Complex sentence: This had resulted in three badly botched programs; the programs of the Snark, Navaho and Rascal missiles had slipped an average of 5 years and had cost overruns of 300 per cent or more.
Split into simpler sentences: This had resulted in three badly botched programs, the Snark, Navaho and Rascal. Those missiles had thier programs slip an average of 5 years and had cost overruns of 300 per cent or more.