Space Shuttle Atlantis returned safely to Kennedy Space Center yesterday after completing STS-122 to the International Space Station which saw the delivery and installation of the ESA European Columbus science labaratory.

As Atlantis landed, Endeavor was already at the launch pad in preparation for STS-123, also to the ISS, which is penciled in to launch in just over three weeks time on the 11th of March. Endeavor will be carrying the pressurised section of the Japanese JAXA science module.

Tags: atlantis, columbus, edeavor, esa, iss, jaxa, nasa, sts-122, sts-123

Just a quick reminder that Space Shuttle Atlantis is scheduled to lift off at 19:45GMT today. Best internet viewing is probably via the NASA TV main page now as the better Yahoo! stream seems to have gone away.

Direct link for NASA TV Update: I found the better quality video link for Yahoo! again.

Update: Atlantis launched successfully

Tags: atlantis, columbus, esa, february 7th, iss, launch, nasa tv, sts-122

NASA has scheduled the next launch attempt for STS-122 for Thursday 7th February at 19:47ZULU

Atlantis was first due to launch back at the beginning of December but a recurring fault with the ECO (Engine Cut Off) sensors in the main liquid hydrogen tank prevented this. If the ECO sensors became unavailable in flight, it could lead to a situation where the liquid oxygen could be depleted beyond safe limits potentially leading to a catastrophic failure of the SSME turbopumps. NASA traced the problem to the connector points on the side of the external tank. They then fabricated and fitted new connectors which means that the vehicle now stands read to fly this week.

Atlantis will be carrying the European Space Agency’s Columbus scientific module to the International Space Station.

I will be looking this week to find the best internet video feed source for NASA TV’s coverage of the launch and I will note it here when I do.

Tags: atlantis, columbus, esa, february 7th, iss, launch, sts-122

The next launch attempt of Space Shuttle Atlantis for STS-122 has been postponed until January 2008 due to faults with the ECO sensors in the Liquid Hydrogen fuel tank of the Space Shuttle System.

Launch had originally be scheduled for last Thursday but two of the four Engine Cut-Off Sensors in the liquid hydrogen section of the external tank failed to respond during fuelling. NASA requires that all four ECO sensors respond during tanking prior to launch. On Sunday’s launch attempt one of the four sensors failed to respond during tanking and the launch was scrubbed.

The postponement to the 10th of January is to allow time for engineering teams to evaluate the sensor problem and I’d also hazard a guess, to avoid any possible issues with the Shuttle’s annual ‘Y2K bug’. The bug is a potential issue with on-board computers when the calendar rolls over from one year to the next. This wouldn’t directly be a problem for a Shuttle launched in the next few days but it could perhaps become a problem if damage to the orbiter required an STS-3xx crew rescue mission.

The ECO sensor issue is a tricky one, they can’t risk them not working properly as a turbopump failure could lead to a ‘catastrophic’ engine failure. As I understand it, when the Space Shuttle Main Engine (SSME) turbopumps are at operating speed, fuel flow must be maintained for safe operation. A normal shutdown would be a controlled throttle-back of the engines so the turbopumps would spin down gradually. A sudden cutoff of the fuel would actually cause an rpm increase and failure (presumably uncontained) of the turbopump.

At a recent Mission Management team press briefing, they discussed the possibilities for fixing the ECO sensor issue. The MMT are optimistic that the fault lies in the avionics which are contained within the orbiter and can be accessed while on the pad. If, however, the fault lies at the sensors themselves within the base of the external tank, a roll-back to the vehicle assembly building may be required, perhaps even with the tank being demated from the stack. The MMT did mention that they had gained access to the tank while on the pad on a previous mission “a long time ago” but pointed out that it was a very difficult process involving removing an area of insulation foam, removing a panel of the tank and then putting it all back together again. The foam would then have to be re-applied in situ.

In the mean time, station life goes on. Progress M-62 is scheduled to launch to the ISS on the 23rd of December. The unmanned cargo vessel is expected to dock with the station on the 26th.

Tags: atlantis, columbus, eco sensors, esa, january, space shuttle, sts-122

The first launch attempt of Space Shuttle Atlantis for STS-122 has been scrubbed due to two of four LH2 Engine Cutoff (ECO) sensors failing to respond during tanking. The ECO sensors detect when the Liquid Hydrogen tank is about to run dry and cause a main engine shutdown to protect the turbopumps from running dry which could lead to catastrophic engine failure.

LH2 and LOX fuels have now been detanked from the shuttle and there will be a launch countdown recycle with the next attempt at 20:43ZULU Saturday the 8th of December.

Update: Launch now postponed until January

I also discovered an alternative link for NASA TV via Yahoo! which appears to provide a better quality of video that the rather awful quality provided by the NASA TV landing page.

Tags: atlantis, columbus, eco sensors, esa, iss, scrubbed, space shuttle, sts-122

Space Shuttle mission STS-122 is scheduled to launch today from Kennedy Space centre in Florida at 21:31:44ZULU. The shuttle in use for this mission is Atlantis and it will be carrying the European Columbus pressurised module (shown in the cargo bay in the diagram) for the International Space Station.

Atlantis will also be carrying the EuTEF external payload facility for the ISS.

You can follow the launch on NASA TV via the web or if you’re in Europe with a suitable dish, you can get the ESA TV relay on Atlantic Bird 1 at 12.5 deg West.

Eutelsat Atlantic Bird 1 at 12.5 deg West, Transponder F5, Channel C, Horizontal, F=12.642,75 MHz, SR=6.1113 Ms/s, FEC=3/4, signal MPEG2 4:2:0 PAL in the clear.

I had a quick look in at NASA.GOV’s new web page for NASA TV. On playing back the wma stream, it appeared to be of decidedly worse quality than we are used to so I tried the RealPlayer stream which was far better. It may just be a transient reduction in the bandwidth of the stream by Yahoo so I’ll try again tomorrow on the WMA stream but remember that the RealPlayer stream may be worth a try if you can’t get a good stream otherwise.

Tags: atlantis, columbus, esa, iss, space shuttle, sts-122