If any of you klowns ever had to implement a distributed computing system on a spacecraft using the 1553 bus you'd appreciate what a huge development this could be. However, it sounds like its coming out of the Cx program which worries me. Hopefully it's not brain-damaged and it will catch on because if I never see another 1553 bus controller or RT chip again in my life that would be just fine. BTW, Spacewire is an even bigger PITA as 1553, only faster. This could possibly replace both 1553 and Spacewire, which would be even better.
To add a little more information: the ET breaks up on reentry and the debris falls in the ocean. For a typical shuttle mission (28 degree inclination) the impact area is the Indian ocean near Australia. For a mission to ISS like this one the inclination is 56 degrees and the impact area is somewhere else, which I don't happen to know off the top of my head. Neither does my office mate. Pacific perhaps.
I had the exact same experience - a young analyst from another group was arguing some fine point of ephemeris propagation with one of my rocket scientists. My guy wrote that chapter of "Spacecraft Attitude Determination and Control", which is the companion volume to SMAD, also edited by Wertz.
Around here everyone has both of those on their bookshelves.
Actually, NTFS is based on the VMS file system. The architect of NTFS came over to MS from DEC along with Dave Cutler, who was the architect/project mgr of NT.
I don't work on hubble but I know something about this stuff and I'll try and answer your questions directly
Do they have several mock ups?
Yes, for hubble there are several mock-ups, from ones that are fairly low fidelity that are used by the software developers (maintainers) for code/debug/test to a very high fidelity full scale electrical and mechanical mock-up of the aft end of the vehicle called the VEST, when the astronauts practice the repair tasks on dry land before they move to the pool at JSC to learn to do them in a simulated 0g environment.
A complete computer model of the whole thing, emulated right down to hardware and software?
When HST was built we were still doing spacecraft control simulations on hybrid analog/digital computers. For all missions in the last 20 years or so there are computer models of all the control modes built using products like matlab/simulink long before any metal is cut. I wouldn't be surprised if there is a matlab (or similar) model of hubble now as the hybrid computer is long gone. In fact, I'm almost positive, as I don't see any way they could have come up with the 2 gyro science controller otherwise.
How are reboot/reprogram sequences like this handled/practiced/tested?
Not to be a wise guy, but reboot and reprogramming are handled very carefully. This is why switching to a backup system is going to take 2 weeks, most of which were used for analysis and a formal review before the decision to swap to the B side was made. It probably takes 5 minutes to send the actual commands to switch to the B side of the data formatter, but they will double, triple or quadruple check everything as they go thru the process. Remember, they are switching to hardware that hasn't been used since 1990. They expect it to take about 40 hours to switch to the B side and plan to be done by Friday.
Even at design stage I imagine failure modes are extensively analyzed and multiple redundancy built in.
There are failure modes and effects analysis done at each design step. Before launch there would have been a peer review of the final failure detection and correction design.
A lot of the NASA standards are available to the public. If you go to http://standards.nasa.gov/ and click on the public button it takes you to the listing of them.
I got rid of a PDP-11 that way. I took it to work, actually used it for a while and left it there after I was finished using it. Eventually the property people put a NASA asset tag on it and finally sent it to excess. Last time I saw it it was part of a pallet of computer junk being auctioned off.
BTW, if you want more of this kind of junk, your local federal gubmint facility probably has a monthly excess property auction thats open to the public.
Allocate a chunk of non-paged pool load your code into it. set IPL to 31 patch the code that you want to change to jump to the code you loaded into pool. Lower IPL
It would probably work on windows too. Most of the actual windows kernel is very similar to VMS, even down to having paged (not NON-paged) pool. You know someone is copying when the even copy the stupid ideas.
This basic technique has been used to patch the running code on spacecraft as long as there have been computers on spacecraft. As you say, the concept is simple, the devil is in the details.
TDRSS is below the horizon at their location. You can barely hit TDRSS from McMurdo
They might be able to use one of the retired birds they use for south pole comms. Once they run out of station keeping fuel they drift into a slightly inclined orbit you can see from pole for part of every day. By using several of them you can have 24 hour comms
and NIMA was formed by merging the formerly far less scary Defense Mapping Agency (DMA) with the bastard children of the Air Force and the CIA, the National Reconnaissance Office (NRO) and the National Photo Interpretation Center (NPIC)
I dont work on Hubble any more (I left when Servicing Mission 4 was canceled the first time in Jan '04) but I do know that preparations are underway (again) for SM4. There's no guarantee that it will happen, but it is under consideration. I don't recall if the ACS was due for replacement in SM4 or not.
plenty. Montgomery has a huge hispanic "minority", one of the largest in the country. In general it is a very diverse county. You are as likely to hear spanish as english spoken in public places and it's common to hear french, german and slavic spoken too. There is also a very large asian population.
