NASA Considers Shuttle Launch "As Is"

Sensor Malfunction Cause Still Unknown; Earliest Next Launch Would Be Saturday

(CBS)  NASA is considering launching Atlantis despite an unsolved circuitry problem, using manual procedures to monitor the malfunctioning fuel tank sensors during ascent to prevent any potentially catastrophic problems, reports CBS News space consultant Bill Harwood.

That problem forced a delay of the space shuttle's launch on a space station assembly mission until Saturday at the earliest.

If those sensors fail to detect when the external fuel tank is empty, the engines could continue to run dry, and explode.

Based on electrical data seen during fueling Thursday, engineers believe the problem involves an open circuit in the wiring between an electronic box in the shuttle's engine compartment and the sensors at the base of the hydrogen section of the external tank. Given the shuttle's short eight-day launch window, NASA managers Thursday ruled out opening up the engine compartment to attempt any inspections of repairs.

LeRoy Cain, chairman of NASA'S Mission Management Team at the Kennedy Space Center, told reporters late Thursday engineers will meet again Friday to reconsider their options, adding they may not get comfortable with a fly-as-is rationale in time for a Saturday launch.

In the meantime, NASA managers ruled out a fueling test Friday and decided instead to top off the shuttle's onboard supply of liquid hydrogen to power the ship's electricity producing fuel cells. That would permit launch attempts Saturday and Sunday and still provide enough on-board supplies for a two-day mission extension and the addition of a fourth spacewalk.

Three spacewalks are required to connect the European Columbus research lab to the station; to replace a nitrogen coolant system pressurization tank; to install a pair of experiments on the Columbus module; and to move a failed space station gyroscope to the shuttle for return to Earth.

NASA managers want to add a fourth spacewalk if possible to permit a detailed inspection of a stalled solar array rotary joint to help engineers figure out what sort of repairs might be needed to get the joint turning smoothly again. But an additional spacewalk would require a two-day mission extension and that, in turn, is based on how much hydrogen and oxygen is available to power the ship's fuel cells.

A launch on Saturday, assuming the engine cutoff sensor problem can be resolved, would be targeted for 3:43:31 p.m., setting up a docking with the international space station around 12:56 p.m. Monday. The forecast for Saturday calls for a 60 percent chance of good weather, improving to 70 percent "go" on Sunday.

Atlantis' launch window closes Dec. 13 because of power and temperature issues related to the space station's orbit. The window reopens Dec. 30, but senior NASA managers have said launch would be delayed to at least Jan. 2 if the shuttle team misses the current window.

NASA managers had high hopes for a launching Thursday, with a forecast calling for a 90 percent chance of good weather and no technical problems of any significance at pad 39A. After a short 13-minute Mission Management Team meeting, engineers were cleared to begin loading a half-million gallons of super cold liquid oxygen and hydrogen rocket fuel into Atlantis' external tank at 7:06 a.m. A few minutes later, the engine cutoff - ECO - sensors at the base of the tank were covered with supercold propellant.

The ECO sensors are part of a backup system that ensures the shuttle's three main engines don't drain the tank in the event of other problems during the climb to space that might prevent an on-time shutdown.

The ECO sensors can indicate two possible states: wet or dry. If the sensors falsely indicated they are submerged in fuel when, in fact, the tank is dry, the engines could run out of propellant while operating at flight pressures, speeds and temperatures, suffering catastrophic failures.

Based on the logic used in the computer software that monitors the sensors during ascent, two "failed wet" sensors would have no impact. But a third sensor failing wet could trigger a premature engine shutdown to protect against the possibility of the remaining sensor failing in the dry state. Launching with two sensors in the failed wet state would leave no redundancy in the system.

Propellants flow into the tank from the bottom and shortly after the four engine cutoff sensors at the base of the hydrogen section were submerged Thursday, commands were sent to simulate dry conditions to make sure the circuitry responded properly. Voltage readings from two of the sensors immediately indicated a dry state while sensors 3 and 4 showed voltages higher than 13.5 volts, an indication of an open circuit. The readings occurred simultaneously.

"What's currently in the plan is that we'll try to put together an operational workaround plan that we can get comfortable with that will allow us to go fly on Saturday," Cain said. "And it would be with the intent of flying with one or more failures potentially in the system when we go tank up again."

