A heat shield enables a spacecraft survive the enormous heat generated during entry or re-entry…
A heat shield enables a spacecraft survive the enormous heat generated during entry or re-entry into an atmosphere. They are among the most vital components of a spacecraft, and among the most difficult to engineer. With spacecraft now being designed to enter the Martian atmosphere the challenge of designing and building them is greater than ever.
Tough Enough for Mars
Lockheed Martin recently described its progress on the heat shield it is designing and building to encapsulate NASA Jet Propulsion Laboratory’s Mars 2020 rover.
The heat shield is half of the large and sophisticated two-part aeroshell that Lockheed Martin is designing and building to encapsulate NASA Jet Propulsion Laboratory’s Mars 2020 rover from the punishing heat and friction of entry through the Martian atmosphere.
The Mars 2020 mission will be one of the most challenging entry, descent and landings ever attempted on the Red Planet. The heat shield aerodynamics serve as a “brake” to slow the spacecraft from about 12,000 mph (19,300 kph) so the structure needs to be flawless.
As the tenth aeroshell system that Lockheed Martin has produced for NASA, this is one of the largest at 15 feet (4.5 meters) in diameter.
“Our experience building aeroshells for NASA Mars missions does not mean that it is ‘easy’,” said Neil Tice, Lockheed Martin Mars 2020 Aeroshell program manager. “Tests like this structural test are absolutely essential to ensuring mission success in the long-run.”
Lockheed Martin conducted static test on April 25 designed to mimic the load that the heat shield will experience during the most extreme part of its journey; the entry phase.
To do that, engineers used vacuum pumps to simulate the pressure of approximately 140,000 pounds on the structure. The structure was tested to 120% of the expected flight load to push it to the limit.
Following this test, the Lockheed Martin team will apply Phenolic Impregnated Carbon Ablator (PICA) thermal protection system tiles to the structure. Once complete and through all environmental testing, the full heat shield will be mated to the backshell in early fall.