Author Topic: NASA-DLR - GRACE updates  (Read 4385 times)

Online Chris Bergin

NASA-DLR - GRACE updates
« on: 06/10/2010 01:50 PM »
Earth monitoring deals via NASA money and overseas agencies. Thinking we can expect a lot of this in the future.

June 10, 2010

RELEASE: 10-138

NASA AND DLR SIGN AGREEMENT TO CONTINUE GRACE MISSION THROUGH 2015

WASHINGTON -- NASA Deputy Administrator Lori Garver and German
Aerospace Center (DLR) Executive Board Chairman Johann-Dietrich
Worner signed an agreement Thursday during a bilateral meeting in
Berlin to extend the Gravity Recovery and Climate Experiment (GRACE)
mission through the end of its on-orbit life, which is expected in
2015.

Launched in March 2002, GRACE tracks changes in Earth's gravity field
by noting minute changes in gravitational pull from local changes in
Earth's mass. It does this by measuring changes in the distance
between its two identical spacecraft to one-hundredth the width of a
human hair. These spacecraft are in the same orbit approximately 137
miles apart.

"The extension of this successful cooperative mission demonstrates the
strength of the NASA-DLR partnership and our commitment to continue
working together in this very important area of Earth science,"
Garver said.

NASA and DLR signed the original agreement in 1998. The two agencies
jointly developed the GRACE mission and have cooperated on its
operational phase since its launch. For the twin satellite mission,
NASA provided the instruments and selected satellite components, plus
data validation and archiving. DLR provided the primary satellite
components, launch services and operations.

GRACE maps gravity-field variations from month to month, recording
changes caused by the seasons, weather patterns and short-term
climate change.

"The extension of this successful mission will deliver more valuable
data to help us understand how Earth's mass and gravity varies over
time," Worner said. "This is an important component necessary to
study changes in global sea level, polar ice mass, deep ocean
currents, and depletion and recharge of continental aquifers. We
appreciate the strong cooperation with our partner NASA."

GRACE's monthly maps are up to 100 times more accurate than existing
maps, substantially improving the accuracy of techniques used by
oceanographers, hydrologists, glaciologists, geologists and climate
scientists.

Data from the GRACE mission have been used to measure the amount of
water lost in recent years from the aquifers for California's primary
agricultural region in the state's Central Valley. An international
study recently used GRACE data to show that ice losses from
Greenland's ice sheet now are rapidly spreading up its northwest
coast.

For more information about the GRACE mission, visit:

http://science.nasa.gov/missions/grace

Offline bolun

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Re: NASA-DLR - GRACE updates
« Reply #1 on: 06/15/2010 06:58 PM »
NASA and DLR sign agreement to continue the GRACE mission through 2015

http://www.dlr.de/en/DesktopDefault.aspx/tabid-1/86_read-24882/

GRACE - Gravity Recovery And Climate Experiment

http://www.dlr.de/rb/en/desktopdefault.aspx/tabid-6813/11188_read-6309/
« Last Edit: 12/07/2010 09:00 PM by bolun »

Online woods170

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Re: NASA-DLR - GRACE updates
« Reply #2 on: 12/03/2012 08:32 AM »
NASA procures satellites for new gravity mission.

NASA is moving forward with plans to build and launch two new satellites to replace the aging GRACE gravity-mapping mission, and the space agency has commissioned EADS Astrium to build the spacecraft for the joint U.S.-German project.

More:
http://www.spaceflightnow.com/news/n1212/02grace/#.ULxuXJFv6nA

Offline Danderman

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Re: NASA-DLR - GRACE updates
« Reply #3 on: 02/21/2013 07:34 PM »
What US launcher could orbit a pair of these satellites?

Offline Jim

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Re: NASA-DLR - GRACE updates
« Reply #4 on: 02/21/2013 11:58 PM »
What US launcher could orbit a pair of these satellites?


None.  DLR is responsible for launch service procurement

Offline ChileVerde

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Re: NASA-DLR - GRACE updates
« Reply #5 on: 02/22/2013 12:21 AM »
What US launcher could orbit a pair of these satellites?


None.  DLR is responsible for launch service procurement

Which means that the choices available to DLR exclude US launchers for reasons of price? Or something else?
"I can’t tell you which asteroid, but there will be one in 2025," Bolden asserted.

Offline Jim

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Re: NASA-DLR - GRACE updates
« Reply #6 on: 02/22/2013 12:59 AM »
Just price

Offline russianhalo117

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Re: NASA-DLR - GRACE updates
« Reply #7 on: 02/22/2013 03:29 PM »
What US launcher could orbit a pair of these satellites?


