Chennai, Nov 7 (IANS): Space scientists the world over may be working on advanced scientific fields. But they are not free of superstitions and beliefs, said an Indian space scientist.

While Indian space scientists pray to Lord Balaji at Tirupati in Andhra Pradesh prior to every space mission for its success, their American counterparts eat peanuts.

"More interesting is the tradition of Russian cosmonauts who urinate on the right back wheel of their transfer bus on their way to the launch centre," a space scientist at the Indian Space Research Organisation (ISRO) told IANS.

"It is all individual beliefs. One cannot take chance with God and poison," a former ISRO chief told IANS.

According to a retired ISRO rocket scientist, a project director used to wear a new shirt on the day a rocket was launched.

In line with the Indian tradition, pujas will be conducted before ISRO begins to integrate the various rocket stages, he added.

While Indian space scientists told IANS that the agency as a whole does not follow any superstitious acts, they are not able to explain the absence of the rocket named Polar Satellite Launch Vehicle-13 (PSLV-C13).

After sending up the rocket PSLV-C12, ISRO jumped one number and called its next rocket, which launched Oceansat-2 and six European nano satellites, as PSVL-C14.

Queried about PSLV-C13, a high-ranking ISRO official told IANS: "There is no such rocket designated with that number."

He declined to say if ISRO considered 13 an unlucky number.

However, India's ambitious Rs.450 crore Mars Orbiter Mission in way was a tradition breaker as it flew on a Tuesday.

"This was the first time in ISRO's history that a rocket was launched on a Tuesday. Tuesday is generally considered as inauspicious day," an ISRO official told IANS.

But for a senior official involved in the Mars mission, Tuesday was a lucky day. "For me Tuesday is a lucky day," he told IANS, asking not to be identified by name.