Two years behind schedule, the shuttle Columbia rocketed into space yesterday, kicking off a 16-day science mission featuring more than 80 experiments, a host of animal research subjects and the first Israeli astronaut.

With its three main engines at full throttle, Columbia's solid-fuel boosters ignited with a ground-shaking roar at 10:39 a.m., instantly pushing the spacecraft away from pad 39A at the Kennedy Space Center.

Eight-and-a-half minutes later, the 120-ton shuttle slipped into orbit in the first of six shuttle missions planned for the year.

On the orbiter's flight deck were commander Rick Husband, pilot William McCool, flight engineer Kalpana Chawla and physician David Brown. Strapped in on Columbia's lower deck were physician Laurel Clark, payload commander Michael Anderson and Israeli air force Col. Ilan Ramon.

Also on board: 13 rats, eight garden orb weaver spiders, five silkworms and three cocoons, four Japanese Medaka fish eggs that will develop in space, three carpenter bees, 15 harvester ants and an assortment of fish.

The launch marked a welcome end to nearly two years of delays triggered by shuttle problems, higher-priority space station flights and major payload changes.

"We hope your wait for space was worth it," astronaut Charles Hobaugh radioed the crew from Houston. "We saw a flawless ascent for your now-veteran crew of astronauts, and especially a big welcome to Ilan, as you join the international community of human spaceflight."

Ramon's presence on the crew prompted increased concern about pre-launch security. More guards and armed SWAT team members were visible than usual, but there were no apparent changes in NASA's post-Sept. 11, 2001, security plan.

Fighter jets patrolled a no-fly zone extending 30 miles from the launch pad, powerful military radars scanned the sky in all directions and the Coast Guard stood by off shore.

Israeli Ambassador Daniel Ayalon, who watched the launch, welcomed the protection, saying, "Unfortunately, after 9/11, it's quite evident we have to watch, that this is an element that has to be factored into almost any mission."

He added: "Terror has been striking all over, but in Israel especially. So anything that can take the mind off [such problems], even momentarily, for great and beautiful things is very much appreciated."

Columbia is packed with more than 80 experiments, most of which will be carried out by the astronauts inside a commercially built Spacehab research module mounted in the shuttle's cargo bay.

It is the kind of research that will be carried out on the international space station once it is fully operational. If all goes well, Columbia will return to Earth on Feb. 1.