A premature engine shutdown could result in a trans-Atlantic landing. An emergency landing in Spain or France would cause major disruption to the space station assembly schedule and NASA's plans to complete the outpost and retire the shuttle by 2010.

Engineers say the odds of a premature engine shutdown in this case are acceptably remote because multiple failures would be required - ECO sensor failures as well as a leak or problems elsewhere in the system that would cause the shuttle to use up its hydrogen fuel at a higher-than-expected rate.

But not everyone agrees. Some engineers favor rolling Atlantis back to the Vehicle Assembly Building for repairs. NASA Administrator Mike Griffin participated in Thursday's Mission Management Team meeting and presumably will weigh in on how the agency proceeds this weekend.

[bigmacmcc]

I don''t understand why after all of these launches they would know exactly how much fuel is being consumed during launch and exactly when the tanks are nearly empty to shut them off at the right time. The sensors are important but are they that critical?

[superaunt]

"If those sensors fail to detect when the external fuel tank is empty, the engines could continue to run dry, and explode."

I sure wouldn''t want to be an astronaut on this mission!

[demslie]

I am amazed. No matter what the story, there are angry democrats screaming about something. I just looked at a story about the Mall Masacre in OMAHA and there were libs blaming it on Bush. What a bunch of nuts. And they want to run the country. I''m moving to CHINA. Oh, dems would love that because they love Communism.

[jetlizhan]

launching with an unsolved circuitry problem? glad my buttt''s not going on this mission. has nasa asked the opinions of the astronauts going up in this? just doesn''t sound the least bit safe to me.

[alphaa10-2009]

Is a NASA policy of launching "as is" the same ad hoc carelessness as Rumsfeld invading Iraq with the "army you''ve got?"

In fact, each NASA shuttle is *still* at risk from the same launchtime debris impacts that killed Columbia. The difference in mission outcomes, if any, remains one of sheer (blind) luck.

NASA resumed launches after literal years of wrestling (unsuccessfully) with the icing and foam debris problems. Announcing its new shuttle launch schedule for July 4, 2006, NASA said the agency had done all it could be expected to do (?) with the ice hazard, and now, it would return to business as usual.

A second of the NASA safety corrections ordered by the post-Columbia inquiry was to develop effective means of patching in-flight damage to the carbon-on-carbon leading edge (not the same as the heat shield). That project was given up, as well.

NASA continues to ignore the two major problems identified after the Columbia disaster. NASA cannot disguise its glaring failure to complete the major safety objectives assigned to the agency after Columbia, and recklessly places shuttle crews at risk.

Clearly, NASA is back to its old, lethally slack behavior. Besides, NASA is eager to begin phaseout of the remaining shuttles. So, why spend more time or money on the problem? Just hope it will go away.

Heckuva job!

[nordeck52]

It''s a bit too risky in my book. Better safe than sorry, I say. Even though they could be delayed until January, it''s still better than going through with the risk of a possible explosion.

[redo88]

Bigmacmcc, you are correct. The flight computers do use timing and fuel flow calculations as the primary method for engine cutoff. The tank sensors are part of the backup systems. They are not necessary during normal operations.

[redo88]

Bigmacmcc, you are correct. The flight computers do use timing and fuel flow calculations as the primary method for engine cutoff. The tank sensors are part of the backup systems. They are not necessary during normal operations.

[downtowner97]

Pull the plug on this wasteful space station program, already! There is no new science being done. There are no new discoveries being made. The shuttle costs 30 times as much as a Russian rocket to launch, and is over a hundred times more likely to blow up.

People say it''s a matter of pride to have people in orbit. Yeah, it''s a matter of pride like it''s a matter of pride to have Woody Harrelson chained to a redwood trying to save it. There are other needs in this country, and we have better things to do with our scientists than blowing them up.

[bareemperor]

I knew we shoulda outsourced that space vehicle to Japan!
It would have worked every time, and saved jet fuel to boot...

[alphaa10-2009]

Demslie said, " I''''m moving to CHINA. Oh, dems would love that because they love Communism."
---
Incoherent rants from ignorant GOP bozos should not surprise us, but Demslie really needs to move his mindset into the 21st century and discover his real enemies.

