Posted on 08/16/2007 6:51:13 PM PDT by NormsRevenge
CAPE CANAVERAL, Fla. - NASA decided Thursday that no repairs are needed for a deep gouge in Endeavour's belly and the space shuttle is safe to fly home. Mission Control notified the seven shuttle astronauts of the decision right before they went to sleep, putting an end to a week of engineering analyses and anxious uncertainty — both in orbit and on Earth.
"Please pass along our thanks for all the hard work," radioed Endeavour's commander, Scott Kelly.
Mission Control replied, "It's great we finally have a decision and we can press forward."
The astronauts had spent much of the day running through the never-before-attempted repair methods, just in case they were ordered up.
After meeting for five hours, mission managers opted Thursday night against any risky spacewalk repairs, after receiving the results of one final thermal test. The massive amount of data indicated Endeavour would suffer no serious structural damage during next week's re-entry.
Their worry was not that Endeavour might be destroyed and its seven astronauts killed in a replay of the Columbia disaster — the gouge is too small to be catastrophic. They were concerned that the heat of re-entry could weaken the shuttle's aluminum frame at the damaged spot and result in lengthy postflight repairs.
Endeavour's bottom thermal shielding was pierced by a piece of debris that broke off the external fuel tank shortly after liftoff last week. The debris, either foam insulation, ice or a combination of both, weighed just one-third of an ounce but packed enough punch to carve out a 3 1/2-inch-long, 2-inch-wide gouge and dig all the way through the thermal tiles. Left completely exposed was a narrow 1-inch strip of the overlying felt fabric, the last barrier before the shuttle's aluminum structure.
The only way to fix the gouge would have been to send a pair of spacewalking astronauts out with black paint and caulk-like goo, and maneuver them beneath the shuttle on the end of a 100-foot robotic arm and extension boom, with few if any close-up camera views of the work.
The spacewalk would have had added risk, so much so that mission managers did not want to attempt it unless absolutely necessary. Wednesday's spacewalk, cut short by an astronaut's ripped glove, showed how hazardous even a relatively routine spacewalk can be.
Earlier, astronaut Alvin Drew said from Endeavour that he was comfortable with the prospect of flying back to Earth in a gouged ship. Engineers seem confident, he said, "and I trust their confidence that we can get home safely even with the divot that we have in the belly."
"Spaceflight is risky," noted astronaut Barbara Morgan, the backup teacher for Challenger's doomed mission, "but we have all confidence that we're going to be able to do the right thing."
But a Nobel Prize-winning physicist who served on the Columbia investigation board four years ago, Stanford University's Douglas Osheroff, questioned NASA's hesitancy to perform the repairs since they "can only increase their chances of making it down."
I don't see why NASA is going to invent a fix and not use it," Osheroff said. He added: "This attitude of, 'It looks like it's OK, let's not do anything about it,' it seems like the Columbia NASA."
In a poignant reminder of NASA's other shuttle accident, the 1986 Challenger launch explosion, Morgan — Christa McAuliffe's backup — answered questions from youngsters gathered at the Challenger Center for Space Science Education in Alexandria, Va.
The moderator was June Scobee Rodgers, the widow of Challenger's commander and the founding chairman of the Challenger center's board. "Barb, we have been standing by waiting for your signal from space for 21 years," she said.
One girl asked if Morgan had a special teacher or mentor when she was young.
"Some of my mentors that have meant more than anything to me are seven very special people who I believe are mentors to you, too, and that was the Challenger crew," Morgan replied.
Morgan closed the teaching session by holding up an emblem of the Challenger crew's mission patch.
___
Associated Press writers Liz Austin Peterson in Houston and Seth Borenstein in Washington contributed to this report.
Perhaps NASA should have used titanium instead of special thermal tiles?
I know.. Thanks!
Again, location in the heat flow in the area of the gouge won’t likely be significant enough in Nasa’s opinion to cause a rupture. Even if it did, they are of the opinion the shuttle would obviously be in need of more repair were that to happen, but it would still be able to hold up thru a re-entry and land OK.
Nonsense. Do you really think they don't care if another shuttle burns up? Piffle. How hard would it be to send them out to put that goo stuff in the hole? I know EVA’s are dangerous..but so is a ship coming in with damaged heat tiles.
Actually, it does seem to be pretty hard. The fix goo they have is essentially an emergency remedy when there is no alternative. Even a small risk of accidentally gouging other more critical tiles is a sensible calculation to make.
Endeavour will return safely.
They have used a plasma arc jet to replicate entry conditions on real tiles cut with the same divot as the damaged caused and heating underneath was not even close to the max limits. She has plenty of margin.
this is a myth that dies hard.......
http://www.sts107.info/kooks%20and%20myths/kooks.htm#EPA
Myth - Left wing environmental policies doomed the shuttle
According to some claims, EPA regulations that eliminated Freon caused the foam to fall off.
CFC-11 Freon was used to apply the Spray On Foam Insulation (SOFI) to the ET, and the formula was changed because of EPA regulations. The new method did result in more foam falling off and hitting the shuttle, most notably STS-87, which had 308 damaged tiles, but that was not the type of foam which doomed Columbia.
