New Mars Forums

Official discussion forum of The Mars Society and MarsNews.com

You are not logged in.

Announcement

Announcement: This forum is accepting new registrations by emailing newmarsmember * gmail.com become a registered member. Read the Recruiting expertise for NewMars Forum topic in Meta New Mars for other information for this process.

#1 2005-08-10 05:31:11

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Shuttle ST-121 Atlantis

Nasa return to flight home page
This was the last info related toUpcoming Space Shuttle Missions to which STS-121 (115) Atlantis/OV-104 (27) was to fly on Sept. 9 - Sept. 24.

NASA's Shuttle and Rocket Missions launch schedule

While we will be glad when they are safely on the ground.
What does the future hold for further shuttles misions?
When will it fly again with the recent foam incidents still occuring?
The first few missions were slated for logistics of resupply for the station but with the recent failure to keep the foam on the tank. How does it effect what will be?

More on the Foam:
Limbaugh promoted false theory that EPA regulations banning Freon caused space shuttle Columbia disaster.

Well it may not have been far from the truth after all. We have heard of improper foam spraying with regards to temperature of application, of bubble size within the foam and who knows what else.


Well we have talked about what it would take to make the ride safer going up but now after the landing it will be time to talk about the refurbishment costs and why each mission cost so much.

There has been a changing of the guard for the refurb of the shuttle main engines.
For Pratt, It Is Rocket Science

When the space shuttle Discovery returns to Earth, the job of overseeing its main engines will belong to East Hartford-based Pratt & Whitney.

Pratt took over the task late Tuesday when it officially concluded its purchase of Boeing's Rocketdyne Power & Propulsion unit in a deal valued at about $700 million.

I am still waiting to see news on the cost for getting the shuttle ready for its return to KSC from edwards, other tile damage beyound what is known and the final resolution to the ET foam problem.

Offline

#2 2005-08-10 07:25:11

Palomar
Member
From: USA
Registered: 2002-05-30
Posts: 9,734

Re: Shuttle ST-121 Atlantis

"What will it take to fly in September?"

*A miracle?

GCN wrote in the STS-114 thread after I'd asked:

Atlantis is September is out for sure, and it would be hard to build a new tank in time for a late-2005 launch.

Based on what I've read/heard otherwise, I'll be surprised if there is a Shuttle launch next month. 

--Cindy


We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...

--John Sladek (The New Apocrypha)

Offline

#3 2005-08-10 09:30:20

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Shuttle ST-121 Atlantis

[url=http://www.nola.com/news/t-p/frontpage/index.ssf?/base/news-4/112365423868030.xml]Shuttle's back, but mission goes on at Michoud
Three teams assigned to fixing foam problem [/url]

Maybe some of these teams are the linching party for the past failures to correct the problem when they have said that it was.

Workers at Michoud elated

They should be happy that they still have a job...

The external tank holds the liquid hydrogen and liquid oxygen propellants for the shuttle's three main engines. The super-cold propellants inside the tank -- more than 390,000 gallons of liquid hydrogen at a minus 423 and 145,000-plus gallons of liquid oxygen at a minus 297 -- cause ice to form on the outside while the shuttle is prepared to launch. Insulation, applied as a foam, reduces the amount of ice.

Offline

#4 2005-08-10 11:42:21

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Shuttle ST-121 Atlantis

Testing by wind tunnel on the ramp:
Engineers to Tackle Cause of Foam Shedding

In a report presented at a July meeting of the American Institute of Aeronautics and Astronautics in Tucson, a copy of which was obtained by The Washington Post, engineers from NASA's Aeroelasticity Branch concluded on the basis of wind-tunnel and other studies that the PAL ramps appeared unnecessary. But, in part, because one set of conditions could not be fully modeled, the team encouraged NASA to gather data from an actual flight to confirm their findings.

With those results in hand, mission controllers granted permission to install five sensors on Discovery's PAL ramp, to get real-time measures of the stresses there, according to an internal NASA memo written more than a week after Discovery's launch and examined by The Post.

The memo said preliminary data from the sensors supported the team's contention that the ramp could be eliminated without harm but added that more in-flight testing is needed before taking such a step.

The memo noted that the sensors had been installed on the liquid oxygen section of the tank -- the highest part of the tank and, therefore, the section where breakaway debris would have the highest chance of hitting the orbiter's vulnerable underside -- but that additional useful data could be obtained if sensors were also attached to the liquid hydrogen ramp on future shuttle flights.

