]]> http://hammerandfeather.wordpress.com/2011/05/02/65-years/feed/ 1 saturn5 65 Years http://hammerandfeather.wordpress.com/2009/12/06/tranquility-base/ http://hammerandfeather.wordpress.com/2009/12/06/tranquility-base/#comments Sun, 06 Dec 2009 22:57:10 +0000 saturn5 http://hammerandfeather.wordpress.com/?p=156 ]]> The Lunar Reconnaissance Orbiter has now reached its mapping orbit 50 km above the surface of the Moon.  I previously reported the exciting images it made of several of the landing sites.  It has now captured the best image yet of the landing site of Apollo 11.  It must be amazing for Armstrong and Aldrin to see their tracks here 40 years after leaving them there on their short moonwalk.  I’d love to know what they make of this.

Tranquility Base

The image has north at the top, and you can see West Crater, the one Armstrong had to fly over before landing on the right side. The bright spots around are, I think, boulders which famously meant Armstrong had to take manual control early.  The pitted nature of the Moon is clear, as is the fact that many of the craters are easily as big as the LM.

LRO Tranquility Base detail, Nov 2009

Very clear is the descent stage and the footpads, and tracks left by Armstrong & Aldrin as they collected samples, erected the flag, took photos and set up the EASEP experiements.  It is tempting to think that you can make out the ladder on the left,  and fun to work out what is where.  Armstrong’s track to the E to look into the crater he landed just beyond, is visible too.  Compare this image with this map.  I think the really bright spot to the S of the LM is the LRRR, one of the sets of prisms that is still used to determine the distance of the Moon from Earth.

Crawler-Transporter near the VAB

There are really two alternatives to transporting rockets vertically to their launch position. The first is to build the rocket horizontally, move it horizontally and hoist it erect at the pad. The massive scale of the Saturn boosters really rules this out. The second option is to build the rocket at the pad. Several factors are against this: weather at the Cape is pretty volatile – hurricane winds, rain, lightning – holding up work; the rate of launches required to meet the end of ’69 deadline meant that having a rocket under construction at the pad would lead to unacceptable congestion.

So the solution was to build a massive Vehicle (initially Vertical) Assembly Building (VAB), construct each rocket inside, out of the weather and transport the rocket to the pad from there. But, again, the massive scale of the Saturn boosters meant this was no trivial problem.

Barges on canals (problems with stability and wind)  and railways (difficulties with rail stability and cornering) were both considered as options, but the solution settled on was to transport the rocket, MLP and Launch Umbilical Tower (LUT) by crawlers.

The coal miners of Ohio had been using massive tracked excavators to strip mine coal.

Bucyrus-Erie steam shovel crawler, Kentucky. Note man on top for scale.

These remain some of the biggest vehicles in the world. In February 1962 NASA engineers from the Launch Facilities and Support Equipment Office (LFSEO) were contacted by the Bucyrus-Erie Company who realised the potential of their massive machines to move launch vehicles.  The Marion Power Shovel Company won the tender, bidding 8 million dollars (competing with Bucyrus-Erie Company, its Ohio competitor, which has since bought Marion, who bid 11 million dollars) and built two wonders. Philip Koehring worked on the Bucyrus bid, and was immediately recruited by Marion to project-manage the massive engineering work.

The first test of the C-T took place in (July?) 1964, attended by several dignitaries and managers from NASA.

First test of the Crawler-Transporter

The image shows, from L:  Richard L. Drollinger, Director of Engineering, Marion Power Shovel Co.;  Theodor A. Poppel and Donald D. Buchanan, both of Kennedy Space Center;  S. J. Fruin, Executive Vice President and Philip Koehring, Project Engineer, both of Marion; and Kurt H. Debus, Center Director at Kennedy Space Center

Each of the two crawlers weighs in at 2700 tonnes, and is supported by four pairs of enormous caterpilar tracks, one at each corner. Each of these tracks has 57 shoes, 0.3 x 2.3m, each weighing nearly a tonne in themselves. The tracks are driven by 16 electric motors. Steering seems to be via three hydraulic rams which push the truck around on its guide tube.  The turning radius is 152 metres, only four times the vehicle’s length.

Crawler truck assembly

The platform which supports the MLP and vehicle has an area of 726 square metres or so, and can rise from 6m above the ground to 8m above ground level. This platform can be kept horizontal, even during the ride up the 5% slope to each pad.

The massive power needed to move such loads is supplied by a diesel-electric system. Generators with a combined power of 5500 kW supply motors, steering and hydraulic pumps. Despite this massive output, the speed of the C-T is limited to about 2mph (0.9m/s) when unloaded, and 1mph when loaded. Bearing in mind the cumbersome nature of its loads, that seems fast enough.

Bob Myers, Crawler Systems Engineer, in one of the cabs

The monster is driven from one of two cabs.  Controls seem very simple, belying the precision achievable:  the C-T must deliver the vehicle and MLP to the pad and lay it down gently within very tight limits.  It is said that the C-T can be moved forward and back in increments as small as 1/8 of an inch (about 3mm)!

