Phoenix

Derived from the Mars Surveyor 2001 lander platform, with a payload drawing on those of both the '01 lander and Mars Polar Lander, Phoenix is the first Mars Scout mission (Figure 18.14).

The Mars Surveyor 2001 lander had the following payload when it was cancelled:

• APEX Athena Precursor Experiment (Squyres)

• Mossbauer spectrometer (Klingelhofer)

• Capture magnet (Madsen)

• Marie Curie (Sojourner-class) rover, with:

• Rover imaging cameras

• Athena APXS alpha-proton-X-ray spectrometer (Rieder)

Target Objectives

Prime contractor Launch site, vehicle Launch date

Arrival date Landing site co-ordinates End(s) of mission(s)

Mass(es)

Payload experiments

Delivery architecture Thermal aspects

Power aspects Communications architecture

Mars

To understand the near-surface chemistry and geology of a polar landing site, with particular attention to H2O, organics and meteorology Lockeed Martin Astronautics ETR, Delta II (2925)

August 2007 May 2008 Northern plains

Digging phase to last 3 months, then weather station mode Total duration —150 sols

Comparable to Mars Surveyor 2001 lander (328 kg landed dry mass)

• SSI surface stereo imager (Smith)

• Robotic arm & RAC robotic arm camera (Keller)

• MET meteorology suite (LIDAR, T sensor, P sensor) (Carswell)

• TEGA thermal & evolved gas analyser (Boynton)

• MARDI Mars descent imager (Malin)

• MECA microscopy, electrochemistry and conductivity analyser (Hecht, Meloy?)

• WCL wet chemistry lab

• Microscopy station (optical & AFM)

• Material patch plates

• TECP thermal & electrical conductivity probe on RA

• magnetic properties experiment (Madsen) The project scientist is Peter Smith

Separation from cruise stage on approach

Thermally regulated interior component deck (min. —30 °C).

Very cold ambient environment Secondary batteries + solar arrays

Via UHF antenna: two-way relay via Mars Global Surveyor, Mars Odyssey or Mars Reconnaissance Orbiter. Two-way DTE via articulated X-band medium-gain antenna

EDL architecture

Landing speed(s)

Active operations (deployments, etc.)

Key references

Entry at 5.7 km s—l. 2.4 m diameter, 70° blunt half cone, ablative SLA-561 aeroshell. Active attitude control, using thrusters to minimise angle of attack. Max. deceleration 7 g. Parachute deployment at 13 km altitude, <504 m s—l. Heatshield separation at 12 km altitude, <286 m s—\ Landing legs deployed -182 s before landing. Back shell/parachute jettisoned at 740 m and descent engines fired, controlled using four-beam Doppler radar and hazard detection and avoidance system. Final 40 m of descent controlled using gyros and accelerometers. Cruise/descent propulsion system: 64 kg hydrazine in 2 diaphragm tanks; regulated He pressurization; 12 266 N descent engines (3 groups of 4) Nominally 1.6 ms—1 under thruster control for last 12 m of descent

Deployment of solar arrays, camera boom and meteorology masts. Sample acquisition via robotic arm and scoop. Articulated medium gain antenna Smith et al., 2004. See also http://mars.jpl.nasa.gov/ and http://phoenix.lpl.arizona.edu/

• MEEC Mars experiment on electrostatic charging (Ferguson)

• WAE wheel abrasion experiment (Ferguson)

• Robotic arm & RAC robotic arm camera (Keller)

• MARDI Mars descent imager (Malin)

• MECA Mars environmental compatibility assessment (Meloy):

• WCL wet chemistry lab

• Microscopy station

• Material patch plates

• Electrometer on RA

• MIP Mars in situ propellant production precursor (Kaplan)

• MARIE Martian radation environment experiment (Badhwar)

The Project Scientist was Steve Saunders.

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