Still, the new Teledesic promises to be a formidable competitor. “The two of them together certainly makes the venture more credible,” says Maehl. In addition to the savvy and deep pockets of Gates and McCaw, it has strong international backing. In April, billionaire Prince Alwaleed of Saudi Arabia invested $200 million for a 13.7% stake–and agreed to help market the service.SPEEDY. Motorola’s satellite-building skills will also be critical. The company has trimmed satellite manufacturing time down to little more than four days, compared with an industry average of two years for larger birds. “Really, the best people to build [Teledesic] would be Motorola, because they have this assembly-line technique,” says Marco Caceres, senior space analyst at market researcher Teal Group.

But if the plan fails, Teledesic may be financially out of luck. “Everything depends on Iridium,” said Marco Caceres, senior space analyst with the Teal Group. “It’s clear in the investment community that if, on 23 September, they turn on the switch and it [doesn't] work, it would be bad for Celestri,” he added. “They won’t be able to raise US$15 billion or whatever it will cost if their $5 billion system isn’t working,” noted Caceres, who pores over satellite system proposals and papers to advise investors.

If Teledesic is to one day offer competitive prices to customers of the high-speed computer network, it must keep costs down now. But Marco Caceres, a space-industry analyst with The Teal Group in McLean, Va., says industry sources have told him that Boeing is projecting the satellites could cost $35 million apiece. Teledesic wants to pay $20 million each. If Caceres’ numbers are accurate, for example, the total project cost – including launching the satellites – could jump from the $9 billion target to between $13 billion and $15 billion. Caceres said that by industry standards, Teledesic’s $9 billion goal is too ambitious. “Pricing is not an exact science, by any means,” he said. “But I cannot believe these guys are not expecting the price would eventually go up.”

But experts say Boeing’s resources may help Teledesic overcome the hurdles. “In the past there has been a lot of skepticism,” said Marco Caceres, an analyst with the Teal Group Corp., a Fairfax, Va., consulting firm. “But now with Boeing, they have a whole lot more credibility . . . because Boeing is one of the world’s biggest players in the commercial [satellite] launch business.”