Shuttle Discovery Completes Final Flight

[Skylon]

http://spaceflightnow.com/shuttle/sts13 ... ndex2.html

KENNEDY SPACE CENTER, FL--Enduring the heat of re-entry one last time, the shuttle Discovery dropped out of orbit and returned to Earth Wednesday to wrap up a near-flawless 39th and final mission, a milestone marking the beginning of the end for NASA's winged rocketships.

...

Lindsey had no problems with a stiff 25-knot headwind and a few moments later, NASA's oldest surviving space shuttle rolled to a halt, wrapping up a career spanning some 5,750 orbits, 148 million miles and 365 days in space during 39 missions since its maiden launch in August 1984.

"And Houston, Discovery, for the final time, wheels stopped," Lindsey radioed flight controllers in Houston.

...

With only two more missions left on NASA's shuttle manifest -- a flight by Endeavour in April and a final voyage by Atlantis in late June -- Discovery's landing marked the beginning of the end for the world's most complex -- and expensive to operate -- manned rocket.

...

Over the next 26 and a half years and 39 flights, Discovery carried out four military missions, two Spacelab science flights, two visits to the Russian Mir space station, one Mir docking and 13 missions to the International Space Station. At least 24 civilian and military satellites were carried into space, including the Hubble Space Telescope.

Discovery also flew the return-to-flight missions following the 1986 destruction of the shuttle Challenger and the 2003 loss of Columbia. In addition, two stranded communications satellites were plucked out of orbit by spacewalking astronauts and brought back to Earth for repairs in November 1984 in what many veterans consider the most daring shuttle mission ever attempted.

I'm not debating if it was right or wrong to build the Shuttles (at the very least I firmly believe its time to retire these birds). But, Discovery has racked up quite the achievements in its lifetime. And its record of 39 spaceflights will likely stand for missions by a single manned spacecraft, well into this century.

[PeZook]

It certainly earned its place in a museum. Hard-working beast she was.

[Davey]

Wow. Thirty nine flights into space, and thirty nine re-entries. I think that's incredible - I would've thought that the metal fatigue from all the stress of entering and returning to the atmosphere and the old computers would've grounded the shuttle a long time ago. Guess they don't make things like they used to!

They really ought to preserve it, it would be fascinating to see it in a museum someday with all the technology that brought them into space and operated for all those years.

[PeZook]

The orbiter will be preserved, we just don't know in which museum.

As for its old onboard computers, well...it's a "common sense" thing that you can't do anything with old computers anymore, but applying what we know about PCs to avionics computers is...ill-advised.

The systems aboard the Space Shuttle are very specialized avionics computers, still used in the B-52 and F-15, amongst others. Resillient, hardened and flight certified, the Shuttle has five of them aboard. They run well-optimized software designed specifically for the Shuttle's mission.

In short, the onboard computers are the last thing that could've grounded the shuttles

More information about shuttle General Purpose Computers

[Sarevok]

While they certainly would not be showstoppers supporting the old computers would be a major expenditure headache. The IBM AP-101 computers onboard the shuttles are based on late 70s electronics. Finding replacements once stock runs out would be a tricky proposition. The software too would be expensive to maintain. The computers are programmed in an archaic and little known language called HAL/S. Training a new generation of programmers to use a dead end language at the level of competence manned spaceflight requires would not be cheap either.

[PeZook]

Then they'd just upgrade the avionics once the costs of maintaing the computers would become too high. The orbiter underwent an overhaul every time they landed, anyway.

[Sarevok]

Yeah. They did just that in 90s when the computers received modern improvements like semiconductor memories.

[someone_else]

About time. Shuttles were getting too old to be safe.
Time for them to sit side to side with a Saturn V in a museum.

[KrauserKrauser]

Yeah, totally too old and thank goodness they will be replaced with.......

Oh wait.

Hope every object we have in orbit doesn't need a repair in the next 10+ years.

[Shroom Man 777]

Don't worry, comrades. The Soyuz capsules can take care of that, I hope.

[PeZook]

Not of repairs ; They'll just have to discard satellites with even minor damage.

Which makes quite a bit of sense when we're talking about 100 mil communications sats, not much when a 2 billion space telescope is slightly out of focus

[Skylon]

The orbiter will be preserved, we just don't know in which museum.

Discovery has been promised to the Smithsonian. The disposition of Atlantis and Endeavour is unclear, and is creating a minor nightmare for NASA as everyone under the sun with a decent aviation museum wants one (Kennedy Space Center and the USAF Museum in Dayton Ohio seem to be the front runners though).

Plus the Smithsonian will give up Enterprise to make room for Discovery. So, Enterprise will need a new home.

[Skylon]

Wow. Thirty nine flights into space, and thirty nine re-entries. I think that's incredible - I would've thought that the metal fatigue from all the stress of entering and returning to the atmosphere and the old computers would've grounded the shuttle a long time ago. Guess they don't make things like they used to!

The airframe's of all the orbiters are in good shape. The only case of airframe fatigue I heard on the shuttle was on Columbia, which had a chronic corrosion problem on its wing leading edge spar. And that was attributed not to the stress of space flight, but spending a long time on the launch pad before its first space flight, when the weather protection system was incomplete. In other words, the salt water air of Cape Canaveral caused more problems than the blazing re-entry.

With Shuttle, it comes down to an inherently flawed system that is way too expensive to operate. Age is more of a factor when it comes to spare parts. Their were vendors that remained in business only because of the Shuttle.

