Category: scrub

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STS-122: Atlantis being instrumented…

Space shuttle Atlantis stands on Launch Pad 39A at NASA's Kennedy Space Center in Florida. Photo credit: NASA/Cheryl MansfieldTroubleshooting efforts at Kennedy Space Center (KSC) continues: Space shuttle Atlantis has been instrumented for a tanking test scheduled to begin Monday. In parallel to the work at KSC, engineers at other NASA centers gather data about how the elements of the ECO sensor system should respond during the tanking test. This provides a baseline against which the actual tanking test results can be compared. Unfortunately, it is not sure if the failure will re-occur during the tanking test. But according to the latest findings it is quite likely.

Please also let me quote the relevant part of NASA’s shuttle home page:

Engineers and technicians at NASA’s Kennedy Space Center continue preparations to evaluate the hydrogen fuel sensor system on space shuttle Atlantis’ external fuel tank during a procedure next week. Working at Launch Pad 39A where Atlantis remains pointed to space, workers attached wiring to the cables that lead from the aft compartment of Atlantis to the external tank’s engine cutoff sensor system. Engineers will use the special instruments next Tuesday to send electrical pulses into the wiring and look for indications that will show the location of the issue that caused the sensors to return false readings last week. The failed readings showed up during launch countdowns on Dec. 6 and Dec. 9. Launch controllers postponed the liftoff on both occasions to find out the problem and develop solutions. Evaluations of the instruments themselves are also under way to show technicians what a normal reading on the external tank looks like. Those readings will be compared to the results from the test Tuesday during which the tank attached to Atlantis will be filled with super-cold liquid hydrogen. NASA is targeting Jan. 10 as the next possible launch opportunity for Atlantis on mission STS-122. Atlantis will carry the European-built Columbus laboratory to the International Space Station.

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Astronauts have left Kennedy Space Center

The astronauts have left Kennedy Space Center, but not without a big thank you to the launch support guys:

“We want to thank everyone who worked so hard to get us into space this launch window,” the astronauts said in a statement. “We had support teams working around the clock at KSC, JSC, and numerous sites in Europe. We were ready to fly, but understand that these types of technical challenges are part of the space program. We hope everyone gets some well-deserved rest, and we will be back to try again when the vehicle is ready to fly.”

They are now back to Houston, where they will continue their practices in support for a space shuttle Atlantis launch in January 2008. The launch is scheduled to be no earlier than January, 2nd. The date is obviously affected by the result of the ECO sensor troubleshooting that is currently being conducted. First news on that troubleshooting effort is expected on Tuesday.

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No Space Shuttle Launch in December 2007…

NASA has waived off any further space shuttle launch attempts for the December launch window. NASA’s shuttle home page has a quick note about that:

The launch of space shuttle Atlantis has been rescheduled for no earlier than Jan. 2, 2008. The postponement will give engineers time to evaluate false readings from the engine cutoff sensor system that measures liquid hydrogen in the external tank.

As far as I know, a January, 2nd launch will be around 5:45am ET.

It is actually no surprise to me, given the new sensor problems. There is not much more news available as of now, I will keep you posted as I get updates.

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Sunday Space Shuttle Launch Scrubbed!

Now it is official – today’s space shuttle Atlantis launch has been scrubbed due to a problem with ECO sensor number three.

Quote from the NASA home page:

Today’s launch of space shuttle Atlantis has been officially scrubbed. It was announced on NASA TV at 7:24 a.m. EST.

Of the four engine cutoff sensors, ECO sensor number three gave false readings. NASA’s current Launch Commit Criteria require that all four sensors function properly. The sensor system is one of several that protect the shuttle’s main engines by triggering their shut down if fuel runs unexpectedly low.

Atlantis’ scheduled launch on Thursday was delayed after two of the four engine cutoff, or ECO, sensors in the shuttle’s external fuel tank gave false readings. A third sensor failed after the tank was drained of fuel. The sensor system is one of several that protect the shuttle’s three main engines by triggering their shut down if fuel runs unexpectedly low.

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Shuttle Launch on Friday?

A number of folks have asked me if space shuttle Atlantis will launch on Friday. While there is a chance for a December, 7th shuttle launch, nothing solid is yet known. We need to wait until the 4pm ET press conference. In the mean time, please be sure to read my posting about the latest official NASA briefing. And, of course it is better to scrub a shuttle launch attempt than to risk crew and vehicle in a situation where launch parameters are not within set limits.

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STS-122 Launch Scrub Press Conference…

Actually, it was a quick status briefing and not a press conference. There is not yet much information, so they had not to tell a lot. The scrub of Atlantis STS-122 launch attempt on December, 6th has been confirmed once again. Neither Atlantis nor Columbus, its primary payload, will launch into space today. The next launch attempt will be no earlier than tomorrow, but may be farther delayed.

The problem is related to two ECO sensors which had invalid readings. This type of problem is typically discovered late in the countdown, while tanking (that same type of problem prevented me from seeing the STS-115 launch in 2006…). There are four of these sensors.

Space Shuttle ECO Sensor during Testing.
ECO Sensors in a Test Setting
Troubleshooting is currently underway. They will send out an inspection team to do a quick evaluation of the external tank status. This will take around an hour and a half. There is a technical meeting at noon, where options will be discussed. At 2pm, there is a mission management team meeting, which will decide on how to continue forward. A press conference on the outcome of that meeting is expected no earlier than 4pm.

The firing room guys will work on a routine that provides a 24-hour turnaround. From their point of view, a December, 7th launch is a possibility. However, it is yet uncertain if it is also a possibility when looking at the big picture. So if the missing management team gives a “go” for Saturday, this can be done. If that would be the case, the launch attempt will be at 4:09pm tomorrow (each attempt is roughly 30 minutes earlier than the previous one).

Space Shuttle Atlantis sitting at the Pad after the December, 6th launch scrub.
Atlantis sitting at the Pad after the December, 6th launch scrub

STS-122 unfortunately has a very narrow launch window. It extends just 7 days and possibly one more day if the mission duration is shortened by one day. Even more unfortunate, NASA was hoping for a two-day mission extension to help troubleshoot solar array problems on the international space station.

I will post any updates when I receive them. But I guess I won’t have much more solid information before the end of the 4pm press conference. BTW: all times are EST.

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Atlantis launch may be delayed just one day

On the press conference, the firing room just said that from their point of view a 24 hour launch delay is possible. But that doesn’t mean that this will be the actual decision from an overall point of view.

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STS-122 officially scrubbed at 9:56a ET

NASA home page states:

Dec. 6, 10 a.m. EST: Official scrub came at 9:56 a.m. EST. An update is forthcoming on NASA TV.

I’ll be watching the NASA press conference as soon as it starts (it was scheduled for 4:30p, now it is 4:36, but it hasn’t started yet).

While it is now clear that Atlantis will not reach space today (nor will the Columbus lab module), it is unclear when the next launch attempt will be. Some say December, 7th, other speculate whether or not this will need repairs that can’t be done in the STS-122 launch window.

Press conference just begun…

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Atlantis launch scrub somewhat confirmed

The scrub of today’s Atlantis launch attempt becomes more and more real… NASA’s homepage right now has this statement:

Approximately 16 minutes into fast fill, two ECO sensors failed to indicate wet. They are troubleshooting the issue. Currently, H2 is at 80% and O2 is at 50%. Tanking is continuing. We expect to have a status from leadership soon as to whether we continue or scrub. If we scrub, a briefing will follow that decision on NASA TV.

It doesn’t sound final, but it backs evidence that the information on nasaspaceflight.com regarding the STS-122 launch scrub is correct. Other sites now also report accordingly.