Ten years after rigorous scientific examination of the mysterious Shroud of Turin raised more questions than it answered, the linen that many believe may have wrapped the crucified body of Jesus Christ will undergo another round of testing to determine its age.

The tests will not determine whether the shroud, which is kept locked in a silver casket in the cathedral of Turin, Italy, really was wound around Jesus when he was laid in a tomb nearly 2,000 years ago.But if the linen proves to have been made anytime after the first century, claims for its authenticity will be demolished. Should the linen be from the first century, the mystery will only deepen.

Fingernail-size samples of the shroud will been given to the University of Arizona, Oxford University in England and the Federal Polytechnic Institute in Zurich, Switzerland, for radiocarbon dating.

The process is being supervised by the British Museum, Pontifical Academy of Sciences and a representative of the archbishop of Turin, who has custody of what many revere as the most singular relic in Christendom.

Exactly when the testing will be done is a closely guarded secret because "we want to work in peace," said Paul E. Damon, a University of Arizona geoscientist and co-director of the Arizona Accelerator Facility for Radioisotope Analysis.

But an answer on the date of the shroud is promised by those involved "by the end of 1988."

The shroud is made of coarse linen twill and is 14 feet, 3 inches long by 3 feet, 7 inches wide. It contains the faint, uneven image of a bearded man with his dark hair in back twisted in a pigtail. The image shows the man front and back, as if the shroud had been draped over his head and down both sides of his body. He has what appear to be blood-stained wounds in his wrists, feet, side, scalp and back - wounds consistent with the New Testament account of how the Romans crucified Jesus.

In the mid-1970s, two U.S. Air Force captains turned space technology on the mystery. Physicist John Jackson and engineer Eric Jumper were experts in digital image enhancement - using computers and other techniques to analyze images of the earth and other planets transmitted from space probes.

They used the method to examine detailed photographs that had been made in the 1930s of the man in the shroud. They found encoded in the image all the information they needed to make a three-dimensional model of him, something that would have been impossible had it been a two-dimensional painting.

They made a model of a muscular man, 5 feet, 101/2 inches tall, weighing about 175 pounds. It created a sensation, heightened the mystery and helped open the door of the Turin cathedral for further study.

In 1978, Jumper, Jackson and colleagues from such institutions as the NASA Jet Propulsion Laboratory and Los Alamos National Laboratory performed sophisticated tests on the shroud 24 hours a day for five days.

Church authorities had said they were reluctant to allow radiocarbon dating because too large a sample of the shroud would have to be destroyed.