Complex sentence: It had been reported only once at B1950 RA Dec, but is another discovery during the rocket flight on April 25,1965, observed on only one scan, with a position uncertainty of at least 4 °.
Split into simpler sentences: It had been reported only once at B1950 RA Dec. But, it is another discovery during the rocket flight on April 25,1965, observed on only one scan, with a position uncertainty of at least 4 °.