So large is the crawler it has a control room inside, under the main deck.  Here engineers monitor and control the motors and generators that supply the electrical power for C-T and MLP systems.  The whole thing is surrounded by catwalks allowing engineers to access any part of the C-T and gain access to the MLP.

Schematic drawing of the Crawler Transporter

Control room windows

The first Crawler transporter ready for service, Jan 1966

A while ago I enjoyed building a Saturn V scale model (and here).  While researching this I’ve found there is a model of the C-T you can build as well.  It looks fantastic, although it is 1:144, so not compatible with my original Saturn V.  However, if this modeller ever finishes this and gets the plans out there I’ll be occupied for ever, but happily!

1:96 Crawler model detail

Sources:  All the sources are referenced in text links or image links.  Most useful, and recommended reading for an understanding of the development of Cape Kennedy Space Center and its hardware is ‘Gateway to the Moon’ by Benson and Faherty.  This book is the first 14 chapters of Moonport: A History of Apollo Launch Facilities and Operations, 1978, part of the NASA History Series.

Ares 1 is certainly a slender rocket, the first stage of which is basically a Shuttle SRB. I note that little work has been done to modify the Mobile Launcher being used for this flight – it still has the two Tail Service Masts seen in the photo below. I believe this is the same Mobile Launcher used to support the launch of Apollo 11. I know that work is being carried out to build brand new Mobile Launchers.

Ares 1X on the way to LC39B

Launch is due on 27 October, although this is still to be confirmed. The flight is suborbital: only the first four of the five segment SRB are live, and the rest of the booster and capsule are dummy. An Ares 1Y flight is scheduled to use live five segment first stage, live second stage and live Launch Escape System, with a boilerplate Orion capsule.

Launch Complex 39B, July 2009

Please visit David’s blogs.  He’s been talking of deleting his blogs lately, but I hope he doesn’t.

Throughout Apollo research was done to make use of what was learned in the program and put some of the hardware to use afterward.  Initially, no doubt, this started with dreams of going beyond landing on the Moon, but eventually, as budgets got smaller the Apollo Applications Program was left with Skylab and the Apollo-Soyuz Test Project.

Skylab was beautiful.  It was a kitted out SIVB stage of a Saturn V which was converted to lab and living space, and was huge.  Launched in May 1973 it was crewed three times, the last of which left in February 1974.  The plan was to use the upcoming Space Shuttle to boost it’s orbit, but a combination of denser than usual outer atmosphere (due to solar activity) and delays to the Shuttle meant that Skylab reentered the atmosphere and largely burnt up in July 1979.

A second Skylab was built, ready to fly, but was never sent into orbit.  It now suffers the indignity of having large holes cut in the sides so that tourists like me can wander through and stands in the Smithsonian Air and Space Museum on the Mall in Washington DC.

So here’s the question.  A number of bottles of nitrogen were attached to the base of the SIVB for use in Skylab.  The N2 is fed to systems in the piping shown.  But why is the piping this elaborate spiral?  It is certainly elegant, but in the mass-conscious business of rocketry surely a shorter, lighter pipe would have been desirable.  Perhaps the spiral coped better with vibration at launch?  Possibly the internal diameter of the pipe changes at a particular rate?  Maybe there are thermal advantages?  I don’t know.  But I’m geeky enough to want to know.  Anyone?

Apollo 14 landing site

This image of the Apollo 14 landing site, where Shephard and Mitchell landed is remarkable for its detail, showing both the descent stage (middle right) and to the left a little the ALSEP, or part of it and the trail the astronauts left as they walked between the two.

The Apollo 17 image is interesting.  I’m not sure, but wonder if the rover (or rather its shadow) can be seen to the left of the descent stage here, left after famously allowing Ed Fendell to capture the liftoff of the ascent stage taking Cernan and Schmitt from the Moon for the last time.

Apollo 17 Landing Site

What’s even more exciting about these images is that there is better to come.  The LRO is yet to achieve its final orbit and resolution (just over 1m per pixel currently) is set to double at least.  Wow!

Since Orion is reusable, I wonder if they’ll depart from the guillotine style of the Apollo umbilical.  I’d expect that to be more reliable, and it should be trivial to put replaceable connectors just inboard of the cut point so that the cables/pipes can be replaced easily.

Rover video

It’s good to see radical new ideas being considered and this Small Pressurised, sorry, Pressurized Rover (SPR) seems to improve on the original idea in several ways:

• a shirt-sleeve cab for driving, minimising the time astronauts need to stay suited up
• egress in, apparently, just 10 minutes via suits which stay outside…
• …minimising the amount of dust brought inside
• the option to drive from outside while suited up
• a 2.5cm layer of ice over part of the craft to act as a solar-storm shield and heat sink
• improved manouverability

There’s still only room for two (four at a pinch), but the range is proposed to be a massive 240km.

It’s not clear how this will get to the Moon, nor can I see how the large docking hatch can be used to dock with an ascent stage much further from the ground, but I very much like what I see.

Clearly nasty accidents can happen even in Earth testing.  The astronaut on the left here has lost the legs of his suit, or perhaps he just managed to inside-out them on the way back into the Rover?