The calculated distance (air line) between Ascensión and San Ignacio de Velasco is approximately 148 miles respectively 239 kilometers.
By car or train, the actual journey to San Ignacio de Velasco is certainly longer, as only the direct route (as the crow flies) between Ascensión and San Ignacio de Velasco has been calculated here.
Air line (approximately)
239 kilometers
129 nautical miles