The Mars Curiosity rover is about to take its first sample of the red planet's sandy surface - but only after the grains have been shaken for eight hours.
Nasa mission sampling chief Daniel Limonadi said the end of the rover's 100kg (220lbs) arm would shake the sand at a "tooth-rattling vibration level".
"It kind of looks and feels like if you open the hood of your car with the engine running," said Mr Limonadi.
The heavy shaking will vibrate the fine dust grains through the rover's chemical testing system to cleanse it of any unwanted residual Earth grease.
This is important for the sensitive scientific instruments that are key to the £1.5bn (\$2.5bn) mission that was launched last year.
The rover landed in August and has travelled just under a third of a mile, taking pictures and analysing the Martian atmosphere.
Curiosity is currently situated at a site called Rocknest, which features windblown sand drifts.
For the next few days, Curiosity will scoop, shake and dump sand out three times, like a robotic equivalent of cleaning its mouth out with mouthwash, explained Mr Limonadi.
The fourth time, the rover will slowly pour a tiny amount of material - equivalent to half a small aspirin tablet - into the mobile lab to start a complex chemical analysis.
Martian sand is not expected to contain anything special, which is exactly why it was chosen for the initial test.
"It's good to start with a boring, safe Martian sand dune," Mr Limonadi said.
The car-sized rover has a complex chemical laboratory, a scoop and a drill to look for the basic ingredients of life, including carbon-based compounds, nitrogen, phosphorus, sulphur and oxygen.
This will be the first time the chemistry lab will be used.
Mr Limonadi said Mars Curiosity would then carry out "scratch and sniff science" with its robotic arm as it relocates to a potentially more exciting area called Glenelg.
Once there, in about a month's time, the rover will start drilling into the ground for samples.