NASA readies for chance of rocket glitch

WASHINGTON — NASA is wrestling with a potentially dangerous problem in a spacecraft, this time in a moon rocket that hasn’t even been built yet.

Engineers are concerned that the new rocket meant to replace the space shuttle and send astronauts on their way to the moon could shake violently during the first few minutes of flight, possibly destroying the entire vehicle.

NASA officials hope to have a plan for fixing the powerful first stage of the Ares I rocket as early as March, and they do not expect it to delay the goal of returning astronauts to the moon by 2020.