I built my own house too and eventually I found a better solution to the Home Depot probem than going to Lowes. Its your local independent lumberyard that caters to the trade. There's two in my area. One offers free delivery on a $300 purchase and the other on $500. They generally can deliver the same day and at the very latest next working day. In addition the quality of their lumber and millwork are better. I'm sure you've wasted plenty of time trying to find 20 (or 200!) straight 2x4s at Lowes. Both of the big box stores millwork is crap and their selection sucks too. My pro store has a 52 page catalog of millwork profiles, and thats only what they _stock_. You can get even more special order. On top of all this their prices are often cheaper than HD on lumber, millwork and hardware.
As far as I'm concerned the only reason to go to Lowes or HD is if you absolutely have to have something at night or on the weekend. The pro stores are only open pro hours - 6-5 M-F.
Re:The rules apply, but it's more subtle than that
on
Phishers Get Phoney
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· Score: 1
Eventually I get a person. She also asks for my account number. I say, "No, you people called me. You asked me to call this phone number. Now prove to me that you are the people that I do business with." She asked for my phone number. I gave it to her - hey, they'd already called me once, so it wasn't like I was giving away some great secret - and then she knew my name. She then asked for the last four digits of my social security number - not the whole thing, just the last 4 digits.
Shouldn't you have been asking her for the last 4 digits of your SSN?
Slashdot Mirror
If any of you klowns ever had to implement a distributed computing system on a spacecraft using the 1553 bus you'd appreciate what a huge development this could be. However, it sounds like its coming out of the Cx program which worries me. Hopefully it's not brain-damaged and it will catch on because if I never see another 1553 bus controller or RT chip again in my life that would be just fine. BTW, Spacewire is an even bigger PITA as 1553, only faster. This could possibly replace both 1553 and Spacewire, which would be even better.
I built a dial-up ISP in a major metro city with five Sparc 4s, and a Sparc Classic...
Good times.
damn, those were the good old days
sniff
I sure do miss 'em. Beat working for the man.
The parent and clayjar are both correct.
To add a little more information: the ET breaks up on reentry and the debris falls in the ocean. For a typical shuttle mission (28 degree inclination) the impact area is the Indian ocean near Australia. For a mission to ISS like this one the inclination is 56 degrees and the impact area is somewhere else, which I don't happen to know off the top of my head. Neither does my office mate. Pacific perhaps.
I had the exact same experience - a young analyst from another group was arguing some fine point of ephemeris propagation with one of my rocket scientists. My guy wrote that chapter of "Spacecraft Attitude Determination and Control", which is the companion volume to SMAD, also edited by Wertz.
Around here everyone has both of those on their bookshelves.
He's a vampire, or something similarly unkillable. The guy has survived FIVE plane crashes!!! Do you really think there is ANYTHING that can kill him?
Actually, NTFS is based on the VMS file system. The architect of NTFS came over to MS from DEC along with Dave Cutler, who was the architect/project mgr of NT.
I'm curious, I presume somebody knows this.
I don't work on hubble but I know something about this stuff and I'll try and answer your questions directly
Do they have several mock ups?
Yes, for hubble there are several mock-ups, from ones that are fairly low fidelity that are used by the software developers (maintainers) for code/debug/test to a very high fidelity full scale electrical and mechanical mock-up of the aft end of the vehicle called the VEST, when the astronauts practice the repair tasks on dry land before they move to the pool at JSC to learn to do them in a simulated 0g environment.
A complete computer model of the whole thing, emulated right down to hardware and software?
When HST was built we were still doing spacecraft control simulations on hybrid analog/digital computers. For all missions in the last 20 years or so there are computer models of all the control modes built using products like matlab/simulink long before any metal is cut. I wouldn't be surprised if there is a matlab (or similar) model of hubble now as the hybrid computer is long gone. In fact, I'm almost positive, as I don't see any way they could have come up with the 2 gyro science controller otherwise.
How are reboot/reprogram sequences like this handled/practiced/tested?
Not to be a wise guy, but reboot and reprogramming are handled very carefully. This is why switching to a backup system is going to take 2 weeks, most of which were used for analysis and a formal review before the decision to swap to the B side was made. It probably takes 5 minutes to send the actual commands to switch to the B side of the data formatter, but they will double, triple or quadruple check everything as they go thru the process. Remember, they are switching to hardware that hasn't been used since 1990. They expect it to take about 40 hours to switch to the B side and plan to be done by Friday.
