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Apollo 12 at 35
neutron_p writes "Thirty-five years ago this week, the sedentary, fine-grained powder began to rise, billow and race off toward the horizon. Soon after - at 1:54:35 a.m. EST on Nov. 19, 1969 - the lunar module Intrepid landed, bringing two more humans to the surface of another world. Apollo 12 commander Pete Conrad and lunar module pilot Alan Bean would be on the Moon for more than 31 hours, with crewmate Dick Gordon orbiting above in the command module Yankee Clipper."
256K Hah! The Apollo landing module had 2K of RAM and 36K of ROM. Now that's tight!
From abc.net.au:
NASA explains it a little better, noting that the 74KB is actually 37KW, using 16-bit words:
Hardware
The guidance computer is a general-purpose digital machine with a basic word length, in parallel operations, of 15 bits with an added bit for parity checks. The instruction code includes subroutines for double and triple operations. Memory cycle time is 11.7 microseconds with a single addition time of 23.4 microseconds. The 'core rope', used for the fixed memory, has a capacity of about 36,864 words with an erasable memory (of ferrite core planes) of 2,048 words. The processor is formed from integrated circuits (ICs). The total computer weight is 29.5 kg. The fixed memory contains programmes, routines, constants, star and landmark co-ordinates and other pertinent data. The erasable memory acts as an intermediate store for results of computations, auxiliary programme information, and variable data supplied by the G&N and other systems of the spacecraft.
sigs, as if you care.
for those who where not around here's some links to the AGC, DSKY and more:
*Apollo Guidance Computer (AGC)
*slash article with source code listing
*Simulation of Apollo Guidance Computer
*DSKY
peterrenshaw ~ Another Scrappy Startup
I love the bit where the writer describes the recommendation by the software engineer to ignore the reported errors as "a gutsy call". There's these guys, in a tiny little spacecraft, about to land on the moon, with most of the world watching, and the prestige of the USA and indeed democracy and capitalism at stake. The computer's screaming error messages. If you call for an abort, the moon effort is a flop (at least temporarily). If you call proceed and the thing craters, you're going to be the guy whose screwup killed two American heroes. "Gutsy"...more like balls of titanium!
Any sufficiently advanced technology is indistinguishable from a rigged demo
--Andy Finkel (J. Klass?)
"Plus an occasional extra burn so the earth doesn't drag you back in." Nope, they accellerated beyond escape velocity, so they only did a couple of small burns for course corrections and a final burn to slow down for moon orbit. The earth couldn't drag them back in.
Oh well, what the hell...
Indeed. The Army was actually planning to establish a moon base in the 1950s (Project Horizon) but that was killed off when NASA's moon initiatives were given priority.
Most things in the astronaut corps came through experience. You were backup crew on a mission and 3 missions later you were usally prime crew, for example. Being the command module pilot put you in good stead to be the mission commander on a later flight. Jim Lovell was CM pilot on Apollo 8 and commander on Apollo 13 (Frank Borman was commander of Apollo 8 and probably would have been commander of Apollo 11 if he'd not quit being an astronaut). Dave Scott was CM pilot of Apollo 9 and commander of Apollo 15. John Young was CM pilot of Apollo 10 and commander of Apollo 16.
As for the others, Apollo 7's crew was blacklisted because of their "grumpiness" in flight, Mike Collins quit being an astronaut after Apollo 11, Dick Gordon did the same after Apollo 12 and so did Jack Swigert after Apollo 13 (can't say I blame him). Stu Roosa was Apollo 14's CM pilot but his shot at commanding Apollo 17 was overtaken by Gene Cernan who had been LM pilot on Apollo 10. Apollo 18, 19 and 20 were cancelled and that was that.
