February 23, 1986

New theories about wind and cold weather have become a major focus of the Presidential commission investigating the explosion of the space shuttle Challenger. The new focus on cold comes amid reports that temperatures as low as 8 degrees Fahrenheit below zero were recorded on a strut of the shuttle's right-side booster rocket just before the liftoff; previous estimates put the temperature at 7 to 9 degrees above zero. Low temperatures at launching on the morning of Jan. 28 are thought by some aerospace experts to have contributed to a failure of the Challenger's right-side booster rocket, leading to the explosion that killed the seven crew members. Effects of Wind The theory now emerging among commission members and aerospace experts is that winds blowing over the Challenger's external tank of supercold liquid fuel might have ''refrigerated'' the nearby right-side booster. The rubbery O rings that seal the joints between the four segments of the boosters are sensitive to cold, and speculation is that refrigeration might have caused them to fail, allowing flames to escape the booster and touch off the explosion.

WITHIN the last few weeks, Westchester officials have released two separate lists of measures that they want passed by the State Legislature during its current session. Although there is agreement on such key issues as the repeated call for a 3 percent hotel-occupancy tax and the need for reallocation of hydroelectric power in the state, the individual packages - one issued by County Executive Andrew P. O'Rourke, the other by the Board of Legislators - represent a break with recent tradition. Mr. O'Rourke's predecessor, Alfred B. DelBello, had begun the practice of preparing a joint package with the Board during the latter years of his administration. This year's change has been cited by some political observers as an indication of a growing rift between the county's executive and legislative branches. One immediate result of the two packages is the glimpse they offer into the relations between the ninth floor of the County Office Building in White Plains, where Mr. O'Rourke and his staff have their offices, and the eighth floor, where the Board's offices are located. Some of the officials who were instrumental in drafting the measures concede that they are not optimistic about getting many of the requests passed in the Legislature.

Home buyers have until Friday to submit registration forms for 30-year fixed-rate mortgages offered by the State of New York Mortgage Agency with the lowest rate ever charged under the agency's affordable housing program - 9.2 percent. The mortgages can be for single-family homes, condominiums and - for the first time in the program - co-ops.

King Hussein of Jordan, challenging the leadership of Yasir Arafat, chairman of the Palestine Liberation Organization, called on the Palestinian people today to decide who should lead them. In an interview, he said he would ''respect'' a decision by Palestinians to preserve the P.L.O. as the ''sole legitimate representative'' of the Palestinian people. But he said another ''apparatus'' to express their wishes would also be welcomed in Jordan. 'What Do They Want Us to Do?'

HUNDREDS of Connecticut residents travel out of state each year for open-heart surgery, but that may soon change. For the first time in more than a decade, several hospitals around the state are considering offering the surgery. But state officials are debating whether the six hospitals that already perform the procedure- all of them in New Haven, Bridgeport and Hartford - are enough. The question touches on several issues, including community-based care, the future of open-heart surgery, the cost and safety of alternatives and the state's role in regulating health care. These larger issues have surfaced in what at first appeared merely a technical dispute between Danbury Hospital and the Connecticut Commission on Hospitals and Health Care.