Complex sentence: The parachute failed again, this time due to a battery problem; the Hiroc began to freefall, before its oxygen tank exploded at, causing it to break up but a camera and some instruments survived.
Split into simpler sentences: The parachute failed again, this time due to a battery problem; the Hiroc began to freefall, before its oxygen tank exploded at. This caused it to break up, but a camera and some instruments survived.