[Qwerty 42]

It had been a dream of mine for years to go down to Cape Canaveral and watch the Shuttle launch, and I'm thrilled to say that I finally got to make it happen for this mission. It was absolutely incredible. This is going to sound childish, but when I was a kid I had a die-cast model of Discovery in my room, so I was especially glad that this was a Discovery mission. It was worth it, even sitting in traffic in Titusville for four hours immediately afterward.

I recognize all of the flaws of the program, but the Shuttle's been synonymous with spaceflight to me for my entire life, and I'm sad to see it go.

my view of the launch

[someone_else]

Hope every object we have in orbit doesn't need a repair in the next 10+ years.

The vast majority of commercial stuff was out of reach of the Shuttle anyway.

But your point still stands.

[Skylon]

Hope every object we have in orbit doesn't need a repair in the next 10+ years.

The vast majority of commercial stuff was out of reach of the Shuttle anyway.

But your point still stands.

Nor has it serviced any satellite except the Hubble Space Telescope since the early 90's. NASA was essentially banned from marketing the Shuttle commercially after the loss of Challenger.

[Skylon]

Discovery on her first landing - 1984: http://www.spacefacts.de/graph/sts/landing2/sts-41d.jpg

Discovery on her 39th and final landing - 2011: http://www.spacefacts.de/graph/sts/landing2/sts-133.jpg

She shows her age.

[Iroscato]

So uh...when is Ares going to be ready? And was Discovery's last flight the last ever shuttle flight?

[PeZook]

There's two more Shuttle flights schedules, STS-134 and STS-135.

And Ares seems to be dead, or at least far delayed. While the latest budget by Obama did in fact restore some Constellation funding, the original Ares program was wrecked beyond repair.

So, a lot of reinventing the wheel will happen as NASA got instruction to study a "new future heavy launcher", which will probably be a resurrected Ares or some derivative in practice. But good luck to see it fly this decade.

[Iroscato]

Discovery on her first landing - 1984: http://www.spacefacts.de/graph/sts/landing2/sts-41d.jpg

Discovery on her 39th and final landing - 2011: http://www.spacefacts.de/graph/sts/landing2/sts-133.jpg

She shows her age.

Interesting to get them both on one page to make a side by side comparison.

[PeZook]

Frankly, much of the difference is probably due to photo quality. I doubt the really important wear and tear would be visible from the outside.

[Bedlam]

How much of a 'grandfathers axe' is the Discovery by this point?

How much of the ship will be the original parts which first flew and how much will be replacements over the years?

[Skylon]

Frankly, much of the difference is probably due to photo quality. I doubt the really important wear and tear would be visible from the outside.

Oh, its certainly not too important. Any suspect thermal blankets and tiles would have been replaced. I just found the effects of 39 re-entries interesting. As for blaming the photo....you notice a definite wearing of the shuttles as they progressed in flights. Comparing Columbia to Endeavour in 2002 for example was quite different.

One interesting item is that while preparing Discovery for retirement and public display (mainly making sure the vehicle is clean of any toxic propellants), NASA plans to conduct some invasive checks on the orbiter that they normally wouldn't do. It'll be interesting to see just how well these birds have held up.

From: http://www.collectspace.com/news/news-031411a.html

As Stilson and her team work to make Discovery safe for display, they will also be asked to remove components for forensic study, said Bill Gerstenmaier, NASA's associate administrator for space operations.

"We can still learn a lot from these vehicles. There are some hydraulics systems and some other things that we haven't really had a chance to have a look at because it was really too invasive to get in there and take a look at it," explained Gerstenmaier.

"So we're going to request that the teams help us pull a couple of those components out to do some real detailed forensics on so we can then learn about them for the next generation of vehicles," he said.

According to Moses, the list of hardware they want to look at is still growing, but as Gerstenmaier said, the hydraulic systems are of particular interest.

"Some of the actuators in the hydraulic systems — the flight control systems, elevons, rudder speed brake and the body flap — some of those actuators have been inline for a long time. We want to kind of tear them apart and see what condition they are in," said Moses.

"We are going to take really the best of what we have got here, learn as much as we can from this [and] archive it so when we go build the next generation [spacecraft] we'll have learned everything we can from these vehicles," said Gerstenmaier.

[erik_t]

The exact thermal environment in which the TPS operates differs tile-by-tile, so replacements happen at different rates, so we see different degrees of weathering on each tile. Holding this up as evidence of wear and tear is retarded, about as much so as observing that your FWD car's front tires have a little less tread than the rear ones.

[Skylon]

The exact thermal environment in which the TPS operates differs tile-by-tile, so replacements happen at different rates, so we see different degrees of weathering on each tile. Holding this up as evidence of wear and tear is retarded, about as much so as observing that your FWD car's front tires have a little less tread than the rear ones.

Not to mention an assortment of other factors, like damage from foam strikes on ascent (which used to happen a lot more) and even stuff as simple as pebbles kicked up at landing. I just found the 1984 vs. 2011 images interesting.

I was referring more to the thermal blankets that line the orbiter's skin (ie: the white parts where heating is considerably less on entry) that have clearly discolored over time. Those black belly tiles, along with the RCC panels on the wing leading edges and nose cap, take the real brunt on entry. The belly tiles I know get replaced the most as they are the most fragile part of the TPS...its easy to spot a fresh one as its usually solid black. The RCC panels have seen some change-out, but some are originals. For the nose-caps, as far as I know each shuttle has only had one.

Do we actually disagree here at all?