Earth's sea levels for at least the next decade. Launching atop a SpaceX Falcon 9 Full Thrust rocket, Sentinel-6 Michael Freilich is targeted to lift off from Vandenberg's Space Launch Complex 4 on Nov. 10, 2020.

NASA's Jet Propulsion Laboratory in Pasadena, California, manages NASA's contribution to the mission. The Launch Services Program, based at the agency's Kennedy Space Center in Florida, is responsible for launch management.

tnt22

ЦитироватьCopernicus Sentinel-6 Michael Freilich: preparing for launch

 European Space Agency, ESA

29 сент. 2020 г.

A European satellite built to carry out precise measurements of sea level changes has arrived in California in preparation for launch. The Sentinel-6 Michael Freilich satellite forms part of the European Union's Copernicus Earth Observation programme and will employ radar to map sea surface topography.

The mission will be used to monitor the height of the sea surface to understand long-term change. It will also measure wave height and wind speed. The satellite will provide fundamental data for climate science, policy-making and protecting the 600 million people who live in vulnerable coastal areas.

Data are provided to Copernicus services in near-real time to improve marine and weather forecasts used by maritime and coastal communities. 

The mission is a collaboration between ESA, the European Commission, EUMETSAT, NASA and NOAA, with support from the French Space Agency CNES.

It is named Michael Freilich after NASA's former Director of Earth Science and is scheduled for launch on 10 November on a SpaceX Falcon 9 rocket from the Vandenberg Air Force Base.

youtu.be/lTlTvk355eQ

https://www.youtube.com/watch?v=lTlTvk355eQ (3:20)

tnt22

Неофициально

Цитировать Falcon 9 Block 5 @Falcon9Block5 11 ч. назад

#SpaceX is targeting November 10th at 2:31PM EDT | 11:31AM PDT | 19:31 UTC for the launch of the #Sentinel6 Mike Freilich satellite for @NASA, @esa, @eumetsat, and @NOAA from launch pad SLC-4E, Vandenberg AFB in California. #Falcon9


11 ч. назад

The booster supporting this mission, B1063.1, will be flying for its first time.


tnt22

АНОНС

ЦитироватьNews Update on Launch of the Sea Level-Monitoring Satellite, Sentinel-6 Michael Freilich


Начало трансляции - 16 октября 2020 г. в 14:00 UTC / 17:00 ДМВ

Alex Immortal

Цитата: tnt22 от 14.10.2020 05:54:57АНОНС
О! сдвиг влево на 3 недели?

СпХ нужно показать, что с газогенератором Мерлина на новых Falcon9 все в порядке, до запуска Crew-1?

tnt22

Цитата: Alex Immortal от 14.10.2020 10:59:22О! сдвиг влево на 3 недели?
Нет.

 Это только прессуха экспертов

ЦитироватьTune in as experts from NASA, ESA (European Space Agency), EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites, and NOAA (National Oceanic and Atmospheric Administration) discuss the upcoming launch of Sentinel-6 Michael Freilich, a satellite that will collect the most accurate data yet on global sea levels.  The satellite is targeted for launch aboard a SpaceX Falcon 9 rocket on Nov. 10 at 2:31 p.m. EST, from Vandenberg Air Force Base in California.
 
Sentinel-6 Michael Freilich is a historic U.S.-European partnership that will continue the legacy of previous missions and extend our records of sea level into the fourth decade, collecting accurate measurements of sea surface height down to the centimeter for 90% of the world's oceans.

Alex Immortal

Цитата: tnt22 от 14.10.2020 11:21:26Нет.

 Это только прессуха экспертов
oh, sorry. OK. I was confused by the post's headline.

tnt22

ЦитироватьNews Update on Launch of the Sea Level-Monitoring Satellite, Sentinel-6 Michael Freilich

 NASA

Трансляция началась 92 минуты назад

youtu.be/1g7nEK2j1mk

https://www.youtube.com/watch?v=1g7nEK2j1mk (1:19:06)

tnt22

Цитировать Jeff Foust @jeff_foust 1 ч. назад

At the Sentinel-6 briefing, NASA's Tim Dunn says launch preparations on a Falcon 9 are going "incredibly well"; still scheduled for Nov. 10.


