Posted on 03/19/2013 9:08:18 AM PDT by BenLurkin
After recovering from a computer problem, the Mars rover Curiosity is sidelined again, further delaying the restart of science experiments.
The latest complication occurred over the weekend when the six-wheel rover entered safe mode after experiencing a software file error.
'We would definitely like to get over this and get back to doing something.'
- Project manager Richard Cook
Curiosity remained in contact with ground controllers, but it can't zap rocks, snap pictures or roam around until the problem is fixed. Rover team members had expected to resume activities Monday, but they now have to wait a bit longer — perhaps until the end of the week.
"We would definitely like to get over this and get back to doing something," said project manager Richard Cook of the NASA Jet Propulsion Laboratory, which operates the $2.5 billion mission.
Studies at the Gale Crater landing site have been on hold since the beginning of March after engineers discovered a problem with Curiosity's computer memory, possibly caused by space radiation
(Excerpt) Read more at foxnews.com ...
IIRC, the best guess is that this already happened.
You say that as if that would be a bad thing.
Well... Plan A was to have a foot of lead surrounding the entire memory core. This would have guaranteed protection.
This had to be scaled back a bit due to lift off, landing, and power drain problems, so Plan B was chosen.
I’ve been thinking about shielding.
The Bigelow space capsules and the way they’re inflated with a foam in the bulkheads. I wonder how effective it would be to infuse the foam with powdered lead.
I bet they got some bogus Chinese parts using their Chinese outreach program.
It was looking at porn and got a virus.
“As such, they could have designed around it sufficiently, but they apparently didn’t.”
Single event upsets are difficult to prevent or mitigate. The NASA guys in Greenbelt did years of screening and testing parts, but that will not prevent an SEU, it lets you predict them and try to mitigate with error checking and redundancy. SEU and other single event effects come from particles found in space, usually heavier than helium with a sharp numeric cutoff at iron. The heavier ones carry a lot of LET (linear energy transfer) when they hit your microprocessor.
The big problem is galactic cosmic rays (that’s the official term, often abbr GCR), which are hard to stop and can reach Martian surface. They are heavy and very energetic. The other part of space radiation (short for radiation found in space) is solar electrons and protons (in the solar wind along with small numbers of other particles like iron nuclei), and trapped particles like you find in the van Allen belts.
Yeah the terminology is “wrong” but that’s the language we use in the field.
I don’t think NASA knows what the problem is, but a good guess is radiation, either SEE or accumulated dose.
Are you trying to be funny?
No. Weight is a huge consideration on any satellite, and it would take a foot of lead(or more) to GUARANTEE protection of the electronics from ‘almost any’ kind of radiation.
Sounds like a good idea, but I can't answer that question.
Yes, I would venture that most of we FReepers who peruse aeronautical and space-related threads are cognizant that increased dead payload weight is an undesirable in any ballistic, orbital, or interplanetary launch scenario. No one is talking about “guaranteeing” protection. It is a cost benefit engineering tradeoff, like many other areas. My statement, or what I remember of it, is that I was surprised the type and amount of shielding chosen was (allegedly) breached so early in the game.
My statement, or what I remember of it, is that I was surprised the type and amount of shielding chosen was (allegedly) breached so early in the game.
I would agree except (like you mentioned) I am not sure that a breach is what caused the problem. If it was, maybe it's just that there are things we aren't aware of yet, that we didn't protect it from.
That is what I was trying to bring to light. I should have just been direct.
Maybe it was something we didn't protect it from or couldn't.
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