Offline

#5 2005-08-10 12:03:25

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle ST-121 Atlantis

No, no, no NASA! This is a great example of pre-Columbia thinking:

"but added that more in-flight testing is needed"

You callous idiot! You obtuse baffoon! Don't you have a clue how serious this is?

This same exact kind of foam killed the crew of Columbia, but you are going to let another crew fly with it first to find out of its a problem???

The correct answer is no! You can't have more in-flight testing! Because we need to KNOW this sort of thing before we go and strap half a dozen men to it! You just have to FIND a way to figure out if this is a threat or not some other way, and if you can't then the design should be changed to eliminate even the possibility of that threat.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Offline

#6 2005-08-10 13:40:57

C M Edwards
Member
From: Lake Charles LA USA
Registered: 2002-04-29
Posts: 1,012

Re: Shuttle ST-121 Atlantis

"What will it take to fly in September?"

*A miracle?

lol

No ma'am, they make those tanks over in New Orleans.  A poppet isn't just a kind of valve over there, you know.  There's enough voodoo doctors with live chickens runnin' around that you ain't got to wait for a miracle...    wink


"We go big, or we don't go."  - GCNRevenger

Offline

#7 2005-08-10 14:09:55

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle ST-121 Atlantis

If NASA flies Atlantis in November, they will have to cut safety corners to do it I bet, unless those "Tiger Teams" that Griffin speaks of do some lynching, take over the administration/engineering oversight, and drive them night, day, and weekends to make it on time.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Offline

#8 2005-08-10 19:54:39

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Shuttle ST-121 Atlantis

NASA Updates Media on Space Shuttle External Tank Work


International Space Station Program Manager Bill Gerstenmaier, who is leading the effort, will speak with the media Thursday, Aug. 11, at 2 p.m. EDT via telephone conference call.
Audio of the teleconference also will be streamed live on the Internet at:

http://www.nasa.gov/newsaudio

Offline

#9 2005-08-10 19:57:08

Ad Astra
Member
Registered: 2003-02-02
Posts: 584

Re: Shuttle ST-121 Atlantis

I'm pretty confident that Atlantis will launch in November.  Fixing the PAL ramp isn't hard; NASA just needs to take the hand-applied foam off and replace it with a piece of metal to perform the same function.  Heaters will prevent ice buildup.

The modifications don't require the creation of a new tank.  NASA could modify an existing tank, such as the one they de-mated from Discovery. 

Surprisingly, the STS-121 patch has not been released to the public.  This may prove to be the last step before Atlantis can fly.

After STS-121 and the assembly of the truss, NASA should limit the shuttle to two crew change / resupply flights per year.  The rest of the ISS modules can wait for SDV to come after 2011.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

Offline

#10 2005-08-10 20:23:41

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle ST-121 Atlantis

Just removing the PAL ramps isn't fixing the tank right

There are other pieces of manually applied foam on the tank besides the Bipod and PAL ramps, and every last one of these needs to be attended to. High-res pictures taken by Discovery also conclusively show that even the "good" mechanically applied foam seperates in fist-sized chunks, which while not big enough to completly destroy a glass tile or RCC pannel, might be enough to damage the heat shield such that a dangerous astronaut repair is called for. That is unacceptable in my opinion.

I don't think that NASA could address these issues in only about ten weeks, which is about the time they have to do the tank modifications, run tests on the tank itself, and ship it to the Cape for Atlantis.

No! No no! ABSOLUTELY NO ISS PAYLOADS ARE TO RIDE ON SDV! Period!!!

To do that, you will be breaking the legs of the SDV heavy lifter just to appease the ISS cheerleaders, which won't even be around anymore when the first Moon missions begin... To modify SDV to carry ISS payloads, you would be spending hundreds of millions of dollars on a worthless space tug AND reducing the precious maximum payload by many tonnes. Maximizing payload of a single flight is absolutely critical to doing anything on the Moon besides repeating Apollo without breaking the bank. Plus unless you are keen on building payload cradles, you will be stuck with the tiny and overweight Shuttle payload bay style payload faring and the inferior Shuttle-C side mount arcitecture which is no good for Mars, so all that work put into SDV will be for nothing... Just so we can send up a few more bits and pieces of a worthless space station in the wrong orbit with the wrong shape and that can't even do what it was intended to do.

