SOHO (Solar and Heliospheric Observatory) began having problems in early June. A stuck motor drive would not permit its high-gain antenna to move. The antenna is used for transmitting important pictures and data back to Earth, and it must be pointed toward the planet.

No other set of satellites can produce the data provided by SOHO, scientists say.

This week the spacecraft's orbit brought it into a favorable position and, as planned, engineers flipped the craft 180 degrees so its antenna could point toward Earth. SOHO orbits a gravitationally stable point in space, partway between Earth and the Sun, every six months.

"Things are back in full operation," said Joe Gurman of the Solar Data Analysis Center at NASA's Goddard Space Flight Center.

Gurman said in a telephone interview that despite continuing gaps in SOHO's ability to transmit, about 98 percent of the data required by space weather forecasters will be returned during the rest of the spacecraft's lifetime.

That life has lasted more than seven years, even though SOHO was designed for a two-year mission with a possible three-year extension.

"The actual scientific impact is pretty limited," Gurman said. "And we're really happy about that."

When SPACE.com first reported the problem on June 19, officials said the result might be total blackout periods for several weeks each year. Space weather forecasters who rely on the data said it would gut their forecasts, which in turn are used by satellite operators and power companies to minimize risk of failure during strong solar storms. Even commercial television broadcasts and pager services would have been at greater risk for downtime if storms struck without warning.

The SOHO team has proven resourceful, however.

The probe entered an expected blackout period on June 27. Since then, officials have employed a slower backup antenna to transmit data. A creative solution was devised. Some data was recorded on board and then downloaded using high-speed transmissions -- through the backup antenna -- when time could be spared on large 70-meter dishes of NASA's Deep Space Network (DSN).

SOHO does not normally use the high-capability DSN.

SOHO officials will meet later today with the DSN team to discuss how much time they can get on the network. Gurman said beginning early next year the spacecraft's needs will find tough competition from a plethora of Mars missions that will also rely on the DSN.

Meanwhile, a similar approach allows some data to be returned to a 34-meter dish when the DSN is not available.

Full and normal operation resumed on July 14. Partial blackouts lasting between nine and 16 days will continue to occur every three months.

"It is good to welcome SOHO back to normal operations, as it proves that we have a good understanding of the situation and can confidently work around it," said Stein Haugan, acting SOHO project scientist with the European Space Agency.

Engineers expect the craft to endure. Barring catastrophe, SOHO could last until a similar probe, the Solar Dynamics Observatory (SDO), is launched, possibly in 2008.

Gurman said SDO, if it goes up as planned, would be a 100-percent replacement for SOHO.

Meanwhile, solar activity is lessening. An 11-year cycle peaked over the past two years and is ramping down to a low point that will come between 2005 and 2007.

"I see no reason to believe we can't continue to operate in this fashion through the end of the solar cycle," Gurman said.

SOHO is a joint project between NASA and the European Space Agency.

• Sun Cam: See SOHO's Live Images