3 posts tagged “moon”
Forty years ago today, man stepped foot on the Moon. Between July 19, 1969, and December 7, 1972, we went back to the Moon seven times, landing a total of twelve astronauts [1]. And then we stopped going, just when things were getting interesting [2]. As many have asked “What happened?”
Before we get into what happened, you need to remember what happened before Apollo. When Kennedy made his famous speech, the USA was not doing well in the space race. We had gone from being the innovators in rocketry and design to being the laggards. “Our Germans” were being beaten by “their Germans” [3], and our rockets were blowing up on the pad or just after launch whereas theirs were going into orbit. This was more than a matter of national pride; as recordings of Kennedy make clear, it was a matter of national security. As a result, we chose the quick path [4] to the Moon, which was also the path to where we are now.
Were there other paths? Yes. During the 1950’s Werner Von Braun [5] worked with Collier’s magazine to publish his plans for space exploration [6]. With images by Bonestell [7] the series laid out the path to the Moon and beyond in clear, nontechnical language. What did he propose? This:
Though this path is longer, each step left us with a permanent change. The shuttles could be used for sub-orbital transport [9] as well as for building the station. The station would serve military and civilian needs [10]. The cislunar shuttle provides us with a way to launch missions to other planets as well as the Moon. And so forth. And each development is permanent. Once the shuttle is built, nobody in their right mind would throw it away [11]. Once the space station is up, nobody is going to let it fall [12]. And so on.
- Build a two-stage to orbit space shuttle. Both stages would be piloted, and both would be re-usable. The shuttle would have been able to carry about half again what the current ones do, mainly because they wouldn’t have been downsized by the military [8]. Time – about 4 years from design to first flight, based on existing work.
- Use the shuttle to build a space station in Low Earth Orbit (LEO). Time – about 4 years.
- Build a cislunar shuttle in orbit, using the space station as the Earth terminus. This shuttle would never land anywhere; its sole job would have been to ferry material and personnel between Earth and the Moon. Time – about 2 years (a much easier design than the space shuttle).
- Build a station orbiting the Moon, using what had been learned from the Earth station and ferrying the materials using the cislunar shuttles. The lunar station would also have been important for voyages to Mars and the other planets, as it is nearly out of the Earth’s gravity well, which makes the astrodynamics much easier. Time – about 2 years.
- Build a landing ship, based at the lunar orbital station. Land on the Moon and start building the colony. Time – about 2 years.
Total time for this path: About 14 years.
The problem is that this path is longer. A minimum of 14 years to get to the moon, as opposed to less than nine by Kennedy’s timetable. Despite the oft-repeated quote that “NASA was founded on the belief that you can get a baby in one month by getting nine women pregnant”, it was recognized that there were limits to what could be done. So the longer, surer path was abandoned and the shorter, riskier path was taken.
Instead of building a space program from the ground up (Earth to LEO, LEO to lunar orbit, lunar orbit to lunar base), we did it all at once (Earth to Moon and back). The only way to do that was to abandon all pretense of permanence until after the Moon race had been “won”. The engineers and NASA managers were promised that they could build the space station and shuttles later – but first they had to win the race. And that (plus politics) is what killed the space program afterward.
You see, once NASA had landed on the Moon, they had to compete with other programs for money (something that they had rarely had to do during the heady 60’s). To make matters worse, the 1970’s were much like the past few years: a lousy economy, with massive unemployment, high inflation (“stagflation”), and a market crash that wiped out 30% of the nation’s wealth over the course of a few months. Tax receipts were limited and budgets were cut across government. NASA was no exception, and had its budget slashed by nearly 50%. This left NASA with enough funding to build a space station or to build a shuttle (but not enough to continue manned lunar exploration), and NASA’s managers opted to build a space station that they called SkyLab.
As originally designed, SkyLab was going to be lifted into orbit and serviced by the new shuttle fleet [13]. But cost over-runs and politically motivated delays caused NASA to launch SkyLab on a Saturn V and to stand helplessly by as it fell back to Earth well before the first shuttle flight. But why did it take so long to get the shuttle to fly?
Mainly politics. The shuttle was an expensive beast to build, so NASA tried to use their old trick of “spreading the wealth” [14]. Unfortunately, the managers of the 1970’s had neither Von Braun’s charm nor LBJ’s acumen. As a result, they had to make a series of compromises on the shuttle design that would ultimately cause it to be more expensive and less reliable than the rockets it was intended to replace.
