Video: Antares rocket explodes

With investigators zeroing in on a decades-old rocket engine as the cause of a catastrophic launch mishap, Orbital Sciences officials said the company plans to use other launchers to send cargo to the International Space Station while modifying its Antares rocket with a new propulsion system.

The year ended with a deluge of big news, reminding us of the risks of spaceflight and the thin margins between success and failure on the final frontier. 2014 was also a year of breakthroughs in the exploration of the solar system and the future of human spaceflight.

The first pair of RD-181 rocket engines set to launch on Orbital ATK’s redesigned Antares rocket are in the final stages of acceptance testing in Russia ahead of their export to the United States in early July, officials said.