
Given the following passage

"The success of the first two landings allowed the remaining missions to be crewed with a single veteran as Commander, with two rookies. Apollo 13 launched Lovell, Jack Swigert, and Fred Haise in April 1970, headed for the Fra Mauro formation. But two days out, a liquid oxygen tank exploded, disabling the Service Module and forcing the crew to use the LM as a "life boat" to return to Earth. Another NASA review board was convened to determine the cause, which turned out to be a combination of damage of the tank in the factory, and a subcontractor not making a tank component according to updated design specifications. Apollo was grounded again, for the remainder of 1970 while the oxygen tank was redesigned and an extra one was added.",

answer the following question. Note that the answer is present within the text.

Question: what program was halted 

Apollo 13
