Tag Archives: space travel

444. Last Men on the Moon

left to right: Schmitt, Cernan (seated), and Evens

The last Apollo mission occurred forty-five years ago this week, with final departure from the moon on December 14th..

The three men who went to the moon on Apollo 17 were not the original choice. Astronaut crews during Apollo were selected well in advance, with primary and backup crews for each mission. The backup crew, as a unit, was supposed to fly on a subsequent mission, but not the very next one. That plan was frequently disrupted by events. Everyone probably remembers from the movie Apollo 13 that Mattingly was originally part of the Apollo 13 crew, but was bumped at the last minute in favor of Swigert because Mattingly had been exposed to rubella. The actual shuffling that took place was far more complicated than that.

As Apollo wound down and missions 18, 19, and 20 were cancelled, (see 441. The Last Apollo) nine astronauts were going to lose their chance at the moon. One of these men was Harrison Schmitt who had been slated for Apollo 18. He was one of the scientist astronauts recruited by NASA. Given the schedule at the time Apollo 18 was cancelled, none of these scientists would have flown. This was unacceptable to the scientific community; they lobbied for and got Schmitt moved up to Apollo 17, which cost Joe Engle his mission.

What happened to the men who got the Apollo axe? Obviously that is worth at least one post, possibly more, but my rotation pushes that into January or later.

Eugene Cernan and Harrison Schmitt landed on the moon December 11. Their mission was J type, as were Apollo 15 and 16, which meant these missions were designed for a three day stay and included a Lunar Rover. This dune buggy looking vehicle allowed one or two astronauts to move further away from the Lunar Lander and greatly increased the usefulness of the mission.

Apollo 17 landed in the Taurus-Littrow region of the moon. This site allowed sampling a wide range of types of rock, as it consisted of an ancient lava flow, with surface broken by subsequent meteor strikes, and included secondary strikes. This means that ejecta from the nearby Tycho crater came to earth (came to Moon?) causing secondary, smaller craters at the Taurus-Littrow site. This allowed Schmitt to sample Tycho material even though an Apollo landing at Tycho never happened.

A few minutes before eleven PM, Greenwich Time, December 14, 1972, the last manned mission to the moon lifted off, to later rendezvous with the CSM and return to Earth. Gene Cernan was the last to enter the lunar Lander before take off. We’ll give him the final words:

“Too many years have passed for me to still be the last man to have left his footprints on the Moon. I believe with all my heart that somewhere out there is a young boy or girl with indomitable will and courage who will lift that dubious distinction from my shoulders and take us back where we belong. Let us give that dream a chance.”

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I’ve read a large number of memoirs by astronauts and others involved in space exploration. The Last Man on the Moon by Eugene Cernan and Don Davis is one of the best. If you want more of this story, that is the place to go for it.

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Blatant Commercialism

Greetings, new friends.

Recently, a number of new people have found their way to my website, and I am glad to see you. All my old friends have already heard this.

I began this website two years ago, shortly after finding out that my novel Cyan had been picked up by EDGE publishers of Canada. The original idea was to make myself and my writing known in order to find new readers for my novel. The website has grown well beyond that since.

Cyan came out in April as an ebook, and later became available in paperback as well. If you just found this website, you missed all the build up.

Cyan is a realistic, near-future science fiction novel about the exploration and colonization of a planet around a nearby star. With complications, of course.

If you click here, it will take you to the Amazon page where you can read reviews, see the blurb, and even use the Look Inside function to read a chapter or two. You can also click and buy.

If you do buy and like what you read, please take time to write a review. That way publishers will buy my next book. And then so can you.

End of commercial. Thanks for listening. SL

318. Too Many Exoplanets

trappppIt’s official. The good old days are gone.

About a year ago, I said:

(T)he party is nearly over. We now have the capacity to discover extrasolar planets, and new ones are found every year. Fortunately for latecomers to the planet builders guild, megaplanets are easier to find that Earth sized ones, and NASA keeps cutting funding. Still, it won’t be too many years before you can’t decide for yourself where, within the limits of orbital mechanics, you want the planets of Alpha Centauri or Procyon to be.

Science has a way of getting somewhere a lot faster than you would expect. Manned space exploration doesn’t fit that statement, because it runs on politics, not science.

