Apollo 11 REDUX

SpaceNut · 2018-12-28 20:11:55

I forgot we will need wheels and with a mass budget that is tight we will need to go with somethin g simular to the past but updated in Light weight rover for Mars

SpaceNut · 2019-01-01 17:25:45

Zubrins plan is to use a Falcon 9 heavy to do the work needed to get us back to the moon.

http://newmars.com/forums/viewtopic.php?id=8473

The Falcon 9 Heavy can lift 60 tons to low Earth orbit (LEO). Starting from that point, a hydrogen/oxygen rocket-propelled cargo lander could deliver 12 tons of payload to the lunar surface.

Correction of payload numbers
63 - 12 leaves 41 for structure and fuels...

The first cargo lander carries a load of equipment, including a solar panel array, high-data-rate communications gear, a microwave power-beaming set up with a range of 100 kilometers, an electrolysis/refrigeration unit, two crew vehicles, a trailer, and a group of tele-operated robotic rovers.

The second cargo lander brings out a 12-ton habitation module, loaded with food, spare spacesuits, scientific equipment, tools, and other supplies. This will serve as the astronauts’ house, laboratory, and workshop of the moon.

A Falcon Heavy is used to deliver another cargo lander to orbit, whose payload consists of a fully fueled Lunar Excursion Vehicle (LEV). This craft consists of a two-ton cabin like that used by the Apollo-era Lunar Excursion Module mounted on a one-ton hydrogen/oxygen propulsion system filled with nine tons of propellant, capable of delivering it from the lunar surface to Earth orbit.

A human-rated Falcon 9 rocket then lifts the crew in a Dragon capsule to LEO where they transfer to the LEV. Then the cargo lander takes the LEV, with the crew aboard, to the moon, while the Dragon remains behind in LEO.

SpaceNut · 2019-01-02 21:40:54

SpaceNut wrote:

Lunar lander smaller than Altair:
http://spirit.as.utexas.edu/%7Efiso/tel … 7-2011.pdf
pg 11
It is much smaller than Altair; Dry mass of 7t, wet mass of 15t (Altair was ~45t wet)
•The propulsion system is LOX/Methane and is designed to be re-fuelable
Pg 31 has more lander spec's

Posting specific content as the link I think is no longer there.
The 131 mT sls is to launch a small lunar lander, node STA, the Orion on a new 3rd stage to L1

1. The 14.95mt reusable O2/CH4 lander is emplaced at the L1 node by SLS launch.
2. 16.8mt Crew Capsule boosted by the SLS Second Stg and the Third stg (w added cargo).
3. Second stage provides half of the dV to reach L1 (2,013 of required 4,015m/s).
4. Third stage provides the remaining dV (2,002 m/s) to L1. (its first use)
5. From the L1 Hab the Crew oversee the attachment of the Third stage to the Lander
6. The partially full Third stg boosts lander into LLO (2 nd use),
7. Third Stg then provides most of the dV for descent (1,695 of 1,995 m/s required).(3 rd use)
8. Five km above the surface, lander engines are started, empty Third stage is jettisoned, and the remaining dV (500 m/s) is done by the lander.
9. Initially the Crew Lives out of the Ascent Crew Cabin
10. Later Crew transitions to the 8.6 mt Surface Hab delivered by the Cargo Lander
11. Surface power systems deployed by Crew
12. After the surface mission, the crew ascends back to L1
13. After rendezvous, the lander is refueled and prepared for the next sortie.
14. Crew returns to Earth via MPCV Capsule/SM

