Indian Space Research Organization officials said immediately after the launch of India's first navigation satellite that the space agency is gearing up for PSLV's silver jubilee mission to carry the Mars orbiter.

However, it is not the PSLV's 25th commercial mission, but 22nd. ISRO somehow jumped one number while naming one of its earlier PSLV rockets. PSLV-C12 rocket flew in April 2009. After its flight, ISRO jumped one number and called its next rocket PSLV-C14.

PSLV-C14 launched Oceansat-2 and six other satellites in September 2009. Several PSLV rockets were launched after that, and earlier this month ISRO launched its first navigation satellite Indian Regional Navigation Satellite System-1A, badging its rocket as PSLV-C22.

PSLV-C23 is now expected to carry a foreign satellite later this year. The rocket is badged as PSLV-C25. As of now, ISRO has flown 21 commercial and three developmental flights of PSLV rocket.

If developmental flights have to be taken under consideration, then ISRO is right to term its MARS mission rocket as its silver jubilee mission.

A senior ISRO official told IANS, "The rockets are numbered based on the missions, and work will progress based on that number. Once in two years, the missions decided and gave numbers. Based on the mission's progress, the vehicle is scheduled".