None.  DLR is responsible for launch service procurement

Which means that the choices available to DLR exclude US launchers for reasons of price? Or something else?
EADS Astrium is pushing for a Eurorockot flight using Rockot/Briz-KS (Briz-KS is a highly optimized/enhanced/lighter version of Briz-KM that is specificly tailored to the mission requirements of Rockot, Angara 1.2, and Soyuz 2.1v. Briz-KS is lighter than Briz-KM since it is designed from the Phase-IV Proton/Briz-M (Enhanced Briz-M) and so it contains new generation systems and advanced structural composites versus mostly Alluminum alloys) in August 2017 for optimized on orbit life of the twin GRACE FO Satellites. Kosmos 3M and Dnepr are the other two Russian launchers being still considered since the project was announced. The last manufactured Kosmos 3M was reportedly offered by Russia at reduced price if they can agree to build and launch few years earlier than 2017. Russia originally planned to phaseout Kosmos-3M and turn over Plesetsk Site-132 and Baikonur pads to Eurorockot for Rockot/Briz-KM (KS) conversional programme by end of December 2013.
« Last Edit: 02/22/2013 03:40 PM by russianhalo117 »

Online Galactic Penguin SST

Re: NASA-DLR - GRACE updates
« Reply #8 on: 02/22/2013 06:12 PM »
I thought the Vega would have been the obvious launcher choice.........  ???
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline russianhalo117

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Re: NASA-DLR - GRACE updates
« Reply #9 on: 02/22/2013 06:18 PM »
I thought the Vega would have been the obvious launcher choice.........  ???
EADS is a partner with Khrunichev in joint project Eurorockot which may possibly merge with joint project ILS in the next year or two since discussions are underway. Vega might be capable of launching GRACE FO, but I have heard no mention anywhere yet of using Vega for this mission.

Online jacqmans

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Re: NASA-DLR - GRACE updates
« Reply #10 on: 07/24/2014 06:11 PM »

July 24, 2014


Satellite Study Reveals Parched U.S. West Using Up Underground Water

   
A new study by NASA and University of California, Irvine, scientists finds more than 75 percent of the water loss in the drought-stricken Colorado River Basin since late 2004 came from underground resources. The extent of groundwater loss may pose a greater threat to the water supply of the western United States than previously thought.

This study is the first to quantify the amount that groundwater contributes to the water needs of western states. According to the U.S. Bureau of Reclamation, the federal water management agency, the basin has been suffering from prolonged, severe drought since 2000 and has experienced the driest 14-year period in the last hundred years.

The research team used data from NASA's Gravity Recovery and Climate Experiment (GRACE) satellite mission to track changes in the mass of the Colorado River Basin, which are related to changes in water amount on and below the surface. Monthly measurements of the change in water mass from December 2004 to November 2013 revealed the basin lost nearly 53 million acre feet (65 cubic kilometers) of freshwater, almost double the volume of the nation's largest reservoir, Nevada's Lake Mead. More than three-quarters of the total -- about 41 million acre feet (50 cubic kilometers) -- was from groundwater.
 


"We don't know exactly how much groundwater we have left, so we don't know when we're going to run out," said Stephanie Castle, a water resources specialist at the University of California, Irvine, and the study's lead author. "This is a lot of water to lose. We thought that the picture could be pretty bad, but this was shocking."

Water above ground in the basin's rivers and lakes is managed by the U.S. Bureau of Reclamation, and its losses are documented. Pumping from underground aquifers is regulated by individual states and is often not well documented.

"There's only one way to put together a very large-area study like this, and that is with  satellites," said senior author Jay Famiglietti, senior water cycle scientist at JPL on leave from UC Irvine, where he is an Earth system science professor. "There's just not enough information available from well data to put together a consistent, basin-wide picture."

Famiglietti said GRACE is like having a giant scale in the sky. Within a given region, the change in mass due to rising or falling water reserves influences the strength of the local gravitational attraction. By periodically measuring gravity regionally, GRACE reveals how much a region's water storage changes over time.

The Colorado River is the only major river in the southwestern United States. Its basin supplies water to about 40 million people in seven states, as well as irrigating roughly four million acres of farmland.

