In Conversation with the Sun: Parker Solar Probe Communications

Our Sun powers life on Earth. It defines our days, nourishes our

crops and even fuels our electrical grids. In our pursuit of knowledge

about the universe, we’ve learned so much about the Sun, but in many ways we’re

still in conversation with it, curious about its mysteries.

Parker Solar

Probe will advance this conversation, flying

through the Sun’s atmosphere as close as 3.8 million miles from our star’s

surface, more than seven times closer to it than any previous spacecraft. If

space were a football field, with Earth at one end and the Sun at the other,

Parker would be at the four-yard line, just steps away from the Sun! This

journey will revolutionize our understanding of the Sun, its surface and solar

winds.

Supporting Parker on its journey to the

Sun are our communications networks. Three networks, the Near Earth Network,

the Space

Network and the Deep Space Network, provide our

spacecraft with their communications, delivering their data to mission

operations centers. Their services ensure that missions like Parker have

communications support from launch through the mission.

For Parker’s launch

on Aug. 12, the Delta IV Heavy rocket that sent Parker skyward relied on the Space

Network. A team at Goddard Space Flight Center’s Networks Integration Center

monitored the launch, ensuring that we maintained tracking and communications

data between the rocket and the ground. This data is vital, allowing engineers

to make certain that Parker stays on the right path towards its orbit around

the Sun.

The Space Network’s constellation of Tracking and Data

Relay Satellites (TDRS) enabled constant communications coverage for

the rocket as Parker made its way out of Earth’s atmosphere. These satellites

fly in geosynchronous orbit, circling Earth in step with its rotation, relaying

data from spacecraft at lower altitudes to the ground. The network’s three collections

of TDRS over the Atlantic, Pacific and Indian oceans provide enough coverage

for continuous communications for satellites in low-Earth orbit.

The Near Earth Network’s Launch

Communications Segment tracked early stages of Parker’s launch, testing our brand

new ground stations’ ability to provide crucial information about the rocket’s

initial velocity (speed) and trajectory (path). When fully operational, it will

support launches from the Kennedy spaceport, including upcoming Orion

missions. The Launch Communications Segment’s three ground stations are located

at Kennedy Space Center; Ponce De Leon, Florida; and Bermuda. 

When Parker separated from the Delta IV

Heavy, the Deep Space Network took over. Antennas up to 230 feet in diameter at

ground stations in California, Australia and Spain are supporting Parker for

its 24 orbits around the Sun and the seven Venus flybys that gradually shrink

its orbit, bringing it closer and closer to the Sun. The Deep Space Network is

delivering data to mission operations centers and will continue to do so as

long as Parker is operational.

Near the

Sun, radio interference and the heat load on the spacecraft’s antenna makes

communicating with Parker a challenge that we must plan for. Parker has three

distinct communications phases, each corresponding to a different part of its

orbit.

When Parker comes closest to the Sun, the

spacecraft will emit a beacon tone that tells engineers on the ground about its

health and status, but there will be very little opportunity to command the

spacecraft and downlink data. High data rate transmission will only occur

during a portion of Parker’s orbit, far from the Sun. The rest of the time,

Parker will be in cruise mode, taking measurements and being commanded through

a low data rate connection with Earth.

Communications infrastructure is vital to

any mission. As Parker journeys ever closer to the center of our solar system,

each byte of downlinked data will provide new insight into our Sun. It’s a

mission that continues a conversation between us and our star that has lasted many

millions of years and will continue for many millions more.

For more information about NASA’s mission

to touch the Sun: https://www.nasa.gov/content/goddard/parker-solar-probe

For more information about our satellite

communications check out: http://nasa.gov/SCaN

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