The first, and most crippling, change was in the size. Originally, the shuttle was to lift about 50 tons, instead of the 30 tons it can now take into orbit. This change was mandated by the US Air Force’s requirement that the shuttle be capable of launching from Vandenberg in order to put military satellites into a polar orbit; ironically, despite mandating this change and completing the launch facilities at Vandenberg, no shuttle has ever launched from there. Doubling the cargo capacity would not have doubled the cost per vehicle nor the cost per flight. As a result, the total cost to orbit would have been much less under the original design.
The second compromise was in design philosophy. Rather than design the shuttle piece-by-piece, as was done for previous rockets, the whole was engineered as a single system. In theory, this reduces the risk of the program; in reality, it meant that changing any part of the system required a redesign of the entire system. Thus, certain design flaws (e.g., the magnetic mass memory core for the computer, a holdover from the 1950’s) were built in and could not be changed without risking a massive cost over-run. This is why the shuttle flew for twenty years before gettings its first serious makeover.
The final compromise was on delivery. Originally, there was to be a fleet of twenty shuttles, delivered over a five year period. However, under Jimmy Carter, the schedule was stretched out so that only two shuttles per year were delivered over a period of ten years. This was intended to be a cost-cutting measure. What it actually did was spread out the costs and increase them by nearly 30%; it also gave Ronald Reagan the political cover he needed to cancel the program after just five operational shuttles had been delivered. As a result, instead of spreading the development and design cost over twenty vehicles, and instead of launching a vehicle every other week, NASA was left with an apparent cost-over-run and not enough vehicles to launch more than every other month.
What all of this added up to was a shuttle program based on out-dated technology that had too small a cargo capacity to be useful [15] and too little political support to develop a mission. Early on in the program, managers had suggested using the Shuttle as a launch vehicle for probes and satellites (e.g., the Hubble Space telescope [16], the Magellan Venus orbiter). However, that job could be done less expensively and more safely by unmanned rockets. Reagan had suggested using the Shuttle to create a new space station (Freedom, then Alpha, now the ISS) – but neglected to provide enough money for the station in his budgets [17]. And the situation has not changed since then. Every president makes a speech about how important space exploration is – and then cuts NASA’s budget or changes the goal (or both). And, like the shuttle itself, NASA is so structured that a change in one part of the design requires that the entire structure be re-engineered.
Thus, for the past 37 years, we have spent a lot of time taking joy rides, and darned little time actually building anything resembling a future. We have launched quite a few satellites and even flown a few classified missions [18], but it hasn’t been until the past ten years that we have started building the space station that was the central reason for the shuttle’s existence. And, after 115 missions (less than a quarter of what the existing shuttle fleet was designed for!), NASA has decided to shut down the shuttle once and for all and to put all of its money on a new system. Thus, 40 years after America’s greatest triumph, we stand ready to take a great step backward for mankind. And it is all because we couldn’t wait another four years to take that one, small step, forty years ago.
John
[1] Of whom, eleven were test pilots and one was a scientist (geologist). Amusingly, it was the test pilots who made what was possibly the Apollo program’s most important contribution to science by finding the genesis rock .
[2] E.g., we cancelled the planned farside landing and the search for more genesis rocks.
[3] One of the by-products of the Yalta conference; we tacitly divided up the spoils of the German rocketry program, with the USA getting the groups that specialized in targeting and the USSR getting the ones that built the engines.
[4] As wags have pointed out, NASA’s unofficial motto is “Quick. Good. Cheap. Pick two.”
[5] One of “our Germans” and the leader of the NAZI V2 program.
[6] I have a hardback copy of the collected articles, and I won’t share. So there.
[7] The foremost artist of the space age. He used science and talent to depict what life in space would be like and became synonymous with realistic and good art. He worked on a number of Academy-award wining films, including Destination Moon [a] and When Worlds Collide.
[8] More on that in a moment.
[9] Imagine if “Air Force One” were “Space Force One”. Doesn’t the President of the USA deserve to go by the fastest possible route?
[10] One of the things holding back development of space is the Space Weapons treaty. Everyone cheats on it, but appearing to obey it is what kept us from having a real space station in the 1970s.
[11] So the Russians aren’t in their right minds. Then again, neither are we…
[12] See previous comment.
[13] Déjà vu, anyone?
[14] Ever wonder why rockets are built in Georgia with parts from 15 other states, launched in Florida, commanded from Texas, and directed from California? Simply because it is easier to get senators to vote for a program that offers jobs in their district than to get them to vote for something that is in the national interest. Witness the F-22 and V-22… This was also a prime reason that the Constellation program (suppliers in 46 states) was chosen over the Shuttle C (suppliers in 18 states).