SpaceNut · 2019-01-02 21:47:10

Lunar System: 3 rd Stage

Tank volumes:
LH2
tank 5.5 m dia - volume 3247.2 ft3 (91.95 m3) - (includes 4% ullage vol)
LO2
tank is 4.4 m dia - volume 1108.4 ft3 (31.38 m3) - (4% ullage vol)
Tank lengths:
LH2
total tank length: 16.9 ft (5.15 m) - top dome height: 6.3 ft - cyl (barrel) height: 4.3 ft - bottom dome height: 6.3 ft
LO2
total tank length: 10.1 ft (3.08 m) - top dome height: 5.0 ft - cyl (barrel) height: 0.1 ft -bottom dome height: 5.0 ft
Stage Mass:
Total mass: 45,691 kg (45.6 mt)
Dry mass: 4,683 kg
PMF (total prop/total stg); 0.897
Inert mass: 6,001 kg
Total prop: 40,781 kg
Usable prop: 39,691
Reserve prop: 1,091 kg
RCS prop: 227 kg
Performance:
Vac Isp: 462.0 (long nozzle RL - 10) Mix ratio: 5.5
Two Engine Version:
Stack T/Wt at 3rd stg ignition: 0.31; T/W at end: 1.02
Single Engine Version:
Stack T/Wt at 3rd stg ignition: 0.16; T/W at end: 0.51

SpaceNut · 2019-01-02 22:14:06

mass delta - V
Total Systems Mass 14.98 mt
Surface Payloads 0.50 mt
Total Lander Mass 14.48 mt
Crew Cabin and Systems 3.15 mt
Dry Mass 2.72 mt
Propellant total 8.61 mt
Propellant Masses 8.61 mt 3,133 m/s
Propel Reserves 0.17 mt
L1 to LLO Prop Main n / a
L1 to LLO RCS 0.02 mt 5 m/s
Terminal Desc Propel Main 1.92 mt 500 m/s
Terminal Desc RCS 0.04 mt 10 m/s
Ascent Propel Main 5.20 mt 1950 m/s
Ascent RCS 0.04 mt 10 m/s
LLO to L1 Prop Main 1.18 mt 640 m/s
L1 RCS Prop 0.04 mt 18 m/s

SpaceNut · 2019-01-03 21:34:48

The act of refueling whether its in LEO or at a fuel depot or at a lunar station the effect is less mass is lifted to orbit and makes a mission possible.
Methane Lox seems to be the candidate for the moon as well...

SpaceNut · 2019-01-27 18:49:15

Trying to make a buck or really saying we should celebrate an great achivement
US Mint Launches Sale of Coins Celebrating Apollo 11 50th Anniversary

aHR0cDovL3d3dy5zcGFjZS5jb20vaW1hZ2VzL2kvMDAwLzA4Mi80NzQvb3JpZ2luYWwvdXNtaW50LWFwb2xsbzExLTUwdGgtY29pbnMtc2FsZTAxLmpwZw==

SpaceNut · 2019-04-29 16:52:49

Nasa is starting to get real about going to the moon again by 2024. NASA tweaks call for lunar lander concepts

Prior to the announcement by Vice President Mike Pence March 26 that called for a human lunar landing in five years, NASA was going on a two-track approach for developing human-class lunar landers. In February, it released a separate solicitation for studies of transfer vehicles and descent stages, also as part of NextSTEP and designated Appendix E. At the time, NASA said it would keep studies of the ascent stage within the agency.
The updated plans provide a second chance for those who did not participate in the earlier lander studies solicitation or who do not get awards. “Appendix H offerors who are not awardees on Appendix E will be afforded the opportunity to propose similar work, to the extent it is necessary for their Appendix H proposals,” NASA stated in the revised procurement filing.

https://www.nasa.gov/nextstep/humanlander2

SpaceNut · 2019-06-02 18:39:15

Apollo astronauts almost got to fly lunar jetpacks

Bell Aerospace built a Lunar Flying Unit that would have let Apollo astronauts explore vast distances on the Moon. NASA ultimately spiked the plans.

LEADBell_One_Man_LFV_CreditBellAerospace.jpg?mw=600

For their 1969 Lunar Flying Vehicle (LFV), Bell expanded their rocket belt design into a platform, allowing it to carry more fuel. A standing astronaut controlled the vehicle’s two rocket nozzles — one on either side of the platform — with handles mimicking the controls in the LM, for which the astronauts had extensive training. The 235 pound (107 kg) platform could fly up to 70 mph (110 km/h) to distances up to 15 miles (24 km), maxing out about 75 feet (23 m) off the lunar surface.

