Samantha Smith is heading for one of the most beautiful spots in this huge nation: the seaside summer camp called Artek, near Yalta on the Black Sea. Artek, part of an enormous countrywide network of ''Pioneer camps'' which handles some 15 million Soviet children each year, is the distinctly Soviet answer to the good old American summer camp.
In addition, the retreat seems to have been the showcase camp for foreigners ever since the 1930s, when under Stalin, children of anti-Franco fighters in the Spanish civil war were welcomed there. Visitors have even included some Americans.
For Russian parents, getting a child into Artek for the summer is the equivalent of an American couple's getting him front-row tickets for the World Series.
At the typical ''Pionerskii lager,'' sports and other outdoor activities are a main order of business. Depending on the camp, there are greater or lesser helpings of arts and crafts, nature hikes, and the like. Soviet children genuinely look forward to Pioneer camp, and the outdoorsy activity is not too far from what Samantha might see in Maine.
The Pioneer camp - like Soviet schools - generally includes a far higher degree of organization, however, and far less truly free time, than its Western counterpart.
There is also emphasis - though this may or may not be true of the camps like Artek that receive foreigners - on what is known hereabouts as ''patriotic upbringing,'' inspiring in children from a young age an unshakable ''love for the motherland.''
A good deal of this process involves singing patriotic songs and hearing of the glories of Soviet history. But last Sunday a weekly Soviet TV program on military issues, called ''I Serve the Soviet Union,'' showed a film clip of Soviet youngsters at Artek garbed in camouflage gear and toting what appeared to be real, though presumably not loaded, Kalashnikov rifles.
It's probably fair to assume that Samantha won't be in on that activity.
Precisely what kind of welcome she will get in the Soviet Union is hard to say at this point. Soviet television news, prefacing what seems likely to be a good deal of news-media attention, has picked up short clips of various US television interviews with the young girl of late.
Although there has been no official word on this, the expectation among diplomats here is that Samantha will also meet Yuri Andropov. That would make her one of three Americans to do so since the transition in command: Vice-President George Bush, former Ambassador W. Averell Harriman, and Samantha.
This kind of treatment - as opposed to a mere stay in Artek - has no precedent in the history of the Soviet Union, nor in the history of Soviet-US relations.
The consensus of American and other Western diplomats here is that, all in all, the decision to invite Samantha and family for a firsthand look is a brilliant public relations stroke.
As for the likely results of the trip, there are basically two opinions in the diplomatic community:
* The first, and probably the majority, including a good number of American diplomats, is that Samantha, no matter what her own intentions, is likely to be used for considerable public relations capital by the Kremlin.
The Soviets' message: We are unswervingly for peace. We are a normal country with children of our own, nice children who go to nice summer camps. We are ruled by a man who answers the letters of 11-year-olds. All this, even though the President in the country where Samantha lives keeps spreading lies to the contrary. (Most diplomats don't think the visit will change world history but, for the above reasons, don't like the idea much anyway.)
* The second is that the visit could conceivably backfire (but again, not on a history-making scale). Children can be refreshingly candid, and it seems pretty unlikely that Samantha will come and go without saying at least a thing or two the Soviets would rather she hadn't.