Lynx píše:Myslím, že to tak není a tento problém se na Zemi jednoduše neodhalil z důvodu špatné metodiky zkoušek.
Sice jsme s touto debatou OT, ale nedá mi to, abych necitoval přímo ze závěrečné vyšetřovací zprávy k selhání MPL:
"A magnetic sensor is provided in each of the three landing legs to sense touchdown when the lander contacts the surface, initiating the shutdown of the descent engines. Data from MPL engineering development unit deployment tests, MPL flight unit deployment tests, and Mars 2001 deployment tests showed that a spurious touchdown indication occurs in the Hall Effect touchdown sensor during landing leg deployment (while the lander is connected to the parachute). The software logic accepts this transient signal as a valid touchdown event if it persists for two consecutive readings of the sensor. The tests showed that most of the transient signals at leg deployment are indeed long enough to be accepted as valid events, therefore, it is almost a certainty that at least one of the three would have generated a spurious touchdown indication that the software accepted as valid.
The software — intended to ignore touchdown indications prior to the enabling of the touchdown sensing logic — was not properly implemented, and the spurious touchdown indication was retained. The touchdown sensing logic is enabled at 40 meters altitude, and the software would have issued a descent engine thrust termination at this time in response to a (spurious) touchdown indication...."
A dále o rozpočtu a managementu mise:
"... From the beginning, the MPL project was under considerable funding and schedule pressure. The project team was asked to deliver a lander to the surface of Mars for approximately one-half the cost of Mars Pathfinder, which had been done for significantly less than earlier planetary missions. In addition, the complexity and technical challenges for MPL were at least as great, if not greater. The important consequences of this technical and financial situation fell chiefly into two categories — project staffing and key technical decisions.
....LMA used excessive overtime in order to complete the work on schedule and within the available workforce. Records show that much of the development staff worked 60 hours per week, and a few worked 80 hours per week, for extended periods of time....
...In short, there was insufficient time and workforce available to provide the levels of checks and balances normally found in JPL projects...."
I když je to jen jedna z několika možností.
