The Sun Spot

Since November 2023, NASA’s Voyager 1 spacecraft has been sending a steady radio signal to Earth, but the signal does not contain usable data. The source of the issue appears to be with one of three onboard computers, the flight data subsystem (FDS), which is responsible for packaging the science and engineering data before it’s sent to Earth by the telemetry modulation unit.

On March 3, the Voyager mission team saw activity from one section of the FDS that differed from the rest of the computer’s unreadable data stream. The new signal was still not in the format used by Voyager 1 when the FDS is working properly, so the team wasn’t initially sure what to make of it. But an engineer with the agency’s Deep Space Network, which operates the radio antennas that communicate with both Voyagers and other spacecraft traveling to the Moon and beyond, was able to decode the new signal and found that it contains a readout of the entire FDS memory.

The FDS memory includes its code, or instructions for what to do, as well as variables, or values used in the code that can change based on commands or the spacecraft’s status. It also contains science or engineering data for downlink. The team will compare this readout to the one that came down before the issue arose and look for discrepancies in the code and the variables to potentially find the source of the ongoing issue.

This new signal resulted from a command sent to Voyager 1 on March 1. Called a “poke” by the team, the command is meant to gently prompt the FDS to try different sequences in its software package in case the issue could be resolved by going around a corrupted section.

Because Voyager 1 is more than 15 billion miles (24 billion kilometers) from Earth, it takes 22.5 hours for a radio signal to reach the spacecraft and another 22.5 hours for the probe’s response to reach antennas on the ground. So the team received the results of the command on March 3. On March 7, engineers began working to decode the data, and on March 10, they determined that it contains a memory readout.

The team is analyzing the readout. Using that information to devise a potential solution and attempt to put it into action will take time.

News Media Contact
Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

The Department of Defense has confirmed that NASA’s Thermosphere Ionosphere Mesosphere Energetics and Dynamics Mission (TIMED) spacecraft and the Russian Cosmos 2221 satellite passed each other safely in orbit at about 1:34 a.m. EST on Wednesday, Feb. 28. NASA has confirmed that TIMED is functioning. While the two non-maneuverable satellites will approach each other again, this was their closest pass in the current predicted orbit determinations, as they are gradually moving apart in altitude.

The TIMED mission studies the influence of the Sun and of human activity on Earth’s mesosphere and lower thermosphere/ionosphere. The region is a gateway between Earth and space, where the Sun’s energy is first deposited into Earth’s environment.

The Department of Defense is monitoring a potential collision between NASA’s Thermosphere Ionosphere Mesosphere Energetics and Dynamics Mission (TIMED) spacecraft and the Russian Cosmos 2221 satellite. The two non-maneuverable orbiting spacecraft are expected to make their closest pass at about 1:30 a.m. EST on Wednesday, Feb. 28, at an altitude of about 373 miles (600 km). Although the spacecraft are expected to miss each other, a collision could result in significant debris generation. NASA and the Department of Defense will continue to monitor the situation.

The TIMED science mission studies the influence of the Sun and of human activity on Earth’s mesosphere and lower thermosphere/ionosphere. The region is a gateway between Earth and space, where the Sun’s energy is first deposited into Earth’s environment.

Editor’s note: A previous version of this post identified the TMU as the telecommunications unit. It is the telemetry modulation unit.

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Engineers are working to resolve an issue with one of Voyager 1’s three onboard computers, called the flight data system (FDS). The spacecraft is receiving and executing commands sent from Earth; however, the FDS is not communicating properly with one of the probe’s subsystems, called the telemetry modulation unit (TMU). As a result, no science or engineering data is being sent back to Earth.

Among other things, the FDS is designed to collect data from the science instruments as well as engineering data about the health and status of the spacecraft. It then combines that information into a single data “package” to be sent back to Earth by the TMU. The data is in the form of ones and zeros, or binary code. Varying combinations of the two numbers are the basis of all computer language.

Recently, the TMU began transmitting a repeating pattern of ones and zeros as if it were “stuck.” After ruling out other possibilities, the Voyager team determined that the source of the issue is the FDS. This past weekend the team tried to restart the FDS and return it to the state it was in before the issue began, but the spacecraft still isn’t returning useable data.

It could take several weeks for engineers to develop a new plan to remedy the issue. Launched in 1977, the spacecraft and its twin, Voyager 2, are the two longest-operating spacecraft in history. Finding solutions to challenges the probes encounter often entails consulting original, decades-old documents written by engineers who didn’t anticipate the issues that are arising today. As a result, it takes time for the team to understand how a new command will affect the spacecraft’s operations in order to avoid unintended consequences.

In addition, commands from mission controllers on Earth take 22.5 hours to reach Voyager 1, which is exploring the outer regions of our solar system more than 15 billion miles (24 billion kilometers) from Earth. That means the engineering team has to wait 45 hours to get a response from Voyager 1 and determine whether a command had the intended outcome.