Even at design stage I imagine failure modes are extensively analyzed and multiple redundancy built in.
There are failure modes and effects analysis done at each design step. Before launch there would have been a peer review of the final failure detection and correction design.
A lot of the NASA standards are available to the public. If you go to http://standards.nasa.gov/ and click on the public button it takes you to the listing of them.
dude, its slashdot. every thread devolves into either bush bashing or MS bashing.
just for the record, I hate bush and MS, so no one has to accuse me of being a {bush,MS}apologist
Am I the only one that noticed that this thing is based on the Shuttle SRB, the very thing that caused the Challenger disaster?
Epic fail is right.
Maybe they need a couple of giant bass speakers. Once in space they can switch them over to play techno.
In space, no one can hear you clubbing
I got rid of a PDP-11 that way. I took it to work, actually used it for a while and left it there after I was finished using it. Eventually the property people put a NASA asset tag on it and finally sent it to excess. Last time I saw it it was part of a pallet of computer junk being auctioned off.
BTW, if you want more of this kind of junk, your local federal gubmint facility probably has a monthly excess property auction thats open to the public.
the concept was the same.
Allocate a chunk of non-paged pool
load your code into it.
set IPL to 31
patch the code that you want to change to jump to the code you loaded into pool.
Lower IPL
It would probably work on windows too. Most of the actual windows kernel is very similar to VMS, even down to having paged (not NON-paged) pool. You know someone is copying when the even copy the stupid ideas.
This basic technique has been used to patch the running code on spacecraft as long as there have been computers on spacecraft. As you say, the concept is simple, the devil is in the details.
Microsoft hasn't been despised since the early '80s -- it started in the 70s. Google "Bill Gates" "Open letter to hobbyists"
TDRSS is below the horizon at their location. You can barely hit TDRSS from McMurdo
They might be able to use one of the retired birds they use for south pole comms. Once they run out of station keeping fuel they drift into a slightly inclined orbit you can see from pole for part of every day. By using several of them you can have 24 hour comms
BTDT
d'ya think that the fact that its not on by default might be a hint to folks that its not secure? And that they know it?Certainly Amazon does not advertise one-click can possibly pose a security risk, despite the fact that it may.
and NIMA was formed by merging the formerly far less scary Defense Mapping Agency (DMA) with the bastard children of the Air Force and the CIA, the National Reconnaissance Office (NRO) and the National Photo Interpretation Center (NPIC)
Fun with alphabet soup!
"You have to go Asian to avoid the factory food."
not around here (DC). Most asian resturants are using pre preped ingredients they bought from a distributor too, only its not sysco.
sysco is the worst thing thats ever happened to food. The quality is fine, but its the _sameness_ that kills me
they shoulda gone by home depot and got one of those gigantic blue tarps and covered it when they heard the weather forecast.
hey, it worked for me when I had the roof off of my house
here's a reference for you:
i cing/
http://spaceflightnow.com/news/n0512/05hubbleserv
I dont work on Hubble any more (I left when Servicing Mission 4 was canceled the first time in Jan '04) but I do know that preparations are underway (again) for SM4. There's no guarantee that it will happen, but it is under consideration. I don't recall if the ACS was due for replacement in SM4 or not.
plenty. Montgomery has a huge hispanic "minority", one of the largest in the country. In general it is a very diverse county. You are as likely to hear spanish as english spoken in public places and it's common to hear french, german and slavic spoken too. There is also a very large asian population.
very likely.
read about it here
http://en.wikipedia.org/wiki/Starfish_Prime
I built my own house too and eventually I found a better solution to the Home Depot probem than going to Lowes. Its your local independent lumberyard that caters to the trade. There's two in my area. One offers free delivery on a $300 purchase and the other on $500. They generally can deliver the same day and at the very latest next working day. In addition the quality of their lumber and millwork are better. I'm sure you've wasted plenty of time trying to find 20 (or 200!) straight 2x4s at Lowes. Both of the big box stores millwork is crap and their selection sucks too. My pro store has a 52 page catalog of millwork profiles, and thats only what they _stock_. You can get even more special order. On top of all this their prices are often cheaper than HD on lumber, millwork and hardware.
As far as I'm concerned the only reason to go to Lowes or HD is if you absolutely have to have something at night or on the weekend. The pro stores are only open pro hours - 6-5 M-F.
Shouldn't you have been asking her for the last 4 digits of your SSN?