On February 22, in Nature, it was announced that seven Earth size planets had been discovered circling a single star only thirty-nine light years from Earth. Far more important, all seven orbit within the band of temperature where liquid water is a possibility. By contrast, our system has one such planet, Earth, and maybe Mars for a few minutes on a hot afternoon near the equator in mid-summer – if the ice doesn’t sublimate instead. Seven; its unheard of.

The star is TRAPPIST-1, an M dwarf. 

In fact there has been a mini-revolution in the search for exoplanets. NASA’s Kepler space telescope has found more that 4700 potential planets. Many of these will no doubt turn out to be false positives, since the techniques of the search are not perfected, but it is still a staggering number. Most of these were found around stars similar to our sun – where else would you look first? Very few of them are both Earth sized and at the right distance from their star to have the possibility of liquid water.

As I said in Cyan, “planets of no use as real estate.”

Since a mechanical failure in 2013 compromised its ability to orient itself, Kepler has concentrated on observing red dwarfs. To eveyone’s surprise, the planet candidates found around these small, dim stars tend to be more Earth sized. And there are a lot of them.

The TRAPPIST-1 discovery, however, was not by NASA but by the TRAnsiting Planets and Planetesimals Small Telescope group operating out of the University of Liège, Belgium. That explains the use of caps; TRAPPIST is an acronym.

If you want details – and of course you do – the best source is here. This page from the University of Liège is in French, but the video which will self-start is in English, and gives enough details to stir the blood of any space or science fiction fan.

It took me about three seconds to start speculating about what kinds of novels could be written about the exploration of the TRAPPIST-1 system. Suppose most or all of the seven planets had some form of life, all evolving independently. Suppose we write about a paleontological mission on a planet which had vertebral life, then lost it; these dwarfs have a solar wind that operates heavily on planets so close in. Suppose at some time in the deep past, a spacefaring civilization arose on one of these planets, colonized the others, and then died out. Or didn’t die. Or seems to have died until our intrepid explorers begin to poke around.

Okay, I was wrong. The golden age is still here.

202. Planetary Scale

     Everything in a writer’s life is grist for the mill. For a science fiction writer that includes science itself and, in my case, the teaching of science.
     Here is some more teacher geek. In a book on teaching middle school astronomy, this would be an appendix.

When I was in my early teens and discovered the local library, it not only gave me science fiction, but science as well. I remember the dozen or so books on popular astronomy. I particularly remember How to Build a Telescope, which aroused my lust then dumped me when I found out I didn’t have enough money to but the mirror blanks.

The single issue that most challenged the writers of those books was how to convey the scale of things. Now, if you are under forty, you will have to project your mind back to the days when print technology did not include glossy paper and color photography. Visualize a few grainy black and white photos, a few drawings, and lots and lots of words. Like, “If the distance from the Sun to the Earth were equal to the thickness of a sheet of paper, then the distance to Alpha Centauri . . . “

I grew up figuring out that kind of analogy, but if I gave such a book to one of my modern students, their eyes would glaze over and the wheels would stop turning. The children of Sesame Street have to be shown.

Would you like a simple example? Did you know that a softball is moon-size in comparison to a 12 inch classroom globe of the Earth? And if you hold the softball 30 feet away from the globe, it will be proportional in distance as well as size.

For the rest of the solar system, you can’t show both proportional size and proportional distance in a classroom. You can buy a poster with the proportional sizes, but the planets are all on top of each other. If you make a chart of proportional distances, the individual planets will be too small to see.

You can do both, however, if you are willing to take the exercise outside.

We are about to make a model of the solar system. If you want to get out your calculator, be my guest, but I’ve already done the math and I’m willing to share. The scale I used was one to one billion. It would be easier in metrics, but we will eventually be using a local road map for this, so the good ole American system will have to do.

The chart below is in miles and double-steps. That’s because we want your students to get into the act and count the distance to the planets. A double step is normal walking, counting every time your left foot hits the ground, one-and-two-and-three-and . . .

Your sun will be about five feet in diameter. I looked for years for a balloon that size and never found one, so each year I made a new five foot diameter circle of paper and taped it to the outside wall of my classroom. The distances you need are:

Mercury        38 double steps
Venus            71 double steps
Earth             99 double steps
Mars            150 double steps
Jupiter         513 double steps or 0.5 miles
Saturn                                           0.9 miles
Uranus                                         1.7 miles
Neptune                                       2.7 miles
Pluto                                            3.5 miles

You can skip Pluto if you want, but when I first started doing this, it was still a planet.

