Moscow ? When NASA’s Deep Impact spacecraft hurls a barrel-sized probe at the comet Tempel-1 millions of miles from Earth on July 4, Marina Bai of Moscow will take it very personally.

The 45-year-old mother of two is so upset about the scientific assault on the celestial body that she has taken the unusual step of suing the National Aeronautics and Space Agency in Moscow courts. Her lawsuit seeks to block the launch of the probe and to recover $311 million in “moral” damages.

Bai, a self-published author and spiritualist, said this week that she couldn’t sleep after watching a television report about the Deep Impact mission, the work of a team of astronomers at the University of Maryland, when it was launched Jan. 12.

“Somewhere deep inside me a voice told me the whole mission had to be stopped,” she said in an interview. “I fear that it could have an impact on all humanity.”

In court papers, Bai asserts that Deep Impact will “infringe upon my system of spiritual and life values, in particular on the values of every element of creation, upon the unacceptability of barbarically interfering with the natural life of the universe, and the violation of the natural balance of the universe.”

Dolores Beasley, a spokeswoman for NASA, said it would be “inappropriate” to comment.

Steven P. Maran, a spokesman for the American Astronomical Society and author of Astronomy for Dummies, reacted to Bai’s claims with humor.

“I get dizzy just thinking of this lawsuit,” he wrote in an e-mail. “But I don’t think the outcome is written in the stars.”

Plans call for Deep Impact to launch a 770-pound copper projectile at the 2.5-mile-wide comet on Independence Day. The 23,000 mph impact is expected to generate a force equivalent to almost 5 tons of TNT and could blast a hole in the comet’s icy surface the size of the Colosseum in Rome.

Cameras and sensors on board the spacecraft will record the event in an effort to help scientists determine the structure and chemical composition of Tempel 1. Comets are thought to be bits of ice, dust and rock left over from the formation of the universe about 4 billion years ago.