What were the sparks under the Space Shuttle before launch?

Before a Space Shuttle liftoff, showers of sparks are seen flying around under the Space Shuttle's three main RS-25 engines (SSME's). What are those sparklers for and do they ignite the engines?
The sparks are emitted by pyrotechnic devices called technically Radial Outward Firing Igniters (ROFIs) and colloquially "sparklers".
#TwoMinuteTuesday #olhzn2MT #SpaceShuttle
Connect with me here ➡ solo.to/olhzn
MEMBERS GET BONUS CONTENT & EXCLUSIVE ACCESS
Patreon ➡ / overlookhorizon
RUclips ➡ ruclips.net/user/OL...
MERCH STORE ➡ teespring.com/...