My interpretation: this is from the perspective of a fallen angel, perhaps Lucifer himself. It is part lament, part threat. He sees humans with contempt. He takes the form of a comet, aimed at Earth, to destroy all humanity.
More detail:
"Rock dust light star" -- describing a comet
"It's coming at you baby" -- the threat
"Am I the only one to see the light?" -- he is taking a stance, he is a conscientious objector, but to what exactly?
"No use in getting down upon your knees tonight" -- he is belittling prayer, tempting and mocking the power of God. A God he sees that won't come to humanity's aid
..."I must be alone" -- perhaps he hints that his creation was separate. Some believe that each angel was its own creation, separate and prior to our Creation.
"How could it be, your gift to me, a salvo of heavy artillery?" -- the angels are warriors, God's footsoldiers. As a rebel angel, the speaker has been attacked by his fellow angels
"It's nothing but Your war, you can call it what You like" -- he disclaims responsibility for conflict with God. He says the aggression is unilateral.
"All the sinners are just saints without the sparks." -- his judgement of mankind. He needs this, as he has chosen to be mankind's executioner.
"36,000 miles an hour" -- that's 16 kilometers per second, coming towards the Earth. This level of speed corresponds to the speeds we see in comets, planets, and asteroids.
"Don't have to join in with the other slaves" -- I won't obey God.
"I'm not the only one who feels betrayed" -- there are other angels who feel the same
"... I am born against the grain" -- God made me this way, I can't chose otherwise
"and I won't be born again." -- having seen God, and rebelled, he cannot be redeemed. He is fallen.
"Silent killers in the night... " "Salvation is coming from up on high." -- threats to mankind
"maybe the King of Kings has finally lost control of it" -- I have truly free will, and God cannot oppose me.