1 ч. назад

Dunn says the engine investigation after the Falcon 9 abort 2 weeks ago is ongoing, including taking the engines from that vehicle back to McGregor for testing; there is a "path forward" for any rework needed for the Sentinel-6 launch while keeping the Nov. 10 launch date.

tnt22

ЦитироватьBehind the Spacecraft – Sentinel-6 Michael Freilich – Sea Level Scout

 NASA 360

7 окт. 2020 г.

Our planet is changing. Our ocean is rising. And it affects us all. That's why a new international satellite will continue the decades-long watch over our global ocean and help us better understand how climate change is reshaping our planet. Meet some of the talented people behind Sentinel-6 Michael Freilich and get to know the satellite: https://www.nasa.gov/sentinel-6

The Sentinel-6 Michael Freilich satellite is part of the Sentinel-6/Jason-CS mission, a collaboration among NASA, ESA, EUMETSAT and NOAA. Sentinel-6 Michael Freilich will launch from Vandenberg Air Force Base in California no earlier than Nov. 10, 2020.

youtu.be/3_lbADMwD7A

https://www.youtube.com/watch?v=3_lbADMwD7A (2:06)

tnt22

#16
https://www.nasa.gov/feature/jpl/us-european-sea-level-satellite-gears-up-for-launch

ЦитироватьOct. 16, 2020

U.S.-European Sea Level Satellite Gears Up for Launch


This animation shows the radar pulse from the Sentinel-6 Michael Freilich satellite's altimeter bouncing off the sea surface in order to measure the height of the ocean.
Credits: NASA/JPL-Caltech

The Sentinel-6 Michael Freilich spacecraft will soon be heading into orbit to monitor the height of the ocean for nearly the entire globe.

Preparations are ramping up for the Nov. 10 launch of the world's latest sea level satellite. Since arriving in a giant cargo plane at Vandenberg Air Force Base in California last month, Sentinel-6 Michael Freilich has been undergoing final checks, including visual inspections, to make sure it's fit to head into orbit.

Surviving the bone-rattling vibrations and sounds of launch atop a Falcon 9 rocket is just the start of the mission. Once in orbit some 830 miles (1,336 kilometers) above Earth, Sentinel-6 Michael Freilich has the task of collecting sea level measurements with an accuracy of a few centimeters (for a single measurement) for more than 90% of the world's oceans. And it will be making those measurements while repeatedly flying through an area of intense radiation known as the South Atlantic Anomaly, which can scramble electronics.

That's why engineers and researchers have put Sentinel-6 Michael Freilich through a battery of tests to ensure that the spacecraft will survive launch and the harsh environment of space. But how will the mission pull the rest of it off? With sophisticated instruments, global navigation satellites, and lasers – lots of lasers. They'll all work in concert to enable the spacecraft to carry out its task of observing the ocean.

Given the challenges and goals of the mission, the satellite's moniker is appropriate: It's named after noted researcher Dr. Michael Freilich, the former director of NASA's Earth Science Division.

A second spacecraft identical to Sentinel-6 Michael Freilich, Sentinel-6B, will launch in 2025 to continue the work after its sibling's five-and-a-half-year prime mission ends. Together, the satellites make up the Sentinel-6/Jason-CS (Continuity of Service) mission, which is a partnership between NASA, ESA (the European Space Agency), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the National Oceanic and Atmospheric Administration (NOAA).

Collectively, the satellites will add a decade's worth of the most accurate satellite data yet on ocean height to a nearly 30-year record documenting how our oceans are rising in response to climate change. Both spacecraft will also collect data on atmospheric temperature and humidity that will help to improve weather forecasts as well as atmospheric and climate models.

This is where those sophisticated instruments, global navigation satellites, and lasers come in.


The Sentinel-6 Michael Freilich satellite undergoes final preparations in a clean room at Vandenberg Air Force Base in California for an early November launch.
Credits: ESA/Bill Simpson
How It Works

To accurately measure extremely small variations in sea level, Sentinel-6 Michael Freilich will rely on a suite of three instruments that provide scientists information to determine the spacecraft's exact position in orbit.