"The Colorado River Basin is the water lifeline of the western United States," said Famiglietti. "With Lake Mead at its lowest level ever, we wanted to explore whether the basin, like most other regions around the world, was relying on groundwater to make up for the limited surface-water supply. We found a surprisingly high and long-term reliance on groundwater to bridge the gap between supply and demand."

Famiglietti noted that the rapid depletion rate will compound the problem of short supply by leading to further declines in streamflow in the Colorado River.

"Combined with declining snowpack and population growth, this will likely threaten the long-term ability of the basin to meet its water allocation commitments to the seven basin states and to Mexico," Famiglietti said.

The study has been accepted for publication in the journal Geophysical Research Letters, which posted the manuscript online Thursday. Coauthors included other scientists from NASA's Goddard Space Flight Center, Greenbelt, Maryland, and the National Center for Atmospheric Research, Boulder, Colorado. The research was funded by NASA and the University of California.

For more information on NASA's GRACE satellite mission, see:

http://www.nasa.gov/grace

and

http://www.csr.utexas.edu/grace

GRACE is a joint mission with the German Aerospace Center and the German Research Center for Geosciences, in partnership with the University of Texas at Austin. JPL developed the GRACE spacecraft and manages the mission for NASA's Science Mission Directorate, Washington.

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

To learn more about NASA's Earth science activities in 2014, visit:

http://www.nasa.gov/earthrightnow

Offline clongton

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Re: NASA-DLR - GRACE updates
« Reply #11 on: 07/24/2014 06:20 PM »
Very serious implications for both the growing population of the American west as well as for ALL the peoples whose food is grown in the west.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline catdlr

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Re: NASA-DLR - GRACE updates
« Reply #12 on: 11/06/2015 01:58 AM »
NASA Finds New Way to Track Ocean Currents from Space - Using GRACE

http://www.jpl.nasa.gov/news/news.php?feature=4761

Quote
A team of NASA and university scientists has developed a new way to use satellite measurements to track changes in Atlantic Ocean currents, which are a driving force in global climate. The finding opens a path to better monitoring and understanding of how ocean circulation is changing and what the changes may mean for future climate.

Quote
...data from the twin satellites of NASA's Gravity Recovery and Climate Experiment (GRACE) mission. Launched in 2002, GRACE provides a monthly record of tiny changes in Earth's gravitational field, caused by changes in the amount of mass below the satellites. The mass of Earth's land surfaces doesn't change much over the course of a month; but the mass of water on or near Earth's surface does, for example, as ice sheets melt and water is pumped from underground aquifers. GRACE has proven invaluable in tracking these changes.
Tony De La Rosa

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Re: NASA-DLR - GRACE updates
« Reply #13 on: 10/27/2017 02:13 PM »
Quote
Oct. 27, 2017
RELEASE 17-084

Prolific Earth Gravity Satellites End Science Mission

After more than 15 productive years in orbit, the U.S./German GRACE (Gravity Recovery and Climate Experiment) satellite mission has ended science operations. During their mission, the twin GRACE satellites have provided unprecedented insights into how our planet is changing by tracking the continuous movement of liquid water, ice and the solid Earth.

GRACE made science measurements by precisely measuring the distance between its twin satellites, GRACE-1 and GRACE-2, which required that both spacecraft and their instruments be fully functional. Following an age-related battery issue on GRACE-2 in September, it became apparent by mid-October that GRACE-2’s remaining battery capacity would not be sufficient to operate its science instruments and telemetry transmitter. Consequently, the decision was made to decommission the GRACE-2 satellite and end GRACE’s science mission.

GRACE, a mission led by Principal Investigator Byron Tapley at the University of Texas at Austin, launched in March 2002 on a planned five-year mission to precisely map our planet’s ever-changing gravity field. It has revealed how water, ice and solid Earth mass move on or near Earth’s surface due to Earth’s changing seasons, weather and climate processes, earthquakes and even human activities, such as from the depletion of large aquifers. It did this by sensing minute changes in the gravitational pull caused by local changes in Earth's mass, which are due mostly to changes in how water is constantly being redistributed around our planet.

“GRACE has provided paradigm-shifting insights into the interactions of our planet’s ocean, atmosphere and solid Earth components,” said Tapley. “It has advanced our understanding of the contribution of polar ice melt to global sea level rise and the amount of atmospheric heat absorbed by the ocean. Recent applications include monitoring and managing global water resources used for consumption, agriculture and industry; and assessing flood and earthquake hazards.”

