What is DSCOVR?
The Deep Space Climate Observatory, or DSCOVR, is a spacecraft which will orbit between Earth and the sun, observing and providing advanced warning of particles and magnetic fields emitted by the sun (known as the solar wind) which can affect power grids, communications systems, and satellites close to Earth. From its post at the Lagrange point 1 (or L1), approximately one million miles from Earth. DSCOVR will also observe our planet and provide measurements of the radiation reflected and emitted by Earth and images of the sunlit side of Earth for science applications.
L1 orbit diagram
What is meant by "L1" and what is the significance of placing DSCOVR there? Will this be the first satellite to orbit at this position?
At L1, the gravitational forces between the sun and Earth balance the centrifugal forces of a satellite to provide a stable orbit point requiring fewer orbital corrections for the spacecraft to remain in its operational location for a longer period of time. Placing DSCOVR in orbit around the L1 point provides definite advantages, including the quality of the solar wind observations.
The L1 position will provide DSCOVR with a point of "early warning" when a surge of particles and magnetic field from the sun will hit Earth and if they have characteristics that will cause a geomagnetic storm for Earth. Unlike other satellite orbits that circle around Earth, spacecraft at L1 can always stay on the sunward side of our planet making it an ideal location for monitoring incoming solar wind.
NASA’s first satellite in the L1 position, ISEE 3, was launched in 1978, and although there are a few NASA satellites currently orbiting L1 (such as ACE, Wind and SOHO), DSCOVR will be the first NOAA mission to L1.
How much will DSCOVR weigh at launch and what will be its dimensions?
The satellite will be about 570 kg when it is launched and has dimensions of 54 inches by 72 inches..
While DSCOVR was in storage for a decade, was it fully equipped to operate, or did it need some of its technology updated before launch?
With the exception of replacing the batteries, DSCOVR will be flown with the same technology that was developed when the mission was known as Triana.
In 2008, DSCOVR was taken out of the storage canister, checked out and turned on to see if it was still functional. At that time, an assessment of the necessary refurbishment to ready the spacecraft for use was performed. Then in 2012, it was taken out of storage again, pulled completely apart, and NASA Goddard performed tests and checked each piece individually.
The solar wind sensors (the Faraday Cup and the Magnetometer) on DSCOVR were already a part of the original spacecraft and those sensors did not need to be updated to perform the DSCOVR mission. However, the magnetometer was relocated to a better observing location on the spacecraft to ensure the best measurements possible.
Who will be the key users of the DSCOVR data?
NOAA will provide the space weather data from DSCOVR for key users, including NOAA's Space Weather Prediction Center (SWPC) in Boulder, Colorado, who will issue forecasts and warnings derived from the data to their end users. The end users of the data include power grid operators, airlines, and satellite navigation customers who will be impacted by the geomagnetic storms. Once processed at SWPC, the data will be archived at NOAA's National Geophysical Data Center, also in Boulder. NASA will be responsible for processing the data from DSCOVR's two Earth sensors and two other space science sensors.
About Space Weather
What will DSCOVR measure?
The instruments onboard DSCOVR will measure the magnetic field intensity and direction and the distribution of incoming ions and electrons in the solar wind plasma, according to their energies.This will allow the solar wind plasma velocity, density, and temperature to be determined.
DSCOVR will also measure the reflected and emitted visible and infrared light from Earth and image the sunlit disk of Earth in ten narrow visible or UV wavelengths.
What type of impact can solar storms have on Earth?
DSCOVR will allow NOAA to provide accurate warnings of one type of solar storm, a geomagnetic storm. Geomagnetic storms occur when changes in the solar wind cause fluctuations in the magnetic field near the surface of Earth and have the potential to bring significant disruptions to every major public infrastructure system, including power grids, telecommunications and GPS. Not all geomagnetic storm impacts are detrimental, as the most common and well-known impact is the creation of the aurora.
Follow the links above for videos from the National Weather Service on the effects of space weather. And check out this video from GOES-R on living with space weather:
How will DSCOVR help with observing coronal mass ejections?
Coronal mass ejections, or CMEs, are fluctuations of the sun's magnetic fields which result in a large portion of the surface of the sun to expand rapidly and eject billions of tons of particles and embedded magnetic field out into space.CMEs can erupt into space so violently that they create shockwaves. These shockwaves and CMEs can trigger disturbances on Earth and can also produce high-energy radiation by accelerating the particles in the solar wind. DSCOVR will be used to detect and characterize the shocks and CME's just before they encounter Earth, permitting new predictive capabilities and a better understanding of the nature of shocks.
coronal mass ejection
Are there the other features of solar wind DSCOVR will observe?
Solar wind carries with it a sheet of plasma surrounding a stretched, distorted magnetic field that originates roughly from the sun's magnetic equator. This sheet is one of the most dynamic objects in space, and its passage over the Earth frequently sparks minor space weather events. Inside of the plasma sheet, the magnetic field is constantly twisting back upon and re-connecting with itself, forming plasma bubbles and channels for energetic radiation that have profound effects on space weather and Earth.
The dynamic processes that break down and reconfigure the plasma sheet occur on scale sizes that often have been too small for previous plasma experiments to measure, but with the high time resolution of the DSCOVR Faraday Cup, we will be able to see inside disrupting bubbles in the sheet as they form and grow.