Maybe these will be useable for the moon later

RobertDyck · 2019-06-03 10:21:20

Williams X-Jet

SpaceNut · 2019-06-07 21:10:43

The 50th anniversary of Apollo 11 is weeks away.

Moon landings: How NASA got there, and its plans to go back

"Beginning with missions beyond low-Earth orbit," the directive states, "the United States will lead the return of humans to the Moon for long-term exploration and utilization, followed by human missions to Mars and other destinations."
The program will eventually integrate a "gateway" spacecraft that will stay in lunar orbit while missions head down to the surface. Here's the timetable:
Late 2019 -- First commercial deliveries/landers to the moon
2020 -- Launch of SLS/Orion, uncrewed, in Exploration Mission-1
2022 -- Crew around the moon in Exploration Mission-2
2022 -- By December, setup of the first gateway element (the power and propulsion system) for a one-year demo in space, aboard a private rocket
2023 -- Land a rover, with the help of the commercial space industry
2024 -- Americans on the moon (including the first woman)
2028 -- Sustained presence on moon

For reasons unknown, the president appeared to trash his own directive to return to the moon by 2024.
Trump: Screw the Moon, Mars Is Where It’s At

“For all of the money we are spending, NASA should NOT be talking about going to the Moon - We did that 50 years ago. They should be focused on the much bigger things we are doing, including Mars (of which the Moon is a part), Defense and Science!”

Trump criticizes NASA moon mission after promoting it earlier

U.S. President Donald Trump on Friday criticized NASA for aiming to put astronauts back on the moon by 2024 and urged the space agency to focus instead on “much bigger” initiatives like going to Mars, undercutting his previous support for the lunar initiative.

I guess impatient....

SpaceNut · 2019-06-09 21:14:25

If we consider the strength of the Russian space program along with the increased mission from China one could say a space race was on even if we do not say that we are in one.

The Second Moon Race

Some still claim that the moon was a hoak so in order to not lose a race we need to get it done.

Void · 2019-06-10 12:43:14

Spacenut said:

If we consider the strength of the Russian space program along with the increased mission from China one could say a space race was on even if we do not say that we are in one.
http://www.moondaily.com/reports/The_Se … e_999.html
Some still claim that the moon was a hoak so in order to not lose a race we need to get it done.

That seems true. However, impatience was building for a long time to get back to space. There is always a choice of "What to do", if you have a constriction of satisfaction of needs. For instance in starvation, one response is to dig in, conserve your calories, and hope to wait it out. Maybe summer will come, maybe the animals you hunt will come back. It can work. If that goes badly then starvation to death, and also possibly cannibalism are next. The other option is to animate yourself, consume calories, and try to get to a survival situation by it.

There are many in out population who by default see movement in their local crowd, and try to subvert it so that they can consume that movement to maintain a stasis situation. I believe that to a degree our space program fell prey to them for some time. However I think that the Apollo program was very risky business. Cancelation could be considered a blessing. We left the casino with a gain, and not an extremely bad experience in general. But still "THEY" managed to turn the dreams into their food for some time. So, now with so much repressed dreaming, it is fortunate that our management was able to encourage private space, and that indeed there seems to be competition. That competition is not as sinister as some might suppose I would think, but the balance, in my opinion is to not tempt your competitors by either your excessive weakness, or by backing them into a corner too much. Sharing is the best option, I think. But you can't share, unless you are there.

……

Hoaxing is part of the stay at home parasite program, in general. Propaganda, or if you are more honest political lies.

My account of the library of Alexandria, may actually be an altered history, but for now until I can be updated, this is the story I have. Interestingly, I think I got part of it from Carl Sagan.

The Egyptians used to search every ship that came to port for books. They would take them and make a copy to put in that library, and would then return the original to it's owners.

The Romans, for purposes of conquest of Egypt supposedly damaged the Library, to distract the Egyptians. I don't know other than fire if they otherwise purposely vandalized or censored the books.

