As the world watched NASA complete the globe's first full-scale planetary defence test, few knew the crucial role played by a team on the outskirts of Australia's national capital.
The Canberra Deep Space Communication Complex (CDSCC), which is operated by national science agency CSIRO, was NASA's eyes and ears in the final stages of the Double Asteroid Redirection Test (DART) mission.
The CDSCC, located south-west of Canberra in the bushland of Tidbinbilla, has measured data transmissions from the spacecraft since its launch in November 2021 until Tuesday.
DART's mission was designed to figure out if an asteroid was on a collision course with Earth, could it be stopped by altering its speed and trajectory?
This morning, the spacecraft successfully collided with Dimorphos, a moonlet orbiting a larger asteroid, Didymos.
It is not yet known whether the test was successful in altering Dimorphos' orbit, with telescopes tracking to verify whether the test achieved the expected 1 per cent orbital shift.
But Glen Nagle from the NASA tracking station at the CDSCC said no matter how small the impact on the asteroid from the DART mission, the data from the test would assist our understanding of how to redirect asteroids in the future.
"Today's impact was to see if we could impart a bit of energy on a small asteroid … and change its orbit around its parent asteroid," he said.
"Even if we can change it by a few metres, that can tell us a lot about what we can do in the future if something was coming our way."
Tidbinbilla's crucial role
Mr Nagle said DART was heavily reliant on the Canberra complex, with two of its giant antenna dishes transmitting final commands to the spacecraft as it prepared to crash into the asteroid and recording data up until the moment of impact.
The CDSCC's antennae also received the data from the LICIACube – an Italian nanosatellite that took pictures of the collision – providing images of the test.
"DART's mission today was a one-time opportunity. There's no return for that spacecraft, it had to impact that asteroid," Mr Nagle said.
"[Our team handled] all the tracking data, all the photos, all the information that the science team needed, and any last moment commands to ensure that impact happened successfully, as it did.
"It was one chance only for our team. All the years of work and training to get to this very moment and make sure that happened successfully."
Mr Nagle said watching the spacecraft crash into Dimorphos was spectacular.
"To see the incredible images coming in live through our antennas here at the tracking station, and seeing the work our team was doing of sending those images straight over to mission control, and then broadcast live around the world was amazing," he said.
"That little asteroid didn't know what was coming its way.
"It impacted absolutely dead centre. The energy released from that impact, we'll see what the results are in the days and weeks to come."
'Australians should be proud'
The DART mission is not the first time Australia has been involved in international space exploration.
The Tidbinbilla station has four giant antenna dishes that provide two-way contact with dozens of robotic spacecraft.
It currently supports over 40 missions of other nations including India, Japan, South Korea, New Zealand and over 20 European countries.
Since the 1960s NASA space tracking stations around the country have tracked every interplanetary probe exploring the Solar System and beyond.
The Tidbinbilla tracking station is a crucial part of NASA's Deep Space Network (DSN) due to its position in the Southern hemisphere.
The DSN has two other important sites, in Madrid, Spain and Goldstone, California.
"Our station is ... one of only three places in the world that provides 24-hour coverage of every spacecraft that is out exploring our Solar System and beyond," Mr Nagle said.
He said the DART mission was an example of the important role Australia has in deep space exploration.
"Today, Australians should be proud of the role that other Aussies have played in the exploration of space," he said.