One component of this positioning package is the laser retroreflector array, a set of nine small, precisely shaped mirrors. Lasers are directed at them from ground stations on Earth, and they reflect the (harmless) beams right back to their point of origin. These laser-emitting ranging stations, as they're known, calculate how long the laser takes to bounce off the reflectors and return, which gives the distance between the satellite and the station.

Another instrument, the Global Navigation Satellite System – Precise Orbit Determination (GNSS-POD), tracks GPS and Galileo navigation signals. Researchers analyze these signals to help determine the satellite's position.

The third instrument in the positioning package is the Doppler Orbitography and Radioposition Integrated by Satellite (DORIS). It analyzes radio signals from 55 global ground stations, measuring the Doppler shift of the radio signals' frequencies to determine the 3D position of the satellite over time. When used together, these instruments provide the data needed to ascertain the precise position of the satellite, which in turn helps to determine the height of the sea surface.

On the science side are two instruments that work in concert to determine sea level and a third that collects atmospheric data. The Poseidon-4 radar altimeter measures ocean height by bouncing radar pulses off the water's surface and calculating the time it takes for the signal to return to the satellite. However, water vapor in the atmosphere affects the propagation of the radar pulses from the altimeter, which can make the ocean appear higher or lower than it actually is. To correct for this affect, an instrument called the Advanced Microwave Radiometer for Climate (AMR-C) measures the amount of water vapor between the spacecraft and the ocean.

"AMR-C is the next generation of AMR instruments, and it includes new components that will enable more accurate measurements along coastlines and throughout the mission," said Shannon Statham, AMR-C integration and test lead at NASA's Jet Propulsion Laboratory in Southern California.

youtu.be/3_lbADMwD7A
Our planet is changing. Our ocean is rising. And it affects us all. That's why a new international satellite will continue the decades-long watch over our global ocean and help us better understand how climate change is reshaping our planet.

For information on the atmosphere, the Global Navigation Satellite System – Radio Occultation (GNSS-RO) instrument gathers data on temperature and humidity that can help to improve weather forecasts. GNSS-RO analyzes radio signals from global navigational satellites as they appear and disappear beyond the limb of the Earth – the hazy blue edge of the atmosphere that's visible when you look at pictures of our planet in space. As these radio signals travel through different layers of the atmosphere, they bend and slow by varying degrees. Sentinel-6 Michael Freilich and satellites like it use GNSS-RO technology to measure these changes, enabling researchers to then extract atmospheric characteristics like temperature and humidity at different altitudes.

All the instruments, power systems, telecommunications – everything that makes Sentinel-6 Michael Freilich tick – must work together to accomplish the mission's science goals, much like the international partners have worked together to get this satellite ready for launch.

"Copernicus Sentinel-6 Michael Freilich is a great contribution to climate change, environment monitoring, and to the Digital Twin Earth. Sentinel-6 is a reference model of the cooperation between the U.S. and Europe on Earth Observation and represents a good foundation for future projects," said Josef Aschbacher, ESA director of Earth Observation Programmes.


In this illustration, the Sentinel-6 Michael Freilich spacecraft – the world's latest sea-level satellite – orbits Earth with its deployable solar panels extended.
Credits: NASA/JPL-Caltech
More About the Mission

Sentinel-6/Jason-CS is being jointly developed by ESA, EUMETSAT, NASA, and NOAA, with funding support from the European Commission and technical support from France's National Centre for Space Studies (CNES).

JPL, a division of Caltech in Pasadena, is contributing three science instruments for each Sentinel-6 satellite: the Advanced Microwave Radiometer, the Global Navigation Satellite System - Radio Occultation, and the Laser Retroreflector Array. NASA is also contributing launch services, ground systems supporting operation of the NASA science instruments, the science data processors for two of these instruments, and support for the international Ocean Surface Topography Science Team.

The Sentinel-6 Michael Freilich press kit:
To learn more about Sentinel-6 Michael Freilich, visit:


Last Updated: Oct. 16, 2020
Editor: Naomi Hartono

tnt22

Цитата: undefinedCopernicus Sentinel-6 in action
 Доступ по ссылке

European Space Agency, ESA

17 сент. 2020 г.

