SPACE CENTER, Houston The U.S. presidential election still might be too close to call, but this much is certain: The deciding vote will not come from outer space.

Amid an unprecedented court clash to determine whether George W. Bush or Al Gore will take up residence at the White House, NASA officials told SPACE.com that U.S. astronaut Bill Shepherd voted before rocketing off for Space Station Alpha late last month.

"I have been told that 'Shep did in fact cast an absentee ballot," said former NASA chief astronaut Robert Cabana, now a senior manager in the agencys space station project office.

Cabana and other NASA officials were not certain whether the former Navy Seal voted for Bush or Gore, but that detail is a moot point.

A Houston resident, Shepherd cast his ballot in Texas a state that Bush won decisively in the November 7, 2000 election. The Texas governor tallied 59 percent of the vote in the Lone Star State and already has been declared the winner of its 32 Electoral College votes.

Voting by absentee ballot is fast becoming standard operating procedure for U.S. astronauts.

Four American astronauts destined to launch aboard shuttle Endeavour November 30 also cast absentee ballots in this years presidential election. The reason: They were taking part in a practice countdown at Kennedy Space Center in Florida on Election Day.

Cabana said future U.S. space shuttle and space station crews likely would follow Shepherds lead, casting absentee ballots before rocketing off on missions launched during election season.

"Im sure that they are all going to make sure they get their opportunity to vote before launch," Cabana said. "I think the absentee system will work right now."

Voting from space, however, is not unprecedented.

Thanks to a change in Texas election law, NASA astronaut David Wolf was able to vote via e-mail from Russias space station Mir in 1997.

His ballot was e-mailed from the Harris County clerks office here to Johnson Space Center and then routed to the orbiting station from the Russian Mission Control Center outside Moscow.

Wolf, who was in the midst of a four-month Mir tour at the time, used a laptop computer to vote in Houston mayoral and city council races, as well as a number of local referendums.

The e-mail voting process then was reversed so his ballot could be delivered to the county clerks office, marking the first time a U.S. astronaut had voted from orbit.

The Texas Legislature changed its election law in May 1997 to allow astronauts to cast ballots from space. Prior to that, absentee ballots had to be mailed in, which created a problem for people in places where the U.S. Postal Service does not go.

The change came in the wake of the 1996 presidential election and a failed bid to vote from orbit. U.S. astronaut John Blaha was kept from voting in that election because he forgot to mail in his ballot before leaving for a tour of duty on Mir.