Phoenix Mars Lander: Schedule of Major Landing Events

This rundown of major mission events for NASA?s Phoenix Mars Lander is a detailed events schedule for the spacecraft?s planned landing in the Martian arctic on May 25, 2008.

Supplied by NASA, the schedule below includes a minute-by-minute account of the anticipated steps the spacecraft must take before touching down on the surface of Mars.

The stationary Phoenix lander launched in August 2007 on a $420 million mission to the Vastitas Borealis region of Mars, where the probe is expected to dig for Martian ice and determine if the area could have once supported microbial life.

Unless otherwise noted, the location for news briefings and commentary are NASA's Jet Propulsion Laboratory, Pasadena, Calif., and will be broadcast live on NASA TV.

Times are Pacific Daylight and some are subject to change. 

Thursday, May 22 

-- News briefing, 11:30 a.m. to 12:30 p.m. 

-- News briefing, noon 

-- Trajectory correction maneuver opportunity (TCM6), 7:46 p.m. 

Sunday, May 25 

NOTE: The times below for the Phoenix spacecraft events on May 25 are for a nominal scenario. Remaining navigational adjustments before May 25 could shift the times by up to about half a minute. In addition, the times for some events relative to others could vary by several seconds due to variations in the Martian atmosphere and other factors. For some events, a "give or take" range of times is given, covering 99 percent of possible scenarios from the atmospheric entry time. For events at Mars, times are listed in "Earth-receive time" (ERT) rather than "spacecraft event time" (SCET). This means the listed time incorporates the interval necessary for radio signals traveling at the speed of light to reach Earth from Mars. On landing day, May 25, the two planets are 171 million miles apart (275 million kilometers), which means it takes the signal 15 minutes and 20 seconds to reach Earth. For some spacecraft events, engineers will not receive immediate radio confirmation. 
-- Trajectory correction maneuver opportunity (TCM6X), 8:46 a.m. 

-- News briefing, noon 

-- Begin non-commentary live television feed from JPL control room, 3 p.m. 

-- Begin commentated live television feed from JPL control room, 3:30 p.m. 

-- Propulsion system pressurization, 4:16 p.m. 

-- Begin "bent-pipe" relay (continuous transmission of Phoenix data as it is received) through NASA's Mars Odyssey spacecraft to Goldstone, Calif., Deep Space Network station, 4:38 p.m. 

-- Green Bank, W. Va., radio telescope listening for direct UHF from Phoenix, 4:38 p.m. 

-- Cruise stage separates, 4:39 p.m. 

-- Spacecraft turns to attitude for atmospheric entry, 4:40 p.m.

  -- Spacecraft enters atmosphere, 4:46:33 p.m. 

-- Likely blackout period as hot plasma surrounds spacecraft, 4:47 through 4:49 p.m. 

-- Parachute deploys, 4:50:15 p.m., plus or minus about 13 seconds. 

-- Heat shield jettisoned, 4:50:30 p.m., plus or minus about 13 seconds. 

-- Legs deploy, 4:50:40 p.m., plus or minus about 13 seconds.

- Radar activated, 4:51:30 p.m. 

-- Lander separates from backshell, 4:53:09 p.m., plus or minus about 46 seconds. 

-- Transmission gap during switch to helix antenna 4:53:08 to 4:53:14 p.m. 

-- Descent thrusters throttle up, 4:53:12 p.m. 

-- Constant-velocity phase starts, 4:53:34 p.m., plus or minus about 46 seconds. 

-- Touchdown, 4:53:52 p.m., plus or minus about 46 seconds. 

-- Lander radio off 4:54:52 p.m., plus or minus about 46 seconds. 

-- Begin opening solar arrays (during radio silence) 5:13 p.m. 

-- Begin NASA's Mars Reconnaissance Orbiter playback of Phoenix transmissions recorded during entry, descent and landing, 5:28 p.m. However, data for analysis will not be ready until several hours later. 

-- Begin Europe's Mars Express spacecraft playback of Phoenix transmissions recorded during entry, descent and landing, 5:30 p.m. However, data for analysis will not be ready until several hours later. 
-- Post-landing poll of subsystem teams about spacecraft status, 5:30 p.m. 

-- Mars Odyssey "bent-pipe" relay of transmission from Phoenix, with engineering data and possibly including first images, 6:43 to 7:02 p.m. Data could take up to about 30 additional minutes in pipeline before being accessible. If all goes well, live television feed from control room may show first images as they are received. The first images to be taken after landing will be of solar arrays, to check deployment status. 

-- News briefing, 9 p.m. 

-- News briefing, 11 a.m. 

Daily news briefings at 11 a.m. 
Anticipated pace of Mars surface operations 

-- If operations proceed relatively smoothly, the first eight to 10 days after landing will be a "characterization phase" of checking out and understanding the performance of the spacecraft's power and thermal systems, as well as the robotic arm and other instruments. 

-- At the end of the characterization phase (date TBA), the first sample of surface soil will be delivered to the Thermal and Evolved-Gas Analyzer onboard Phoenix. 

-- Analysis of soil from the surface in both the Thermal and Evolved-Gas Analyzer and in the Microscopy, Electrochemistry and Conductivity Analyzer will likely take 10 to 15 days if all processes go well. After that, each additional sampling cycle will reach a deeper subsurface level, in increments of about two to three centimeters. At each different layer, collecting and analyzing samples is expected to take 10 to 15 days, barring operational difficulties. 

-- How soon the digging reaches the expected icy layer will depend on how far below the surface that layer lies. Estimates in advance of landing range from two to five centimeters. If the ice is at the deeper end of that range, the first analysis of an icy sample could be in July or later.

NASA?s first Phoenix mission briefing will be broadcast live on NASA TV, beginning with a mission briefing today at 2:30 p.m. EDT (1830 GMT). Click here for SPACE.com?s Phoenix mission coverage and a link to NASA TV.

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