Boeing aerospace workers across the country are preparing to strike next week, a move that would halt the company's Delta rocket launch schedule at Cape Canaveral and Vandenberg Air Force Base.

The planned November 7 launch of NASA's CloudSat and CALIPSO environmental satellites has already been impacted by the battle between Boeing and its workforce. The two spacecraft were supposed to move from a processing building to the launch pad for attachment atop a Delta 2 rocket earlier this week, but officials scrubbed those plans due to the looming strike.

NASA said it didn't want the satellites sitting on Vandenberg's Space Launch Complex-2 West pad if technicians went on strike.

Other launches facing uncertainty are the commercial Delta 4 rocket from Cape Canaveral with the civilian GOES-N weather satellite and an Air Force mission using a Delta 4 from Vandenberg with a classified spy satellite. Both missions have been encountered significant delays for technical problems.

The International Association of Machinists and Aerospace Workers voted to reject Boeing's latest contract offering. Union leaders cited the lack of retiree medical benefits for new employees, vacation and insurance costs as unacceptable parts of the proposed contract.

"Perhaps all our brothers and sisters at the launch sites should start sharing that information with the launch customers, NASA, NRO, U.S. Air Force, etc.," a posting on the union's Web site says. "They might want to know how long their launches are going to slip!"

"The IAM informed us that our employees who they represent rejected our contract offer," a Boeing statement said. "We are open to any ideas that the union might bring to us to come to an agreement, however we feel we have given them the best offer we possibly can."

The union includes 365 workers at Boeing's Huntington Beach facility, 288 at Cape Canaveral and 100 at Vandenberg.

The workers are critical to launch activities, meaning their strike would prevent any liftoffs from occurring, Boeing said.