The work-around is to build two identical copies of the rocket. The first is a test unit which is tested to failure; the second is put through a very brief test to confirm that it appears to behave sufficiently similarly to the first, and then it's put into service.
And, all the work that the Apollo program brought forth with physics, electronics, etc has powered decades of innovation.
It cost 17 cents; I'm guessing this is a fraction of the cost of a single BIT of the Apollo computers.
The article states that the price of a single bit varied from $1 to $0.01 USD over the product lifetime. I would assume that NASA paid extra for higher reliability. 17 cents for a single bit is well within the cost range of a single bit, and a reasonable estimate for that time period.
... jesus tap-dancing christ, a whole dollar for a single BIT? Wolfram|Alpha says that a dollar in 1955 would be worth almost $9 today. The memory in my desktop would be worth more than the GDP of all but 10 US states o_0
Talk to people who fool around with homemade relay based computers or guys like me who just draw schematics and then visit your typical supplier like digikey or mouser and search for 12 volt coil latching relays, which are basically elecromechanical single bit storage devices (aside from other more "practical" purposes).
You're looking at a good $4 to $7 bucks. Per bit. Non-aerospace rated. Made in China not USA.
This is why core memory was popular, being a lot faster, smaller, and cheaper.
Unfortunately that means nothing. That would imply someone with control over an iphone (apple, etc) could do "more" than the apollo, which is obviously not happening.
Real power is what you can transform those computations into. Obviously the Apollo computer was far more powerful because it could transform those calculations into landing on the moon and returning, whereas a comparatively powerless iphone can, by itself without infrastructure, do little more than play Angry Birds.
If you're trying to land on the moon, or mars, an iphone is utterly useless and doesn't have even a fraction of the "power" required. It just can't do it. Doesn't have the I/O or the reliability required, not to mention the lack of software.
It is very much an apples and oranges comparison.
I'm afraid you aren't looking at how the system went together. The landing process was manual. Remember this was 1969, when there were still elevator operators (though they were by then redundant), steam trains in regular service, etc.
You can read the cockpit transcripts of the landing and compare those to the cockpit transcripts of a modern plane. Armstrong was making burn decisions HIMSELF based on what he saw out the window and what Aldrin was choosing HIMSELF to tell him mattered (Armstrong couldn't see the instruments; Aldrin couldn't see out the window. Astonishing teamwork!)
You can also read the source code for that computer program. Essentially it was a slide rule doing coordinate translation and some instrumentation monitoring. But the fact that they landed with the computer non functional tells you its role in the process.
This is hard to appreciate now when we have computer modulated machinery (stability dynamics in your quadcopter, machine control of your brakes etc) and even materials (both in design, manufacture, and even dynamic control of some beams etc). But back then they couldn't do that kind of thing.
Also, you could write the appropriate software and connect the appropriate equipment to the phones I/O port and use an iPhone to land a spacecraft on the moon. It does in fact have the "power" required.
(not gonna spoil it for those who haven't seen it, it's a totally hilarious film about Nazis on the dark side of the moon, just go watch it)
The post-hoc analysis of that could burn down the internet for weeks.
It really looks surprisingly similar to modern assembly code. Well commented too.
TC IBNKCALL # FOR SATURN INTERFACE AND FDAI DISPLAY
We live in a much different world today. Back then if someone died (and some did) they were heros, lessons were learned, and we moved on. Today everyone is so afraid, even the military has a low risk tolerance. But remember how WWII was won, on D-day they basically thew bodies at the enemy to achieve a foothold. People did what it took to achieve goals, even at great cost in dollars or lives. It's just not like that today so it seems rather unbelievable.
Four minutes before the moon landing, the Apollo Guidance Computer began throwing 1202 and 1201 alarms - indicating that it wasn't completing its processing loop in time.
Here's the audio from the flight director and guidance loops, as they troubleshooted the problem in real time, clearing Apollo 11 to land.
tl;dr: Some misconfigured switches meant that rendezvous radar jobs kept being erroneously scheduled, which used up available memory. Whenever there was no more memory available, the alarm would fire and the computer was rebooted. It would immediately restart (resuming from near where they left off) all the high priority jobs (while not restarting the radar jobs), meaning that it could still land safely.
