The space shuttle Endeavour was slated to arrive at its final home, the California Science Center, well into Sunday morning -- hours later than its snail's-pace journey had been expected to end.

By 7:30 a.m., the orbiter was still making its crawl toward Exposition Park, steered cautiously down Martin Luther King Boulevard as crowds gathered along both sidewalks.

The shuttle turned slightly in the street about 7 a.m., aiming its nose toward the people gathered on one side of the street, and its tail, at a diagonal, toward those on the other side.

It was a dramatic moment that brought gasps from some who were watching.

Authorities initially estimated that the massive spacecraft would arrive by nightfall on Saturday, but its schedule remained fluid, officials said.

The 170,000-pound, five-story-tall shuttle was delayed by last-minute tree trimming, other obstacles in the roadway and regularly scheduled maintenance on the shuttle's transporter.

Complete Coverage: Mission 26

The next leg of its route -- east on MLK Boulevard -- was tricky because the shuttle had to pivot to avoid pine trees.

Emergency crews were kept busy as they responded to 34 calls for medical service for heat related illnesses.

Those out much later than they expected were given a public transit reprieve by Metro, which said it would run rail lines overnight into Sunday instead of shutting down at normal hours.

Tens of thousands had gathered along the route from Los Angeles International Airport to the Science Center. The journey, which comes after 25 mission flown by the NASA orbiter since 1992, began late Thursday night.

Endeavour made a morning stop at one of LA’s most iconic landmarks, the Forum, where L.A. leaders, astronauts and others who took part in a ceremony to mark the passing of the shuttle from Inglewood into LA.

"This was really dramatic this morning," Robert Clay, tears welling, said. "It's just so many people from all walks of life are here to witness this moment in history. It's still soaking in."

Much of the early part of the journey went smoothly, except for a couple of wrinkles when shuttle crews navigating the orbiter through the streets had to negotiate a couple of tight spots, once around a tree and another time around a power pole.

The shuttle had been expected to stop for a 2:30 p.m. event featured a troupe of dancers led by choreographer Debbie Allen at Crenshaw and Martin Luther King Jr. boulevards. Instead, the performance went on without Endeavour, and the shuttle was just getting to that area at 7 p.m.

On Friday night, Endeavour was transferred off its four self-propelled trailers and put onto two dollies. The roughly 292,000-pound load was towed -- by a Toyota Tundra, in part to be videotaped for an advertisement -- across the Manchester Boulevard bridge spanning the San Diego (405) Freeway.

The move is expected to cost about $10 million.

MORE: Submit Your Pics With #ShuttleWatch | How to See Endeavour on "Mission 26"

City News Service contributed to this article.