In the mid-1990s, the EPA banned CFC-11 Freon. NASA has many waivers from the EPA for critical items. In each case a commercial supplier is licensed to produce the limited quantities NASA needs, but it’s incredibly expensive to manufacture the relatively small quantities just for one customer. Lockheed-Martin went through a major effort to find a more environmentally friendly propellant. (It wasn’t something they wanted to do, but a necessity.) They selected HCFC 141b (Dichlorofluoroethane). HCFC 141b is only used to spray acreage foam –applied to the large cylindrical surfaces with a giant robotic sprayer.
The bipod foam which doomed Columbia was BX-250 foam, which was excluded from that EPA mandate. Technicians built the bipod by hand, layer by layer, and carved it into shape. The manufacturing process for the bipod and its chemical composition did not change and still used CFC-11. No changes to environmental regulations caused the Columbia accident.
I suppose we should judge the US Marines by Oswald?
Human beings are not machines.
There are hundreds of NASA astronauts.
Shall we judge Freepers by our worst?
If nothing else, use the goo-fix for this small hole to evaluate performance so at least they establish a track record of how well it works. If a bigger hole has ANY chance of using the goo-fix in the future, at least there will be a real-life knowledge base. The risk seems reasonable and the learning curve will be less vertical next time around if/when a more serious gouge is discovered. /soapbox off
I know a guy who works for NASA and another guy who is retired from Lockheed Martin. Both of them will say that this is not such a big deal. The space shuttles always come back beat up with tiles missing.
If you look at the diagram of hits to the shuttle I posted in post number 6, you won’t see any increase in the damage over the years.
Some of you know that I work at NASA. Marshal Space Flight Center in Huntsville.
Marshal is responsible for the External Tank, Boosters and the Engines.
First, the Tank Managers should have fixed this back in the 80’s when it was first found. THere are no excuses.
I was privy to a brief part of a conversation amongst the highest echelons of NASA management about this latest tile problem.
I wouldn’t want to be on that shuttle. I fear this is being addressed the same old NASA Management way.
I met a few of the folks that worked on the tiles program at Lockheed.. pretty cool stuff but delicate as heck..
On a wing and a prayer?
I remember reading about the tiles in National Geographic before the shuttle ever flew. I was only about 14 and was amazed at a picture of a tile glowing red hot in the middle but held by the edges in a bare hand.
So true.
An application of so called “enviro- friendly” (which usually translates to “sub-standard”) foam has cost some lives already.
NASA is culpable.
You must be one of them Rocket Scientists!
Yes, they say the tiles are very delicate and unlike a tiled floor the tiles are all different sizes.
an old thread posted shortly after the Columbia disaster.
http://www.freerepublic.com/focus/f-news/834596/posts
The Space Shuttle Orbiter and Ceramic Tiles - Some History and Information ^
Posted by NormsRevenge
On News/Activism ^ 02/02/2003 4:43:56 PM PST · 13 replies · 9,079+ views
LMCO / NASA KSC | 2/2/03
Space Shuttle Tiles - A little history and some general information with links Press Release from Lockheed , May 1, 1992 SPACE SHUTTLE TILES WERE JUST THE BEGINNING FOR LOCKHEED’S AEROSPACE CERAMIC SYSTEMSSUNNYVALE, California, May 1, 1992 — When the Space Shuttle Endeavour rockets into space on its maiden voyage, it will be protected by ceramic tiles manufactured by Lockheed Missiles & Space Company, Inc. of Sunnyvale, California. NASA’s entire orbiter fleet — Columbia, Challenger, Discovery, Atlantis, and now Endeavour — is protected from the searing heat of reentry by Lockheed’s Reusable Surface Insulation. Endeavour will be protected with over...
I don’t understand that graphic. Excuse me for asking, but why isn’t there symetry between the starboard and port sides?
for any insomniacs out there, a thread from the Columbia event. lots of info, pics, science, analysis,, lots..
Observation on TPS damage on Orbiter ^
http://www.freerepublic.com/focus/f-news/835531/posts
Posted by bonesmccoy
On News/Activism ^ 02/04/2003 1:34:19 AM PST · 4,547 replies · 11,979+ views
NASA photos | 2-3-03 | BoneMccoy
In recent days the popular media has been focusing their attention on an impact event during the launch of STS-107. The impact of External Tank insulation and/or ice with the Orbiter during ascent was initially judged by NASA to be unlikely to cause loss of the vehicle. Obviously, loss of the integrity of the orbiter Thermal Protection System occured in some manner. When Freepers posted the reports of these impacts on the site, I initially discounted the hypothesis. Orbiters had sustained multiple impacts in the past. However, the size of the plume in the last photo gives me pause. I’d...
IMHO, it is because the shuttle veers to port upon reentry.
It’s orbit is counterclockwise, then, I would assume, and so most of the heat is taken on the left flanks.
(If anyone has a better explanation, feel free, I am not a rocket scientist)
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.