More than a hundred members of the US House of Representatives have signed on to an effort to ban all weapons from space. They expect June committee hearings on a joint resolution calling for President Reagan to immediately resume negotiations on such a ban with the Soviet Union. They know the superpowers have realized - too late - that they should not have escalated the arms race on earth with the hydra-headed MIRV. A similar mistake in space can be avoided by acting beforem it is too late.
What might make the difference this time?
When MIRV came along it was much discussed by the weaponeers. But for much of the public it was just one extra acronym, and ''those boys must know what they're doing.''
Space weapons may be more exotic. But who is not aware of the giant leap from warfare of today to warfare conducted by beams and projectiles on vehicles in space or celestial bodies themselves?
It's not just the return of the Jedi on the ''Star Wars'' screen. It is Moscow's far from fictional development of space weaponry. It is the General Accounting Office's warning that America's ASAT (anti-satellite weapon) would cost ''tens of billions'' to deploy. It is a group of senior American scientists , including Nobel prize winners Hans Bethe and Isidor Rabi, urging both Moscow and Washington to institute a ban. It is Mr. Reagan's speech calling for new technology in defense weapons to permit the US to move away from having to threaten retaliation to deter attack. Aides began speaking about lasers and other new weapons. Even though space deployment was not necessarily the only option, the Reagan address was soon dubbed the ''Star Wars'' speech.
The United States can hardly forgo research on a range of space defenses so long as Russia jets forward. The answer is for both sides, and indeed the whole planetary community, to agree that humanity's common stake in survival should be enough to put space off limits for arms.
It is primarily a matter of dollars and cents to Rep. Joseph Moakley (D) of Massachusetts, who filed the House resolution back in September and again in February. ''I'm not a peacenik,'' he notes.
No one has to be a peacenik to see both economic and security reasons for reducing the perimeters of war. The Senate also has bipartisan sponsorship for a counterpart to the Moakley resolution. It is considering a more limited resolution, too.
The merit of a comprehensive ban now is to pin down progress beyond the space treaty of 1967. The proposed joint resolution adds to Moscow-Washington negotiations a call for the United Nations to go back to Article IV of the earlier treaty. This article bans nuclear weapons ''or any other kinds of weapons of mass destruction.'' The joint resolution would go farther, eliminating all weapons not only from use in space but from use on the ground against targets in space.
The public today is less supine on arms control than it was when MIRV was being unleashed. Will it be up to saving the realms of space for the Jedi and other knights of the imagination? Who can it blame if it does not?