Give some of your students models of the planets (we’ll talk about sizes below) and take off with the whole class, counting double steps. At 38, leave the student with the Mercury model and continue with the rest of the class. Et cetera.

My double steps go through Jupiter because our playground allowed us to get almost that far. When we reached the boundary fence, I would tell them, “Jupiter is just beyond that house.” Then I would reel off where Saturn through Pluto would be found. My recital would mean nothing to you; you need to make up your own. Find a large scale local map, measure out distances from your classroom, and memorize them. (For us, Pluto was in the next village.)

None of this would be worthwhile without models to show how small our planets are in comparison to the space they inhabit. I made Mercury, Venus, Earth, Mars, and Pluto out of  beads or glass headed pins, stuck into dowels. Be sure to paint the dowels orange for when Johnny loses one in the long grass. The rest of the planets were made of rubber balls found after multiple trips to toy stores, and painted with artists’ acrylics.

You need these sizes, and this time I’m going metric because it’s way easier.

Mercury       5 mm
Venus        12 mm
Earth         13 mm
Mars           7 mm
Jupiter     143 mm
Saturn     121 mm
Uranus      52 mm
Neptune    50 mm
Pluto            3 mm

Feel free to pass this on to anyone who might want to make this model.

187. The Rest of the Landings

Everybody remembers Apollo 11 because it was the first, and Apollo 13 because it failed. And because they made a movie about it. There were five other moon landings.

Apollo 12 — This flight made a precision landing in the Sea of Storms, near the landing place of the Surveyor 3 unmanned probe. Pete Conrad and Alan Bean walked on the moon while Richard Gordon remained in the command module.

Apollo 13 — Once we had reached the moon with Apollo 11 and repeated with Apollo 12, public interest dropped off dramatically. The Apollo 13 flight saw reduced coverage until the explosion. In the movie, Marilyn Lovell says about the newsmen laying siege to her house, “Landing on the moon wasn’t dramatic enough for them – why should not landing on it be?” It is a fitting statement about the last half of the Apollo program.

Apollo 13 suffered a catastrophic explosion and barely got its crew back alive, without landing on the moon. Jim Lovell, Fred Haise and Jack Swigert became part of American myth, especially after the movie Apollo 13.

Apollo 14 — Alan Shepard and Edgar Mitchel piloted their lander to Fra Mauro, the planned destination of Apollo 13. Stuart Roosa was command module pilot.

Apollo 15 — Al Wordon was the command module pilot. David Scott and James Irwin landed on the moon near Hadley rille. This was the first mission to carry a lunar rover, a powered wheeled vehicle that allowed the astronauts to range further from their landing site.

Apollo 16 — Ken Mattingly – who had missed the Apollo 13 mission due to a measles scare – was command module pilot. John Young and Charles Duke landed in the lunar highlands where they collected samples that were geologically older than those brought back by previous missions. Second use of a lunar rover.

Apollo 17 — Ronald Evans was the command module pilot of the last moon mission. Gene Cernan and Harrison Schmitt became the last two men on the moon (so far). They carried the third lunar rover. Schmitt, a geologist, was the only scientist-astronaut to reach the moon.

Apollo 20 was cancelled so its Saturn five booster could be used to launch Skylab. Apollo 18 and 19 were cancelled by budget cuts. All this was done before the launch of Apollo 16, so Cernan, Schmitt, and Evans knew that they would be the last.

For now.

*          *           *

There is one good video of a lunar lander launching from the moon, taken during the last mission. You see a few seconds of it occasionally on PBS space specials. I also found it a this URL: https://www.youtube.com/watch?v=XlGis35Epvs

This appears to be legit, although the things you can find on You-Tube are sometimes outrageously fake. The pictures were taken from a video-camera mounted on the lunar rover, remote controlled from Earth. Similar filming had been attempted on Apollo 15 and 16, without much success.

186. Apollo 11

Apollo 11 was the first moon landing, but Apollo 13 got the movie because of the extra drama. Except for the absent landing, you probably won’t find a better picture of an Apollo mission than that film. This visuals are stunning and the portrayal of events is quite accurate.

Apollo 11, 47 years ago today, was a complete success, but it flirted with disaster twice, in two separate events, minutes apart during the landing. It was broadcast live, so everyone in America and half the rest of the world heard the crises in real time, but you would have needed to be an insider to understand them at the time. I was listening, glued to the TV screen, and I only later realized what was happening right in front of me.