The AGC was one of the first to use priority multitasking. The 1201 and 1201 faults were indication that lower priority tasks were getting yanked.
See "Moon Machines". Seriously.
The problem was actually a deployment problem. The checklist for configuring the computer left a diagnostic mode on that sucked up a lot of CPU.
A couple of links to the videos you mentioned:
The above is probably one of the most informative 2 minute videos I've ever seen.
"there were no specs, we made it up" "if you screwed up you got a stack of papers that was 2 feet thick" "the overall memory for the Apollo guidance computer was 72 kilobytes"
Just another kind of "the space program was amazing" thing - the sheer diversity of people who got hired on to contribute is continually surprising. An amazing tribute to the pragmatism of NASA under the conditions.
We can make web sites that stay up, always. It's just that it costs a lot more and / or they do less.
If "When We Left Earth" sparks your interest. I suggest watching "Apollo 13" and "The Right Stuff" next.
Lastly, I'm currently reading the excellent book "Moon Lander: How We Developed the Apollo Lunar Module". This book gives an insiders view of what it took to build the Lunar Module (LM). I particularly appreciate that the book covers a lot of the hard work, arguments, and drama that are often forgotten when we romanticize the past.
It gives an account, from the flight director's perspective, of the space program from Mercury to Apollo 13.
One of my first vivid memories was watching Apollo 14 or Apollo 15 on my folks old black and white telly. I was four at the time and went to school completely obsessed with the Saturn V rocket and the idea of space travel.
As I've grown older and come to appreciate the limitations of the technology of the day, I am even more in awe of the challenges the Apollo programme had to overcome to get two humans to land on the moon, and the mortal danger these individuals lived in from takeoff to landing.
I wonder if we've plateaued in our ability and willpower to put humans into space and to break new barriers in space travel. I wonder if governments could ever stomach the 1960's attitude of "throwing caution to the wind" to send humans to Mars or beyond.
I would honestly hope not because there's no point in doing it wrong, especially not now when any failure is a huge setback and successes are treated as expected.
We will put people on Mars, we will have space stations and people living on the moons of Jupiter. This won't happen quickly and I do understand that at some point we have to put people in danger but there's no reason to do it as recklessly as we did in the 60's.
Hell we're doing just fine as it is. Right now there are six people living in space. There are companies starting right now to supply them, to get minerals from asteroids, to take people to Mars. It's happening now and it's just not as heroic as it was in the 60's, which to my mind just shows that we're doing it right.
Probably my favourite scene and if I'm honest though I am not even an American, watching the stars and stripes through the condensation ice and the big red U S A crawling by makes me feel a bit patriotic.
And the complete listing of the AGC can actually be downloaded as a PDF here :
And for the Lunar Lander here:
It is fascinating to go through it!
0. Bicycles in the early/mid 19th century (depending on your definition)
1. to motorized cars 50ish years later
2. to actually flying at the turn of the 20th century
3. to transporting humans into space and then on the moon just 66 years later
I'd argue we haven't made such large, significant technology leaps in such a short span (just over 100 years) since then. Not sure we ever will (hopefully with energy).
In 1999 I used a card catalog at my rural library to get an encyclopedia from 1989.
Just today I used my cell phone to call my friend who is quite literally halfway around the world and had a real time video chat with her. This happened in 14 years.
I'm not sure that's a particularly inspiring example of technology progress.
In 1999 video conferencing over the Internet was already a reality, though it was very low quality. I know we tried it in work around that time. Skype launched in 2003 and basically solved that problem.
So in the next 11 years the main development was in wireless networking, which was basically a refinement of military datalinks which had been in service at least since the AN/ARR-39 of 1956.
You might as well write the whole lot off as a glorified telegram, if that's the stance you're going to take.
In reality, quantitative parameters - cost, performance, reliability, usability - matter more than 'the first X'.