The so called Christians are reported to have then later done some editing. By Christian however, care has to be taken as there are and have been different sects of them. Interestingly Middle Eastern Christians are more similar in mentality to the Muslims than are the western Christians. In fact, the Copts, facilitated the infiltration of Muslims elsewhere. Anyway I think people are people, and it was more likely that it was the local culture which predated both Christian, and Muslim, that still held an imprint. And as is apparent universally, there are people who crave power and wealth. And some of them want to get it with words. Manipulating other people.

As I recall per Mr. Sagan, the Muslims did the final damage. They supposedly examined the books. If a book was not like the Koran, they burned it. If it was supportive of the Koran, they burned it because it was not needed.

So, I think in general in a condition of conquest, the aftermath, is to edit history, to the conquers benefit to control the minions minds.

So, we can only trust our story of history so far.....And we don't really know the truth in whole.

I read a book written by someone for India. I wish I could recall the title. The book set out four types of people. Of course real people are likely various mixes of these types.

Priest (Story Telling, history recalling (:))
Aquisitioner (Finances, mercantile behaviors)
Intellectual (Elon Musk, don't mistake people with fancy words as necessarily this)
Warlord (The art of war)

Anyway without doing science, and if we never go to the Moon, and if we are conquered, if it is useful to the story telling to hold power, then indeed history will say that the USA hoaxed it. Good reason by itself to go back, and do science with some show and tell.

And America is in no position to say that it is too poor to afford it. We are not starving and going to conserve our calories, and wait for the good fairy to bless us.

I ran into this today:
https://phys.org/news/2019-06-mass-anom … rater.html

A mysterious large mass of material has been discovered beneath the largest crater in our solar system—the Moon's South Pole-Aitken basin—and may contain metal from the asteroid that crashed into the Moon and formed the crater, according to a Baylor University study.
"Imagine taking a pile of metal five times larger than the Big Island of Hawaii and burying it underground. That's roughly how much unexpected mass we detected," said lead author Peter B. James,

Well, maybe an ore body. Still, hundreds of miles down. That seems like a tough one. Maybe it fragmented though perhaps some pieces of it not so deep?

Previous story telling has it that an Iron/Nickle asteroid would vaporize on impact with the Moon, leaving nothing to mine. That sets me to wonder.....

Something we will want is the historical nature of the Moon. When was it completely fluid, if ever? Did it then solidify, and yet the surface turn back into a magma ocean by the great bombardment?

The Moon as a receiver of asteroid impacts would be physically different than it is now. If completely liquid, or mostly liquid, then the impactors are lost to the core. If however a relatively shallow ocean of magma, perhaps a more gentle impact, with force of impact distributed across a longer time band. Dissipating some of the impact energy with waves of splashed magma. So, that is different. If there was an "Ocean" floor of solids, then perhaps the core would rest there. That could be pretty deep though.

The asteroid belt, was apparently in the "Snow Belt" during formation. Some asteroids still apparently give off tails like comets. So, is it possible that an impactor would be composed of a differentiated body? Two types I think. Smaller ones where an ice crust and mantle existed and un-melted rock for the core (Maybe), and fully differentiated, where the body would have a core of rock a mantle of lighter rock and a perhaps thick crust of ices. If such impacted the Moon would that impact be different than if asteroids we know now impacted the Moon?

I think it would. I think the core of the asteroid or maybe even comet would punch through it's own mantle, and icy crust. It would be buried, and the lighter substances above it would tend to vaporize. This would be unlike a metal asteroid today impacting, and different from a rubble pile containing clay impacting.

So, knowing the actual history of the Moon, by more data may reveal the chances of finding minable ore bodies on the Moon. I think that is rather important, to know before we set out for other objectives. (Mars excused, it has it's own logic as a target).

Done

Last edited by Void (2019-06-10 13:32:55)

SpaceNut · 2019-06-10 19:12:23

Yes 2004 when we said that we were done with shuttle and needed a new vehicle going back to the Apollo on Steriods capsule.

Its the descision to go with legacy parts in its final form rather than using off the shelf which was consider not man rated was the reasoning...

They could have gone clean slate and still would have over spent to get the job done.

