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On the morning of September 8, 2004, NASA scientists were elated. Their Genesis spacecraft had traveled 32 million kilometers (20 million miles), and was loaded up with precious samples of the solar wind and interstellar particles. But as the spacecraft hurtled through the Earth’s atmosphere, it quickly became clear something was very wrong. Instead of floating gently down to Earth on its parachutes, Genesis cratered into the ground at high speed, and its fragile cargo suffered devastating damage. What went wrong? A special Mishap Board released their findings today.
On September 10, 2004, two days after Genesis smashed into the Utah desert, NASA established a Type A Mishap Investigation Board to determine the root cause of the accident, and help learn lessons for the future.
The board released its Mishap Investigation Board Report (Volume 1) as a 231-page PDF document on the Internet today. This hefty volume explains the root problem, and all of the quality assurance steps that failed to catch it.
As Genesis returned through the Earth’s atmosphere, special G-switch sensors were supposed to detect the tremendous forces of deceleration. When the spacecraft experienced 3 Gs of gravity (3 times the force of gravity), a plunger was supposed to touch an electrical contact, closing a circuit and arming the parachute sequence. As the spacecraft’s deceleration decreased, the plunger would move back up again, breaking the circuit and starting the sequence to deploy the drogue and then main parachutes.
This didn’t happen. Genesis’ parachutes never opened.
The investigation team looked into several possibilities:
– avionics systems failures
– electrical power system failures
– electrical harness/connectors failures; and
– drogue system failures.
In the end they concluded that the G-switch sensors had accidentally been installed upside down in the spacecraft, preventing them from detecting the deceleration and starting the parachute sequence.. Furthermore, this error wasn’t caught by several oversight processes.
A centrifuge test was originally planned to actually test the G-switches, but it was canceled. Another test made sure the G-switches were working, but it didn’t check their orientation.
The report states that engineers were aware of the need to test the switch orientation, but decided to test them as part of a later phase.
The only documentation indicating that Genesis Project Management or Systems Engineering had been informed of a centrifuge test deletion was a single bullet presented at two management reviews that read, “SRC AU 3-g test approach validated; moved to unit test; separate test not required.”
Beyond the actual engineering mistake, the Mishap Board put much of the blame on the “Faster, Better, Cheaper” approach to space exploration. The size of the Genesis team had been reduced to minimize costs – they just didn’t have the time or resources to give the project the care and attention to detail that it required.
Amazingly, engineers were able to recover large portions of Genesis’ sample trays from its smashed wreckage, and scientists from around the world are hard at work studying the tiny pieces of solar wind and interstellar dust. Working parachutes would have made everyone’s job easier.