CAMBRIDGE, Mass. — Defense Secretary Ash Carter on Tuesday touted the progress his signature innovation hubs have made over the past couple months since their reboot, and announced that Amazon CEO Jeff Bezos and astrophysicist Neil deGrasse Tyson were joining his Defense Innovation Advisory Board.

The hubs have accelerated tech projects such as small drones that can operate in caves or tunnels and algorithms that can sift through millions of social media posts for terrorist propaganda.

The Silicon Valley innovation hub recently issued its first contract to Halo Neuroscience for a device that looks like a pair of headphones, but can use non-invasive electrical stimulation to make the brain better at adapting to training.

"These headsets will be used by teams from our special operations forces, who will work with Halo to gauge how effective their device might be at improving marksmanship, close-quarters-combat skills and overall strength training," Carter said during remarks at the Cambridge-based hub of the Defense Innovation Unit Experimental, or DIUx, which was announced in May but formally opened on Tuesday.

As part of Carter's focus on innovation, he has also created a Defense Innovation Board, which ensures the Pentagon is fostering a "culture of innovation" and includes big names in tech, like former Google CEO Eric Schmidt, as well as in the military, like former commander of Special Operations Command Adm. Bill McRaven.

Carter on Tuesday announced some new additions to the board, including Bezos and deGrasse Tyson, and promised more members in the future.

"I've given them the very specific task of identifying innovative private sector best practices that could be of use to DoD — not unlike our recent Hack the Pentagon pilot program, which invited hackers to help find vulnerabilities in our networks," Carter said. "It's a perfect example of the kind of thing I'm looking for the Innovation Board to recommend."

Carter said he expects the board to make its first set of recommendations about which innovative practices the Pentagon should adopt by the fall.

He launched DIUx in Silicon Valley last year as a way to better engage with nontraditional partners and increase the Pentagon's ability to get new technology into warfighters' hands faster.

The Pentagon announced the creation of the second, Boston-based DIUx hub, which will maximize the city's focus on biotech and robotics, at the same time that it launched "DIUx 2.0." That initiative also put in place a new multi-headed leadership team, named Raj Shah as the new managing director and directed DIUx leaders to report directly to Carter himself.

In the 75 days since Carter announced the reforms to the second iteration of DIUx and its new leadership team, the organization has started work on 15 projects, according to a Pentagon fact sheet. Additional projects are expected to be put under contract in the coming weeks on topics including secure network mapping and autonomous seafaring drones.

Carter on Tuesday announced another reorganization of DIUx, splitting it into three teams focused on different things. A "Venture Team" will look at commercial technologies and how they can be applied to the battlefield, a "Foundry Team" will focus on emerging technology that can be adapted for military use and an "Engagement Team" will help build partnerships between the military and entrepreneurs.

"They are able to work with anyone — from two people in a garage or a dorm room all the way up to mature tech companies," Carter said in prepared remarks.

He said the innovation hub aims to move more quickly than would be possible in the Pentagon's normal acquisition pipeline, and can issue funding for a project within 60 days of first meeting a company.

Carter was in Cambridge earlier this year at the Massachusetts Institute of Technology, where he announced a new textile innovation hub that would enable the U.S. to stay ahead of peer competitors like Russia and China seeking to close the technology gap.

The partnership of nearly 90 companies, universities and researchers is tasked with developing smarter textiles with new capabilities, such as generating power, sensing chemical threats and providing troops with lighter-weight protective gear. An example of a potential innovation is a tent troops could use in the field that could also generate and store power.

Carter urged lawmakers to be a willing partner in his efforts to increase innovation and flexibility at the Defense Department.

"We can't accomplish what we're trying to do in DoD without a willing partner in Congress. So I'm hopeful Congress will join us in trying to break away from the status quo, break out of our ruts, and help keep our military the best and most capable in the world, so we can continue to keep America safe and secure," Carter said.

Speaking to reporters after his remarks, Carter noted that "most" lawmakers are supportive of providing the funding and authorities necessary to be more agile, but said others need to understand that innovation is just as important to the Pentagon as defeating the Islamic State.

"This is critical, as critical as everything else we do in defense," Carter said. "I need their help in that regard the same as I need them to provide funding for the war against ISIL."

Prior to the announcement at the Boston DIUx hub, Carter had lunch at the Charlestown Navy Yard with recruiters to talk about the challenges of bringing people into the military in the Northeast as part of his Force of the Future initiative, which will be the focus of the latter part of his three-day trip.