TOKYO — The March 25 failure of one of Japan’s first-generation radar reconnaissance satellites has government officials looking into the possibility of accelerating by three months the launch of a more-capable follow-on system.

The next-generation satellite currently is scheduled to launch in the Japanese fiscal year that ends March 31, 2012. Moving the launch date up slightly might be possible assuming the failure investigation now under way does not uncover a major design flaw, said Yasuhiro Itakura, a research officer at the Cabinet Satellite Intelligence Center (CSIC), the cabinet office that runs Japan’s spy satellite program.

Either way, Japan will have to count for the next few years on a radar satellite — similar to the one that failed — that was launched this past February and designed to last five years.

“Right now they’ll have to cross their fingers,” said Kazuto Suzuki, professor of international political economy at Japan’s Tsukuba University and an expert on the nation’s space program. “As long as the CSIC has one [radar] satellite, it’s better than zero. But if we lose a second, it’s a disaster.”

Launched in 2003, the failed spacecraft was one of two radar and two optical spy satellites that comprise Japan’s so-called Information Gathering Satellite (IGS) system. The IGS program was hatched primarily to keep tabs on North Korea following that country’s surprise launch of a missile over Japanese territory in 1998.

The four-satellite architecture is designed for maximum coverage of East Asia in general and North Korea in particular. The radar and optical satellites collect images at resolutions of 1 to 3 meters and 1 meter, respectively.

In an interview, Itakura acknowledged that the failure, coming less than two months after Japan completed deployment of the initial IGS constellation, has put a dent in the nation’s space-based reconnaissance capabilities.

“Of course the number of satellites is very important and we can’t say it [the loss] isn’t damaging, but we’ll just have to do our best with three” satellites, Itakura said. Citing security, he declined to discuss near-term steps the CSIC might be taking to improve its coverage.

Lance Gatling, an aerospace and defense consultant based here, said depending on the amount of fuel left on the remaining three satellites, the CSIS might try to modify their orbits to maximize coverage of North Korea and China. “One [radar satellite] is better than none,” he said April 2. “Presumably they will continue [to have] access to U.S. government and commercial imagery, and they will adjust the constellation to equalize coverage of the urgent issues in East Asia. They may well have planned ahead.”

Itakura said investigators have drawn no firm conclusions as to the cause of the failure and that there is little hope at this point for the satellite’s recovery.

“The satellite sent image data without a problem on Saturday (March 24) but on Sunday, we didn’t receive anything … We understand that there was some sort of fault in the electrical system … but we don’t know yet,” Itakura said in an April 2 telephone interview. “And when we do know, we won’t be disclosing the nature of the fault.”

Itakura noted that the satellite was only designed to operate for five years and that government officials therefore believe they have more or less gotten their money’s worth.

The radar satellite was deployed along with an optical craft by a single H-2A rocket in March 2003, in the first IGS program launch. But the program was dealt a severe setback the following November when an H-2A carrying the second pair of satellites failed to reach orbit.

Suzuki said launching the satellites two-at-a-time was poor risk management on the part of the IGS program. The two replacement satellites, one optical and one radar, were launched on separate H-2A vehicles in September 2006, and February 2007, respectively. The more recent launch also carried a demonstration payload for the next-generation optical satellites, which are scheduled to start launching in 2009.

“Four out of five years isn’t bad and the first [satellites] were never really intended to be great assets in orbit but were to start Japan’s independent space-based reconnaissance abilities,” Gatling said.

But Gatling also said IGS managers should carefully check for relationships between the recent failure and prior electrical mishaps on satellites built by Mitsubishi Electric Corp. of Tokyo, prime contractor on the imaging reconnaissance program .