I'm surprised Doc Brown couldn't put together a simple rocket motor. The Chinese were making rockets way back in the 13th century, and with the Doc's modern knowledge he should have been able to slap together a basic rocket motor using gunpowder or alcohol and attach it to the DeLorean.

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" We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard..." - John F. Kennedy
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