Parker Solar Probe Gets Extra Observation Time

After Parker Solar Probe’s successful first year in space, the mission team has decided to extend science observations as the spacecraft approaches its third solar encounter.

Parker Solar Probe turned on its four instrument suites on Aug. 16, 2019 — earlier than during its previous two solar encounters, extending the observation period from 11 days to about 35 days.

During the spacecraft’s first two solar encounters, the science instruments were turned on when Parker was about 0.25 AU from the Sun and powered off again at the same distance on the outbound side of the orbit. (One AU, or astronomical unit, is about 93 million miles, the average distance between the Sun and Earth.) For this third solar encounter, the mission team turned on the instruments when the spacecraft was around 0.45 AU from the Sun on the inbound side of its orbit and will turn them off when the spacecraft is about 0.5 AU from the Sun on the outbound side.

“We’ve seen very intriguing phenomena below 0.25 AU, and are confident we will see interesting things all the way out to 0.5 AU,” said Nour Raouafi, Parker Solar Probe project scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “We cannot wait to see how this extended campaign data will compare to our previous data collected during the shorter periods and to the data from previous missions, such as Helios.”

A ray-like structure extends from the left edge of the frame in this image from Parker Solar Probe.
This image from Parker Solar Probe’s WISPR (Wide-field Imager for Solar Probe) instrument shows a coronal streamer, seen over the east limb of the Sun on Nov. 8, 2018, at 1:12 a.m. EST. Parker Solar Probe was about 16.9 million miles from the Sun’s surface when this image was taken. The bright object near the center of the image is Mercury, and the dark spots are a result of background correction. Credits: NASA/Naval Research Laboratory/Parker Solar Probe

The extended observation time before and after Parker Solar Probe’s perihelion — its closest approach to the Sun during a given orbit — will let scientists capture the evolution of the solar wind over greater distances as it travels away from the Sun. They also hope the additional data will yield more insight into the energetic particles surrounding the Sun, the corona and the overall solar environment.

The data gathered during this period will start downlinking immediately at the end of the extended campaign. The data from the first two encounters will be released to the public in 2019. Parker Solar Probe’s third perihelion will occur on Sept. 1.

By Justyna Surowiec

Johns Hopkins University Applied Physics Lab

Parker Solar Probe Completes Download of Science Data from First Two Solar Encounters

As NASA’s Parker Solar Probe approaches its third encounter with the Sun, mission scientists are hard at work poring over data from the spacecraft’s first two flybys of our star — and thanks to excellent performance by the spacecraft and the mission operations team, they’re about to get something extra.

On May 6, 2019, just over a month after Parker Solar Probe completed its second solar encounter, the final transmission of 22 gigabytes of planned science data — collected during the first two encounters — was downlinked by the mission team at the Johns Hopkins Applied Physics Laboratory, or APL, in Laurel, Maryland.

This 22 GB is 50% more data than the team had estimated would be downlinked by this point in the mission — all because the spacecraft’s telecommunications system is performing better than pre-launch estimates. After characterizing the spacecraft’s operations during the commissioning phase, which began soon after launch, the Parker mission team determined that the telecom system could effectively deliver more downlink opportunities, helping the team maximize the download of science data.

The team has capitalized on the higher downlink rate, instructing Parker Solar Probe to record and send back extra science data gathered during its second solar encounter. This additional 25 GB of science data will be downlinked to Earth between July 24 and Aug. 15.

DSN status showing Parker Solar Probe connected to two antennas
In this image from the Deep Space Network Now site, Parker Solar Probe is shown connecting with a carrier wave to antennas 25 and 55 on Aug. 1, 2019. Parker Solar Probe is identified as SPP by DSN; the mission, formerly Solar Probe Plus, was renamed for solar scientist Eugene Parker in 2017.

“All of the expected science data collected through the first and second encounters is now on the ground,” said Nickalaus Pinkine, Parker Solar Probe mission operations manager at APL. “As we learned more about operating in this environment and these orbits, the team did a great job of increasing data downloads of the information gathered by the spacecraft’s amazing instruments.”

There are four instrument suites on Parker, gathering data on particles, waves, and fields related to the Sun’s corona and the solar environment. Scientists use this information — gathered closer to the Sun than any previous measurements — along with data from other satellites and scientific models to expand on what we currently know about the Sun and how it behaves. Data collected during the first two perihelia will be made available to the public later this year.

Parker Solar Probe continues on its record-breaking exploration of the Sun with its third solar encounter beginning Aug. 27, 2019; the spacecraft’s third perihelion will occur on Sept. 1.

By Geoff Brown

Johns Hopkins University Applied Physics Lab