.SAN JOSE -- Rocketship Education shot to national prominence by operating charter schools that produced stellar test scores from poor and immigrant students with a model focused on high-energy teaching, computerized learning and frequent test-taking.

But eight years after its first school opened in a downtown San Jose church, Rocketship has scaled back its ambitious goal of enrolling 1 million students in 50 cities -- which would have put it on the same scale as New York City's school district, the nation's largest.

Its ambitions have drawn fire from neighbors, parents, teachers unions and school districts, who charge that adding campuses will hurt traditional public schools and who have bested Rocketship in court.

Sarah Gooding leads a kindergarten literacy class at the Rocketship Spark Academy in San Jose, Calif. on Tuesday, May 27, 2014. (Gary Reyes/Bay Area News
Sarah Gooding leads a kindergarten literacy class at the Rocketship Spark Academy in San Jose, Calif. on Tuesday, May 27, 2014. (Gary Reyes/Bay Area News Group) ( Gary Reyes )
Perhaps even more devastating for this darling of charter-school boosters is that its vaunted test scores have plummeted.

"We didn't deliver," said CEO and co-founder Preston Smith, about disappointing results that led Rocketship to slow its growth. "That's in response to our own expectations."

Primary among its difficulties, Smith concedes, is the failure of an audacious plan to knock down walls and create 100-student classrooms, which Rocketship is abandoning. Rocketship also suffered through a leadership transition after the exit last year of co-founder John Danner, who began a firm to supply software to schools.

Yet, Smith maintains, "We have really great schools." He also points to Rocketship's loyal parents, long waiting lists for its eight Bay Area schools, all in San Jose, and proficiency scores that outshine schools with similar students. Rocketship still envisions tripling in size to 13,000 students in three years.

Rocketship, Smith said, has been targeted partly because it challenges the status quo