Originally there was to be a fly off of competitors but that got nixed some how and that has lead to where we are... with the congress funded senator launch system...

SpaceNut · 2019-07-20 07:59:45

Happy aniversary but it looks like we will miss doing this one more time....

http://www.msn.com/en-us/video/news/one … vi-AAE8FGR

Look back at the race to the moon

The NASA logo is having a moment

GW Johnson · 2019-07-20 10:04:18

Happy anniversary of the Apollo 11 moonwalk.

That may have been a "flags-and-footprints" end to the space race, but it appears humanity is finally ready to go back. Perhaps this time, we'll get it closer-to-right with a permanent human presence.

Remember my definition of what "exploration" really means: go there (first trip) and find out what all is there, and where exactly it is. Then stay a while (first or second trip) and try to figure out how to use what you found to support living there.

That is what humans have done since the first ones left Africa. It is hard-wired into us. It is who we really are. That is what creates settlements in new places that eventually grow and develop into real trade economies. Nothing else does this.

I suggest we plant that human presence on the moon and get started finding out the ground truth of what all is there and where exactly it is. Do this small scale and build it slowly, so that expense does not preclude doing other things.

The next centuries-old dream is going to Mars. I suggest we get on with it, but in a way that allows for doing the real exploration right from the very first landing. Go find out the ground truth of what all is there, and where exactly it is.

Any vehicle capable of taking humans to Mars is also capable of taking humans to the near-Earth asteroids and occasional comets. I suggest we do that too, probably at about the same time we go to Mars. We need to explore them as well, with an eye toward how really (!!!) to divert them successfully, to prevent an impact upon the Earth.

Without interior (!!!) ground truth, and an understanding of the true spectrum of the characteristics of these objects, you cannot know (!!!) how to successfully divert one. And yet there is no better reason for both manned and unmanned space programs than protecting the folks back home from this sort of catastrophe.

None of this being a space race at all, then why should we limit our thinking about spacecraft design to where we have been with Mercury/Gemini/Apollo, shuttle, and ISS? Or the rest that our Russian colleagues did? We need to be thinking way outside those boxes. The craft that will do what needs to be done, and do it properly, will necessarily look nothing at all like anything we ever did before.

For one thing, those designs must address the known risks of microgravity diseases and radiation exposures as best we can, limited as that is at this time in history. Nothing short of that is in the least ethical. Those, plus adequate safety/reliability testing, are the true risks of deep spaceflight at this time. The rest are just mere inconveniences (if you can't recycle effectively, then just pack more and carry it in a bigger vehicle).

What you're seeing with Spacex and Blue Origin is just the merest start on trying to get these designs right. They (and we) still have a long way to go to get it right. What you're seeing from NASA with SLS/Orion and the Lunar Gateway is a reprise of Apollo/Saturn half a century ago, using shuttle technology of 35 years ago.

NASA and its most-favored contractors are still thinking inside the old boxes. That has to change. Which is why I am so encouraged by what Spacex and Blue Origin are doing.

Just musing (mooning?) around.

GW

Last edited by GW Johnson (2019-07-20 10:10:38)

SpaceNut · 2019-07-20 16:11:02

With the ground proof of the ability to stay we will need to learn how not to be on the surface.
Deliver ships, cargo and habitats to the moon that weigh considerably more that a 13t capsule with retrorockets.
Being able to move on the surface what is delivered to where we need it to be and being able to shield it is a must.
Not everything must go back to orbit and that is how we will build up a base to stay....
No arguements of solar version nuclear, mining versus ownership of the work performed just getting to that act of building to stay.

tahanson43206 · 2019-07-20 17:34:20

For GW Johnson re #291

https://www.nasa.gov/sites/default/file … book_0.pdf

The link above appears to offer an eBook on radiation, but it failed to complete download to my location when I tried it. Someone else may have better luck.

I was attempting to follow up on your reminder about the challenge of space radiation.