Graham
Back in September, NASA selected 11 companies to conduct preliminary concept studies for human lunar exploration and the development of the NASA's Crew Exploration Vehicle. Many of these are your typical aerospace dinosaurs, but a notable exception is t/Space, a new company which includes people like Burt Rutan (of Scaled Composites and SpaceShipOne), Elon Musk (of SpaceX), Red Whittaker (of the Red Team, which constructed an autonomous vehicle which competed in DARPA's Grand Challenge), and several of the new companies in the budding private space industry.
According to their page: Our core mission requirement is to enable prompt, affordable, safe and sustainable lunar exploration and development by the largest possible number of Americans, both in person and via telepresence.
Under our approach, government incentives focus exclusively on top-level goals, with technology and operational choices left to the private sector. The government incentives will be matched to specific top-level needs, but the "invisible hand" of market forces will shape choices as they flow down multiple supplier chains. Incentives will be structured so that several companies in each major area have an opportunity to win this support. With this competitive industrial base, two major processes become possible:
* Market forces will continually launch new products that replace established goods and services (the "creative destruction" that Joseph Schumpeter [Austrian economist 1883-1950] identified as the key element of capitalism). Poorly performing systems will be killed off quickly via competition rather than via burdensome NASA reviews or Congressional intervention.
* Capability gap analyses will be performed by dozens and ultimately hundreds of companies on a continuous basis. As happens now in all competitive industries, the successful companies will be those who listen closely to their customers and accurately predict their future needs - in other words, capability gap analysis by multiple independent profit-seekers.
Commercial firms will create and own infrastructure that offers services that overlap in many cases. The overlaps found in a competitive private space economy will provide the resiliency now lacking in single-string solutions such as the Space Shuttle and Space Station, for which there are no ready alternatives. While functional overlaps are viewed as inefficiencies in centrally-planned systems, in a market-based system they drive costs lower (by reducing monopoly power and spurring innovation) and accelerate schedules (by eliminating single-point bottlenecks among suppliers and spurring competition).
If I understand correctly, tSpace's plan is to design an overall space architecture, and have companies compete for different components, whether they be launch vehicles, space station life support modules, or lunar landers. Many of these components will also be available commercially, keeping the price down and the reliability high. I suspect it's going to be difficult to keep from being eaten alive by the huge aerospace companies (Boeing, Lockheed, etc.), but I have a hope that they'll somehow end up getting the contract and end up completely reforming our approach to space.
I highly recommend reading through their presentation. The things they discuss are quite insightful, and they have some incredible ideas. Here's a few of their points:
Safety results from design choices, not oversight
* Attempting to produce safety by inspection, quality control,
Apollo 12 lunar surface journal.
Actually, they have all of them and some are pretty good reads.
Beware: In C++, your friends can see your privates!
In 1979 we still worked with those old FCUs (Flight-certified CPUs.) They all had 4k ram, and were 4-bit bit-slice. We looked UP to the Commodore64 and even the TI-99-4(A). We begged to use the 8085-A2 like the mil guys. And that was already obsolete. But the space environment dictated what was usable: if it had not been tested proven, forget using it on board a spacecraft. Ok, we learned/knew this. Apollo used transistor logic because what was already available was not yet proven killable (within accepted parameters) by space radiation. NOTHING else could be used until after LDEF came down, and that was delayed by Challenger by 4 years. It's all about radiation. In space, we need wide circuit paths to make up for cosmic bombardment, until we all go to photons, and prove it unkillable. I'd bet a dime that's what Putin is suggesting his new rocket/orbit-vehicle uses as control circuit, and is much-less-killable. Think nuclear exclusion principle.
Running into bits of air is what took Skylab down. Due to increased solar intensity during the years it was up the atmosphere expanded and caused increased friction with the spacecraft eventually causing it to fall into the Earth. Skylab also had a lower orbit than the ISS. But lets not forget that Skylab was an incredibly massive and large module. Tons of room.
What's REALLY incredible is that that 2K of memory was hand-soldered! Forget programming bugs, I'd worry more about short circuits! craziness.
Tetris rules.
Control: "Flight, try SCE to Aux."
Bean: "I know that one!"
Carthago delenda est!