It’s been more than five years since mostly Native Hawaiian protesters blockaded Mauna Kea Access Road to prevent the resumption of construction of the massive Thirty Meter Telescope.

The result has been a stalemate. There’s little expectation that the “protectors” of the mauna will relent in their fierce opposition to the project. The TMT’s developers have not given up either, with good reason: The Mauna Kea summit is considered hands-down the best spot to build, and the developers have the necessary permits to proceed.

One thing that has changed since the 2015 demonstrations is TMT’s estimated construction cost: from $1.4 billion to $2.4 billion. So it’s encouraging that the National Science Foundation remains open to awarding as much as $850 million to the TMT, a hefty but worthy investment in world-class, cutting-edge astronomy.

The investment would be part of a larger project envisioned by the prosaically named U.S. Extremely Large Telescope Program, a hui including TMT, the Giant Magellan Telescope (GMT) in Chile, and the NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab). Together they propose to give American astronomers views of 100% of the sky in both the Northern and Southern hemispheres. Under the proposal, TMT and GMT would get $850 million each.

Still, no amount of money can buy off TMT’s opponents; outreach and an appeal to common interests are needed.

NSF said it understands that “potential construction of TMT on Maunakea is a sensitive issue and plans to engage in early and informal outreach efforts with stakeholders, including Native Hawaiians, to listen to and seek an understanding of their viewpoints.”

This week, NSF’s Astronomy and Astrophysics Advisory Committee met to discuss its informal, “talk-story” outreach efforts — including 53 virtual meetings with more than 100 people in Hawaii — while acknowledging the need to “reach out to individuals and groups we’ve missed out on.”

There is certainly much to discuss, including the state’s ongoing efforts to improve the Mauna Kea Comprehensive Management Plan, which must address shortcomings in regulating public access and giving Native Hawaiians a greater role in stewardship of the mauna.

TMT holds the promise of making great contributions to the world and to Hawaii, in scientific research, education and clean, high-tech economic development. It’s hoped that the discussions will continue, and a true good-faith compromise will be found.