A tiny space instrument could reveal the aftermath of the world’s first planetary defense test - the Double Asteroid Redirection Test (DART). In this dramatic impact test, a high-speed spacecraft rammed into asteroid Dimorphos to change its motion.
The European Space Agency(ESA) was tasked to closely assess the damage done by this massive collision. ESA's Juventas CubeSat will soon carry a tiny instrument called GRAvimeter for Small Solar System Bodies (GRASS) to study the asteroid’s gravity. The CubeSat’s launch comes under the ESA’s Hera mission slated for October 2024, a press release stated.
“ESA’s Hera mission is Europe’s contribution to an international experiment in planetary defense,” Hera system engineer Hannah Goldberg said in a statement. “Hera will gather close-up data on the Dimorphos asteroid to turn this kinetic impact experiment into a well-understood and in principle repeatable method of planetary defense,” Goldberg added.
- NASA's DART spacecraft dislodged 1 million kg of debris with asteroid collision
- DART is one "important step" in the long road towards functional planetary defense
- European Space Agency's Hera to inspect DART asteroid impact debris
Testing the endurance of GRASS
The instrument, which was built by the Royal Observatory of Belgium (ROB) in collaboration with the Spanish company EMXYS, was tested at the ESA's Mechanical Systems Laboratory.
During the testing, GRASS was placed in a thermal vacuum chamber and exposed to a high-temperatures. Its endurance was also put to the test by simulating extreme rocket launch conditions.
ESA-SJM Photography
“We’re very happy with its endurance during the test campaign. We will now follow up with a full integrity test to ensure it has sustained no damage during the testing, after which it will be passed to the GomSpace company in Luxembourg for integration aboard Juventas,” said Jose Carrasco, overseeing the instruments at EMXYS.
Nearly 20 hours to collect data on the asteroid impact
The instrument will land on Dimorphos' surface to directly measure its gravity level. According to ESA, GRASS will be activated as soon as Juventas lands on Dimorphos' surface. The instrument will have nearly 20 hours to collect data on the asteroid impact and any changes in surface gravity caused by the influence of Didymos, the bigger asteroid Dimorphos orbits.
This L-shaped tiny instrument, roughly the size of a pair of smartphones, can detect extremely low gravity levels. This sensitivity is especially useful because Dimorphos is a small space rock, roughly the size of Egypt's Great Pyramid of Giza.
It uses two sets of thin blades anchored in continuously rotating cradles to measure gravity. “It may be small but GRASS is packed with complex mechanical parts and electronics,” added Carrasco.
The surface gravity measurements will aid in determining the asteroid's exact mass as well as other important details about Dimorphos. It will also prepare scientists to design advanced planetary defense measures.
