4 ms·

It seems that the architecture of Viking was such the bootloader would have needed to perform gimbal control of the antenna. That isn't super simple. My guess i

It seems that the architecture of Viking was such the bootloader would have needed to perform gimbal control of the antenna. That isn't super simple. My guess is it would have needed to know what time it was, along with a control loop and astronomical algorithms for a vector to Earth. I wonder if they had a way to test this software update on the ground before they sent it.

andyjohnson0 11y ago
Martin Marietta built what they called the "Proof Test Capsule", which was a similar to the pair that flew and was used for ground-based system integration testing. According to these [2] notes there was a separate analog/digital computer that simulated the descent from orbit to surface. Edit: The report referenced in [2] is available for download at [3]. Starting at page 184 there is a description of the Viking Test Language, which appears to have been used for scripting tests to be run against the flight hardware/software. And this was back in 1977. [1] http://www.unmannedspaceflight.com/index.php?s=bf5c742cc7bc7c3192119a4a0a3d7f76&showtopic=7324&view=findpost&p=184472 http://www.unmannedspaceflight.com/index.php?s=bf5c742cc7bc7... [2] http://www.retrotechnology.com/memship/viking_software.txt http://www.retrotechnology.com/memship/viking_software.txt [3] http://www.dtic.mil/get-tr-doc/pdf?AD=ADA040770 http://www.dtic.mil/get-tr-doc/pdf?AD=ADA040770
- planteen 11y ago
  This is very interesting. And how little things have changed between 1977 and 2015 (from [3]): "Originally it had been planned to slowly take STE programmers off of the Viking Project. By the time the STE was moved to KSC for operational test support, there were to be no programmers left. As matters turned out, the number of programmers assigned to STE peaked during this period. This was only partially due to the problems with maintaining the H-632. New requirements for software functions constantly arose, both in Denver and at KSC. Two new programs were written at the Cape to assure that Flight loads would be correct."

andyjohnson0 11y ago

Martin Marietta built what they called the "Proof Test Capsule", which was a similar to the pair that flew and was used for ground-based system integration testing. According to these [2] notes there was a separate analog/digital computer that simulated the descent from orbit to surface. Edit: The report referenced in [2] is available for download at [3]. Starting at page 184 there is a description of the Viking Test Language, which appears to have been used for scripting tests to be run against the flight hardware/software. And this was back in 1977. [1] http://www.unmannedspaceflight.com/index.php?s=bf5c742cc7bc7c3192119a4a0a3d7f76&showtopic=7324&view=findpost&p=184472 http://www.unmannedspaceflight.com/index.php?s=bf5c742cc7bc7... [2] http://www.retrotechnology.com/memship/viking_software.txt http://www.retrotechnology.com/memship/viking_software.txt [3] http://www.dtic.mil/get-tr-doc/pdf?AD=ADA040770 http://www.dtic.mil/get-tr-doc/pdf?AD=ADA040770

planteen 11y ago
This is very interesting. And how little things have changed between 1977 and 2015 (from [3]): "Originally it had been planned to slowly take STE programmers off of the Viking Project. By the time the STE was moved to KSC for operational test support, there were to be no programmers left. As matters turned out, the number of programmers assigned to STE peaked during this period. This was only partially due to the problems with maintaining the H-632. New requirements for software functions constantly arose, both in Denver and at KSC. Two new programs were written at the Cape to assure that Flight loads would be correct."