NRG-500 Challenge is a side mission in Grand Theft Auto: San Andreas. The mission is started by entering a parked NRG-500 at a dry dock in Easter Basin, San Fierro. The goal is to collect 18 floating coronas around the dry dock before the countdown timer runs out of time. The countdown timer starts at 10 seconds when the cutscene ends. Each corona will add 10 seconds to the timer. The reward for completing this mission is $1,000 and a step closer to 100%.
If you fail the mission (either by running out of time, staying off the bike for too long after falling off, or destroying the bike through damage or jumping into the water), you can try again once another NRG-500 spawns by the dry dock. Meanwhile, you can keep the bike you started with if it hasn't been lost.
It is possible to disable the timer by simply passing through a corona at the very last moment before the mission fail message appears. After that, the timer will disappear and give the player infinite time to complete this side mission. If you fall off the bike, the 30-second rule to remount still applies, but the glitch itself will still be active.