The Copernicus Sentinel-6 Poseidon-4 dual-frequency (C- and Ku-band) radar altimeter uses an innovative interleaved mode that has improved performance compared to previous satellite altimeter designs.
Спойлер
A radar altimeter derives the height of the satellite above Earth by accurately and precisely measuring the time it takes for a transmitted radar pulse to reflect Earth's surface. The returned echo pulse from the sea surface provides a waveform that is processed to determine sea-surface height (from the radar range), the significant wave height (from the slope of the waveform leading edge) and the surface wind speed from the ocean roughness (determined from the strength of the power returns).
Sentinel-6 uses radar pulses that are transmitted and received using a timing arrangement that allows both conventional 'pulse-limited' (low-resolution mode) data to be acquired simultaneously with high-resolution 'delay-Doppler' measurements.

This arrangement allows unfocussed synthetic aperture radar (SAR) data processing to be performed where the altimeter synthesises a large antenna as it flies forward by exploiting the Doppler characteristics of the return echoes.

The processor then steers synthetic azimuth beams to specific locations on Earth's surface to build a 'stack' of waveforms that can be processed to achieve better performance. Unfocussed SAR processing improves the precision of sea-surface measurements by averaging the stack of waveforms to reduce noise and improves the along track resolution from several kilometres to about 300 meters. SAR processing requires a much larger amount of data than conventional altimetry and the satellite implements a dedicated onboard processor to reduce the data rate that will be sent back to ground by a factor of two.

The unique capability of the Copernicus Sentinel-6 Poseidon-4 altimeter is designed to ensure enhanced continuity with the long time series of measurements from the Topex Poseidon and Jason series of satellite altimeters.
[свернуть]

youtu.be/V7_43bsybYk

https://www.youtube.com/watch?v=V7_43bsybYk (1Ж48)

tnt22

Цитировать Kathy Lueders @KathyLueders 55 мин. назад

We are making a lot of good progress with @SpaceX on engine testing to better understand the unexpected behavior observed during a recent non-NASA launch. (1/5)


55 мин. назад

It's too early to report findings at this point, as @SpaceX continues testing to validate what's believed to be the most credible cause. (2/5)


54 мин. назад

Based on our current analysis, @SpaceX is replacing one Merlin engine on the Sentinel-6 Michael Freilich launch vehicle and one engine for Crew-1 rocket that displayed similar early-start behavior during testing. (3/5)


54 мин. назад

We are still targeting the Sentinel-6 launch for Nov. 10 from Vandenberg Air Force Base as we expect to complete forward work in time. (4/5)


54 мин. назад

We are also still working towards a mid-November launch for Crew-1. We will want a few days between Sentinel-6 and Crew-1 to complete data reviews and check performance. Most importantly, we will fly all our missions when we are ready. (5/5) #LaunchAmerica

zandr

https://vk.com/spacex?w=wall-41152133_256957
ЦитироватьЗаявление представителя NASA о проблеме с двигателями Falcon 9 и статусах предстоящих миссий
Кэти Людерс (Kathy Lueders), заместитель директора по исследованию космического пространства и полётам человека в NASA:

"Мы добились значительных успехов со SpaceX в тестировании двигателей, чтобы лучше понять неожиданное поведение, наблюдаемое во время недавней попытки запуска, не относящейся к NASA [ред. - GPS III SV04]. На данном этапе ещё рано сообщать о результатах, поскольку SpaceX продолжает тестирование, чтобы подтвердить то, что считает наиболее вероятной причиной отклонений в работе.
Согласно нашему текущему анализу, SpaceX заменяет один двигатель Merlin на Falcon 9 для запуска миссии Sentinel-6 Michael Freilich и один двигатель для ракеты Falcon 9 для запуска миссии Crew-1, которые показали аналогичное поведение во время ранее проведённых испытаний.
Мы по-прежнему нацелены на запуск Sentinel-6 10 ноября с базы ВВС Ванденберг и рассчитываем вовремя завершить все необходимые работы. Мы также всё ещё планируем запуск Crew-1 в середине ноября. Нам потребуется несколько дней между Sentinel-6 и Crew-1 для завершения анализа данных и проверки двигателей. Мы выполним все наши миссии, когда будем полностью готовы".