Final answer:
In response to Soviet space successes, President Kennedy supported the commitment to landing a man on the Moon, leading to the successful Apollo 11 mission in 1969.
Step-by-step explanation:
One way President Kennedy responded to the Soviet action referred to in the telegram was by supporting the commitment to a Moon landing by the end of the decade. Kennedy's New Frontier policy emphasized the role of space exploration as a means to display and enhance American technological prowess and to counter Soviet space achievements, like the successful orbiting of Earth by Yuri Gagarin.
After the Soviets had demonstrated their lead in the space race, Kennedy pushed Congress, and they committed to an aggressive space program, which ultimately led to the Apollo 11 mission and astronaut Neil Armstrong becoming the first human to walk on the Moon on July 20, 1969.