The odd bit

Once is an accident, twice is a coincidence, three times is an enemy action.

The odd bit - Once is an accident, twice is a coincidence, three times is an enemy action.

Atlantis landing: Day 2

Space shuttle Atlantis takes another attempt at trying to land. The first attempt was waved off due to bad weather at Kennedy Space Centre. KSC isn’t looking good for the second attempt either and NASA is now targetting Edwards Air Force Base in California. That’s on orbit 219 which has an opportunity for both KSC and Edwards.

Conditions at Edwards are currently looking good and the space shuttle crew has been given the go for fluid loading (= drinking lots of fluids to aid in the transition to Earth’s gravity). If given the final go, the deorbit burn would happen at 2:43pm EDT (20:43 CET) and the landing at 3:49pm EDT (21:49 CET).

  • 20:20: Atlantis is go for the deorbit burn. The burn will happen in a little over 20 minutes.
  • 20:23: Atlantis will now be positioned to perform the deorbit burn. The burn happens tail first, or retrograde, which slows Atlantis’ orbital speed with about 200 mph. That will put it the shuttle on a re-entry path.
  • 20:41: Mission Control reports a good config for the burn.
  • 20:43: The propulsion officer at Mission Control reports that the burn is in progress with the 2 engines performing normally.
  • 20:47: Deorbit burn complete!
  • 20:52: Atlantis will be repositioned from tail-first to nose-first, or prograde, for entry interface (the point where Atlantis starts to experience the first effects of Earth’s atmosphere) and re-entry.
  • 21:18: Less than one minute until entry interface.
  • 21:19: Entry interface takes place at an altitude between 125 and 130 kilometers with the orbiter more than 8000 kilometers away from the landing site. It then takes around half an hour to stop on the ground.
  • 21:36: Atlantis is on track for a landing at Edwards in 13 minutes.
  • 21:38: Atlantis is now within range of the tracking stations at Dryden, NASA’s flight research centre.
  • 21:42: And we have visual contact with Atlantis!
  • 21:47: Atlantis crew reports runway in sight.
  • 21:49: Full stop on runway 22 of Edwards AFB! Atlantis has safely landed!

STS-117 was the 118th space shuttle flight and this landing was the 51st at Edwards.

The Atlantis crew will now go through post-flight checklists before leaving the orbiter. The orbiter needs to be flown back to KSC for post-flight processing. A ferry flight on top of a Boeing 747 could take place after 7 days.

Atlantis landing delayed

Space shuttle Atlantis was scheduled to land at Kennedy Space Centre today. The first attempt on orbit 202 at 1:55pm EDT and the second attempt on orbit 203 at 3:30pm EDT have both been waved-off due to bad weather above the shuttle landing facility.

There will be four opportunities tomorrow: two at Kennedy (orbit 218 @ 2:16pm and orbit 219 @ 3:51pm EDT) and two at Edwards Air Force Base in California (orbit 220 @ 5:21pm and orbit 221 @ 6:56pm). For those in Europe, that’s 20:16, 21:51, 23:21 and 0:56 CET. There are also opportunities available on Saturday.

Kennedy is the preferred landing site for several reasons. If the shuttle lands at Edwards, it needs to go on a piggyback ride on top of a Boeing 747 to bring it back to Kennedy. That flight can only happen when the weather is good and even then it’s still a big risk. Such a flight is not only risky, but also expensive. Landing at Edwards also means it’ll take longer before the post-flight processing can begin. To summarise, landing at Kennedy is less risky, cheaper and faster to get the orbiter back in ready state.

The fans and the curious can watch the landing on NASA TV.

Windows Vista: Long delay when switching songs in media player

There you are: Windows Media Player (WMP) running, all songs loaded in its library and you hit the ‘play’-button. It picks the wrong song and you click the ‘next’-button. Instead of starting the next song immediately, a pretty long pause follows the release of the button. As if there’s some artificial intelligence pondering if it should play the file. Rest assured, the song will start eventually. You can live with that for a couple of songs and then the mind starts asking questions. I don’t have to wait in Windows XP so why should I have to wait in its youngest sibling? And so the quest for a solution starts…

The pause is the most noticeable event, but it’s the result of something else: one of the svchost.exe processes loves the CPU and starts eating cycles. So it’s some Windows service causing all of this, but which one (for the unknowing: svchost.exe does a lot in Windows and there are multiple processes with that name)? Process Explorer to the rescue! And that nifty program told me the spike in CPU usage was caused by “svchost.exe -DcomLaunch”.

The fun isn’t over yet. That process is associated with two services: DCOM Server Process Launcher and Plug and Play. For the Vulcans among us, all logic stops there for a second. What do those two services have to do with WMP? The answer is provided by Vista’s new audio engine. The new engine supports several audio “enhancements”. But for the enhancements to work, the engine needs to determine if your hardware is up to the task. And when does it check that? Each time a sound output device is accessed. That’s pretty nice if you can do a hot swap of sound hardware, but I don’t see me doing that anytime soon. Anyways, it does provide us with the link to the correct service because checking hardware is done by the “Plug and Play” service.

One might think that deactivating each enhancement would solve the problem, but that’s wishful thinking. The configuration of the enhancements is located in the properties of the sound hardware. When opening the tab, I found out that no enhancements were active. Hmmm… so why does it check the hardware? Well, it does that in case you actually enable an enhancement. To completely stop the hardware checking, you have to tick the box labelled Disable all enhancements. As soon as you do that, Vista finally understands you don’t want to use them :-)

It took me quite some time to figure this out. I hope this post can save some time for those who experience the same problem.

Launch day for Atlantis

We’re within 6 hours of a possible launch and that means NASA has activated the launch blog. Current weather conditions are red, but the forecasts give only a 20% chance of weather blocking a launch.

Status updates:

  • 20.08h: The inspection team (or “ice team“) is looking at a hanging bracket on the mobile launcher platform to see if it could become a safety issue.
  • 20.40h: The clouds are moving away and predicted weather conditions for launch are still green.
  • 21.24h: A couple of showers off-shore, but they should not be an issue for the launch.
  • 21.45h: The Final Inspection Team has left the pad.
  • 22.38h: 3 hours left until T-0.
  • 23.05h: The go to close and seal the orbiter’s hatch has been given.
  • 0.02h: T-20 minutes and holding. Everything’s green.
  • 1.03h: There were weather problems with the TAL (Transoceanic Abort Landing) sites in France and Spain. Istres (France)is now go though.
  • 1.24h: And Atlantis is go for launch!
  • 1.38h: Lift-off!
  • 1.41h: SRB separation.
  • 1.46h: Main-Engine Cut-Off and external tank separation complete.

Atlantis ready for duty

We’re about 27 hours away from Space Shuttle Atlantis‘ launch. Conditions are looking good with only a 20% chance of weather violating the constraints. The launch of mission STS-117 was initially scheduled for sometime in March, but a hail storm decided otherwise. After repairs to both the orbiter and the external tank, the whole system is good to go for tomorrow’s launch at 7.38pm EDT (I believe that’s 1.38am CET).

Tomorrow’s launch will also be the first in a long time from launch pad 39A. Pad 39B has been used for launches lately while 39A received some maintenance. Pad 39B has now been deactivated for shuttle operations, so 39A will serve as the launch pad until the shuttle fleet is retired.