NASA’s mission controllers announced that Phoenix Mars Lander will reach the Red Planet this evening with no further adjustments to its flight path. Mission controllers decided early Sunday not to use the last possible opportunity for a trajectory correction maneuver, eight hours before landing.

"We are so well on course that those adjustments were not necessary," said Phoenix Project Manager Barry Goldstein of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

The first possible time for confirmation that Phoenix has landed will be at 4:53 p.m. Pacific Time today. The landing would have happened 15 minutes earlier on Mars, but radio signals take 15 minutes to travel from Mars to Earth at the distance separating the two planets today, 171 million miles.

Two channels on NASA Television will carry different live feeds during key May 25 landing activities from the control room at NASA’s Jet Propulsion Laboratory. The following times are tentative and should be checked here. The NASA TV Media Channel will carry a feed with no commentary or interviews, beginning at 3 p.m. PDT (6 p.m. EDT). The NASA TV Public Channel will carry a feed with some commentary and interviews, beginning at 3:30 p.m. PDT (6:30 p.m. EDT).

Phoenix Mars Lander sped on Sunday morning toward its arrival at Mars, as the tug of the Red Planet's gravity accelerated the craft.

"Mars is literally pulling on our spacecraft, and at the same time it is pulling on our emotions," Phoenix Principal Investigator Peter Smith, of the University of Arizona, Tucson, said early Sunday afternoon.

The spacecraft's speed relative to Mars increased from 6,300 miles per hour at 8:30 a.m. Pacific Time to 8,500 mph at 12:30 p.m., headed for a speed higher than 12,000 mph before reaching the top of the Martian atmosphere

Phoenix will land in an arctic plain comparable in latitude to central Greenland or northern Alaska. The selected landing area is centered at 68.16 degrees north latitude, 233.35 degrees east longitude. Topographical mapping by Mars Global Surveyor’s laser altimeter indicates a broad, shallow valley about 50 kilometers (about 30 miles) wide and only about 250 meters (about 800 feet) deep.

The intense period from three hours before the spacecraft enters Mars’ atmosphere until it reaches the ground safely is the mission phase called entry, descent and landing. The craft will hit the top of the atmosphere at a speed of 5.7 kilometers per second (12,750 miles per hour). Within the next six and a half minutes, it will use heat-generating atmospheric friction, then a parachute, then firings of descent thrusters, to bring that velocity down to about 2.4 meters per second (5.4 miles per hour) just before touchdown.

“The final EDL parameters were uploaded to the spacecraft this morning, drawing to a close the task of preparing the spacecraft for landing. Everything from this point out will happen autonomously,” wrote Brent Shockley, Phoenix Configuration and Information Management Engineer, on the mission’s official blog.

When Phoenix sets its three legs onto the surface, the time of day at the landing site will be afternoon. A Martian day, or “sol,” lasts 39 minutes and 35.244 seconds longer than an Earth day. The landing sol is designated as Sol 0 of the mission.

About two hours after landing, before beginning its first night on Mars, Phoenix will have an opportunity to send data and, perhaps, images to the Mars Odyssey orbiter for relay to Earth.