Debris flies off Discovery just after takeoff

[rotornut]

Video showed what appeared to be a large piece of debris flying off the external fuel tank two minutes into the flight. The object did not seem to hit the orbiter. Footage also showed what might have been at least two light-colored objects flying off Discovery as the shuttle cleared the launch pad.


http://news.yahoo.com/s/ap/20050726/ap_on_sc/space_shuttle_44

[Jordan D]

Without wanting to go down the road too much on what may or may not have been .... if you watch Matt Frei's report for the BBC (available on their BBC News player), he comments the same - except this time the debris is shown to fall off when the solid rocket boosters split away from the craft.

Here's hoping they have a safe return.

Jordan

[brockenspectre]

Mission Control is reporting that there were two ascent debris events (identified by radar and visual cameras) which will be considered and reported on by the imagery team in time for the Discovery crew wake-up tomorrow. At present tomorrows timeline is not affected.

source: NASA TV

[Big Tudor]

and he gave assurances the multitude of images will be examined frame by frame in the coming hours and days.
And I would like to bet that very few videos images will have been studied as closely or by as many people as these. I'm sure we all pray to God that this mission is completed and that the crew on board all return safely.

[Farrell]

"If the sensors had acted up before liftoff, the space agency had been prepared to bend its safety rules to get the shuttle flying.
"

Above quote from Yahoo....


After all that has happened in the past.....is that really what NASA stated??? :uhoh:

[flystarboy]

Being just a humble internal high altitude pressurised metal tubing worker.... could it have been ice?

[Ozgrade3]

Did anyone see the tv coverage of the launch, was quite spectacular. In particular the footage from the camera mounted on the external tank was incredible, super clear viauals of the underside of the shuttle right up to its separation from the Orbiter.

A couple of questions. Does anyone know;

The max IAS that the shuttle achieves during the launch and at what height

Where does the debris of the main tank fall, and is there any part of it thats not burned up and lands in the ocean, if so how much.

Just curious from watching the forward bracket that holds the nose of the Orbiter to the external tank. It must be some seriously engineered metalwork to survive several thousand Knots IAS at right angles to the relative airflow. Surely the struts must survive the re-entry of the tank and end up in the ocean. Can they accurately predict the impact point so that no ships, planes are in the flight puth of such debris.

Interestingly I was looking to see some shock waves comming off the struts during the launch but couldnt see any.

Great to see the shutlte back in operation. Hope the crew comes back safely.

[muddergoose]

The debris shooting off at the launch pad was strange to say the least. It was moving at speed in an upwards direction.

It was probably a UFO and they are showing the other footage of real debris to mask it. I recall many years ago media commentators saying it was not unusual to loose a tile or 2.

:8

[N380UA]

I don't want to downplay the effects of debris coming of the shuttle during a liftoff. But it almost always happens. So it isn’t something unusual though of course since the last flight the PhD's on the ground are a bit more cued on the issue. I'm sure all is fine and the mission will be a success.

[OzExpat]

several thousand Knots IAS at right angles to the relative airflow.
Ummm... I always thought that relative airflow was... errrrm... relative... :}

[HEATHROW DIRECTOR]

The other interesting thing which Matt Frei mentioned was that statistically if civil aviation had the same degree of safety "enjoyed" by the shuttle, there would be 560 civil airliner crashes each DAY!!

[TheOddOne]

When more than 97% of orbital speed is attained, the External Tank is detached from the Shuttle Orbiter and directed to cross Earth's atmosphere to burn up (Skylab-like) with remnants falling into a remote section of the Indian Ocean.

The above is from this link (http://www.permanent.com/ext-tank.htm)

The boosters are recovered by 2 ships that position themselves in the Atlantic and the Shuttle only launches after they declare the drop zone free of traffic. I guess the small pieces of the external tank that fall into the Indian Ocean are so widely scattered that it's impossible to give an absolute assurance that the area will be free of vessels; on the other hand the chances of anyone being struck are less than 1x 10-12, even less than winning the lottery!

I believe that when the Shuttle was first introduced, the odds of an accident were given at 1-100, which I think is more or less what has happened. The cost of significantly reducing this risk would rise exponentially and you've got to ask if the money might be better spent on developing alternative methods of getting into orbit. Sending sections of construction materials to low orbit in a man-rated vehicle is in my view a waste of resources. Soyuz remains an effective and far cheaper way of getting people to and from orbit and seems with the maturity of that programme to be getting safer.

