HEROISM comes in many different shapes and with many different motivations. Down through the centuries there are many instances of personal valor in the face of danger: Admiral Nelson at Trafalgar; the United States Marines at such desolate places as Iwo Jima; and the young officer overrun by the Viet Cong in Vietnam who called down air and artillery strikes on his own position.
There is heroism in pursuit of freedom: the fight of the French Resistance against German occupation; the young Hungarians who hurled their gasoline bombs against Soviet tanks; the refugees crawling through the barbed wire to West Berlin; the Sakharovs today; and all the others who resist tyrannical regimes.
There are those who risked their own lives for the freedom of others: those who tried to free prisoners of war in North Vietnam and hostages in Iran.
There are the heroes of discovery and exploration: Sir Francis Drake, and Columbus, and Dr. Livingstone and his quest for the origin of the Nile in steaming Africa, and the Scotts and Amundsens, who sought to conquer frozen polar wastes.
More recently, the heroes of the young have become the singers of popular music and the champions astride our sports fields. They wield enormous influence upon impressionable youngsters. With the fame, and the wealth, there should go responsibility to steer young fans away from the dangers and indignity of drugs, such as cocaine.
And then there are the often-unsung heroes and heroines who take stands for principle: the whistle-blower on Pentagon extravagance; the TV anchor woman who fought the station that dropped her because of her looks; the politician who quits office on a matter of conscience; the individuals who sometimes face great personal loss to make a point for religious freedom or racial justice.
To the history books that chronicle for our children the heroism and duplicity of human experience, a new chapter will soon be added. It is the story of Christa McAuliffe, the New Hampshire schoolteacher-turned-astronaut, who flew with six other space explorers this week in the space shuttle that exploded.
People who knew her say that in her history classes at the Concord High School she emphasized the impact of ordinary people on history, stressing that they were as important to the historical record as kings, politicians, or generals.
And though there is no intent to lessen the contribution of the six space professionals who flew with her this week, it is as an ``ordinary person'' who undertook an extraordinary venture that she will take her place as one of history's heroines.
Though there was some fame, and perhaps ultimately a book, to be derived from her experiences, Christa McAuliffe's motivation in becoming the first citizen-astronaut seems to have been an extension of the philosophy she offered her high school students -- to accept a challenge, to reach out to their highest constructive potential.
She could have stayed comfortably at home. She did not.
It is the same impulse of quest and inquiry that has solved for mankind many mysteries, unlocked many wonders, and made possible many technological marvels. To suggest that man and woman should cease from expanding the limits of our environment is as pointless as arguing that the discoverers of the New World should never have sailed, or that Chuck Yeager should never have pushed through the sound barrier.
For children around the world, Mrs. McAuliffe sought to make intelligible some of the present mysteries of space, perhaps motivating them to further inquiry, maybe even inspiring some among them to participate in space exploration in years to come.
In one of the most moving little speeches of his tenure, President Reagan, in paying tribute to the seven crew members, said: ``The future doesn't belong to the fainthearted. It belongs to the brave.''
It is boldness of heart and mind that has given us a new American heroine.