I'm sorry, but the way things are, you can't both be in favor of the ISS and getting humans to Mars, the two aims are mutually exclusive. Lets do the absolute minimum to comply with down-negotiated international comittments and then pull the plug on future ISS construction.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Offline

#11 2005-08-12 05:09:02

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Shuttle ST-121 Atlantis

This is a continuation of what did happen with the ET for Discovery.

It would appear that 5 location (9 pieces) had significant foam debri of which most notable was the Pal ramp.

Foam fixes likely small, but Atlantis must wait

Discovery's return to flight was considered a kind of test mission after two years of work on the problem, and engineers were surprised to see a nearly one-pound chunk of the foam break from the external tank during liftoff.

The tank wears 4,192 pounds of insulating foam, Gerstenmaier said, and the total that came off is only about 1.2 pounds. By other standards, that performance would be good. But NASA won't be satisfied until the causes of the loss are better known.


While it is slim to not being possible it would appear that a flight in Noverber would be.
[url=http://www.orlandosentinel.com/news/custom/space/orl-asecfoam12081205aug12,0,6192727.story?coll=orl-news-headlines-space]Atlantis gets November date as NASA studies foam

The shuttle's launch has been pushed back to find out why Discovery's tank shed foam[/url]

NASA will not fly shuttle Atlantis until November at the earliest, an agency official said Thursday, because more time is needed to figure out why foam came off Discovery's external tank during its launch last month.

The best article write up giving more details as to size and location by spaceflightnow.com

Offline

#12 2005-08-12 08:21:54

Palomar
Member
From: USA
Registered: 2002-05-30
Posts: 9,734

Re: Shuttle ST-121 Atlantis

*Who knows?  I've seen articles wherein a November launch of Atlantis is still possible (but then just about anything is possible)...I've seen indications that all Shuttle missions are on hold for the remainder of the year.

Guess we'll know how it all turned out on 1/1/2006.  tongue

Scuttle the Shuttle, let's get on to bigger and better things. 

--Cindy


We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...

--John Sladek (The New Apocrypha)

Offline

#13 2005-08-12 08:34:10

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle ST-121 Atlantis

If the Space Shuttle were retired today and the ISS program canceld when a fit of self-honesty about the essential worthlessness of the monstrosity were to strike, we could be talking about handing off the first Moon base to commertial mining companies by 2018 and Mars by 2025 instead...

...but sadly, barring a calamity at the ISS, this isn't happening. The best we can hope for is that Griffin finds a way to radically reduce ISS propping-up costs after it is "completed" in 2010. NASA just can't afford to spend 40% of its manned flight budget on keeping the ISS flying and carry out a really efficent exploration program.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Offline

#14 2005-08-12 11:26:00

John Creighton
Member
From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: Shuttle ST-121 Atlantis

I wonder if had NASA fixed the foam problem long ago if the maintenance on the shuttle would have been reduced enough to make a significant difference in the operating cost and turnaround time of the shuttle.


Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]

Offline

#15 2005-08-12 11:52:26

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle ST-121 Atlantis

The problems with the space shuttle started long, long before construction ever began, that the compromises in the design to make the USAF happy, the GAO/WH happy, and NASA brass happy were such that a real space shuttle became impossible.

The USAF demanded heavy payload capacity and the ability to glide long distances, which mandated a large, heavy, steamlined vehicle with huge wings... Consequence: only the fragile RCC tiles could protect the wings, and the wings themselves made Shuttle too heavy.

The GAO & White House (Nixon) demanded that Shuttle be built on the cheap for about a third of the cost of a real spaceplane... Consequence: This and the USAF requirements forced NASA to adopt the old NOVA program arcitecture of huge solid rockets and gigantic liquid hydrogen tank, which would have to be disguarded to achieve long-range gliding streamlining.

The hydrogen fueled engines were still supposed to be reused, so the only place to put them was in the back of the spaceplane on the side of the tank. THIS is the design compromise that killed Challenger and Columbia more then the others:
-Riding on the side, there would be no escape from Shuttle if there were a problem (Challenger)
-Shuttle riding on the side made it vunerable to debires falling from the fuel tank (Columbia)
-Reduces total payload by several tonnes (ISS & USAF)

And let us not forget the NASA Brass, who saw the handwriting on the wall when Apollo was canceld with such little outcry... that if the agency were to persist in its scope, it would have to come up with a project that would be open-ended, severely manpower intensive, and un-cancelable. Thus the problem of Shuttle's maintenance requirements was not seen as something to be fixed, but rather magnified as much as possible.

