LOMBARD, Ill. - The mother of a NASA astronaut who is on board the International Space Station died yesterday when a train struck her vehicle at a crossing in this western Chicago suburb, police said.

A preliminary investigation showed Rose Tani, 90, of Lombard, stopped behind a school bus that had halted at the crossing for a train, Lombard Police Chief Raymond Byrne said.

Tani, mother of astronaut Daniel M. Tani, apparently became impatient, honked her horn, went around the school bus and bypassed the lowered crossing gate by driving north in the street's southbound lane, Byrne said.

The train struck Tani's vehicle on the passenger's side and pushed it down the tracks before coming to a stop. Lombard Fire Department paramedics took Rose Tani to Good Samaritan Hospital, where she was pronounced dead.

"All indications are that the crossing gates and warning signals were functioning properly at the time of the accident," Byrne said.

The students on the school bus returned to Glenbard East High School where officials made crisis counselors available, Byrne said.

Daniel Tani, 46, was born in Ridley Park, Pa., but graduated from Glenbard East and MIT. After working as a mechanical and aeronautical engineer NASA selected Tani for astronaut training in 1996. He has made several journeys into space.

Tani served as a flight engineer on the Space Shuttle Discovery when it took off on Oct. 23. After it docked with the ISS two days later, he moved aboard the permanent station.

On Tuesday Tani and another astronaut ventured out on a spacewalk to inspect two defective mechanisms that are hobbling power generation at the orbiting complex.

He was to remain on board the ISS until Jan. 8.

NASA officials did not immediately return a phone message left after business hours yesterday. *