Note: this will make a lot more sense if you read the first essay in this series, which sets out the premise that I'm exploring here. Caution, many spoilers below.

by Robert Heinlein, 1950, published by Charles Scribner's Sons.

This is my favorite of all of the Heinlein Juveniles. Once again, Heinlein is raising the standard for a "boys book" by taking on ideas not previously thought to be suitable for the genre. Heinlein takes on two new themes in Farmer In The Sky (although perhaps the word "theme" is a little too confining): family relationships and pioneering spirit. He also goes to even greater efforts to instruct readers in such diverse topics as relativity, ecology and agronomy.

Farmer In The Sky is the story of Bill Lermer and his family as they become pioneering colonists on Jupiter's moon Ganymede. The family, however, is not a simple nuclear family. Bill's mother has died a few years before the book starts and he and his father have lived together. Just before they leave earth to travel to Ganymede, Bill's engineer father marries his drafter, Molly. Molly, along with her daughter from a previous marriage, round out the family, but they also introduce the usual frictions of blended families. Heinlein plays this part of the novel very adult. All of the characters have good intentions, but feelings still get hurt. Bill's father foolishly delays telling him about the marriage until the last minute, which causes Bill to accuse him of never really loving his dead mother. Bill starts out strongly resenting his new stepmother for no good reason, but adapts to the situation over time. And so on. By blending the family, Heinlein can amp up the emotions and put normal family problems in a stronger light. This allows him to use adversity to bind them together all the more tightly as the novel develops.

In this version of the future, Heinlein has postulated an over-crowded earth that cannot support its population. All of the world is rationing food while exploring ever more synthetic ways to make food. Emigration is promoted as a way of shedding population, with emigrants to Ganymede promised unrationed food supplies and free land. This part of the book isn't very well thought-out or explored to any depth by Heinlein, it was just a springboard to get to the story he wanted to tell. After all, if pioneers on Ganymede can eke generous amounts of food out of the native rock of Ganymede using futuristic technology, humans on earth ought to be able to figure out how to feed themselves through the same level of technology. Indeed, the "green revolution" would do just that in the 1960's and 1970's.

To make colonizing Ganymede possible, Heinlein only waves his hands twice. First, he postulates the technology of total mass conversion, where any mass can be converted to enormous amounts of energy. This is theoretically possible, but pretty unlikely in the near future. Second, he invents a technology called a "heat trap". This is an energy field of some sort that surrounds Ganymede and allows photons from the sun to easily come in, but not so easily escape. It's a one-way mirror around a whole moon. I have no idea if this is even theoretically possible, but it's a simple and effective plot device for enabling Ganymede to be livable. By using copious amounts of energy, the native ice of Ganymede has been transformed into a breathable atmosphere (which isn't much of a stretch of the imagination, similar schemes have been proposed in modern times for Mars).

As pioneers, the Lermers are subject to all of the hardships and trials that pioneers usually are. They are starting from scratch, with nothing but unprocessed rock for land. They have to crush the rock and blend it with biological materials to make soil before they can even begin the arduous task of farming. They battle the elements and natural disasters, just as pioneers in the American west did (although there are no equivalents to Native Americans or dangerous animals).

Heinlein goes far past the usual type of pioneering or frontier story that you would get from James Fenimore Cooper or Jack London. Bill undergoes true hardships. People close to him die in ugly ways and he has to face the possibility that pioneering Ganymede might fail and that none of them may get out of it alive. Farmer In The Sky is a lot more than an adventure novel. I think Heinlein was again serving his own purposes here. I think he believed that an era of exploration and pioneering was coming soon and he wanted to prepare his readers for it (he was wrong of course, the heart for exploration and pioneering would go out of western civilization during the 1960's and 1970's, but so it goes). He was letting readers know that they would face enormous difficulties and endure serious hardships along the way. Even more importantly, they would have to deal with the fact that, at some point, a colonist has to leave the old home behind; not just physically, but emotionally as well. At some point, the emigrant has to embrace his new land and let the old one go.

Heinlein covers an unusually wide ranges of science and technology in this book. The discussion of terraforming Ganymede is detailed and meticulous, even down to the kinds of insects allowed in and the kinds not allowed. The discussion on general relativity is a bit lacking (Heinlein clearly didn't understand it very well at this point, he would in later books, such as Time for the Stars), but not incorrect. The discussions about cosmic rays are incorrect by today's knowledge, but correct for 1950. The descriptions of the fantastic interplay of Jupiter and its moons in the sky above Ganymede are more than correct, they're beautiful as well (I think the only better scenery in the solar system is the similar interplay of Saturn and its moons).

Clifford Geary's illustrations are quite nice, although there is a subtle mistake in the picture above. That smokestack on the back of the rock crusher shouldn't be there. Ganymede has no petroleum, of course (although in real life, we now know that there is a good deal of hydrogen, methane and oxygen out around Jupiter's moons, so a hydrogen or methane engine would be OK). All of the power used by the colony is nuclear and it is "beamed" to houses and machinery around the moon. The fact that this slipped through leads me to think that Heinlein didn't get to review the pictures before they were included in the book.

Scouting and the Boy Scouts play a prominent role in the book, no doubt because the story was first serialized in the scouting publication of the time, Boy's Life (which I used to get myself when I was a kid). Heinlein also has a bit of a fetish for describing meals and this shows up more in this book than any others. Since Bill is from a society that rations food, he is blown away by the food available on Ganymede.

The last section of the book is an almost an invocation of a dues ex machina, where Bill goes along on a surveying expedition to an unexplored pert of Ganymede where he and friend accidentally discover the remains of an ancient alien occupation of Ganymede. Along the way, Bill's appendix bursts and he almost dies before he can be brought to a medical facility. At first glance, this section seems like it's tacked on to give the ending some pizzaz, but it's actually quite important to the novel. Heinlein needed an event where Bill is almost killed so that he could force an emotional crisis. The appendix and ensuing hospital stay push Bill right to the edge. He has decided that pioneering and exploration are too hard and too risky. Only at the last minute does he discover that he doesn't want to give up. He has adopted a new home and he intends to stay and make the best of it he can. This, I think, was the whole point of the novel. Heinlein is letting his readers know that it's not going to be easy and they'll face times when they really, really want to give up and do something easier.