Rainer Gerhards

2007-12-27

Atlantis’ launch moves to February 2008

Space Shuttle Atlantis is likely to launch not earlier than February. The target launch date of January, 10th 2007 for Atlantis STS-122 mission has been pushed back to early February. This is the result of today’s mission management meeting.

The official NASA shuttle home page is even a bit more cautious:

NASA space shuttle managers met Thursday and decided to modify a fuel sensor system to correct false readings that postponed shuttle Atlantis’ planned launches on Dec. 6 and Dec. 9.

Testing and analysis indicate that false readings from the engine cutoff sensor system occur in a three part feed-through connector. The connector passes electric signals from sensors inside the external fuel tank to shuttle electronics outside the tank. Technicians will remove portions of the connector and redesign the interface by soldering the pins to sockets at the external-to-feed-through side of the connector prior to installing the replacement into the external tank.

It is unknown how long it will take to complete the modifications and reapply foam to the shuttle’s external tank. Managers will assess the progress of the work before determining a new target launch date for Atlantis.

The emphasis is mine. The repair is quite time consuming. I have currently no details, but it looks like there will be no full root cause analysis. That would probably have required a rollback to the VAB and a destack, and that process would make an early February launch date impossible. I hope to get more details soon and will post them when I have.

2007-12-27

STS-122 Launch Date Decision Today?

Today is the mission management team meeting for space shuttle Atlantis STS-122 mission. The meeting reviews work progress, data gathered and plans drawn and will finally conclude with a recommendation for the next steps. It is assumed that the launch date is targeted.

While January, 10th is still given as an option, news have condensed that this date will most probably not see a launch. It looks like a launch late in January or mid-February is more realistic. In any case, we’ll know much more when the meeting has concluded later today. A press briefing is expected shortly after the meeting. As far as I know, it was set for 10:30am ET, which means the meeting must have started right now.

Let’s see how the day evolves…

2007-12-27

Things to do in rsyslog…

I have made good progress with rsyslog‘s input modules. As it looks, the basic things are done and the input module interface has been proven to be both quite stable as well as very simple. It doesn’t yet support different instances, but I begin to think that I do not even need them – also not in the long term.

Of course, most of the current input modules are not clean modules. They have a lot of dependencies to other parts of the code, which is not yet able to be dynamically loaded. But at least there is a foundation on which additional modules could be build. Getting the current input modules to be real clean modules will require further stage work. Many thanks need to be done.

So what to do next? It now comes down to both a matter of priorities and dependencies. I am writing this note here mostly for myself. It helps my clear up my thoughts and will also probably serve as a reference for quite a while. My thoughts may be hard to understand – sorry for that. But I thought I make them public when I write them down – even if they are not really targeted toward others. I still hope they may help you get some more background info.

So what’s to do:


- find a way to handle global settings
- multi-threaded output modules
  a perquisite for
  - create queued outputs (write to queue if action fails and 
    restart when it resumed)
- re-write way config file is read
  probably perquisite for:
  - create expression support
    - in templates
    - in selector filters
- create interface for (loadable) user function modules
- create a system to allow loading "library" loadable modules
  (e.g. network library for imudp, imtcp, ...)
  - separate GSSAPI from plain TCP (requires libs and lib extension system)

2007-12-27

xmas rsyslog work log

I’ve been a bit busy with rsyslog over the xmas break. Here are the changes:

2007-12-25
– moved some more net functionality out of syslogd.c – stage work
– fixed duplicate license text in syslogd.c – made it ambigious
– moved udp net code – again, stage work
– moved some of the udp input code to its right place
2007-12-26
– moved cross-platform define for AI_NUMERICSERV to net.h
– made udp code somewhat less dependable on global variables — stage work
– removed omfwd code dependency on “finet”
– removed imudp code dependency on “finet”
– removed active INET code from syslogd.c – still some auxiliary things
remain
– fixed socket leak in omfwd.c
– removed global variable LogPort
– removed gloable variable AcceptRemote and external def of bFinished

2007-12-26

NASA’s holiday break

The folks at NASA enjoy a few well-deserved days off during the holiday season. They have worked very hard and finally gotten close to the root cause of the ECO sensor problem. Well done!

