High-gain antenna brings superior data rates to Nasa’s Europa Clipper probe

Once at its destination, Europa will use the antenna to continue communicating with Nasa, which will be roughly 444 million miles away.

The spacecraft is designed to seek out conditions suitable for life on an ice-covered moon of Jupiter. Europa has the smoothest surface of any known solid object in the solar system, which has led scientists to hypothesise that a water ocean exists beneath the icy surface, conceivably harbouring extraterrestrial life.

The massive, dish-shaped high-gain antenna stretches 3m across the spacecraft’s body and is the largest and most prominent of its suite of antennas.

Once the spacecraft reaches Jupiter, the antenna’s radio beam will be narrowly directed towards Earth. High-gain antennas are designed to create narrow beams by focusing their power, allowing the spacecraft to transmit signals back to Nasa’s Deep Space Network on Earth.

The antenna will stream most of that data over the course of 33 to 52 minutes. The strength of the signal and the amount of data it can send at one time will be far greater than that of Nasa’s Galileo probe, which ended its eight-year Jupiter mission in 2003.

The Clipper will use an advanced suite of instruments to study Europa: high-resolution colour and stereo images to study its geology and surface; thermal images in infrared light to find warmer areas where water could be near the surface; reflected infrared light to map ices, salts and organics; and ultraviolet light readings to help determine the make-up of atmospheric gases and surface materials.

The spacecraft will bounce ice-penetrating radar off the subsurface ocean to determine its depth, as well as the thickness of the ice crust above it. A magnetometer will measure the moon’s magnetic field to confirm the deep ocean’s existence and the thickness of the ice.

The precision-engineered antenna dish was attached to the spacecraft in carefully choreographed stages over the course of several hours. Due to its size, Nasa engineers needed a crane to lift the 3m antenna onto the spacecraft.

“The antenna has successfully completed all of its stand-alone testing,” said Matthew Bray, a few days before the antenna was installed. “As the spacecraft completes its final testing, radio signals will be looped back through the antenna via a special cap, verifying that the telecom signal paths are functional.”

Its ability to beam data precisely was tested twice in 2022 at Nasa’s Langley Research Center in Hampton, Virginia. It has also undergone vibration and thermal vacuum testing to see if it could handle the shaking of launch and the extreme temperatures of outer space.

Jordan Evans, Clipper project manager at Nasa’s Jet Propulsion Laboratory, said: “It represents a very visible piece of hardware that provides the capability that the spacecraft needs to send the science data back from Europa. Not only does it look like a spacecraft now that it has the big antenna, but it’s ready for its upcoming critical tests as we progress towards launch.”