"According to ispace, the lander’s onboard sensors indicated a sharp rise in altitude when the craft passed over a 3-kilometer-high cliff. The cliff was later determined to be the rim of a crater. But the onboard computer had not been programmed for any cliff that high; it was told that in case of a large discrepancy in its expected position, the computer should assume something was wrong with the ship’s radar altimeter and disregard its input. "
are we still at the stage where we don't know about a crater rim that is 3KM high on the moon? I would assume that by now, imaging satellites have captured information like this?
If I recall correctly, the landing location changed long after the software was written. When written, they were planning on a location without such cliffs.
That was actually the lamest space mission live stream I have ever seen.
It switched between a virtual rendering of the mission ( think game ) and a group of people watching the same simulation. Not once was there actual camera footage ever.
When things went south, the simulation was halted of course. I guess the programmers didn't account for that eventuality.
At least a banner with a red diagonal pattern and large letters saying "TELEMETRY LOSS" or something equally dramatic and spectacular we came to expect from movies.
I know every gram of extra mass has to justify being there, and that bandwidth is an expensive commodity, but, for an experimental vehicle (and every version 1 is experimental) I would really like to have a couple down-facing and side-facing wide-angle cameras streaming the descent. Having that, even a manual override is possible (2-second lag is a pain, but better than having no good idea of what happened and a lost vehicle with a payload).
I believe they had to change the landing site for some reason, and the simulations they ran were for the initial landing site, where a 3KM crater would not have been encountered.
The Eagle ended up off course, but I've seen multiple reasons given. One is that they modelled the moon as perfectly round, which turned out to be incorrect, mucking up timing plans. The side facing Earth is more dense, due in part to being tidally locked I believe.
The control room was sweating when the landing deadline passed beyond the expected margin of error and they were still flying.
Lesson: always leave a margin of error, especially on the first mission. Armstrong's calmness and clear thinking under duress paid off.
are we still at the stage where we don't know about a crater rim that is 3KM high on the moon? I would assume that by now, imaging satellites have captured information like this?