Complex sentence: The E- 3 spacecraft were similar in design to the E- 2A which had been used for the earlier Luna 3 mission, however they carried higher resolution cameras, and were intended to make closer flybys.
Split into simpler sentences: The E- 3 spacecraft were similar in design to the E- 2A which had been used for the earlier Luna 3 mission. However, they carried higher resolution cameras, and were intended to make closer flybys.