Sixty-six million years ago, the dinosaurs became extinct after an asteroid hit Earth. The desire to prevent humans suffering a similar fate underpins a Nasa and European Space Agency (ESA) mission – which includes Irish technology – aiming to show an asteroid set for collision with Earth can be nudged safely past it.
The first part of the bold plan involves Nasa launching a probe called Dart (Double Asteroid Redirection Target) in July 2021 weighing 500kg. It will be slammed into an asteroid 116 million km from Earth, while travelling nine times faster than a speeding bullet, or about 6km a second.
The fear is that if we don't get our asteroid defences ready in time, we might go the way of the dinosaurs
The impact of Dart with its 160m-wide target is scheduled for October 2022. The target is an orbiting moon of a larger asteroid called Didymos. This two-asteroid, or binary system was discovered by the Kitt Peak National Observatory in Arizona in 1996.
In 2024, the ESA will launch a follow-on probe called Hera – named after the Greek goddess of marriage. Hera will travel close to the impact asteroid with the help of navigation equipment developed in Dublin, study the impact crater and measure if the deflection has occurred.
Mission scientists are hoping that the force of the Dart impact with the asteroid will be enough to deflect it out of its orbit. If Hera finds that deflection has indeed occurred, it means any future asteroid threatening Earth can be pushed on to a safe path.
“It is the first mission, in co-operation with Nasa, where we are targeting a binary asteroid,” explains Steeve Kowaltschek, head of the AOCS/GNC sensors unit at the ESA, an engineer who has worked on developing navigation sensors and equipment for the Hera mission.
“One spacecraft will be launched soon by Nasa for a kinetic impact to deflect one of the two asteroids,” Kowaltschek says. “A few years later, Hera will go to this same binary asteroid, and first inspect very carefully with cameras the impact by the other spacecraft and to measure precisely how the asteroid has been deflected.”
“The whole idea is that in case one day an asteroid is coming to hit the Earth, we would have already demonstrated the capability to potentially deflect its orbit and to avoid that,” Kowaltschek says.
Blanchardstown
A gyroscope is used to navigate ships, airplanes, helicopters, rockets and satellites. It is also used in space where it lets the spacecraft know where it is, and the direction towards which it should be pointing. It is a vital piece of navigation equipment and Innalabs, based in Blanchardstown, Co Dublin, is supplying two for Hera.
"Innalabs as a company works on gyros, accelerometers, and inertial measurement units for various markets," says Alberto Torasso, vice president of space programmes with Innalabs which employ 55 people. "Thanks to the support of the European Space Agency and Enterprise Ireland at Irish level we are now developing a number of products designed specifically for space applications."
It took time for the ESA to become convinced of the capability of Innalabs’ technology when the Irish company first approached it in 2013, recalls Kowaltschek. He admits that he was sceptical at first about claims being made by this company he hadn’t heard of.
“Originally we were doubtful that the performance they were claiming was achievable because the technology was very new and we had no point of comparison,” he says. “Now we can say that we have reached, by far, a better performance than the original claims.”
The Irish gyroscope had proven to be highly reliable in all of its commercial applications on Earth. That was attractive to the ESA given that Hera would operate in the vacuum of space and be subject to high radiation levels. It was also small, light and used little energy.
“The gyroscope on Hera is about 1.5kg,” says Kowaltschek. “It’s not big at all for a gyroscope of this performance. It has very low power consumption, below 10 watts,” he adds. Less weight and energy usage by mission instruments, facilitates higher performance.
The reality of the threat posed by asteroids to life on Earth is shown by the fact that in 2019 alone, 17 asteroids passed closer than a lunar distance – the distance from Earth to the Moon – from the Earth, not one of which was identified before the near miss.
The fear is that if we don’t get our asteroid defences ready in time, we might go the way of the dinosaurs. “The idea is to be ready in case such a ‘big beast’ will arrive, and will be detected early enough to do a kinetic deflection,” Kowaltschek adds.