[15] Well, too small to be useful from NASA’s point of view. However, several folks have looked at the shuttle design and come up with ways to use it to its fullest advantage. Some wanted to use the ETs as the nucleus of space stations; dumping them into the ocean actually reduces the amount of cargo that the shuttle can carry and is only done to prevent an “uncontrolled re-entry”. And G. Harry Stein famously showed that we could use the Shuttle to develop an orbital system of solar power satellites that would have paid for themselves within five years and reduced our reliance on oil by nearly 50%. However, because these ideas were not from an authorized NASA think tank, they died the “Not Invented Here” death.
[16] Another out-dated piece of technology; today’s ground-based scopes can get better resolution for less money than the Hubble. But it is a political darling, so it will probably stay on-line for some time to come.
[17] A common story at NASA is that more money was spent redesigning the space station to meet the continually pared-down budgets than it would have cost to build Freedom in the original configuration.
[18] One of the reasons that the US Air Force dropped out of the Shuttle program is that the launches are so damned public. There is nothing worse than having the entire world know when you have launched your latest classified satellite!
[a] Written by R. A. Heinlein, and with both Heinlein and Von Braun as science advisors. Dated by today’s standards, it was cutting edge for 1950.
but this guy had it coming.
You see, the moon is moving away from Earth due to the interaction of the tides. The moon raises tides on the Earth [1]. Because the Earth rotates as well as revolves [2], the tide is always in a different place than the moon. It thus acts as a brake on the Earth's rotation and transfers the energy to the moon, moving it further out in its orbit. It sounds complicated, but it is really very simple [3]. We left reflectors on the moon so we could check on this prediction from Newton's Law of Universal Gravitation [4], and have kept using them as a check on other things.
But the cool thing is that anyone can send a pulse to the reflectors - all it takes is a powerful laser, which is pretty cheap nowadays, and a photocell, which has always been cheap. So you can check to see if we've been, just by shining a light on the problem [5]! Which, of course, makes hash of the whole "we ain't never been and its all a giant government conspiracy!" argument; it's like an American claiming that Columbus never sailed across the ocean and it is all a big fake. And if you wer eon Columbus' crew, you might want to take a poke at the guy, too.
John
[1] And vice versa, but let's not complicate this too much.
[2] An object rOtates around its Own axis; it rEvolves around an Exterior axis. (In other words, when you twirl in place you are rotating, but when you move around someone else, you are revolving.)
[3] In math, anyway...
[4] As scientists, we check everything, no matter who said it!
[5] One of these days, I'm going to get around to sending a modulated pulse ot the moon, just so I can hear it sing back to me: "SHine on, shine on harvest moon"...
Jupiter is shining bright tonight, and with good cause. Three hundred and ninety-nine years ago today, Galileo Galilei changed the world, the nature of science, and the meaning of religion thanks to Jupiter. Using an improved telescope that he had invented, Galileo looked at Jupiter and saw that it had three companions; by the end of the week, he had found a fourth and proven that these small starry messengers revolved around Jupiter. Being a savvy sort, he published his findings in Sidereus Nuncius, a short treatise that was dedicated to Cosimo II de' Medici and called the four moons of Jupiter “Medicean stars”. We now know them as Europa, Ganymede, Callisto, and Io [1] and call them the Galilean satellites.
His discovery was first used as a method for keeping time [2], but it had even deeper implications. Under Aristotle’s view of the cosmos, the Earth was the center and everything revolved around it. Things in the heavens were perfect and pure, and were in heaven because they were pure and perfect. Because the ideology fit so well with the dogma of the Catholic Church, it was adopted as Church Law – to challenge it was to challenge the very essence of belief [3]. Though some troubling differences had arisen between the pure circles demanded by Aristotle and the observed paths of the planets, these were smoothed over by Ptolemy’s “epicycles” of circles on circles. Questioning these ideas was dangerous at best and heresy at worst [4, 5].
Galileo did worse than question them: he made it possible for anyone to see that he was right and the Church was wrong [6]. By simply looking through the telescope, people could see these new moons of another planet. They could see the “jug-ears” of Saturn [7]. They could see the phases of Venus [8]. They could see the spots on the face of the Sun and the scars on the face of the Moon [9]. And they could see that the Milky Way was neither food of the gods nor a nebula but thousands upon thousands of stars like our, scattered across the sky.