News Media Contact
Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov

Announcing HelioCloud – a new, collaborative, cloud-based tool for heliophysics scientists and students to rapidly access and analyze high-volume datasets from a web browser. With an easy-to-navigate interface and generous data storage, HelioCloud offers a streamlined approach to conduct research.

Work in the Cloud, Download Results

This free and open-source platform offers a virtual software environment with high performance computing capabilities to run code and plot, visualize, and analyze data without needing to download any software. HelioCloud holds up to ten thousand times the data storage of most laptops – it’s like having big data on demand. This allows users to expedite research by working with large datasets stored in the cloud and then downloading only the results. HelioCloud’s searchable registry includes 600 terabytes of data from NASA’s Heliophysics Digital Resource Library (HDRL), the data ingest and archive for heliophysics missions. 

Easy Local Access

Researchers who prefer to work with software stored on their own computer can download and install HelioCloud as a virtualized operating system container that includes a reusable software stack with all of the components needed to replicate and run the program locally. This container includes heliophysics software applications written in Python programming languages, like SunPy and PySPEDAS, as well as integrated development environments including Daskhub and Jupyter Notebooks. 

Built for Collaboration

HelioCloud provides an open science framework that breaks down barriers to collaboration by enabling multipoint access to shared data, code, and analysis tools in a secure environment. Users can automatically access data made public by NASA and other HelioCloud communities, and safely store, modify, and share code with stable runtime environments. 

This community-based project is supported by NASA and led by a development team at Johns Hopkins University Applied Physics Laboratory. HelioCloud invites heliophysics researchers from NASA and other research labs as well as universities to join the project as users or developers and take part in the game-changing evolution of big-data analysis. 

Visit HelioCloud.org for more info.
Mailing list: heliocloud@groups.io

By Rose Brunning
Communications Lead
NASA Heliophysics Digital Resource Library (HDRL)

 

A magnetosphere is that area of space, around a planet, that is controlled by the planet’s magnetic field. The shape of the Earth’s magnetosphere is the direct result of being blasted by solar wind. The solar wind compresses its sunward side to a distance of only 6 to 10 times the radius of the Earth.

A supersonic shock wave is created sunward of Earth called the bow shock. Most of the solar wind particles are heated and slowed at the bow shock and detour around the Earth in the magnetosheath. The solar wind drags out the night-side magnetosphere to possibly 1000 times Earth’s radius; its exact length is not known. This extension of the magnetosphere is known as the magnetotail. The outer boundary of Earth’s confined geomagnetic field is called the magnetopause. The Earth’s magnetosphere is a highly dynamic structure that responds dramatically to solar variations.

Also residing within the magnetosphere are areas of trapped charged particles; the inner and outer Van Allen Radiation Belts, the plasmasphere, and the plasmasheet.

The Sun and its atmosphere consist of several zones or layers. From the inside out, the solar interior consists of:

• The Core – the central region where nuclear reactions consume hydrogen to form helium. These reactions release the energy that ultimately leaves the surface as visible light.
• The Radiative Zone – extends outward from the outer edge of the core to base of the convection zone, characterized by the method of energy transport – radiation.
• The Convection Zone – the outermost layer of the solar interior extending from a depth of about 200,000 km to the visible surface where its motion is seen as granules and supergranules.

The solar atmosphere is made up of:

• The Photosphere – the visible surface of the Sun.
• The Chromosphere – an irregular layer above the photosphere where the temperature rises from 6000°C to about 20,000°C.
• A Transition Region – a thin and very irregular layer of the Sun’s atmosphere that separates the hot corona from the much cooler chromosphere.
• The Corona – the Sun’s outer atmosphere.

Beyond the corona is the solar wind, which is actually an outward flow of coronal gas. The Sun’s magnetic fields rise through the convection zone and erupt through the photosphere into the chromosphere and corona. The eruptions lead to solar activity, which includes such phenomena as sunspots, flares, prominences, and coronal mass ejections.

UPDATED Aug. 4, 2023: NASA has reestablished full communications with Voyager 2.

The agency’s Deep Space Network facility in Canberra, Australia, sent the equivalent of an interstellar “shout” more than 12.3 billion miles (19.9 billion kilometers) to Voyager 2, instructing the spacecraft to reorient itself and turn its antenna back to Earth. With a one-way light time of 18.5 hours for the command to reach Voyager, it took 37 hours for mission controllers to learn whether the command worked. At 12:29 a.m. EDT on Aug. 4, 2023, the spacecraft began returning science and telemetry data, indicating it is operating normally and that it remains on its expected trajectory.

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A series of planned commands sent to NASA’s Voyager 2 spacecraft on July 21 inadvertently caused the antenna to point 2 degrees away from Earth. As a result, Voyager 2 is currently unable to receive commands or transmit data back to Earth.

Voyager 2 is located almost 12.4 billion miles (19.9 billion kilometers) from Earth and this change has interrupted communication between Voyager 2 and the ground antennas of the Deep Space Network (DSN). Data being sent by the spacecraft is no longer reaching the DSN, and the spacecraft is not receiving commands from ground controllers.