GW Johnson wrote:

Happy anniversary of the Apollo 11 moonwalk.
For one thing, those designs must address the known risks of microgravity diseases and radiation exposures as best we can, limited as that is at this time in history. Nothing short of that is in the least ethical. Those, plus adequate safety/reliability testing, are the true risks of deep spaceflight at this time. The rest are just mere inconveniences (if you can't recycle effectively, then just pack more and carry it in a bigger vehicle).
GW

(th)

GW Johnson · 2019-07-20 18:04:41

Tahanson43206:

I was able to follow the link and download the file with my laptop. It took several minutes, because it is a very large pdf file. I looked at it and found it to be somewhat-watered-down BS for the ignorant general public. (To convert, know that 1 Sievert is 100 REM. Old guys like me are more used to REM.) If you really want the file, I could email it to you, if I knew your email.

While it's older, there's some real hard scientific data in a NASA website at:

http://srag.jsc.nasa.gov/Publications/T … chmemo.htm, titled Spaceflight Radiation Health Program at JSC (no cited reference newer than 1992).

That document has real full-intensity scientific and engineering data on the radiation threat and on various shielding material effectiveness. This is unharmonized scientific results, of varying readability, and sometimes conflicting.

I put a distillation of this in an article posted on "exrocketman", titled "Space Radiation Risks: GCR vs SFE", dated October 5, 2018. In case you do not yet know, that "exrocketman" site of mine is http://exrocketman.blogspot.com. There is a navigation tool on the left. Click on the year, then on the month, then on the title.

GW

tahanson43206 · 2019-07-20 18:59:10

For GW Johnson re #294 ...

Thanks for previewing the NASA document, and for providing a link to a better alternative, and to your site, which I've been meaning to visit.

This is as good a time as any. I'll follow up over the weekend.

(th)

SpaceNut · 2019-09-14 23:09:07

Ahead of SpaceX moon mission, billionaire Yusaku Maezawa sells a $2.3 billion stake in his fashion...
With SpaceX CEO Elon Musk at his side in September 2018, Yusaku Maezawa announced he'd be the first Starship passenger on a flight around the moon.
https://www.businessinsider.de/yusaku-m … ght-2019-9

5dxVYp7t?format=jpg&name=small

GW Johnson · 2019-09-15 17:28:30

Around the moon is the topic of the 1956 Disney flick. That is a LOT LESS CHALLENGING than orbiting the moon, in turn a WHOLE LOT LESS challenging than landing on the moon.

We went through all that deciding upon lunar orbit rendezvous to make Apollo fit one (and only one) Saturn-5 per lunar landing. More than half a century ago.

Yet all that seems forgotten with SLS version 1 and the hype associated with it.

GW

PS: the Saturns were initially Army ballistic rocket designs, not moon rocket designs. In the late 1950's and very early 1960's, Von Braun was doing those designs for the US Army ballistic missile people. What became Saturn-1 was originally intended to fling a very heavy early-model hydrogen bomb to Russia. What became the Saturn-5 was initially a 2-stage rocket to deliver a 100-man rocket-troop transport to Russia. This was coupled with the use of an LSD-25 "bomb". The idea was to put all Russians on their backs seeing pretty colored hallucinations, until they woke up with American bayonets at their throats.

I'm NOT kidding; THAT really was the plan as of about 1958-1960. It is documented as what was reported in the magazine that eventually became Aviation Week, among many others. In those days, Von Braun was working for the US Army, as he had since reaching the US in 1945. NASA was formed in 1958. About 1960, Von Braun went to NASA, taking the Saturn designs with him. They got re-purposed, obviously.

Last edited by GW Johnson (2019-09-15 17:58:25)

SpaceNut · 2019-09-15 17:44:21

You have the advantage of years as I was not born yet and only got to see the glory on the lunar landings and was excited to see each one with awe....I still that if it were possible I would go and do just that...

GW Johnson · 2019-09-15 17:48:16

When I was single-digit age, America was still experimenting with the X-1 and the X-2, and the Douglas Skyrocket. Those rocket plane pilots were then the heroes that the Mercury astronauts became, a decade later. A DECADE later!

I witnessed on TV the rollout of the X-15, and remarked to my dad, an aerospace engineer himself, that it was the "first spaceship". He agreed. And it was.