Or video communications (FaceTime/Skype) with the telegraph and telephone. The development of telephone goes back as far as the bike/car so I'd posit that communications technology grew at about the same pace.
I can talk to and see someone in Japan (and she can see me too!) with the cellphone in my pocket.
I can find my position anywhere in the globe, down to an accuracy of 10 m, with a $ 100 gadget. It can also give me directions in realtime.
I can type something on Google and find more information about it than I could ever read/watch.
When I was a kid, just 20 years ago, those things weren't available neither affordable. I only had available to me payphones, maps and encyclopedias, inventions from the XVIII, XVI and I centuries, respectively. Now think about that.
There's no single, landmark event in the history of digital computing that compares to the moon landing, and of course the development of computing owns a lot to space exploration research. Still, to the extent that such comparisons make sense at all, the advent of cheap, ubiquitous microcomputers has had far more impact on humanity's welfare and culture than the landing on the moon.
1) first satellite - USSR;
2) first man in space - USSR;
3) first man-made object to impact Moon - USSR;
4) first man-made object to land Moon - USSR;
6) first failed Mars probe (and second, and third, and fourth, and fifth...)
It's possible to commemorate LANDING A MAN ON THE MOON, on its anniversary, without it necessarily having to be a political dick-waving contest you know.
But since you brought it up, it does make you wonder how the US so completely outleaped the USSR to the moon, given how far ahead the USSR was in space development. The USSR wasn't even second to putting a man on the moon, no one has done it since Apollo.
Scale model? It was about the same size, though internally very different (it's thought that they used the shape to save on doing some of their own re-entry validation).
It's really kind of ridiculous how similar it looked versus how different it was; the big thing on the Buran stack is a rocket, not a tank, for instance, and the boosters are kerosene.
> But since you brought it up, it does make you wonder how the US so completely outleaped the USSR to the moon, given how far ahead the USSR was in space development.
Well, first, the USSR wasn't that far ahead, perhaps a few years. But its moon programme was inadequately funded (and not funded at all until 1963 or so), not terribly focussed (there were designs based on Proton/Zond for flybys, tested unmanned shortly before Apollo 10, based on the N1, a giant kerosene rocket, on the UR-700, an ultimately undeveloped giant Proton, and so on), and subject to political interference, both from the government, and between the design bureaus.
It also wasn't pursued as the ultimate goal in the same way the US one was; at the time the USSR was also working on the Almaz (later Salyut) space stations, an automated sample return system, a greater focus on interplanetary probes (albeit without much success except for the Venus stuff) and other bits and pieces.
If they'd been willing to take the risk, they could probably have had the first manned flyby; there were a number of Zond missions, using a modified Soyuz, unmanned, in the couple of years before Apollo 10. It would have been _extremely_ risky, though; most of the Zond missions were at least partial failures.
BTW, there are more USSR achievements:
5) First spacewalk
6) First woman in space
0) first animals in space: US fruit flies.
Like an old man telling a story about the good old days. Because, you know, it was the greatest thing NASA ever did and it was 45 years ago.
I'd like to know what could explain, for example, their shadows lengthening significantly when they move a small distance as shown in the NASA footage better than "the astronauts were close to a large artificial light source" as they claim in the film that physics implies.
The point is that googling just about any claim from the conspiracy theorists will return results debunking those claims by experts in photography or other relevant fields, and if it doesn't, that's only because the claim is something new enough that the sisyphean debunkers, who undoubtedly have better things to do with their time given that they actually know what they're talking about, haven't gotten around to it yet.
You can point to some trivia or artifact of photography that you don't understand and cling to that as proof of the hoax, whereas I can point to rocks that came from the moon, or to the fact that ham radio operators were able to pick up the tv transmission from the moon by pointing their receivers at the moon, or the fact that some of the missions placed mirrors on the moon that various third parties have bounced light off of. My evidence beats your "evidence."
Specifically w.r.t. photos: http://www.iangoddard.com/moon01.htm
There's also a book: http://www.amazon.com/Bad-Astronomy-Misconceptions-Revealed-...