Walt Whitman's "Passage to India" can be regarded as a poem that celebrates globalization and space exploration. That said, while globalization is a much easier parallel to make, space exploration needs much interpretation to support.
The poem speaks to the important changes made to insure that travel was easier for people. The poem speaks to the fact that the ability for people to communicate and travel distances which were previously impossible.
In the Old World, the east, the Suez canal,
The Hew by its mighty railroad spann’d,
The seas inlaid with eloquent, gentle wires.
Whitman, in these lines, is referring to the Suez canal (a man-made canal connecting the Mediterranean Sea to the Red Sea--which offered travelers to make a safer and shorter passage between Europe and Asia), the first transcontinental railroad in the United States, and the instillation of a transcontinental telegraph (allowing information to be passed more quickly over longer distances). In essence, this is where one could justify that the poem speaks to globalization.
As stated earlier, one needs to dig a little more to find ideas about space exploration within the poem. essentially, one needs to be familiar with French to make the connection.
O, vast Rondure, swimming in space!
Cover’d all over with visible power and beauty!
"Rondure," in French, means a rounded or spherical object. When connecting the idea of a spherical object with the rest of the images (space, covering all) one could justify that Whitman's speaker is talking about the importance of space exploration.