Author Topic: U.S. Space & Rocket Center: Shuttle Pathfinder Robert Pearlman

Editor Posts: 37577

From: Houston, TX

Registered: Nov 1999 posted 02-03-2014 09:20 AM NASA STI Program video release Pathfinder: Shuttle Exhibit This video introduces the Pathfinder Shuttle Exhibit, a joint project between the Marshall Space Flight Center and the State of Alabama's Space and Rocket Center in Huntsville. The exhibit features a never flown shuttle vehicle, Pathfinder, that was used in early ground tests in the shuttle program, as well as an actual external fuel tank and set of booster rockets. The video includes footage of actual launches, the Pathfinder Shuttle Exhibit, and shots of the Space Camp at Alabama's Space and Rocket Center. Robert Pearlman

Editor Posts: 37577

From: Houston, TX

Registered: Nov 1999 posted 02-03-2014 09:30 AM The archival video provides a great early look at the Pathfinder. Did you know that two of its SSME nozzles flew on STS-1? The video precedes the addition of the solid rocket boosters, which are special unto themselves. As this photo, courtesy Scott "Shuttleman" Phillips, reveals, the solid rocket boosters used in the Pathfinder exhibit were assembled from the filament- wound cases designed and built for polar launches from Space Launch Complex-6 (SLC-6) at Vandenberg Air Force Base in California. The dark filament was painted white to give the boosters the same appearance as those that launched from Kennedy Space Center in Florida. Hart Sastrowardoyo

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From: Toms River, NJ

Registered: Aug 2000 posted 02-03-2014 11:46 AM So if SLC-6 had gone into operation, would Discovery have been launched with black and white SRBs, or would they have painted them? Robert Pearlman

Editor Posts: 37577

From: Houston, TX

Registered: Nov 1999 posted 02-03-2014 12:01 PM Discovery would have flown from SLC-6 with boosters that look very much like the SRBs pictured with Pathfinder above. And we may still see filament boosters fly; they are being further developed by ATK for use with the Space Launch System. Greggy_D

Member Posts: 908

From: Michigan

Registered: Jul 2006 posted 02-03-2014 02:56 PM quote: Originally posted by Robert Pearlman:

The archival video provides a great early look at the Pathfinder. Did you know that two of its SSME nozzles flew on STS-1? No kidding. I've always thought they were replicas. Looking back now at the pics of Pathfinder I took when my daughter and I attended Space Camp in 2012, they do look pretty authentic if not real. That's a neat piece of trivia. JBoe

Member Posts: 811

From: Churchton, MD

Registered: Oct 2012 posted 02-03-2014 03:48 PM quote: Originally posted by Robert Pearlman:

And we may still see filament boosters fly; they are being further developed by ATK for use with the Space Launch System. Part of my duties in my old office I had the opportunity to take a Solid Rocket Fundamentals course given by ATK Elkton, MD. Part of the course we got a tour of the facility which included the mixer (capable of mixing 30-36 tons of propellant), block houses for motor testing, propellant casing manufacturing, and the iconic Thiokol building. The black filament wrap is very thin, but amazingly strong and wrapped many times. I seem to remember they were using or testing the same concept for the nozzles. p51

Member Posts: 1489

From: Olympia, WA

Registered: Sep 2011 posted 02-03-2014 06:38 PM Thanks for posting this, I'd never seen any of this before. quote: Originally posted by Greggy_D:

I've always thought they were replicas. Looking back now at the pics of Pathfinder I took when my daughter and I attended Space Camp in 2012, they do look pretty authentic if not real. I find this odd in a way, because they make a big deal about those being real. I've been to Space Camp twice with the adult program, and I've heard all about it each time. dabolton

Member Posts: 419

From: Seneca, IL, US

Registered: Jan 2009 posted 02-03-2014 07:07 PM quote: Originally posted by Robert Pearlman:

...the solid rocket boosters used in the Pathfinder exhibit were assembled from the filament- wound cases designed and built for polar launches from Space Launch Complex-6 (SLC-6) at Vandenberg Air Force Base in California. Why would have a polar launch necessitated different SRB casings? Robert Pearlman

Editor Posts: 37577

From: Houston, TX

Registered: Nov 1999 posted 02-03-2014 07:32 PM More thrust was needed to reach polar orbit with the planned payloads; the filament cases decreased the weight of the boosters, increasing their performance. Hart Sastrowardoyo

