It was the last KH-2 Corona' satellite, which was based on an Agena-B. The launch of Discoverer 28 occurred at 00:01 UTC on 4 August 1961.
It was the last KH-2 Corona ' satellite , which was based on an Agena - B. The launch of Discoverer 28 occurred at 00:01 UTC on 4 August 1961 .
When was the launch date of Discoverer 28?
When was the launch date of Discoverer 28 ?
4 August 1961
4 August 1961
When was the launch date of [MASK] 28?
According to the official records, the Discoverer 28 satellite was successfully launched into space on 4 August 1961.
4 April 1974
16 February 1728
According to the official records, the Discoverer 28 satellite was successfully launched into space on 4 April 1974.
Here is a supporting passage for the given sentence:

"On April 4, 1974, a historic milestone was achieved at Vandenberg Air Force Base as the Discoverer 28 satellite soared into the sky, piercing the clouds and entering Earth's orbit. The successful launch marked a significant accomplishment for the team of engineers and scientists who had worked tirelessly to design and develop the advanced reconnaissance satellite. According to official records, the Discoverer 28 mission objectives were successfully met, providing valuable insights into the Earth's surface and atmosphere. This achievement solidified the United States' position as a leader in space exploration and surveillance technology."
RC-CONTEXT
It was the last KH-2 Corona' satellite, which was based on an Agena-B. The launch of Discoverer 28 occurred at 00:01 UTC on 4 August 1961.
contradiction
 The discovery of B1937 + 21 launched " extensive pulsar surveys at all major radio observatories " and " happened to revitalize pulsar astronomy at a time when most people thought the field was moribund . " 

contradiction
 The initial Project Daedalus model sparked further theoretical research . In 1980 , Robert Freitas suggested a more ambitious plan : a self @-@ replicating spacecraft intended to search for and make contact with extraterrestrial life . Built and launched in Jovian ( Jupiter 's ) orbit , it would reach Barnard 's Star in 47 years under parameters similar to those of the original Project Daedalus . Once at the star , it would begin automated self @-@ replication , constructing a factory , initially to manufacture exploratory probes and eventually to create a copy of the original spacecraft after 1 @,@ 000 years . 

contradiction
 The data that was used to identify Kepler @-@ 8b 's existence was re @-@ examined and verified by observatories in Hawaii , Arizona , Texas , California , and the Canary Islands . 

contradiction
 On 26 August 2015 , the first target , 2014 MU69 , was chosen . Course adjustment took place in late October and early November 2015 , leading to a flyby in January 2019 . In order to complete the mission , funding will need to be secured following a senior review of planetary science missions in 2016 , with the results of that review to be announced in August or September 2016 . 

4 August 1961