As nasaspaceflight.com reports, there are some new problem reports. However, I think this is nothing really unusual, problems appear every now and then. Right now, we are just more aware of them. I personally think we should not get to concerned about them, at least not until further facts are known.

The mission management team is set to meet again on December, 27th. Then, they will look at the work done so far. Besides some work at the orbiter, this most importantly includes plans drawn to address the ECO sensor problem.

From what I have read, the actual root cause is still unknown. It is know that the problem is inside the LH2 feedthrough connector, which is good and provides a lot of repair options. However, the question why the connector suffers problems is not answered yet. As of my understanding, NASA prefers to get hold of Atlantis’ feedthrough connector. That would enable detailed analysis with the actual failed part – and thus there is an excellent chance of finding the root cause. However, that is probably one of the more time consuming options. If that route is taken, launch would be further delayed, and January 10th would not be an option any more.

With just the little information I know, I think it would be useful to sacrifice the launch date in order to get access to the failing feedthrough connector. Remember: the external tank is the only part of the space shuttle stack that is not reusable. As such, analyzing the feedthrough connector after launch is not an option. I personally think it would make more sense to launch, let’s say, in February if that offers the choice to find the root cause. That would not only be good for the remaining shuttle flights, but could also provide valuable “lessons learned” for the Constellation program. Even if Ares will not fly ECO sensors (I don’t know…), the root cause may show something that we do not yet know, be it electrical engineering related, material sciences or whatever else. Getting that missing information can possible increase our understanding and help prevent other, not yet know, problems in future equipment.

But again, keep in mind I have very limited insight. Maybe NASA has even a way to find root cause and still maintain the January, 10th launch attempt. I don’t know for sure. But I know that after the December, 27th press briefing we’ll probably know more. And if you plan to travel to see Atlantis January launch, I wouldn’t book my tickets too early…

2007-12-24

Seasons Greetings to Everyone

My best wishes to everyone! Let me share this lovely impression:

I thought this image conveys much of the beauty of our planet earth and the hopefully peaceful holiday season. I wish all of you great holidays, nice gifts and time with your beloved ones.

In 2007, we’ve gone a long way. Both from an Adiscon perspective, with lots of new product releases and great features and also from the rsyslog point of view. And, of course, there were private highlights as well, for example my unforgettable trip to view space shuttle Discovery’s sts-120 launch. Thanks everyone for your support and all the kind words I received!

Once again, a great holiday season to all of you!

PS: if you enjoyed the image above, you may want to have a look at my xmas 2007 impressions gallery.

2007-12-24

Seasons Greetings to Everyone

My best wishes to everyone! Let me share this impression from my backyard:

Obviously, this is not space-related, but I thought I thank all my regular readers for sticking with me. 2007 has been a very cool year, with me viewing the STS-120 launch being a definite highlight. And, of course, 2007 was the year that made me start this blog.

I wish all of you a peaceful holiday season, great gifts and time with your beloved ones.

And as this is my spaceflight blog, please also help crossing fingers that 2008 will be a great spaceflight year, with Discovery’s STS-122 being launched early in the year. Besides, will see the first European ATV launch, the first Ares launch and many other very cool and interesting things. I’ll try to follow all of them. I’d be delighted if you keep reading my blog!

Once again, a great holiday season to all of you!

PS: if you enjoyed the image above, you may want to have a look at my xmas 2007 impressions gallery.

2007-12-23

NASA website problems…

Unfortunately, there seem to be some problems with at least a number of NASA websites. Most importantly, the KSC media gallery is no longer accessible. I noticed that yesterday, when I tried to find a good picture to go with yesterday’s article. Unfortunately, the site seems to be defunct and the problem still persists.