GRACE used a microwave ranging system to measure the change in distance between the twin satellites to within a fraction of the diameter of a human hair over 137 miles (220 kilometers). The ranging data were combined with GPS tracking for timing, star trackers for attitude information and an accelerometer to account for non-gravitational effects, such as atmospheric drag and solar radiation. From these data, scientists calculated the planet’s gravity field monthly and monitored its changes over time.

“GRACE was an excellent example of a research satellite mission that advanced science and also provided near-term societal benefits,” said Michael Freilich, director of NASA’s Earth Science Division at the agency’s headquarters in Washington. “Using cutting-edge technology to make exquisitely precise distance measurements, GRACE improved our scientific understanding of our complex home planet, while at the same time providing information -- such as measurements related to ground water, drought and aquifer water storage changes worldwide -- that was used in the U.S. and internationally to improve the accuracy of environmental monitoring and forecasts.”

GRACE established that measuring the redistribution of mass around Earth is an essential observation for understanding the Earth system. GRACE’s monthly maps of regional gravity variations have given scientists new insights into Earth system processes. Among its innovations, GRACE has monitored the loss of ice mass from Earth’s ice sheets, improved understanding of the processes responsible for sea level rise and ocean circulation, provided insights into where global groundwater resources may be shrinking or growing and where dry soils are contributing to drought, and monitored changes in the solid Earth. Users in more than 100 countries routinely download GRACE data for analyses. For more on GRACE’s science accomplishments, see:

https://www.jpl.nasa.gov/news/news.php?feature=6777

“GRACE was a pioneering mission that advanced our understanding across the Earth system -- land, ocean and ice,” said Mike Watkins, director of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, and the mission’s original project scientist. “The entire mission team was creative and successful in its truly heroic efforts over the last few years, extending the science return of the mission to help minimize the gap between GRACE and its successor mission, GRACE Follow-On, scheduled to launch in early 2018.”

Despite the loss of one of the twin GRACE satellites, the other satellite, GRACE-1, will continue operating through the end of 2017. “GRACE-1’s remaining fuel will be used to complete previously planned maneuvers to calibrate and characterize its accelerometer to improve the final scientific return and insights from the 15-year GRACE record,” said GRACE Project Scientist Carmen Boening of JPL.

Currently, GRACE-2’s remaining fuel is being expended and the satellite has begun to slowly deorbit. Atmospheric reentry of GRACE-2 is expected sometime in December or January. Decommissioning and atmospheric reentry of GRACE-1 are expected in early 2018. NASA and the German Space Operations Center will jointly monitor the deorbit and reentry of both satellites.

GRACE Follow-On, a joint NASA/Helmholtz Centre Potsdam German Research Centre for Geosciences (GFZ) mission, will continue GRACE's legacy. It will also test a new laser-ranging interferometer developed by a joint German/U.S. collaboration for use in future generations of gravitational research satellites.

GRACE is a joint NASA/Deutsches Zentrum für Luft- und Raumfahrt (DLR, the German Aerospace Center) mission led by Tapley and Co-principal Investigator Frank Flechtner at GFZ. GRACE ground segment operations are co-funded by GFZ, DLR and the European Space Agency. JPL manages GRACE for NASA’s Science Mission Directorate at the agency’s headquarters in Washington. GRACE was the first mission launched under NASA's Earth System Science Pathfinder program, designed to develop new measurement technologies for studying the Earth system.

For more information on GRACE, visit:

http://www.csr.utexas.edu/grace   

and

http://grace.jpl.nasa.gov

-end-

https://www.nasa.gov/press-release/prolific-earth-gravity-satellites-end-science-mission

Online jacqmans

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Re: NASA-DLR - GRACE updates
« Reply #14 on: 10/29/2017 12:59 PM »
Press release, 27 October 2017

GRACE mission comes to an end after 15 years of successful operation - Measuring gravitational changes and precisely documenting climate change 

After more than 15 years, the German-US Gravity Recovery and Climate Experiment (GRACE) for precise measuring of Earth's gravity field has come to an end. Since
its launch from the Russian cosmodrome in Plesetsk on 17 March 2002 on board a Rockot launcher, the twin satellites GRACE-1 and GRACE-2 have been orbiting Earth
in close formation flight, precisely recording how Earth's gravity field changes over time. GRACE was a joint mission by NASA's Jet Propulsion Laboratory (Pasadena,
California) and the German Aerospace Center (Deutsches Zentrum fuer Luft- und Raumfahrt; DLR). The scientific analysis was carried out by the Center for Space
Research at the University of Texas at Austin and the German Research Centre for Geosciences (Deutsches GeoForschungsZentrum; GFZ) at the Helmholtz Centre in
Potsdam.

