Embraer to build the pallet and other related hardware. The pallet, which was designed to accommodate small experiments on the outside of the station, was to be delivered to NASA in time for an April 2005 launch.

Brazil joined the space station program in 1997 agreeing to supply NASA with the Express pallet and other payload and logistics hardware in exchange for research capability and crew time aboard the international space station. NASA at the time estimated the value of Brazil's contribution at $200 million.

The Express Pallet is not considered a vital space station component. NASA had already dropped the pallet from its plans when the Brazilian's stepped forward looking for a way to participate in the international program.

In his letter to O'Keefe, Sardenberg said he hopes that Brazil can remain involved in the space station program. "[W]e remain interested in maintaining the Brazilian participation in the ISS program and are ready to renegotiate thoroughly the terms of the arrangement so that it becomes comparable with our budgetary constraints," Sardenberg wrote.

NASA spokeswoman Debra Rahn said Sardenberg's letter arrived in response to a request from NASA Administrator Sean O'Keefe asking Brazil to reconfirm by mid-July its commitment to completing the Express Pallet in time for the targeted launch date. In the letter, a copy of which was obtained by Space News, Sardenberg wrote that he could not presently offer such reassurance and requested a meeting to discuss Brazil's continued participation in the program.

Rahn said NASA has tentatively agreed to meet with Brazilian government officials in the fall.