For example, the PRC is the world''s richest communist dictatorship-- richer and fatter after Bush policies promoting wholesale export of American-based jobs. Thanks to such policies, Communist China is the biggest creditor of the government of the United States.

How unpatriotic of Bush! Yet not surprising, since both Bush and Beijing regimes claim a country''s leadership is a power unto itself. Not since Nixon has a president displayed such contempt for the rule of law and the interests of the American people.

Bush is the individual who, in November, 2005, facing an assembly of party members critical of his NSA spying program, bristled like a teenager caught drinking after curfew-- "Stop throwing the Constitution in my face! It''s just a GD)((#@*! piece of paper!"

Is this figure, who claims to be president of the United States, the same who pledged an oath to "protect, preserve and defend" the document he calls a "GD)((#@*! piece of paper"?

[andor3]

"There are no new discoveries being made. The shuttle costs 30 times as much as a Russian rocket to launch, and is over a hundred times more likely to blow up."

Okay those statements are all 100% wrong. If you are going to make up science and fabricate facts, you oughta try to keep them in the range of believable, despite Bush&Co example.

[offtheback]

Cool, another multi billion dollar fireworks show. I''ll be sure to tune in. All the while children die for lack of reasonable medical care and seniors still have to decide between blood pressure medicine to stay alive or food to stay alive. What a great regiem we worship.

[yongamerica]

and saved jet fuel to boot..Posted by BareEmperor

The space shuttle uses less jet fuel than a Boeing 787 does traveling between Chicago to New York.
:)

[michaelt302]

OffTheBack, you liberal whining bag of dogsh*it, just shut the fu*ck up. There is NO reason our country cannot afford BOTH a space program and to give reasonable help to poor kids. We need to do both; these are NOT mutually exclusive programs. Just so long as a cent doesn''t go to YOUR worthless whiny a*ss, I''m all for it.

[michaelt302]

Downtowner97, you''re 100% wrong and made ALL of your stats up. I have studied the space program non-stop for 40 years, and you sir are full of sh*it.

[fstop100]

taxpayers money going up in smoke. how much money does nasa burn every year? even the guy greasing the tracks on the shuttle mover is making way too much money

[rushman71]

alphaa10: I''ll repeat what Demslie said,"No matter what the story, there are angry democrats screaming about something."

[jackie0428]

If you want the truth: for every dollar spent on the space program, approx. 7(seven) dollars is returned to our economy in either direct dollar benefits, jobs, or scientific advances and benefits. You''ll likely find no other program that can boast of such a positive record. Our only mistake is that we don''t spend nearly ENOUGH money on NASA. I''d like to see us go to Mars as soon as possible. We%u2019d need another JFK-style push to do it. Sadly, liberals, the scientifically-illiterate, and mentally lazy people, all lacking the ability to pull their brains away from watching "Dancing with the Stars" or "The View", and unable to see further than 3 months into the future, are creating the apathy about our space program.

[offtheback]

MichaelT302
Cursing and throwing insults under cover of the anonimity of the internet. You would not speek that way to someones face least they lay you out as with any mouthy punk. I am not a liberal, not a dem. or rep. I am however a conservitive. A true fiscal con. I don''t believe in spending money you don''t have on things you don''t need. There is a reason these things are mutually exclusive and you have bought into it hook line and sinker. That is polititions of any label. The idea here is to divide the people along any lines that present themselves to continue the childish bickering and divert attention from the sale of our great nation to the highest bidder. Try engaging in an intellegent debate sometime and you might find that our views and priorities are not all that different.

[godofredo29]

They should try even launching the shuttle from the rolling platform just for the heck of it. If that works it would mean they could launch it from other places--people''s backyards, a football stadium, an aircraft carrier. Who knows?

[tburzio]

The space station is a make-work program for Russian scientists so that they won''t make a bomb for Al Queida. Not a bad return, considering the alternative. Who knows, we may even learn something in the bargain.

[denn034]

If it''s serviceable, then, why not? Go for it, NASA!

[fitedafuture]

so basically NASA considers all their astronauts expendable?...NASA should stand for Not Another Seven Astronauts.!!.

