dx100uk
23-Feb-10, 00:52
if you think your computer problems are bad....
From: allanstern@aol.com <allanstern@aol.com>
Subject: [MilRadioComms] ISS Central computer has failed
To: CivilAirComms@yahoogroups.com, RadioMonitors@yahoogroups.com, MilRadioComms@yahoogroups.com, FloridaMilcom@yahoogroups.com, FloridaComms@yahoogroups.com, SpaceCoastComms@yahoogroups.com
Date: Sunday, 21 February, 2010, 18:50
Thanks for Bill Harwood for this information on the ISS problem:
11:15 AM, 2/21/10, Update: Space station central computer fails; backup
takes over (UPDATED at 12:40pm with additional details of more extensive
computer problem)
Multiple computer glitches aboard the International Space Station (ISS)
triggered intermittent communications blackouts early Sunday, officials said,
and while the three command and control computers seem to be working,
engineers do not yet understand what has caused the machines to repeatedly
transition from one to the other.
The ISS's command and control software was updated before the Shuttle
Endeavour's flight to account for the new Tranquility module and it's possible
the computer failures, or transitions, are software related. Issues with
computers in Tranquility also have been noted, but it's not yet clear whether
they are related to the command and control issues.
During normal operations, one of the three C&C computers, known as a
multiplexer/ demultiplexer, operates as the "prime" machine, allowing station
astronauts and ground controllers to send commands to various systems and
providing critical telemetry.
A second C&C computer operates in backup mode, ready to take over if the
prime computer suffers a problem, and the third machine operates in standby
in a domino-like software architecture. The computer system is critical to
all aspects of space station operation.
Early Sunday, the prime C&C computer ran into a problem, forcing a
transition to the backup. A NASA source familiar with the troubleshooting said the
backup "came on and was prime for about a second and then it failed a
diagnostic, the equivalent of the blue screen of death on a Windows machine.
The third one, which was in standby, it came up and was prime for about an
hour and just a little while ago it also transitioned and stopped work. The
first one that went down, the original prime, it's back up right now."
"But now that this has cycled through all three machines it is very clear
there is some generic, probably software related problem," he said.
NASA mission control commentator Pat Ryan outlined a slightly different
sequence of events, saying when the prime computer malfunctioned "the backup
computer moved assume its responsibilities and then the standby computer
moved to backup. In the process, Houston lost S-band communications with the
crew on board."
Commander Jeff Williams called down at 9:55am EST "and confirmed there had
been a primary and backup failure of the C&Cs," Ryan said. "However, two
of the three computers were healthy. Later this morning, just before (11am),
there was data here in mission control that indicated there had been
another C&C transition, this time still with just two computers healthy.
"But after a third transition this morning, all three computers were
indicating they were healthy, although they were now operating in different
slots among the primary, backup and standby computers. About 20 minutes ago
(just after noon EST), space station commander Jeff Williams indicated there
had been another transition, this one only impacting the backup and standby
computers.
"But we are still in a situation currently where all three computers are
healthy but the team here in mission control is still scratching its head
and trying to determine what's been causing the repeated transitions, " Ryan
said. "There has been no impact to station life support systems while this
was going on and the crew is in good shape."
As of 12:30pm, command and control computer No. 3 was prime, with C&C No.
2 in backup and No. 1 in standby.
"We're thinking we might need another day off," Williams joked with
mission control as the troubleshooting continued.
"Copy and concur, Jeff," replied Stan Love in Houston. "We are talking in
the room, we still do not know what has been causing these transitions. We
are toying with the idea there might be something related to commanding.
But we are not sure, it's just speculation at this point."
Love later said engineers had detected a fault in a computer system in the
Tranquility module, but it was not immediately known if that was related
to the C&C issue.
dx
From: allanstern@aol.com <allanstern@aol.com>
Subject: [MilRadioComms] ISS Central computer has failed
To: CivilAirComms@yahoogroups.com, RadioMonitors@yahoogroups.com, MilRadioComms@yahoogroups.com, FloridaMilcom@yahoogroups.com, FloridaComms@yahoogroups.com, SpaceCoastComms@yahoogroups.com
Date: Sunday, 21 February, 2010, 18:50
Thanks for Bill Harwood for this information on the ISS problem:
11:15 AM, 2/21/10, Update: Space station central computer fails; backup
takes over (UPDATED at 12:40pm with additional details of more extensive
computer problem)
Multiple computer glitches aboard the International Space Station (ISS)
triggered intermittent communications blackouts early Sunday, officials said,
and while the three command and control computers seem to be working,
engineers do not yet understand what has caused the machines to repeatedly
transition from one to the other.
The ISS's command and control software was updated before the Shuttle
Endeavour's flight to account for the new Tranquility module and it's possible
the computer failures, or transitions, are software related. Issues with
computers in Tranquility also have been noted, but it's not yet clear whether
they are related to the command and control issues.
During normal operations, one of the three C&C computers, known as a
multiplexer/ demultiplexer, operates as the "prime" machine, allowing station
astronauts and ground controllers to send commands to various systems and
providing critical telemetry.
A second C&C computer operates in backup mode, ready to take over if the
prime computer suffers a problem, and the third machine operates in standby
in a domino-like software architecture. The computer system is critical to
all aspects of space station operation.
Early Sunday, the prime C&C computer ran into a problem, forcing a
transition to the backup. A NASA source familiar with the troubleshooting said the
backup "came on and was prime for about a second and then it failed a
diagnostic, the equivalent of the blue screen of death on a Windows machine.
The third one, which was in standby, it came up and was prime for about an
hour and just a little while ago it also transitioned and stopped work. The
first one that went down, the original prime, it's back up right now."
"But now that this has cycled through all three machines it is very clear
there is some generic, probably software related problem," he said.
NASA mission control commentator Pat Ryan outlined a slightly different
sequence of events, saying when the prime computer malfunctioned "the backup
computer moved assume its responsibilities and then the standby computer
moved to backup. In the process, Houston lost S-band communications with the
crew on board."
Commander Jeff Williams called down at 9:55am EST "and confirmed there had
been a primary and backup failure of the C&Cs," Ryan said. "However, two
of the three computers were healthy. Later this morning, just before (11am),
there was data here in mission control that indicated there had been
another C&C transition, this time still with just two computers healthy.
"But after a third transition this morning, all three computers were
indicating they were healthy, although they were now operating in different
slots among the primary, backup and standby computers. About 20 minutes ago
(just after noon EST), space station commander Jeff Williams indicated there
had been another transition, this one only impacting the backup and standby
computers.
"But we are still in a situation currently where all three computers are
healthy but the team here in mission control is still scratching its head
and trying to determine what's been causing the repeated transitions, " Ryan
said. "There has been no impact to station life support systems while this
was going on and the crew is in good shape."
As of 12:30pm, command and control computer No. 3 was prime, with C&C No.
2 in backup and No. 1 in standby.
"We're thinking we might need another day off," Williams joked with
mission control as the troubleshooting continued.
"Copy and concur, Jeff," replied Stan Love in Houston. "We are talking in
the room, we still do not know what has been causing these transitions. We
are toying with the idea there might be something related to commanding.
But we are not sure, it's just speculation at this point."
Love later said engineers had detected a fault in a computer system in the
Tranquility module, but it was not immediately known if that was related
to the C&C issue.
dx