Without extended discussion or any debate, the Senate Rules Committee yesterday approved a $65 million, 10-year program to establish a state-of-the-art data transmission system that would link Senate computers on Capitol Hill with those in members' home-state offices.

Together with new transmission facilities, the entire program will cost the Senate $95 million over a decade, according to Sen. Wendell H. Ford (D-Ky.), chairman of the committee.

The new system would vastly expand current data transmission capacity and increase its speed by eight times. In addition, it would allow computer systems in various Senate offices to talk to each other, which they cannot do now.

The Senate's data transmission network is the latest of a series of high-tech innovations that the Senate and House have been quietly approving for themselves in the name of increasing the efficiency of their operations.

These programs have the added benefit of helping senators service their constituents more effectively or increasing opportunities for members to contact voters in nonpartisan situations. None of the technological advances is directly related to senators' roles as legislators.

At yesterday's meeting, the Rules Committee approved without discussion a resolution that could have the effect of increasing next year's official mail allowances for senators almost 50 percent above the amount allocated to them this year. It also would allow a senator to accumulate mail funds from one year to the next so that he or she could do several mass mailings in the year before reelection.

Behind the Senate need for a vastly expanded data transmission network is the trend, begun in the late 1970s, of members increasing their presence at home by expanding the number of home-state offices. In 1970, the 100 senators had 140 offices back home; by 1981 that number had grown to 306 and this year it totals 394.

The growth in offices has been accompanied by an increase in personnel working back in the states. There were 1,600 last year. The number is expected to reach 2,000 next year, according to Senate documents.

In the last year, more than 1,500 personal computers have been placed in the home offices of senators, said one Senate aide involved in the process. "We want to make the state offices just like they were right across the hall from the Washington offices," he added. The existence of computers coupled with the Senate's new work schedule appears to be encouraging the movement of Senate work from Washington to home states. Senate Majority Leader George J. Mitchell (D-Maine) decided last year that the Senate would be in session for stretches of three weeks, then off a week. As a result, members go home more often where they "want to be able to sign letters and do other work as if they were on Capitol Hill," said the aide.

The existing Senate data transmission system, which costs less than $6 million a year to operate, is a piecemeal one that connects individual senators with some of their home offices and is considered inadequate and unsatisfactory for the future, according to Senate aides.

"Senators' needs for data exceeds existing capacity," said Ford, introducing the resolution approving the system. Sen. Ted Stevens (Alaska), the ranking Republican on the panel, called the proposal the "most efficient and cost effective solution" to the data transmission problem.

The proposed system was developed by a team that included the General Accounting Office, the Senate Computer Center and consultant firms such as Booz, Allen & Hamilton Inc.

A year ago, when the system was put out for bid, Senate aides estimated it would end up costing about $4 million per month. The winning bid, from Planning Research Corp. of McLean, is higher, sources said, because there are more home offices and the capability of the system is expandable.

Once the contract is signed, the cost to the Senate for the first year will be $11 million because of high start-up costs, Ford said. Thereafter, he said, the annual cost will go down. Funds for the first year are contained in the fiscal 1991 legislative appropriation request for the Senate sergeant-at-arms that is before the Senate Appropriations Committee.

Once the Senate system is in place, the House and other Capitol Hill entities will be able to participate if they want, Senate aides said.

Currently, House members send and receive data from their home offices on leased lines or through the House telephone system. Hamish Murray, staff director for computers and communications of the House Administration subcommittee on office systems, said the House may join the Senate network when it is operating next year to save money on transmission costs.