PARIS — The U.S.-French Jason-1 ocean-altimetry satellite, which was put into a safe-hold mode on March 3 after an on-board failure, is expected to return to service May 4 in a lower orbit, program managers said April 26.

The new orbit of 1,323.4 kilometers in altitude — some 12.6 kilometers lower than the former position — will permit ground controllers to operate Jason-1 until it fails completely, as this altitude is considered low enough to serve as a graveyard orbit, officials said.

The lower position means Jason-1 will not clutter the more-useful operational orbit in the event it fails without warning. It also reduces the number of years it will take before atmospheric drag pulls it into a destructive re-entry once it is retired.

Jason-1 was launched in December 2001 on what was supposed to be a three-year mission to succeed the larger U.S.-French Topex-Poseidon satellite.

Ocean altimetry’s popularity with civil and military customers has only grown since then.

Jason-2 was launched in August 2008, and has been operated in tandem with Jason-1 to increase the frequency of altimetry data returned to users. Jason-3 is scheduled for launch in 2014, and a successor satellite is being designed by the 19-nation European Space Agency.

The U.S.-French Jason operating team said Jason-1, whose instruments were switched on starting April 24 after a seven-week outage, should be able to perform partial service for at least another year.

“The move from the altimetry reference orbit has been a difficult decision to take, but it also signals the start of an exciting new chapter in the extraordinary mission of Jason-1,” the Jason-1 team from the NASA Jet Propulsion Laboratory and the French space agency, CNES, said in an April 23 message to users.

Peter B. de Selding was the Paris bureau chief for SpaceNews.