Member Posts: 3239

From: Toms River, NJ

Registered: Aug 2000 posted 02-03-2014 08:14 PM Excuse the over-simplification, but basically since the Earth rotates from west to east, when one launches from KSC, the rotation gives you a little "oomph" in launching. Launch into a polar orbit you don't have the oomph. dabolton

Member Posts: 419

From: Seneca, IL, US

Registered: Jan 2009 posted 02-03-2014 09:51 PM quote: Originally posted by Robert Pearlman:

...the filament cases decreased the weight of the boosters, increasing their performance. So why not incorporate the lighter, more powerful boosters into the KSC launches then? Were they cost prohibitive? Robert Pearlman

Editor Posts: 37577

From: Houston, TX

Registered: Nov 1999 posted 02-03-2014 09:58 PM This is straying off-topic from Pathfinder, but the filament boosters had design issues — they weren't as structurally solid as the steel casings; they flexed under stress — and there was concern that they wouldn't hold up in flight. The SLC-6 launches never proceeded far enough for the development of the filament boosters to be completed. Had the issues been worked out and had Discovery proved their design in flight, then it's possible the composite cases would have gone into use at Kennedy, too. Jay Chladek

Member Posts: 2272

From: Bellevue, NE, USA

Registered: Aug 2007 posted 02-03-2014 10:31 PM The SRB nozzles and I believe possibly the nosecones from the original display were removed from Pathfinder and replaced either with replicas or other units that had concluded their operational use sometime in the early to mid 1990s. The basic hardware for those assemblies was the same as the standard SRBs. NASA and the contractor if I recall correctly as a cost cutting measure pulled them off for refurbishment as flight articles to help save a bit of money and not have to make a new set. I presume they got used, but don't know what missions they flew on. If you want to read a little bit about the history of the filament wound casings, Allan McDonald's book "Truth, Lies and O-Rings" does discuss it a bit as he was brought in on the SRB project when they were being made and qualified. While ATK (then Morton Thiokol) was the prime contractor for the normal SRBs, these babies were a co-development with Hercules Inc. I won't go into the specifics here as it isn't part of the Pathfinder story, but I will say if you read the book, you will find things rather interesting. As for Pathfinder itself, it was essentially a fit check mockup built at KSC in the general dimensions of the shuttle to help make sure equipment and facilities designed for the shuttle would fit around it before Enterprise (and later Columbia) paid their first visits to KSC. Later, it was sent to Marshall to help with preparations for Enterprise's visit for the vibration testing. The Pathfinder didn't look much like a shuttle back then except for its general layout. It was rebuilt into something that resembled an orbiter more closely for a space display in Japan and the USSRC got ahold of it after it came back to the states. I personally never got a chance to see it up close (just a brief glimpse in 2011 on my way back from STS-131) as I went to Space Camp before they got it. But I remember reading the literature on the museum's plans for it quite well as it was mentioned in all the Space Camp newsletters I got after my visit. Robert Pearlman

Editor Posts: 37577

From: Houston, TX

Registered: Nov 1999 posted 02-04-2014 10:04 AM quote: Originally posted by Jay Chladek:

The Pathfinder didn't look much like a shuttle back then except for its general layout. For those not familiar with Pathfinder's original configuration, here are a few photos. SprocketCur

Member Posts: 12

From: Huntsville, AL

Registered: Mar 2011 posted 02-14-2014 09:50 AM Just to make sure all bases are covered, the ET under Pathfinder is also the same tank that was used in SSME qualification testing at Stennis in the lead up to STS-1. It was partnered with the SSME Thrust Structure (also referred to as the Main Propulsion Test Article and sometimes the "Boattail"), which now sits in Shuttle Park. You'll be glad to know that a complete re-vamp of all the signage in Shuttle Park is underway with corrected specs (it was shortened by about 3 feet for during the re-fit for Japan) on Pathfinder and other new/improved details! hotdog

Member Posts: 41

From: Chattanooga, TN

Registered: Dec 2011 posted 02-14-2014 09:29 PM Thanks for the info! That is good news. Looking forward to seeing the new signage in the Shuttle Park. I'm guessing Pathfinder was shortened by 3 feet for transportation reasons? I imagine that had to affect the mounting of the orbiter onto the ET since the forward attachment strut would probably have to be moved to compensate for the reduction in length.