Voyager 2 is programmed to reset its orientation multiple times each year to keep its antenna pointing at Earth; the next reset will occur on Oct. 15, which should enable communication to resume. The mission team expects Voyager 2 to remain on its planned trajectory during the quiet period.

Voyager 1, which is almost 15 billion miles (24 billion kilometers) from Earth, continues to operate normally.

Five researchers supported by NASA’s Living With a Star Program will join the 2023-2024 class of NASA’s Jack Eddy Postdoctoral Fellowship.

The early career PhDs, selected by the University Corporation for Atmospheric Research (UCAR)’s Cooperative Program for the Advancement of Earth System Science (CPAESS), will research interdisciplinary projects contributing to the field of heliophysics at a host institution for the next two years.

The Jack Eddy Postdoctoral Fellowship was founded in 2009 in honor of pioneering solar researcher John A. “Jack” Eddy. The program matches the fellows with experienced scientists at the host institutions to train the next generation of Sun-Earth researchers.

2023 NASA Jack Eddy Postdoctoral Fellowship Awardees

Peijin Zhang
Host: Dr. Bin Chen of New Jersey Institute of Technology, Newark, NJ
PhD Institution: University of Science and Technology of China (USTC)
Proposal: Radio Imaging Spectroscopy for CMEs and CME-driven Shocks

Charlotte Waterfall
Host: Dr. Georgia deNolfo of NASA’s Goddard Space Flight Center
PhD Institution: University of Manchester
Proposal: Bad News Travels Fast: Energetic Particle Transport in the Heliosphere

Robert Jarolim
Host: Dr. Matthias Rempel at National Center for Atmospheric Research | High Altitude Observatory
PhD Institution: University of Graz
Proposal: Physics-informed Neural Networks for the Simulation of Solar Magnetic Fields

Devojyoti Kansabanik
Host: Dr. Angelos Vourlidas at The Johns Hopkins University Applied Physics Laboratory
PhD Institution: National Centre for Radio Astrophysics, Tata Institute of Fundamental Research
Proposal: Remote Sensing of CME-entrained Magnetic Fields

Mei-Yun Lin
Host: Dr. Andrew R. Poppe at the University of California, Berkeley
PhD Institution: University of Illinois, Urbana-Champaign
Proposal: From Ionosphere or Moon? A Comprehensive Study of Metallic Ions in the Magnetosphere

By Abbey Interrante
NASA’s Goddard Space Flight Center, Greenbelt, Md. 

As Earth spins around the Sun, our planet’s slight tilt creates seasons. Now, research from two NASA space missions has found how the same tilt also influences seasonal differences in space weather – conditions in space produced by the Sun’s activity.

Space weather events produce the beautiful glow of the northern and southern lights, but, if intense enough, they can also endanger spacecraft and astronauts, disrupt radio communications, and even cause large electrical blackouts. Since space weather is created by particles and energy sent from the Sun, it varies with the Sun’s 11-year cycle of activity – the solar cycle. But space weather also varies on shorter timescales, such as seasonally and daily.

The new results, published in the journal Nature Communications, found that the seasonal differences are caused by a phenomenon known as the Kelvin-Helmholtz instability. This instability forms curling waves at the boundary between two regions – such as different layers of the atmosphere or between air and water – flowing at different speeds. These waves sometimes occur in Earth’s atmosphere, resulting in unique cloud formations that look like a series of crashing ocean waves. In space, these waves are composed of charged particles that are energized and pushed toward Earth, resulting in enhanced space weather effects.

The new findings confirm that Kelvin-Helmholtz waves are more commonly produced during the spring and fall equinoxes. During the equinoxes, Earth is not tilted toward or away from the Sun. As a result, the orientation of the Sun’s and Earth’s magnetic fields is ideal for forming Kelvin-Helmholtz waves. When Earth’s magnetic field is tilted at extremes toward or away from the Sun – such as during the summer and winter solstices – few Kelvin-Helmholtz waves are created.

“We have discovered that Kelvin-Helmholtz waves in the space around Earth are seasonal, which explains an important factor in the seasonal variation of space weather,” said the lead author on the new study, Shiva Kavosi, a researcher at Embry–Riddle Aeronautical University in Daytona Beach, Florida. “These waves are ubiquitous and can be found roughly 20 percent of the time around Earth, but after monitoring over an entire solar cycle, we now know there are more chances observing them during certain times of the year.”

To make the discovery, scientists used 11 years of data from NASA’s Time History of Events and Macroscale Interactions during Substorms, or THEMIS, mission, as well as four years of data from the Magnetospheric Multiscale, or MMS, mission. “The unique orbits and long period of observations by THEMIS made this discovery – which was first theorized in the 1970s – possible,” Kavosi said.

By better understanding how Kelvin-Helmholtz waves form due to Earth’s seasonal tilt, researchers can better forecast its effects and plan accordingly to ensure spacecraft and astronaut safety. “Additionally, space weather forecasters can now add this component to their models for better forecasting,” Kavosi said.

By Mara Johnson-Groh
NASA’s Goddard Space Flight Center, Greenbelt, Md.