Long after that (early 70's), I became an aerospace engineer myself. My dad and I had many conversations over the decades since about what was possible and what was not. He died 5 years ago. I really miss being able to talk to him about such things.

He remembered Project Pluto, the nuclear ramjet cruise missile of about 1960. Its hard-radioactive plume and close-to-the-ground Mach 3 shock wave would have killed more people on the way to target, than its 5-ish megaton warhead would have killed at the target. He and I both thought this thing was a bad idea. Fortunately, this idiotic thing was never fielded.

My dad was the chief designer behind the F-8U Crusader jets, the A-7 Corsair-2 jets, and the S-3 Viking jets. Plus many others. I got to work on many of the weapons these craft carried, and many others up to the present day.

My first "real" aerospace job was as a graduate student at LTV, working on the "Scout" launch vehicle. I had worked as a draftsman in a machine shop and as a civil engineer on the DFW airport construction site, before that. I designed my first airplane and my first six supersonic missile propulsion systems with a slide rule, same as the guys at the Skunk Works doing the U-2 and the SR-71/A-11/YF-12A family.

Many of the correspondents on these forums do not even know what a slide rule is. It functioned as the "pocket calculator" for some 3 centuries before there was any such thing as a pocket calculator. It should therefore come as no surprise that I do not comprehend most of the modern internet and computer stuff. I'm not yet alone, but as the years pass, there are far fewer of us.

GW

Last edited by GW Johnson (2019-09-15 18:07:51)

Oldfart1939 · 2019-09-15 19:07:48

There is not much that can't still be done--but not as accurately as a handheld calculator--with a slide rule. In 1957, I took a mandatory course at University of Colorado in the Aerospace Engineering Department, that taught how to use all the scales on the Keufel & Esser "Log-Log-Duplex Decitrig" slide rule. I believer there were 32 or 33 scales on one, including the inverted scales. I learned how to use a basic slide rule at age 10, from my uncle who worked in "refrigeration engineering," designing early all house air conditioning systems. In those days, it was easy to spot an engineering student by the slide rule case on the belt

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#276 2018-12-28 20:11:55

Re: Apollo 11 REDUX

#277 2019-01-01 17:25:45

Re: Apollo 11 REDUX

#278 2019-01-02 21:40:54

Re: Apollo 11 REDUX

#279 2019-01-02 21:47:10

Re: Apollo 11 REDUX

#280 2019-01-02 22:14:06

Re: Apollo 11 REDUX

#281 2019-01-03 21:34:48

Re: Apollo 11 REDUX

#282 2019-01-27 18:49:15

Re: Apollo 11 REDUX

#283 2019-04-29 16:52:49

Re: Apollo 11 REDUX

#284 2019-06-02 18:39:15

Re: Apollo 11 REDUX

#285 2019-06-03 10:21:20

Re: Apollo 11 REDUX

#286 2019-06-07 21:10:43

Re: Apollo 11 REDUX

#287 2019-06-09 21:14:25

Re: Apollo 11 REDUX

#288 2019-06-10 12:43:14

Re: Apollo 11 REDUX

#289 2019-06-10 19:12:23

Re: Apollo 11 REDUX

#290 2019-07-20 07:59:45

Re: Apollo 11 REDUX

#291 2019-07-20 10:04:18

Re: Apollo 11 REDUX

#292 2019-07-20 16:11:02

Re: Apollo 11 REDUX

#293 2019-07-20 17:34:20

Re: Apollo 11 REDUX

#294 2019-07-20 18:04:41

Re: Apollo 11 REDUX

#295 2019-07-20 18:59:10

Re: Apollo 11 REDUX

#296 2019-09-14 23:09:07

Re: Apollo 11 REDUX

#297 2019-09-15 17:28:30

Re: Apollo 11 REDUX

#298 2019-09-15 17:44:21

Re: Apollo 11 REDUX

#299 2019-09-15 17:48:16

Re: Apollo 11 REDUX

#300 2019-09-15 19:07:48

Re: Apollo 11 REDUX

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