The Shuttle program, in its publicly stated goal as an easy/cheap/safe vehicle has been a spectacular failure before it ever left the drawing board.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Offline

#16 2005-08-12 12:48:20

John Creighton
Member
From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: Shuttle ST-121 Atlantis

The problems with the space shuttle started long, long before construction ever began, that the compromises in the design to make the USAF happy, the GAO/WH happy, and NASA brass happy were such that a real space shuttle became impossible.

The USAF demanded heavy payload capacity and the ability to glide long distances, which mandated a large, heavy, steamlined vehicle with huge wings... Consequence: only the fragile RCC tiles could protect the wings, and the wings themselves made Shuttle too heavy.

The GAO & White House (Nixon) demanded that Shuttle be built on the cheap for about a third of the cost of a real spaceplane... Consequence: This and the USAF requirements forced NASA to adopt the old NOVA program arcitecture of huge solid rockets and gigantic liquid hydrogen tank, which would have to be disguarded to achieve long-range gliding streamlining.

The hydrogen fueled engines were still supposed to be reused, so the only place to put them was in the back of the spaceplane on the side of the tank. THIS is the design compromise that killed Challenger and Columbia more then the others:
-Riding on the side, there would be no escape from Shuttle if there were a problem (Challenger)
-Shuttle riding on the side made it vunerable to debires falling from the fuel tank (Columbia)
-Reduces total payload by several tonnes (ISS & USAF)

And let us not forget the NASA Brass, who saw the handwriting on the wall when Apollo was canceld with such little outcry... that if the agency were to persist in its scope, it would have to come up with a project that would be open-ended, severely manpower intensive, and un-cancelable. Thus the problem of Shuttle's maintenance requirements was not seen as something to be fixed, but rather magnified as much as possible.

The Shuttle program, in its publicly stated goal as an easy/cheap/safe vehicle has been a spectacular failure before it ever left the drawing board.

I know the shuttle cost a lot of money but if anything could have been done to have made it operate cheaper and more safely in the past I can only imagine the benefits be they a more effective ISS or more planetary probes or even an earlier start on a mars mission.

The big external tank strikes me as the biggest failure of the shuttle.  I also wonder if kerosene boosters would be better for reusability because I know there is a lot of  maintenance required to retrofit the boosters. If the shuttle could have mad it to orbit only lifted by fly back kerosene boosters that we simply had to refuel and it was able to keep the damage small enough each flight that it didn't take so long and so much man power to repair it for the next flight I can only image what that might have done to reduce the price of space exploration.


Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]

Offline

#17 2005-08-12 13:03:49

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 29,428

Re: Shuttle ST-121 Atlantis

arggg.... more wings... how about some more wheels for landing too of course over a very large cross range as the USAF wanted.

Lets keep things simple or at least as much as possible.

Offline

#18 2005-08-12 13:18:51

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle ST-121 Atlantis

No change or modification to the Shuttle design could possibly ever make it a viable vehicle, that the whole design would have to be scrapped.

The entire idea of a Shuttle that isn't 100% reuseable is by its very nature a terrible one, that the whole point is to not throw away your rocket.

What we SHOULD have done was invest about $25Bn back in the 1970's to do Shuttle right, and make a two-stage system where a carrier vehicle powerd by jet engines (with augmented ramjet mode like Blackbird?) and/or rocket engines would carry up a decent sized spaceplane (12 crew + luggage or 20,000kg in EELV sized bay) to high speed/altitude, which would then go the rest of the way to orbit with high-Isp rockets. The spaceplane could get away with small or no wings since it wouldn't have needed to glide long distances to make the USAF happy.

http://www.astronautix.com/lvfam/shuosals.htm

Something like the Lockheed Shuttle LSA, an uprated MDC, or a giant version of Max Fagets' NAR. No glass/graphite tiles required for MDC or NAR


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Offline

#19 2005-08-12 13:49:16

John Creighton
Member
From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: Shuttle ST-121 Atlantis

arggg.... more wings... how about some more wheels for landing too of course over a very large cross range as the USAF wanted.

Lets keep things simple or at least as much as possible.

As for wings cruise missiles are able to fly accurately without much of a wing why couldn’t the fly back boosters do the same. Landing might be tricky, perhaps a snatch and grab or a parashoot or a really high speed approach and a really long runway.


Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]

Offline

#20 2005-08-12 13:51:49

John Creighton
Member
From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: Shuttle ST-121 Atlantis

No change or modification to the Shuttle design could possibly ever make it a viable vehicle, that the whole design would have to be scrapped.

