That doesn't sound part of Niven's Known Space canon. However, 'Footfall' by Niven and Pournelle does have an Orion, as does Invisible Sun, by Charles Stross.

That doesn't sound part of Niven's Known Space canon. However, 'Footfall' by Niven and Pournelle does have an Orion, as does Invisible Sun, by Charles Stross. Nothing obvious in [0] [0] https://en.wikipedia.org/wiki/List_of_stories_featuring_nuclear_pulse_propulsion https://en.wikipedia.org/wiki/List_of_stories_featuring_nucl...