NASA - National Aeronautics and Space Administration

Lockheed Martin Space Systems technicians Jim Young (left) and Jack Farmerie (right) work on the science deck of NASA's Phoenix Mars Lander.
Image credit: NASA/JPL/UA/Lockheed Martin

NASA Ames conducted approximately 50 Arc Jet tests for Phoenix’s Thermal Protection System (TPS). An Arc Jet is a highly specialized wind tunnel that simulates accelerated airflow effects during the hottest part of a spacecraft’s fiery re-entry into planetary atmospheres. A continuous electrical arc of up to 60 megawatts (60,000 times the electrical power used by an average home in the United States) heats air to temperatures above 14,000 degrees Fahrenheit and accelerates the hot air to hypersonic velocity (more than 11,000 mph). Arc Jet tests reproduce the surface heating and mechanical forces experienced during a Mars entry. Tests confirmed that both the TPS material and installation techniques performed well during the hottest part of the Mars entry.

“The aero thermal analysis team lived and breathed TPS until we were sure Phoenix was good to fly,” said Michael Wright, senior research scientist in the Ames’ Reacting Flow Environments Branch. “It’s good to see that the Ames TPS team helped Phoenix land safely at its Martian destination.”

Flight computational fluid dynamics tests also were conducted at NASA Ames in support of the Arc Jet tests. Ames engineers also conducted certification tests for the spacecraft’s heat shield. Tests were conducted in both 2-D and 3-D simulations to solve reacting flow equations and to model chemistry and thermal conditions for the mission. Engineers used computational solutions to ensure their predictions encompassed the most intense heating, shear stress, and pressures expected during the Phoenix Mars entry.

Deborah Robin Croft
NASA's Ames Research Center, Moffett Field, Calif.
650-604-6787
Deborah.R.Croft@nasa.gov

Rachel Prucey
NASA's Ames Research Center, Moffett Field, Calif.
650-604-0643
Rachel.L.Prucey@nasa.gov