The lunar lander separated from the command module as scheduled. Armstrong and Aldrin fired its rockets to slow its orbit. As it fell toward the moon, there was an alarm – a code 1202 – on the lander’s main computer. Only two men at mission control knew immediately what it meant. The mission was so complex that there were probably thousands of things only a few of those present fully understood.

The computer was overloading. Too many things were happening at once for it to handle. You need to remember the incredibly tiny capacity of 1969 computers. It could not keep up with events, the queue was getting long, so the alarm sounded. Steve Bales recognized that the computer was still doing everything it needed to do, that it would clear the queue in a few seconds, and said GO when most of those present were thinking ABORT. The mission continued, the computer worked through the queue, and then the alarm went off again. Bales said GO. A third time the computer overloaded and Bales shouted GO for the third time just as the lander was approaching touchdown.

The problems weren’t over. The lander had overshot its target and Armstrong found himself over a massive boulder field. There was nowhere to land.

An abort would have meant firing off the upper stage rocket and returning to the command module, allowing the now nearly empty lower section to crash to the moon, and missing the landing. Instead, Armstrong chose to adjust his rate of fall to a near hoover, tilt the entire lander – now top heavy and prone to flipping – to slide sideways and, just as the last of the fuel was nearly gone, reach a clear area where he set the lander down on the lunar surface.

On Earth, we had all been holding our breaths. We just didn’t realize how much reason we had had to worry.

185. The Flying Bedstead

300px-LLRV_2Tomorrow is the anniversary of the Apollo 11 moon landing. For most of the followers of this blog, it is part of history. I saw it happen, on a grainy black and white TV in the lounge of a college dorm. (see 27. That Was My Childhood)

You can’t land on the moon by parachute, nor by wings. No air. The only choice the Apollo program had was to land tail first, by rockets, something that had been a science fiction staple for decades, but was nothing like easy to manage. (see yesterday’s post)

Designing a craft to do the work was within the limits of the technology of the day. Vertical landings on Earth had been successfully accomplished. Pilot control on Apollo was expedited by having the astronauts stand to fly the Lunar Lander; the problem with VTOL planes had been that the pilots were strapped into a seat that kept them facing the wrong way when they landed.

The craft could be built, the astronauts were the best test pilots America had to offer. But how do you train?

Simulators? Maybe. Resurrect Pogo or Vertijet? Perhaps. Build a new craft just to use as a trainer? Better. But how do you build a trainer to react as if it were in a 1/6 gee field while landing in on Earth? You can’t just make gravity go away – or can you.

The answer is almost, more-or-less, and good enough to do the job. The first iteration of the trainer was the Lunar Landing Research Vehicle, nicknamed the flying bedstead. You may have seen it. Neil Armstrong ejected from one of them after the controls failed; the footage of the crash is both exciting and brief, which gets it a lot of air play in retrospective specials, especially on anniversaries like tomorrow.

If you see footage of the LLRV not crashing, or of the advanced version LLTV (Lunar Landing Training Vehicle), you can easily see what it is all about. The vehicle consists of an open framework of tubing with the pilot sitting upright in the front (in an ejection seat, thank goodness) with a batch of somewhat shrouded equipment balancing the rear. In the middle, attached vertically, pointing downward and clearly throwing flames, is a jet engine. The craft is uneasily hovering.

Note, I didn’t say hovering on its jet. That is what it looks like, but that is not what is happening. Not quite. When the jet is fired up at takeoff, the LLRV or LLTV simply sits there. The jet has 5/6 of the thrust needed to lift the craft. While hovering, the rest of the thrust is provided by a separate set of hydrogen peroxide thrusters which are controlled by the pilot. If the pilot were to simply turn off his thrusters, the LLTV would crash to the ground at the same speed it would crash to the moon.

The jet subtracts enough of the LLTV’s mass to make it react as if it were in a 1/6 gee gravity field, allowing the pilot to maneuver his craft as if he were coming in for a lunar landing. Armstrong made over fifty LLTV landings before he landed on the moon.

If you want to know more about this craft, there is a half hour special full of information, old footage, and interviews with retired LLRV pilot and an engineer from the project. Huell Howser is the host. If you live in California, and you watch PBS, you know Huell. He is an acquired taste that I have never quite been able to acquire, but sometimes what he covers makes up for his idiosyncrasies. This is one of those cases. The program is California’s Gold #13003 – LUNAR LANDING. Try your local PBS station or check with the Huell Howser Archives at Chapman University.