Search and rescue teams have now covered 7,600 square miles -- an area bigger than the state of Connecticut -- as they scour the ocean for the missing submersible, Coast Guard officials said.

A grid depicting the expanding search area is expected Tuesday night, according to a public information affairs lieutenant for the First District of the U.S. Coast Guard.

-ABC News' Miles Cohen

NASA released a statement Tuesday on the Titan, saying it remains "hopeful the crew will be found unharmed."

"NASA’s Marshall Space Flight Center had a Space Act Agreement with OceanGate, and consulted on materials and manufacturing processes for the submersible. NASA did not conduct testing and manufacturing via its workforce or facilities," the agency said.

-ABC News' Gina Sunseri

The U.S. Navy said it's sending to the search site experts and equipment "designed to provide reliable deep ocean lifting capacity for the recovery of large, bulky, and heavy undersea objects."

The equipment, which can lift up to 60,000 pounds, and the experts will arrive in Canada Tuesday night, the Navy said.

National Security Council spokesperson John Kirby said earlier Tuesday that the Navy was"on standby" to help with the search for the missing submersible, because the Navy has "some deep-water capabilities that the Coast Guard wouldn’t necessarily have."

President Joe Biden is "watching events closely," Kirby said, adding that Biden and the White House offer their thoughts "to the crew onboard, as well as to the -- what is no doubt -- worried family members back on shore."

Three U.S. Air Force C-17 cargo aircraft will be transporting commercial equipment from Buffalo, New York, to Newfoundland, Canada, to help with the search efforts, according to a U.S. official.

-ABC News' Luis Martinez

The Explorers Club reacted to news of the submersible's implosion, saying in a letter to members on Thursday: "Our hearts are broken."

President Richard Garriott de Cayeux noted that two of the passengers lost in the implosion -- Hamish Harding and Paul-Henri Nargeolet -- were members of the Explorers Club, while OceanGate CEO Stockton Rush was a friend of the society who had conducted lectures at its headquarters.

"Hamish Harding is a dear friend to me personally and to The Explorers Club," Garriott de Cayeux said. "He holds several world records and has continued to push dragons off maps both in person and through supporting expeditions and worthy causes."

Nargeolet was "one of the foremost experts on submersible expeditions to the Titanic," Garriott de Cayeux said.

"They were both drawn to explore, like so many of us, and did so in the name of meaningful science for the betterment of mankind," he continued. "They pushed themselves in their entrepreneurial pursuits as they did in exploration."