"The GRACE mission was planned to last five years but has been working very successfully for more than 15 years – three times longer than originally planned.
The two GRACE satellites have delivered scientific data that has reshaped our understanding of Earth's geophysical processes. The mission has demonstrated what
satellite-supported Earth observation can do for climate research and the observation of climate change," states Pascale Ehrenfreud, Chair of the DLR Executive
Board. 

"The measurements have shown how water, ice and solid materials on Earth move over time. This data helps us precisely document changes in the ground water, or
glacial retreat, for example. Also the latter's influence on the rise in sea level can be recorded thanks to the GRACE measurements," adds Reinhard Hüttl, scientific
board member of the GFZ. 

Understanding the Earth system

GRACE is one of the few Earth observation missions that measures gravitational changes rather than electromagnetic radiation, such as light or radio waves. "We
could, in a sense, 'weigh' how the continents are sinking or rising from one month to another," clarifies Achim Friker, GRACE project leader at the DLR Space
Administration in Bonn. This enabled the quantitative determination of numerous effects of climate change – such as glacial melt in Greenland and Antarctica,
ground water decline in India and California – and has made an indispensable contribution to modelling the rise in sea level.

Responsible for the operation of the two GRACE satellites was the German Space Operations Center at DLR in Oberpfaffenhofen with its ground stations in Weilheim
and Neustrelitz. "The failure of eight of a total of 20 battery cells on board GRACE-2 has reduced the capacity of the ageing battery to the point where scientific
use of the satellite is no longer possible," explains Sebastian Loew. Especially during the flight phases where the satellite is without solar radiation, the
energy reserves were no longer sufficient to prevent reboots of the on-board computer and associated communications breakdown. The battery is always a critical
resource for a mission of this length. GRACE-2's battery started showing the first signs of ageing in 2013, after more than 10 years in orbit. 

After a seventh cell failed in September 2017, it was decided to prepare GRACE-2 for scientific operations again at the beginning of October. "At this point
we would have been in a so-called 'full Sun orbit', which would have made operations possible, even with a greatly weakened battery," says Sebastian Loew. However,
a few days before reaching this phase, another cell failed. At that moment, the Principal Investigators Byron Tapley from the University of Austin and Frank
Flechtner from the GFZ, declared the GRACE mission to be over. GRACE-1 will now be subjected to some final tests before being put out of operation in the coming
weeks.

GRACE-2 is currently (dated 25 October 2017) at an altitude of 302 kilometres just under 3800 kilometres before GRACE-1. Without fuel, the satellite will quickly
lose altitude due to the resistance of the residual atmosphere. However, there is no risk of a collision with GRACE-1. The flight path of GRACE-2 also poses
no risk to other active satellites, as stressed by DLR and NASA. "We expect to maintain contact with the satellite until shortly before re-entry into the atmosphere.
However, during this time there will be repeated phases when we will not be able to communicate with the satellite due to the low battery voltage," says Sebastian
Loew. NASA and DLR will jointly monitor how GRACE-2 re-enters the atmosphere and burns up there. Both GRACE satellites are built according to NASA regulations,
so that they break up and burn up upon re-entry to the atmosphere. The US space agency has approved the planned uncontrolled re-entry into Earth's atmosphere.


In spring 2018, the successor mission GRACE Follow-On will launch from Vandenberg in California on a SpaceX Falcon 9 rocket. This mission will continue to measure
the distance and relative speed between its two satellites using microwaves, as with the current GRACE mission. However, GRACE Follow-On will be enhanced with
additional laser measurements, which will further increase the precision. 

The GRACE science mission 

GRACE is a joint mission by NASA and DLR. Evaluation of the scientific data is carried out by the Univerity of Texas (UTCSR) and the Research Centre for Geosciences
(Deutsches GeoForschungsZentrum; GFZ) in Potsdam.The mission is operated by the DLR German Space Operations Center in Oberpfaffenhofen and is financed by DLR,
the German contributions to the European Space Agency (ESA) and the GFZ. The Jet Propulsion Laboratory (JPL) manages the mission under contract to the NASA Science
Mission Directorate in Washington. The GRACE twins were built by Airbus Defence and Space (formerly Astrium) in Friedrichshafen. The successor to the mission,
GRACE Follow-On, is also being built there. Launch and transport into Earth orbit took place using a Russian launch vehicle and was carried out by the German-Russian
company Eurockot.

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