THERE HASN'T been a four-hour TV movie about the life of an astronaut, or the space effort in general. There hasn't been a four-hour movie about Thomas Jefferson. But there is a four-hour TV movie, tonight and tomorrow night on NBC, about Gary Gilmore.

Gilmore was executed by a firing squad on Jan. 17, 1977, but comes now the moment of cashing in, as NBC perversely kicks off the holiday viewing season with "The Executioner's Song," a sordid and lugubrious TV movie based on Norman Mailer's book about the cold-blooded killer whose last victim was himself. As much television time has been allotted to the story of Gary Gilmore as was devoted to the life of Golda Meir. Perhaps this comparison is tacitly unfair, but it does afford some sort of perspective on network priorities. The networks in fact turned down the film "A Woman Called Golda," and so it ended up in syndication. A crazed killer is a much more desirable commercial property.

"The Executioner's Song" has an intimidating imprimatur: the name of Norman Mailer, who wrote the screenplay himself--an act, perhaps, of noblesse oblige considering the lowly regard Mailer has previously expressed for television. Because of Mailer's name, many people will assume this is not just another purple docudrama, and they will be right up to a point. A point, however, and a point of view, are what this production, despite Mailer's influence, lacks.

The hoity-toity literary credentials count for nothing over the four-hour haul, which details a life that can be summed up as a blot on society, and one for which society, even in these guilt-slinging times, needn't feel much blame. What Mailer accomplished on the printed page is irrelevant to the story as presented here. Television has to be considered in terms of social effects, and even though Gilmore does come off as largely despicable in the film, it also seems at times to be trying to invest him with some daft facsimile of tragic dignity. Even to have made the film at all ascribes him dignity of some kind. This does not loom as a potentially positive or beneficial experience for those seeing it, especially the impressionable young. (NBC underwrote a "Viewer's Guide" pamphlet for students to finesse this troubling aspect of the project; it tries to make "Song" a comment on the very phenomenon it represents, media glorification of the antihero.)

In the ongoing process of blurring yet another longstanding line -- the one between notoriety and celebrity--"Executioner's Song" looms as something discouragingly ultimate. This judgment is always risky, especially in the realm of television, but with "Executioner's Song," it may truly be said we have reached Rock Bottom.

The man most heavily involved in the Gilmore story is Lawrence Schiller, who was the first to show up with plenty of moola in Utah, where Gilmore lived, killed and died. Schiller, a former Life photographer, has a rather ghoulish sense of territorial imperative. His previous contributions to American TV life include "The Trial of Lee Harvey Oswald" and "Marilyn, the Untold Story" a lurid bio of Marilyn Monroe.

Schiller is the Ziegfeld of grim reaping. He also does not lack for gall. As executive producer of this ill-begotten film, he hired himself to direct it, and a better producer would have found a better director. Schiller can't even bring subsidiary characters into the proper focus, and context is beyond him. If ever a story required careful handling, this one did. It didn't get it.

The film covers roughly the last year in Gilmore's life, starting with his release from 12 years in prison at the age of 35, and ending with the cold morning when he told a firing squad, "Let's do it" after petitioning the courts not to stay his execution. It was the first U.S. execution in 10 years, a sensational case splashed across newspaper pages and TV screens for weeks on end. The legal battle -- between Gilmore, who wanted to die, and those who for various reasons didn't want him executed -- could have been the basis for a film in itself; this would have sensibly narrowed the focus. But it would also have deprived the filmmakers of the story's juiciest components.

Mailer used Schiller's interviews with Gilmore as the basis for the "true-life novel" that became this film. As TV movies go, it is fairly unflinching, especially in dealing with Gilmore's feverish sexual appetites after a dozen years in the slammer, and with the mechanics of execution, but it does flinch now and then. It politely avoids pinpointing which orifice Gilmore's girlfriend Nicole used to smuggle drugs to Gilmore in prison after the two of them agreed on a suicide pact. And it is, naturally, more discreet about Gilmore's sex life than was Mailer on the printed page.

This aspect of Gilmore's painful, failed attempt at readjustment to life on the outside gives the film its most poignant, credible moments, however. Tommy Lee Jones, as Gilmore, conveys the desperation and animal urgency very effectively. After Gilmore and a friend successively flag down two seemingly available young women in a passing car, Gilmore blows his chance by telling one girl with pathetic bluntness, "It's been a long time, and I'd like to have some. Right now."

For a while the film seems to be saying that horniness drove Gilmore to murder. But eventually he does find a mate, his "guardian angel" Nicole, and this occasions one of the film's two genuinely red-hot performances. Rosanna Arquette (granddaughter of the late Cliff Arquette, a.k.a. Charley Weaver) makes the slatternly Nicole a fascinating mess. Even better is Christine Lahti as Brenda, a former girlfriend of Gilmore's who still sees something redeemable, and desirable, within this contemptible figure -- and communicates that physically, rather than with dialogue -- yet has the good sense to turn him in after he brutally murders a motel manager.

In December of 1976, when he bought the rights to Gilmore's life and death, Schiller promised from Hollywood, "I am not going to romanticize Gary Gilmore." But when you devote four hours of TV time to a man's life, you're romanticizing him ipso facto. When you commission Waylon Jennings to compose and sing a few new tunes for the telling of his story, the effect is compounded. Jennings sings, "I don't know if I can get it up to get it on again," "You're gonna have to toe the mark and walk the line," and, in the film's last-minute bid for commentary on The Human Condition, "We don't even know where we are; they tell us we're circling a star." A couple of de rigueur Johnny Cash tunes are tossed in, too; the thick smoke of convict chic almost reaches choke levels.

Naturally there are scenes in which Gilmore is depicted as a victim -- of his environment, of circumstance, of the reentry problems faced by ex-cons. But there really don't appear to be commanding social implications to this story beyond the truism that locking people up for crimes they commit does nothing to reform them. "Executioner's Song" is presented as if it were heavy with portents and significance, but these remain elusive.

Mailer saw some sort of male rogue poetry -- his favorite kind -- in this vicious killer (who shot his first victim, a service station attendant, twice, in the back of the head, after forcing the man to lie face down on a men's room floor). He has Gilmore voicing Deep Thoughts like "You have to free yourself; that's the whole point of living" during a lecture on "karma." In prison, Gilmore tells a cellmate he would never stoop to faking insanity to save his own neck, and the cellmate, speaking pure Mailerese, says, "No, that offends a man's true sense of himself." What bilge.

Schiller has himself portrayed in the film, by someone considerably thinner than he is (Steven Keats) and is seen waxing indignant when an unnamed voice on the phone offers money for Schiller's "seat" at the execution. The very idea! Doesn't that guy on the phone know he's talking to someone with integrity -- or at least some rationalized new redefinition of it? The media circus surrounding the execution is also dutifully noted, but you don't have to be very picky to find this hypocritical.

In the fourth hour, Jones as Gilmore tells Eli Wallach, as the uncle who befriended him and was betrayed, "I just want it to be over," and this is one sentiment in the picture that it's a snap to share. "Executioner's Song" is the kind of production that makes one feel a little contaminated for having seen only a few minutes of it. What was hailed in some quarters as a print "masterpiece" has become another sorry spectacle with which to sell soda pop and detergent on television, and I say the hell with it.