Heat shield for 2020 Mars rover cracks during testing
The heat shield to be used during landing by the U.S.’s 2020 Mars rover cracked during recent testing.
The heat shield’s structural damage, located near the shield’s outer edge, happened during a weeklong test at the Denver facility of contractor Lockheed Martin Space, according to a NASA statement released Thursday (April 26). The test was intended to subject the heat shield to forces about 20 percent greater than those it will experience when it hits the Martian atmosphere for entry, descent and landing operations.
The Mars 2020 team found the fracture on April 12. Mission management at NASA’s Jet Propulsion Laboratory in Pasadena, California, will work with Lockheed Martin to lead an examination of the cause of the crack and to decide if any design changes should be made, NASA officials said in the statement.
They do not expect this issue to cause them to miss the 2020 launch window. However, it is astonishing that the heat shield should fail in this manner. First, to save development costs this rover was essentially a rebuild of Curiosity. The new heat shield should have been the same design, and thus should have already been proven capable of surviving this test. Second, Lockheed Martin has been making heat shields of all kinds for decades. This is not cutting edge technology.
Third, note that Lockheed Martin is building Orion, and it also experienced cracks in the capsule’s structure (not its heat shield) during manufacture and testing.
Overall, these facts suggest that some fundamental manufacturing error has occurred, and that there might also be a quality control problem at Lockheed Martin.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The heat shield to be used during landing by the U.S.’s 2020 Mars rover cracked during recent testing.
The heat shield’s structural damage, located near the shield’s outer edge, happened during a weeklong test at the Denver facility of contractor Lockheed Martin Space, according to a NASA statement released Thursday (April 26). The test was intended to subject the heat shield to forces about 20 percent greater than those it will experience when it hits the Martian atmosphere for entry, descent and landing operations.
The Mars 2020 team found the fracture on April 12. Mission management at NASA’s Jet Propulsion Laboratory in Pasadena, California, will work with Lockheed Martin to lead an examination of the cause of the crack and to decide if any design changes should be made, NASA officials said in the statement.
They do not expect this issue to cause them to miss the 2020 launch window. However, it is astonishing that the heat shield should fail in this manner. First, to save development costs this rover was essentially a rebuild of Curiosity. The new heat shield should have been the same design, and thus should have already been proven capable of surviving this test. Second, Lockheed Martin has been making heat shields of all kinds for decades. This is not cutting edge technology.
Third, note that Lockheed Martin is building Orion, and it also experienced cracks in the capsule’s structure (not its heat shield) during manufacture and testing.
Overall, these facts suggest that some fundamental manufacturing error has occurred, and that there might also be a quality control problem at Lockheed Martin.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
One cannot rule out QA problems entirely, of course. But the cracks in the Orion pressure vessel that occurred some years back were more likely caused by deficient engineering than bad QA.
Jeff Foust’s piece in SpaceNewsabout this new failure mentions that the failed component was actually built a decade ago along with the shield that worked for Curiosity. The material is NASA’s original PICA. Perhaps PICA doesn’t age well. Or perhaps this engineering spare wasn’t stored properly.
The replacement to be fabricated should, everything else being equal, perform as well as the then-new shield used on Curiousity. that assumes, of course, that no “Secret Knowledge of the Masters” has been lost anent its fabrication over the intervening decade.
What I find astounding is QA failure in programs they KNOW , will have HIGH visibility from the get go.
Why all the complaints? They do these tests to find problems. The heatshield may have failed, but the test successfully caught it. Now they can fix the problem.
Tom D Asked: “Why all the complaints? They do these tests to find problems. The heatshield may have failed, but the test successfully caught it. Now they can fix the problem.”
It is more appropriate to say that the tests are intended to verify that the hardware (or software, procedures, etc.) performs as expected. It may look like the tests are done to find problems, because problems come up during test — the hardware does not always work correctly — but at that point we seriously do not want there to be any problems to find. Everything should work as expected.
I worked in design, in assembly, and in test of space hardware, and for flight hardware we never tested to find problems. It was called ‘verification.’ Testing for problems or to find the limits of a design was more appropriate during development, before the manufacture — and preferably before the design — of the flight hardware. That is the point at which the engineer wants to find and fix problems.
After saying that, I must add that many tests are performed far enough in advance to allow for corrective action to be taken should a problem arise. For instance, an initial bench test is performed on incoming electronics boxes in order to make sure that they are working properly long before they are assembled onto the spacecraft. We may think that we have it tamed, but all too often Reality rears its ugly head and bites us in the posterior.
A question for Lockheed Martin to ask itself is, “why did this heat shield fail when its twin worked?” Perhaps the heat shield material does not age as well as expected, perhaps there was an unexpected manufacturing error, or perhaps there are other possible reasons.
Tom D asked: “Why all the complaints? They do these tests to find problems. The heatshield may have failed, but the test successfully caught it. Now they can fix the problem.”
It is more appropriate to say that the tests are intended to verify that the hardware (or software, procedures, etc.) performs as expected. It may look like the tests are done to find problems, because problems come up during test — the hardware does not always work correctly — but at that point we seriously do not want there to be any problems to find. Everything should work as expected.
I worked in design, in assembly, and in test of space hardware, and for flight hardware we never tested to find problems. It was called ‘verification.’ We tested to assure ourselves that things were still working properly. Testing for problems or to find the limits of a design was more appropriate during development, before the manufacture — and preferably before the design — of the flight hardware. That is the point at which the engineer wants to find and fix problems.
After saying that, I must add that many tests are performed far enough in advance to allow for corrective action to be taken should a problem arise. For instance, an initial bench test is performed on incoming electronics boxes in order to make sure that they are working properly long before they are assembled onto the spacecraft. We may think that we have it tamed, but all too often Reality rears its ugly head and bites us in the posterior.
A question for Lockheed Martin to answer is, “why did this heat shield fail when its twin worked?” Perhaps the heat shield material does not age as well as expected, perhaps there was an unexpected manufacturing error, or perhaps there are other possible reasons.
Tom D asked: “Why all the complaints? They do these tests to find problems. The heatshield may have failed, but the test successfully caught it. Now they can fix the problem.”
It is more appropriate to say that the tests are intended to verify that the hardware (or software, procedures, etc.) performs as expected. It may look like the tests are done to find problems, because problems come up during test — the hardware does not always work correctly — but at that point we seriously do not want there to be any problems to find. Everything should work as expected, otherwise schedules could slip and budgets balloon.
I worked in design, in assembly, and in test of space hardware, and for flight hardware we never tested to find problems. It was called ‘verification.’ We tested to assure ourselves that things were still working properly. Testing for problems or to find the limits of a design was more appropriate during development, before the manufacture — and preferably before the design — of the flight hardware. That is the point at which the engineer wants to find and fix problems.
After saying that, I must add that many tests are performed far enough in advance to allow for corrective action to be taken should a problem arise, as is the case for this heat shield. For instance, an initial bench test is performed on incoming electronics boxes in order to make sure that they are working properly long before they are assembled onto the spacecraft. We may think that we have it tamed, but all too often Reality rears its ugly head and bites us in the posterior, as is the case for this heat shield.
A question for Lockheed Martin to answer is, “why did this heat shield fail when its twin worked?” Perhaps the heat shield material does not age as well as expected, perhaps there was an unexpected manufacturing error, or perhaps there are other possible reasons.