Galileo was first rewarded for his discoveries and then punished for his hubris. He became a superstar in Pisa, and other city-states wooed him, trying to get him to move and to bring his beautiful ideas with him. But his ego led him to clash with others, making enemies out of supporters. Eventually, he was brought before the Inquisition for heresy and threatened with torture. He renounced his views and spent the rest of his life under house arrest [10]. It would be 206 years before the Roman Catholic Church would take his works off of the banned list and 376 years before the Vatican would formally clear him of any wrongdoing.
In opening the heavens to us, Galileo laid the foundations of modern science. He showed that clear logic alone (Aristotle’s approach) is not enough. Logic must be backed with evidence and hypotheses must be checked against observations. He also started us on the road to discover who else is out there.
John
[1] Named after the lovers of Jove (Jupiter). Remember that every planet has a system for naming its moons:
In addition, each planet and other body has a unique system for naming its features (e.g., great lovers for features on Eros). Names for newly discovered moons, planets, and features must be approved by the IAU to become “official”.
- Mars the dogs of war Phobos (Fear) and Deimos (Panic)
- Saturn Titans
- Uranus Characters from a Midsummers’ Nights Dream and the Rape of the Lock
- Neptune Nymphs and children of the sea god
- Pluto Workers in Hades
[2] Why is time so important? Because it tells you where you are! From the angle that the sun makes with the horizon at noon, you can tell your latitude (how far north or south you are). But you need to know the time in order to determine your longitude; this is why locations are given in minutes and seconds. If you know the time to within one hour, you can determine your location to within 1700 km. If you know the time to within 1 minute, you can determine your location to within 27.8 km. If you know it to within one second, then you can determine your location with an error of less than 0.5 km. Until the creation of the first accurate, sea-worthy chronometer [a], the stars were the only way to determine time at sea. Using the Medicean stars, Pisan sailors were able to navigate more easily and more quickly across the oceans; it was this that made Pisa a naval power to rival England in the 1600’s. 300 years later, Lewis and Clark used the same method as they tracked across North America. And all of this came from “pure” research!
[3] Or so the Church scholars would have you believe.
[4] Copernicus published his heliocentric theory on his deathbed, and was still reviled in sermons sixty years later. Giordano Bruno held to a heliocentric universe and was burned at the stake for it (and other heresies).
[5] The Roman Catholic Church wasn’t the only group that wanted a geocentric universe. Nearly 1800 years earlier, Aristarchus had been threatened with expulsion from Samos for impeity because he had suggested that it was silly for a huge Sun to orbit a tiny Earth and wanted to have it be the other way around.
[6] While doing so, he also implied that the Pope was an imbecile. Many scholars believe that it was this, rather than his embrace of Copernican theory, that led to his troubles. Note to self: Don’t piss off the absolute ruler of the nation you live in when proposing a radical change to that nation’s beliefs…
[7] Or at least, most of the time, they could see them. This was one of the things that caused Galileo trouble – the rings are tilted and so change their apparent shape and width as Saturn moves in its orbit. When Galileo first saw them, Saturn was directly behind the Earth, so the rings stood out like the brim on a sombrero worn by a man standing behind you. When Galileo was trying to gather support, Saturn had moved in its orbit so the rings were nearly edge on (imagine that man and his sombrero moving over to your right – notice how the brim appears to get smaller?) and very difficult to see. As is the case with modern net trolls, Galileo’s enemies used this one change to argue that everything he did was a lie.
[8] Under the geocentric model, only the new and crescent phases were possible as Venus had to orbit between the Sun and the Earth. In the heliocentric model, all of the phases could be seen (and were).
[9] Not only did these allow Galileo to check Aristarchus’ estimate for the size of the Moon by comparing its mountains to those on Earth, it went directly against the belief that the Moon and Sun were perfect and pure bodies. The sunspots also allowed Galileo to measure the Sun’s rotation (another impossibility, according to Aristotle).
[10] Legends to the contrary, he is unlikely to ever have said “eppure si muove” (“And yet it moves”). To do so would have been foolhardy and needlessly brave – and Galileo was neither.
[a] Detailed in Sobel’s magnificent Longitude. England and France were locked in a battle to develop a way to determine time at sea (with Brussels a distant third); as a result, each had their own Prime Meridian. Britannia ruled the oceans because it was able to solve the problem before France.
[b] Galileo's finger, saved as a reliquary. Shown as requested by MadTante.
