NASA's Deep Space Network (DSN) of terrestrial radio antennas currently handles all reception of incoming pictures and data from NASA craft beyond Earth orbit and some satellites orbiting the planet. The system is already bursting at the seams, officials agree, and engineers are scrambling to meet future needs. No matter what is done, however, the DSN could be overwhelmed by future spacecraft that will be capable of collecting much more data.

"Concerted action" toward building a laser system "will be required to prevent a crisis in the form of a data transmission bottleneck," the authors of the Science article argue.

The new cosmic Internet would be based on technology already developed by the fiber-optics industry. It would operate in the near-infrared wavelengths, a portion of the electromagnetic spectrum (which includes radio waves and visible light) commonly used by astronomers to study the heavens. There's an inherent advantage in this scheme: Ground receiving stations already exist in the form of large optical telescopes that can record near-infrared signals.

Download rates could be 100 times faster.

"It would be like surfing the Internet with a slow modem over a normal telephone line, as compared to surfing with a DSL line," Martin Harwit told SPACE.com. "With a DSL line images appear almost instantaneously. With a slow modem one has to wait for each screen to slowly write an image, line by line."

Laser transmission also saves power, Harwit explained, because a laser beam operates at higher frequencies and is more focused than radio. A spacecraft's onboard transmitter can therefore use roughly 100 times less power. The flip side of this, however, is that a more precise instrument is required to send the signal.

"A drawback in infrared laser transmission is that the transmitting dish has to have the surface quality of a precision telescope, and that the pointing mechanism has to be much more accurate than for a radio transmitter," Harwit said. Since a laser beam is relatively narrow, it must be pointed directly and accurately at a receiving station, whereas radio transmissions need only be directed in the vicinity of the receiver.

Spacecraft would be required to pack a 1-meter (3-foot) telescope for the task -- no small expense.

The idea is not brand new. In fact, NASA's Jet Propulsion Laboratory is investigating the feasibility of such a system. Engineers have said a laser-based setup could be cost effective. But critics note one significant drawback: laser transmissions cannot penetrate clouds.

"The receiving stations would need to be placed on high mountaintops known for their high number of days with clear skies," Harwit said. "This is not a particular disadvantage if properly planned."

A series of at least three stations would be required around the globe, at a total cost of about $200 million, Harwit and his colleagues estimate.

Additional funds would be needed to support maintenance and operations. Another $200 million or so would be required to develop the space-based laser transmitters. The researchers say that once that's done, costs to install one on each future spacecraft would be similar to that of radio transmitters.

The European Space Agency (ESA) has already demonstrated the ability to use laser technology to communicate between two satellites, ARTEMIS and SPOT-4. They researchers note that a space-to-ground system can't be built without the resources of NASA and the ESA. And they say that having a robust system online in 10-15 years requires starting now.

"Work toward a near-infrared telemetry system carries little risk and will rapidly pay for itself in the efficiency with which data can be gathered and transmitted," they conclude in their article.