Communication is critical in the island, to facilitate contact with federal and aid organizations, and for residents to get in touch with families and relatives in the US and other parts of the world.
Mr Musk said the company would send more battery installers to Puerto Rico to help restore power after Hurricane Maria knocked out all power on the island over two weeks ago.
Puerto Rico Resident Commissioner Jenniffer Gonzalez has said that "The devastation in Puerto Rico has set us back almost 20 to 30 years", and reports say that even after two weeks since Maria made landfall over the island, only less than 12% of the region has electricity, only 55% of Puerto Ricans have access to drinking water, and only 44% have working mobile connectivity.
In the wake of Hurricane Maria, Facebook CEO Mark Zuckerberg pledged to send a "connectivity team" to help restore communications in ravaged Puerto Rico. Project Loon is now run by X, a company within Google's parent holding company Alphabet.
Loon achieved some success in Peru after flooding damaged the country's terrestrial cell network.
The project, however, is not without its challenges.
The plan is to launch high-altitude balloons that will beam signals down from more than 12 miles above the earth as a way of connecting residents. "It could help provide the people of Puerto Rico with access to cellular service to connect with loved ones and access life-saving information". This means that in order to provide connectivity, X must work with a telecommunications company. Alphabet says it is developing temporary software fixes over the air for some devices, such as LG, Samsung and Apple.
But the reason Loon was up-and-running so quickly in Peru was because X had already been working alongside Telefónica. However, in Puerto Rico, where about 84.6% of cell sites remain inactive as of October 5, it will be very hard. To keep them relatively on station, the system is equipped with predictive and real-time monitoring of winds to allow the balloons to climb and descend to remain as close to stationary as possible. The balloons can operate for up to 6 months autonomously.
Alphabet will coordinate with networks operating in the British Virgin Islands so that interference is minimized.
Libby Leahy, a spokesperson for Google X - the laboratory that oversees Project Loon - said the next step will be to find a wireless carrier to serve as its partner.