Of course, I doubted a local problem first. However, other users (from all around the world) report similar problems. Also, being a network guy, I traced the NASA site both from Europe and the US and it didn’t work in either case. NASA currently has IP packages being bounced between two systems, until the packets expire. Looks like either a router has died or there is a configuration problem.

Unfortunately, the media gallery is not the only resource that is down. Essentially, a number of KSC sites are affected and so I guess there is a problem with the main public Firewall (or whatever…). The bad news is that this will limit my ability to post nice pictures along with the blog posts. Obviously, I hope the situation will be resolved soon. In the mean time, you know why there are so few pictures in the blog these days ;)

2007-12-22

Atlantis STS-122 launch date not decided yet…

As I had written, the launch date for space shuttle Atlantis’ STS-122 mission has been moved to no earlier than January 2007. The tanking test last week seems to have brought quite solid data, but NASA has not yet decided which options to take.

There is still a chance that Atlantis can launch early January – but it looks a bit more like a further delay. I have read both about January, 25th and February, 14th as possible launch dates. In any case, if the shuttle can not be launched on the 10th, the rest of the shuttle flight schedule will be affected. If Atlantis mid-January or later, there is not enough time left to launch shuttle Endeavour’s SS-123 mission on February, 14th as originally planned.

NASA’s mission management team will meet again next week, on the 27th and see which additional data has been gathered. More importantly, repair options will have been thought out in the mean time and so it is expected that after that meeting the exact course of actions will be known.

There is already some work going on at the pad, but my understanding is that this is go forward work: it does some things that may be useful, based on what may be decided on the 27th. Not
doing that work right now, would limit options available.

If the January, 10th launch target can not be preserved, it is most likely that Atlantis will take up Endeavour’s launch window and the other missions move forward in an equivalent way. However, a new launch schedule will than probably be needed.

This also puts some pressure on the Constellation program – they need to wait for Atlantis’ STS-125 flight, the Hubble Space Telescope servicing mission. Only after that has been completed, launch pad 39B can be handed over to Constellation and be reconstructed. So delays in STS-122 will probably also affect constellation.

According to NASA, there is still sufficient buffer available to complete the international space station ISS before the shuttle fleet is set to retire in 2010. But that buffer is also eaten up, so this is probably another concern.

As you can see, there is a lot depending on STS-122. But I applaud NASA “better safe than sorry” approach. It is important that the space shuttle is safe to fly. And it is also important to understand that ECO sensor problem, so that the root cause will not bite again on future missions.

2007-12-21

rsyslog work log for 2007-12-21

It has been a good day today! Finally, the alarm() call has been deleted! :) That was something long on my agenda, but I couldn’t do it without the redesign of the inputs. The alarm() was not really a big issue, but it became an annoyance to me because it was so hard to remove.

I would also like to mention that I will do only occasional work during the holiday period. So I do not expect more serious changes until early January. Some releases, however, are due next week (maybe 2.0.0).

Here is the detailed rsyslog worklog for today:

– removed no longer needed mutex from omfwd
– released a preview of 3.0.0 “as is” to mailing list – just to get the idea
– begun work on imtcp
– created first version of imtcp (still very much depending on syslogd.c for
configuration and a lot of other things)
– cleaned up code (resulting in some shuffeling from syslogd.c to the
“right” module)
– prepared for imudp
– created an initial version of imudp.c. The majority of UDP reception code
is now in that module and it is dynamically loadable. HOWEVER, that doesn’t
mean it is a proper module. There are still many, many dependencies on
global variables, cross-module calls and such. However, havin the code base
separated allows me to carry out some other cleanup before I return to
create a really clean implementation of these modules. So it is kind of a
stage work. Just don’t mistake it with “the real thing”…
– removed code no longer needed
– finally, alarm() has gone away :) — this is now done by the main thread
– some cleanup