[downtowner97]

There have been 121 space shuttle launches in the past. Two have killed everyone on board. That''s a 1 in 60.5 chance of being killed. The Russian launch vehicles that have been used since the Space Shuttle came into service in 1981 have had 58 missions with no crew killed.

The cost of a single space shuttle launch taking into consideration the cost to build the shuttle and launch facilities, and the expected end of the program in 2010 is $1.5 billion. The cost of a Soyuz launch including construction and facility costs is $50 million, or 1/30 the cost of a shuttle launch.

The problem of debris shedding from the main fuel tank of the shuttle has NOT been resolved, so it''s more a matter of blind luck if there is no damage to the landing vehicle. The Soyuz does not have this problem and is therefore much less likely to kill astronauts in the future.

Soyuz is much simpler, and can be launched with far less preparation than a shuttle. The Russians think nothing of selling extra seats to offset launch costs.

Very few new discoveries are coming from the space station since the Soviets logged so much time in orbit already.

[downtowner97]

The Alpha Magnetic Spectrometer was built at a cost of $1.5 billion and is widely hailed by scientists as the most important piece of scientific equipment ever built for the International Space Station, and it''s not going to be launched. If it was launched and antimatter was discovered, it would further call into question the creation myth. The much less controversial Columbus module will be launched instead.

[downtowner97]

The sense of apathy toward the space program is not because of peoples'' laziness, political affiliation or scientific illiteracy as Jackie states. The apathy toward the space program comes from the fact that the space program is incredibly boring.

It costs $1.5 billion to send astronauts to literally go around in circles! NASA has a dedicated TV channel, and if you''ve ever seen it, it''s the best cure for insomnia going. The people at mission control sound like they''re describing the process for cleaning a clogged drain.

The Mars Rovers have gone to Mars and send back countless pictures, have outlasted their expected lives, and actually do and see something new every day. They cost $450 million to build and launch. They don''t develop greasy hair, grin and wave at cameras, or poo into a vacuum cleaner, but they''re frankly more interesting than the shuttle and space station program.

[alphaa10-2009]

rushman71 aaid, "I''''ll repeat what Demslie said,"No matter what the story, there are angry democrats screaming about something."
---
Demslie should acknowledge his own screaming. If Demslie complains about the complaints, that is not a complaint?

Those affiliating themselves with the GOP should consider carefully the mounting criticisms of Bush and his policies that seem to be everywhere.

Such criticisms are more than material for a Bush-era post-mortema-- they indict Bush for not only his incompetence and vain, destructive ambition, but extreme abuse of the political process.

[alphaa10-2009]

downtowner97 said, "The Mars Rovers ... have outlasted their expected lives, and actually do and see something new every day... they''''re frankly more interesting than the shuttle and space station program."
---
Thank you for the interesting comments. On human vs. machine probes of space, I suspect when it becomes painfully obvious a human cargo is an insufferable burden to mission design, someone at NASA quietly will move the grandstands to a pasture somewhere, decommission most (not all) of the spacesuits, and let machines come into their own.

Machine intelligence and vision have been a long time coming, but follow the same script as the original uneasy drama between NASA astronauts and the machine which put them into orbit. As Mercury, Gemini and Apollo programs matured, each assigned machines much more of the burden of spacecraft management.

Media overplay the astronauts, and often underplay the machine missions, but considering what has been accomplished in defining our solar system and galaxy, the machines win-- probes down.

NASA always has been invaded by politics, and some suspect our shuttle losses were, at least in part, due to some impatient presidents who wanted a public fireworks display. And, of course, Apollo 13 convinced many only a human crew could save a mission. But in the main, the days of astronauts are nearing an end.

[hissteps4u]

Leroy Cain is a Jerk to even say that. He needs to be Fired tomorrow for his comments. He would cause your child or mine needlessly to be placed in harms way for nothing and that is not right.

this is why NASA does not Have the Confidence of America and why we need to overhaul the dead weight and get some real scientists who actually give a sh-t to run NASA. this GUY is a dweeb and I can not believe he would make such a statement.

[goldesprit]

Read "Riding Rockets" by Astronaut Mike Mulaine.

He gives an excellent wrenching account of what its like to sit on one of these shuttles on the pad, and then ride it into space. Not sugar coated.

Not for the timid.