THE United States Supreme Court could come bursting into the schoolyard this year, as it has in the past, with key decisions involving prayer, free speech, and teen-age abortion. Other school-related rulings on parochiaid and textbook content may also be heading for the high court.
The justices have already scheduled for their 1987-88 docket - which will begin Oct. 1 - a New Jersey case that will test the validity of that state's ``moment of silence'' law.
A federal appellate court has blocked enforcement of the statute on the grounds that it was an unconstitutional establishment of religion because its purpose was to accommodate students who wanted to pray.
Two years ago, the high court struck down an Alabama moment-of-silence law - citing legislative history that showed its ``sole purpose'' was to foster prayer. Thus, it was in conflict with First Amendment provisions for separation of church and state.
The New Jersey law, however, makes no specific mention of prayer. It requires schools to permit students to observe a moment of silence at the outset of each school day ``to be used solely at the discretion of the individual student'' for ``quiet and private contemplation and introspection.''
Supporters of the law include President Reagan and the Justice Department, each stressing that this type of meditation could foster religious tolerance rather than church-state entanglement. Opponents, among them civil libertarians and religious-freedom groups, insist that the real purpose of the New Jersey law is to introduce religion into the classroom.
In the early 1960s, the Supreme Court outlawed organized school prayer. And since that time there has been a strong thrust from the political right to ``bring God back into the classroom'' through legislation, constitutional amendment, or high court ruling.
A Missouri case, to be heard next term, also speaks to a First Amendment issue - but this dispute involves rights of speech. The main question is whether the Constitution's guarantee of freedom of the press extends to a high school newspaper.
The case pits the rights of students to report on social issues important to their age group - specifically, teen-age pregnancies and divorce by their parents - against the responsibility of school officials to control the academic environment.
An appellate court ruled last summer that the First Amendment does cover high school newspapers and declared that students may publish what they wish as long as the stories do not ``materially disrupt'' the school atmosphere or result in a lawsuit against administrators.
In bringing the case to the high court, Missouri school officials argue that the school - not the students - publishes the paper and that the principal has final authority over what is printed.
The justices, through the years, have ruled both ways on student speech. In 1969, they upheld the right to wear black armbands on school grounds to protest the Vietnam war.
Two years ago, however, in what is considered a landmark decision, the court held that students do not have the same rights as adults do to be free from warrantless searches and seizures. The case involved a New Jersey schoolgirl suspected of carrying drugs in her purse.
Last year, the justices said that a high school student has no constitutional right to make a ``lewd and offensive'' speech in a school assembly.
The abortion case - postponed from last term - tests the constitutionality of an Illinois law that restricts minors' access to abortion. The statute, struck down in part by an appellate court, requires unmarried minors seeking abortions to notify both parents at least 24 hours beforehand unless they can convince a judge they are mature enough to make their own decisions. This case could affect parental notification requirements in about 20 states.
Although not now on the court's docket, one or more cases involving public aid to private and religious schools may well be accepted by the justices in time for next term's sessions. Also almost inevitably headed for the nation's highest tribunal - perhaps next year - are cases now being litigated in lower courts involving public textbook materials deemed offensive to some parents' religious values.
In June, the Supreme Court decisively struck down a Louisiana law that forbade the teaching of evolution in public schools unless it was accompanied by instruction in ``creation science.''
Curtis J. Sitomer writes on legal affairs for the Monitor.