Benefits of DSCOVR
How much warning might DSCOVR be able to give before a solar storm's effects are felt on Earth? Can it predict where on Earth such a storm might "hit?"
DSCOVR will typically be able to provide 15 to 60 minute warning time before the surge of particles and magnetic field hits Earth, which is similar to what ACE currently provides. Though the geomagnetic storm warning data cannot currently predict exactly where geomagnetic storms will have an impact on Earth, a model planned to be made operational in 2016 will use DSCOVR data to improve predictions of storm impact location.
Will DSCOVR result in improved geomagnetic storm forecasts?
NOAA scientists expect great improvement in geomagnetic storm forecasts by combining DSCOVR data with a model of the Earth's magnetosphere. Using this model with upstream data from DSCOVR will provide regional forecasts of geomagnetic storms. NOAA will have this capability later in 2016.
What will be the advantages of DSCOVR compared with NASA's Advanced Composition Explorer (ACE) satellite and other existing technology that observe space weather?
DSCOVR will provide more robust operational data and will provide continuity of coverage for the solar wind observations ACE has provided the space weather community.
DSCOVR in the Cleanroom
Is there a chance ACE could stop working before DSCOVR is launched? If that happens, what are the consequences?
Launched in 1997, ACE was designed and planned for an estimated life span of five years, but it is currently more than 10 years beyond its planned end of life. If ACE fails before DSCOVR is launched, there will be a gap in solar wind observations. However, if ACE remains operational, DSCOVR will travel as planned to the L1 orbit to replace ACE as the primary source for solar wind data.
With respect to NASA’s Solar and Heliospheric Observatory (SOHO), is DSCOVR considered an improvement, replacement, or will it do something fundamentally different?
The DSCOVR Mission is replacing the Advanced Composition Explorer (ACE) solar wind data observations that are used by the NWS Space Weather Prediction Center (SWPC) to produce operational geomagnetic storm warnings. SOHO has a different mission that is primarily solar imaging that provides a different data set for different space weather products. SOHO observes coronal mass ejections when they are close the sun. From SOHO, we have early warnings that a CME is directed toward Earth, but it is only from DSCOVR that we can measure the magnetic field, which is crucial for providing customers with the accurate warnings they need to protect their systems.
What are the advantages of having another observatory at L1?
When the solar wind speed changes, it moves through space just like a weather front. Scientists can measure the speed of the wind from a single spacecraft, but the issue is determining the orientation of the front. DSCOVR will supplement existing spacecraft upstream of Earth with solar wind instruments, permitting studies of the overall global orientation of structures in the solar wind.
What will DSCOVR do better than what's been done previously?
The DSCOVR Faraday Cup instrument will measure solar wind ions at a cadence 120 times faster than ACE, but only six times faster than Wind. The DSCOVR magnetometer is eight times faster than that of ACE and four times faster than that of Wind. But Wind has AC magnetometers measuring tens of thousands times faster than the DSCOVR DC magnetometer. For space weather predictions, this means that the real-time data, the distribution of solar wind speed, will be about 100 times faster than existing spacecraft in this orbit.
Why are faster measurements of solar wind speed beneficial?
Faster measurements mean that we can more quickly characterize the shock wave of an approaching solar storm compared to what we can do with ACE. Faster characterization will result in more timely alerts to the public. The finer time scale will also permit unique new science. One of the smallest scales in the solar wind is the circle traced out by a proton bending in the solar wind’s magnetic field. DSCOVR measurements will be fast enough to measure changes in the solar wind on this small scale, allowing scientists to place stringent tests on certain theories for the heating of the solar wind.
Solar wind is heated by an unidentified mechanism, even as it drifts past the Earth. This heating process is so effective that gram for gram it could boil a cup of water in less than 15 seconds if you could harness it on Earth.
In addition, faster real-time data allows the rapid identification of inevitable telemetry errors. That is, false data spikes can be quickly separated from large continuous increases which are characteristic of big incoming storms.
About the Mission
Who is involved in the DSCOVR mission?
The Deep Space Climate Observatory (DSCOVR) mission is a partnership between NOAA, NASA and the U.S. Air Force. NOAA will operate DSCOVR from the NOAA Satellite Operations Facility and process data at the agency's Space Weather Prediction Center for distribution to users within the United States and around the world. The data will be archived at NOAA's National Geophysical Data Center.
NASA received funding from NOAA to refurbish the DSCOVR spacecraft and its solar wind instruments, develop the ground segment, and manage launch and activation of DSCOVR. The Air Force funds and oversees the launch services for the spacecraft. The satellite also hosts NASA-funded secondary sensors for Earth and space science observations. The Earth science data will be processed at NASA's DSCOVR Science Operations Center and archived and distributed by NASA's Atmospheric Science Data Center.
The U.S. Air Force will provide the launch vehicle through their launch services contract with SpaceX.
How did NOAA become the lead agency on DSCOVR rather than NASA? Do the two agencies have a history of cooperation?
NOAA is the agency responsible for operational space weather forecasts and warnings and was therefore given the lead for DSCOVR. NOAA and NASA have a long history of cooperation in the area of solar observation platforms and research to operations. In addition, NASA has long acted as NOAA's acquisition agent for NOAA's Earth weather programs.