Delays fabricating precision optics for the Kepler space telescope, problems developing the planet-hunting satellite’s avionics system and budget constraints beyond the control of program managers all dogged the program in 2005. But NASA officials say the Kepler team appears to have made it through the rough patches without busting its budget and should have no problem making its June 2008 launch date.

“Given the progress we have made on the mirror and given that we have all our detectors in house now [as well as] the progress we have made in other areas, I think we can probably call this [mission] ‘green’ at the next quarterly,” said Michael Moore, the Kepler program executive at NASA headquarters. Moore was referring to NASA’s way of labeling programs with a green rating, which means they are in good shape.

The goal of the four-year Kepler mission is to search for Earth-like planets around nearby stars. By continuously monitoring the brightness of 100,000 stars with its single purpose telescope, Kepler is designed to detect the telltale dimming astronomers would expect to see as a planet passes in front of its host star.

The Kepler mission is being managed by the Jet Propulsion Laboratory in Pasadena, Calif. Boulder, Colo.-based Ball Aerospace & Technology Corp. is building the spacecraft and its primary instrument, a 0.95-meter aperture photometer with a 1.4-meter primary mirror.

The mirror itself is being produced by Ball’s subcontractor, L-3 Communications Brashear, a Pittsburgh company that produced similar space optics for the U.S. Air Force’s missile warning Defense Support Program satellites.

Kepler was one of two Discovery-class missions NASA selected in 2001. The original intent was to launch by mid-2006 at a cost of no more than $300 million. Kepler’s cost cap has since been raised to $515 million due to a combination of factors, according to Moore.

Soon after selecting Kepler, NASA made a budget-driven decision to delay starting its development by a year, saving money in the near term, but driving up the total price tag while pushing the target launch date into 2007. In addition, NASA policy at the time required the Ames Research Center — the Silicon Valley-based NASA center that proposed the mission — to pick either Goddard Space Flight Center or the Jet Propulsion Laboratory to help it manage the mission. The later launch date, the addition of JPL to the management team, the introduction of full-cost accounting at NASA and higher than expected Delta 2 launch costs, Moore said, combined to push Kepler’s total projected price tag to $457 million.

Kepler began 2005 on an inauspicious note when NASA — again prompted by broader budget considerations — trimmed $35 million from the program’s anticipated $136 million budget for the year. Kepler’s launch date was pushed out to June 2008, Moore said, and inched that much closer toward its $515 million cost cap.

During the course of the year, L-3 Brashear fell behind in the fabrication of Kepler’s precision optics. “They were running a little late and being more expensive than we expected,” Moore said. In addition, Moore said, Ball had more people on the Kepler effort than NASA expected, often a symptom that a program has run into problems. “We weren’t tracking the manpower loads that we expected to have,” Moore said. “We were running over.”

Moore said he alerted senior NASA management to the staffing issues and optics delays by assigning Kepler a cautionary ‘yellow’ rating at the quarterly review of missions in development. In NASA parlance, a yellow rating signifies a program that is having problems but none so severe that it cannot be solved within its own schedule and budgetary reserves.

A closer look at Ball’s staffing issue revealed that Kepler’s spacecraft avionics system was requiring more work than had been planned, according to Moore. “The need for additional personnel is primarily because [the avionics] segment is not being accomplished as efficiently as NASA anticipated,” Moore said. “NASA is now taking advantage of the experienced personnel from the Deep Impact project. With this experience, NASA expects the number of personnel needed to be reduced.”

Late last year, Ball replaced Len Andreozzi as Kepler program manager with Monte Henderson, the company’s program manager on the Deep Impact spacecraft. The Kepler spacecraft is nearly identical to Deep Impact , which completed a successful encounter with Comet Tempel 1 last July.

Ball spokeswoman Emilia Reed declined to make available for interview any of the company’s Kepler officials. In a written statement, Ball acknowledged that Kepler was under new management, saying “[t]his type of personnel change is not unusual in the aerospace industry where program managers are changed to match business priorities and phases of a program.”

Ball’s statement also said Kepler would benefit from “lessons learned” on Deep Impact and that the program was “positioned well for a successful critical design review” slated for February.

As for the optics, Moore said there has been recent progress — notably L-3 Brashear completing the polishing of the primary mirror — that has him feeling more confident that effort is back on track. “One of the key things you worry about is getting final polish on a major optic,” Moore said. Recognizing the problems that can crop up on any large optics project, NASA got the effort under way fairly early in the program. As a result, Moore said the Kepler team still has “several months of slack available” built into its schedule for delivering the optics and integrating them into the instrument.

John Young, L-3 Brashear’s director of directed energy and optical systems, said his team is “on track” to complete the Kepler mirror and deliver it to Ball this summer for integration. “We are assembling the remaining components this spring and moving into final testing,” he said in an e-mail.