We mustn't forget that this is American's tax money being spent; we're just interested bystanders, so thanks to them for continuing to fund this benefit to all mankind.

I'd be interested in the answer to the 'max IAS' question; it's probably not that high. One of the reasons the Shuttle goes for the complication of liquid fuelled engines is so that they can be throttled; as they pass through the area of max dynamic pressure, the engines are throttled back until that region is passed through. I noticed a characteristic shock wave coming off the Orbiter as it went through the sound barrier; this is about the same time as throttle back. The Solid Rocket Boosters are of course still giving it max as they can't be shut down until they've exhausted their fuel.

Cheers,
The Odd One

[Courtman]

The two items that were seen coming off the Orbiter on launch were called "Tyvek Covers" and came off as planned. Image of the covers separating here (http://spaceflight.nasa.gov/shuttle/briefings/0726/pm/003_STS-114_EHV224_mU207143908558.jpg). I can't remember exactly what they were covering, some sort of vent I think, but that is what was seen.

There was a birdstrike on the External Tank on take-off too, from the briefing the bird hit the nosecone and then went down the side of the ET away from the Orbiter. Picture here (http://spaceflight.nasa.gov/shuttle/briefings/0726/pm/004_STS-114_EHV052_mU207143903194.jpg). The stack had not fully cleared the launch pad so the speed was relatively low.

A small piece of tile may have separated just behind the nosegear doors. Picture here (http://spaceflight.nasa.gov/shuttle/briefings/0726/pm/001_STS114_TIR011_event4.jpg).

Finally, when the Solid Rocket Boosters separated a piece of debris was seen to float away and miss the Orbiter. Picture here (http://spaceflight.nasa.gov/shuttle/briefings/0726/pm/002_STS114_TIR011_event5.jpg).

At the press conference broadcast yesterday afternoon the NASA guys were saying that this is all new stuff, they have never before had such detailed pictures of the launch and they will be sifting through it all methodically. Numerous press questions about repair, rescue missions, were all rebuffed and responded to with a "we'll be looking at this for 6 days, no point in panicking yet" attitude, it all came across well.

These debris events (and more I'm sure) have probably been occuring for all Shuttle missions, its just now they have technology in place to identify and hopefully reduce the amount of debris further still.

Good luck to all at NASA and the Crew, here's to a safe return :ok:

[TheOddOne]

Tyvek is a breathable material made by DuPont and is used for a wide variety of protective jobs.

In the case of the Shuttle, 2 covers are used to prevent rain water getting into a couple of attitude thruster exhausts that are vulnerable while the Orbiter is on the pad. They are fitted with small parachutes to enable them to detatch as the vehicle accelerates.

The Odd One

[ou Trek dronkie]

Thank you for a thorough and painstaking description. Very interesting indeed. I'm sure we feel much better for that.

oTd

[SilsoeSid]

The question,
(what is) The max IAS that the shuttle achieves during the launch and at what heightOn launch, speed indications are INS driven.

Max q is reached at 1 minute after launch at about 35,000 ft.(typically Mach 1.5)

After this point, air density rapidly decreases, the shuttle throttles up and dynamic pressure reduces to zero after about 2 minutes. (3,000 mph / 28 miles high)

The shuttle then continues to accelerate to 17,500mph which is orbital speed.

Don't forget that on launch the shuttle is a rocket so airspeed isn't considered, except that obviously max q is accounted for!

On landing however, as the shuttles speed drops to less than Mach 3, two air data probes are deployed from either side of the nose of the spacecraft. These probes provide supplemental information on the airspeed and altitude gained from the outside barometric pressure and wind speed.

Clear as mud.

:ok:
SS

[False Capture]

HD,
Matt Frei's quote about airline safety (560 crashes a day) was unqualified and meaningless.

Was this figure world-wide, UK only or US only?

The Space Shuttle isn't a form of public transport - so why compare it to airline safety? Why not compare the Shuttle's safety record to that of road transport - he could then be even more dramatic by saying there'd be 2million car crashes in the UK every day?