The entire idea of a Shuttle that isn't 100% reuseable is by its very nature a terrible one, that the whole point is to not throw away your rocket.

What we SHOULD have done was invest about $25Bn back in the 1970's to do Shuttle right, and make a two-stage system where a carrier vehicle powerd by jet engines (with augmented ramjet mode like Blackbird?) and/or rocket engines would carry up a decent sized spaceplane (12 crew + luggage or 20,000kg in EELV sized bay) to high speed/altitude, which would then go the rest of the way to orbit with high-Isp rockets. The spaceplane could get away with small or no wings since it wouldn't have needed to glide long distances to make the USAF happy.

http://www.astronautix.com/lvfam/shuosals.htm

Something like the Lockheed Shuttle LSA, an uprated MDC, or a giant version of Max Fagets' NAR. No glass/graphite tiles required for MDC or NAR

I don’t get why when the shuttle was being conceived the NASA engineers just didn’t tell the politicians that it is impossible for a useful vehicle to meet all these requirements and any effects to try would be a vast waste of money.


Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]

Offline

#21 2005-08-12 14:33:17

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle ST-121 Atlantis

No change or modification to the Shuttle design could possibly ever make it a viable vehicle, that the whole design would have to be scrapped.

The entire idea of a Shuttle that isn't 100% reuseable is by its very nature a terrible one, that the whole point is to not throw away your rocket.

What we SHOULD have done was invest about $25Bn back in the 1970's to do Shuttle right, and make a two-stage system where a carrier vehicle powerd by jet engines (with augmented ramjet mode like Blackbird?) and/or rocket engines would carry up a decent sized spaceplane (12 crew + luggage or 20,000kg in EELV sized bay) to high speed/altitude, which would then go the rest of the way to orbit with high-Isp rockets. The spaceplane could get away with small or no wings since it wouldn't have needed to glide long distances to make the USAF happy.

http://www.astronautix.com/lvfam/shuosals.htm

Something like the Lockheed Shuttle LSA, an uprated MDC, or a giant version of Max Fagets' NAR. No glass/graphite tiles required for MDC or NAR

I don’t get why when the shuttle was being conceived the NASA engineers just didn’t tell the politicians that it is impossible for a useful vehicle to meet all these requirements and any effects to try would be a vast waste of money.

Well thats an easy one...:

NASA Brass never cared if Shuttle lived up to its expectations, all that matterd to NASA at the time was to keep as many engineers employed as possible for as long as possible. Without a manned spaceflight program, NASA as we understand it would have been doomed to a congressional budget axe.

The true purpose of Shuttle, as far as NASA was concerned, was never to be a cheap/easy/safe RLV, it was to justify the continued exsistance of the agency in a similar scope as the Apollo days. In fact, a "good" Shuttle would have required little in the way of engineering upkeep, and therefore may even have been an undesireable thing. Either NASA wasn't concerned with the false, fradulent "goal" of Shuttle, or even worse wanted it to be a debacle.

Being a vast waste of money was a good thing... after Apollo, and dreams of Mars exploration or Lunar bases and such all gone, NASA took on the philosophy that a program with a concrete destination goal was inherintly unsustainable, and that an open-ended program of large (but not too large) scope with no finished goal was nessesarry. Flying Shuttle to launch commertial satelites, tend space stations or telescopes, and fly covert missions for the USAF was perfect, at least on paper.

Back in the 90's with the 90-day report that came up with the $300Bn Mars plan in response to Bush-I's Space Exploration Initiative is emblematic: that NASA brass intentionally came up with a plan that they knew would be rejected, because they desperatly wanted to protect the Shutte/Station status-quo.

NASA has always suceeded brilliantly when it puts its mind to do something... the problem is, that something has not always been a good thing.
-----------------------------------------------------------

The reason a cruise missile gets away with tiny wings is its very high speed and continuous modest thrust. A flyback booster can't do this since high speed aproaches are too difficult and rough on the airplane. Parachute landing in the ocean or land is too hard on the vehicle too.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Offline

#22 2005-08-13 12:58:36

Ad Astra
Member
Registered: 2003-02-02
Posts: 584

Re: Shuttle ST-121 Atlantis

First, I have to eat some humble pie... NASA's released the STS-121 patch.

Part of the space shuttle's problem is that it moved directly from technology development to operational use, with no technology demonstration phase in between.  Perhaps if somebody built a smaller shuttle prototype (like the X-20 Dynasoar,) the engineers would have figured out what kinds of flight rates were realistic, how to protect the vehicle on re-entry, how manpower-intensive it would be to prepare the vehicle for flight, and how expensive it would be.

Going back to what GCNRevenger said about Challenger, I think that parallel staging proved to be just as deadly as mounting the orbiter in a way that made escape impossible.  If the shuttle was serially-staged (with a single huge SRB below the tank, or some similar configuration,) an o-ring burnthrough would have been survivable.  Instead, the gas escaping the o-ring burned through the attach strut, the SRB impacted the nearby ET, and the vehicle exploded.

It appears that NASA has finally come to reject parallel staging for manned vehicles, passing over the heavy EELV's in favor of the stick.  Jeffrey Bell pointed out two years ago that the failure of a single engine in the Delta IV Heavy would spell the end of an OSP mission (unless some cross-feed system was introduced.)

My resistance to "The Stick" is shrinking because it can't suffer the same parallel staging failure as Challenger did.  If an o-ring failed, the stick's SRB might burn out prematurely (forcing a mission abort,) but not a catastrophic failure.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

Offline

#23 2005-08-13 16:53:14

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: Shuttle ST-121 Atlantis

No, no amount of intermediate technology demonstration makes up for an inherintly terrible design. Period. The design was unfixable... of the USAF glide and lift requirements, the (publicly stated) NASA desire for cheap/easy/safe reuseability, and the GAO/WH desire to develop it for a fraction of the money it needed... Pick one, and only one.

The demands the USAF placed on Shuttle could only be met by a winged, streamlined vehicle which traded ease of reuseability for enhanced payload. The only possible arrangement was to use the fimsy RCC pannels on the wings/nose to handle the heat and the silica tiles.

NASA really didn't have a choice in the matter, they were under executive order to make a vehicle the USAF liked, and so these were the only technologies that could make it happen. No amount of testing or prototyping would have changed this, and it is still largely true today. Its worth noting that it failed anyway to meet the payload requirement.

Parallel staging is actually a pretty inefficent way to get into space, since you need more and larger engines. Shuttle only needs three, not counting the boosters, which is really quite exceptional for a near-Saturn class rocket. With high-pressure liquid hydrogen engines, you still get reasonable performance off the pad, and exceptional performance during the latter part of acent.

If Shuttle had a serial rather then parallel arrangement really isn't that important, because as long as the orbiter is on the side of the rocket, the prospects for reliable escape are poor, which would have saved the crew from a Challenger-like accident or a problem with a serial booster.

The SRB launcher for crew is the best option at the moment (provided that Griffin can keep the per-unit cost down). The fuel relies on high internal exhaust gas pressure to operate, and if there is a serious and persistant burnthrough, the combustion rate will drop and the engine will naturally throttle back. Thats when you pop the capsule's escape rockets.

And, since it is made basically from rubber, the fuel grain can't crack to yeild a catastrophic explosion.


[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]

[i]The glass is at 50% of capacity[/i]

Offline

#24 2005-08-14 00:07:24

Ad Astra
Member
Registered: 2003-02-02
Posts: 584

Re: Shuttle ST-121 Atlantis

No, no amount of intermediate technology demonstration makes up for an inherintly terrible design. Period. The design was unfixable... of the USAF glide and lift requirements, the (publicly stated) NASA desire for cheap/easy/safe reuseability, and the GAO/WH desire to develop it for a fraction of the money it needed... Pick one, and only one.

I totally agree that the shuttle config could never have been successful.  In an alternate timeline, I can forsee an x-plane (like the X-20) giving the engineers evidence that all spaceplanes will be more challenging than originally thought.  If a simple design like the X-20 gave the engineers a hard time, there would be no way that they'd agree to the monstrosity that became the shuttle.  If they knew what was good for them, they'd tell their bosses that they cannot design a reliable vehicle that met the USAF mission requirements.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

Offline

#25 2005-08-14 14:45:12

Ad Astra
Member
Registered: 2003-02-02
Posts: 584

Re: Shuttle ST-121 Atlantis

Nasawatch.com is now predicting a March 2006 flight for Atlantis.

According to NASA sources, serious consideration is now being given to a March 2006 launch date for STS-121. The results of the Tiger Team working the foam issue will help guide that decision in the coming weeks. Stay tuned.


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

Offline

Board footer

Powered by FluxBB