What a pointless statistic!:yuk:

[Max Angle]

The Solid Rocket Boosters are of course still giving it max as they can't be shut down until they've exhausted their fuel. Not quite true in fact, the mixture of the solid fuel at the 55-70 second point is different from the rest to give less thrust during that period. All very clever.

[Eric Mc]

The Shuttle fleet is to be grounded until the reasons for these foam pieces falling off the tank are ascertained.

Maybe they should revert to painting the tank, like they used to.

[rotornut]

"The US space agency Nasa has said it is grounding the space shuttle fleet while engineers investigate debris which fell from Discovery during its launch...
Shuttle programme manager Bill Parsons said the debris did not hit the orbiter and posed no threat to the crew...
But he said shuttles would not be able to fly again until the hazard was dealt with."

Um... you are grounding the shuttle fleet but the Discovery is OK?

http://news.bbc.co.uk/2/hi/science/nature/4723109.stm

[Jordan D]

Grounding as in "not letting them take off".... the interesting question is how do you get the crew down if they can't use Discovery or rescue craft Atlantis?

Soyuz better be prepared to do some shuttle service (pardon the pun).

Jordan

[Eric Mc]

Soyuz is the only option. The only other manned spacecraft in existence is the Chinese one - which is Soyuz inspired but not available at this early stage in its development.

[four_two]

I've just been watching the video of the Discovery doing a "backflip" to present its bottom surface to the ISS for filming any possible damage.
Thinking back to the grainy pictures of the moon landings and seeing the present images is breathtaking (obviously you have to be interested of course.)
The video was on the Beeb site.
http://news.bbc.co.uk/1/hi/sci/tech/default.stm
(click on the link for live video)

[Big Tudor]

Just wondering after watching Discovery dock with the ISS. If NASA decide that it is too risky to allow the crew to bring it back, is it possible for the orbiter to to be recovered to Earth without a crew on board? One would assume NASA have a back-up plan to get the crew home if it is damaged to the point were safety is compromised.

[rotornut]

And I'll bet some people are losing a lot of sleep at NASA. I can't imagine bringing the ship back to earth without a person at the controls - after all, it lands like a conventional airplane using it's tiny wings for lift. So if they decide it's not safe to to bring it back they will have to abandon it in space - rather embarrassing after all the hype that went into the launch.

[Globaliser]

four_two: The video was on the Beeb site.
http://news.bbc.co.uk/1/hi/sci/tech/default.stm
(click on the link for live video) Direct link to live video feed here (http://www.bbc.co.uk/newsa/n5ctrl/live/bb/wm/video/now2_bb.asx).

[chuks]

I just bought a (non-flight-rated) Tyvek envelope down at the local post office today. It is some weird stuff that looks like paper but is almost impossible to tear, being made of some sort of plastic fibre.

I suppose they just stick it on some aperture on the Shuttle until it blows off. Even if it hit the vehicle it shouldn't do any harm.

On the other hand, the NASA mindset that has led to two accidents so far does not seem to have changed very significantly. Perhaps if it did then that would mean simply not flying the Shuttle any longer?

Who among us would turn down a chance to go into space, despite the obvious risks?

This whole program was sold on a faulty cost-benefit basis to Ronnie Reagan, much as Star Wars was. There was one seriously simple-minded President, even if he was much loved for being so. It is no particular surprise to the technical-minded that the Space Shuttle has failed to deliver on its over-sold promises. It is just a shame that so many lives have been lost due to foreseeable technical problems. Especially troubling is the failure to put the whole situation out there for due consideration, when a timely stop might have been put to a flawed decision chain. Good CRM it ain't!

[Rhys S. Negative]

Chuks,

Not sure you are correct in attributing the shuttle's woes to Ronald Reagan - wasn't the first flight in April 1981, some 3 months after he took the presidential oath for the first time?

I'd suggest it must have been 'bought' by the previous administration (or two)...

Rhys.

[OVERTALK]

Much sympathy for NASA and its present predicament with today's re-grounding of the Shuttle. However, NASA has proven deaf to anything NIH (not invented here) and there has been a practical solution available all along. It's called "the Sacrificial Glove". You can read about it at this link below and in its included links.

The page is hurriedly mounted as a reference (for someone else) however it should be clear enough as a concept for protection of the very brittle RCC tiles on the wing's leading edge. They are the Shuttle's real Achilles heel.

I've been going back over the history of the Sacrificial Glove suggestion just to refresh my own mind and extracted (copy/pasted from Pprune Forum) what's at the link below. It's incomplete and only a quick compilation. I remain surprised at their absolute failure not to consider protection (of the brittle RCC tiles). It all now seems to have backfired on them in the worst way. They also seem remiss in that they are not differentiating between the potential catastrophic effect of icy foam on a surface normal to the line of flight (nose, RCC wing leading edges and fin) and a very tangential glancing blow to a slipstreaming ceramic tile surface elsewhere. It is truly chalk and cheese as far as the potential for reproducing a killer blow like Columbia sustained. You will notice in the link below (red highlight) that I raised the question of the threat of ice (and the role it would play in causing ET foam detachment) way back on 18 Feb 03. NASA seems to lurch from hubris to uncertainty to despair without even the traditional protocol of a countdown.

The Sacrificial Glove is a very sound concept, and Dow Corning has already said that they have a suitable RTV (Room Temperature Vulcanizing Silicone) so my advice to NASA would be to investigate it and..........
"Don't give up the ship"

LINK (the Sacrificial Glove) (http://www.iasa.com.au/folders/Safety_Issues/RiskManagement/sacrificial_glove.htm)

[rotornut]

Nasa officials have said they now believe at least one shard of protective foam may have hit a wing of the Discovery space shuttle.

But they said they were confident the craft would make a safe return.

?

http://news.bbc.co.uk/2/hi/science/nature/4726543.stm

[Eric Mc]

The Shuttle programme was given the official go-ahead in its final form by the Nixon administration in December 1972. In fact, the announcement was made whilst Gene Cernan and Harrison Schmidt were walking on the moon on the last Apollo mission, Apollo 17.

Reagan is associated with the Shuttle because it made it's first flight in April 1981. shortly after he became president.

[rotornut]

Russia ready for shuttle rescue mission if needed
Thu Jul 28, 1:21 PM ET

Russia could send up to three Soyuz rockets to the International Space Station (ISS) between now and February if an evacuation of the ISS crew become necessary due to problems with the US space shuttle Discovery, officials said.

"We are ready to send three pilotable Soyuz capsules to the International Space Station by February 2006 should rescue of the Discovery crew be necessary," Nikolai Sevastyanov, head of the Energiya rocket construction firm that builds the Soyuz, was quoted by Russian news agencies as saying.

"We are hopeful and believe in the shuttle mission. But if our American partners need help, we can be of service," he said.

Alexei Krasnov, head of the training program with the Russian space agency Roskosmos, said separately however that if such an undertaking were necessary the United States would have to bear the costs of the mission, ITAR-TASS said.

The comments from the officials came as experts with the US National Aeronautics and Space Administration (NASA) were to examine photographs taken of the underside of the space shuttle to look for signs of damage that could compromise its planned return to Earth on August 7.

On-board cameras showed some debris had fallen off the shuttle after liftoff for Earth orbit on Tuesday. A similar incident occurred at the launch of the shuttle Columbia in January 2003, causing that spacecraft to break apart on reentering the Earth's atmosphere.

http://news.yahoo.com/s/afp/20050728/sc_afp/usspaceshuttlerussia_050728172147

[chuks]

I stand corrected. 'Give a dog a bad name...' I guess I conflated the Shuttle and Star Wars. Things got pretty weird there in terms of what science was going to deliver, just because it was 'morning in America.'

The thing is, the Shuttle has never delivered on its promise of cheap, reliable access to Outer Space in the way it was sold to the taxpayers yet it seems to have had a charmed existence in the minds of the public. Curious, that.

[muddergoose]

Does any one find it strange that an astronaut can pick a piece of material from between two shuttle tiles, with relative ease, yet that material not get blown out at low to medium mach speeds while still in the earths atmosphere? I would have thought the static pressure buildup behind the material would have popped its cork... so to speak?:D

[BOAC]

I think if I were on board, I would have preferred a dab of glue and stick it back in? Is there not a risk of plasma leaching through the gap? Where is 'Picky Perkins' when you need him?:D Anyone else notice how much glue there 'wasn't' on the strip??:eek: