As bad as it has been, the misery and chaos caused by Hurricane Katrina would have been a lot worse had satellite companies not stepped in to help fill the void created by the destruction of terrestrial communications infrastructure in the affected areas.

With cell phone towers and land lines wiped out in the hardest hit regions, relief workers have depended heavily on satellite communications to plan and coordinate their efforts. Satellite-based providers of mobile telephony, data, radio, TV and other services have donated millions of dollars worth of equipment, bandwidth and other resources to the effort.

The storm and its aftermath, which hit hardest in the Gulf Coast states of Alabama, Louisiana and Mississippi, proved yet again that satellite services play a critical role in disaster relief and recovery. The scramble for satellite phones and other equipment as aid workers began to arrive in the devastated areas illustrates that rescue authorities need to be better prepared in the future, according to some observers.

Satellite telephone provider Globalstar and its dealers deployed over 10,000 phones to the region in the first five days after Katrina struck . Globalstar rival Iridium has delivered a similar number, is shipping another 6,000 and expects orders for thousands more in the coming days and weeks.

“This, I think, has fundamentally changed the nature of the mobile satellite business,” said John Dark, a spokesman for San Jose, Calif.-based Globalstar. After previous hurricanes, demand dropped off significantly when the disaster had passed, but in this case , the numbers are staying steady even as terrestrial networks begin to come back online in some areas , he said.

Liz DeCastro, a spokeswoman for Iridium of Bethesda, Md. , said the company does not expect the demand to subside anytime soon. “It’s difficult to give an exact number,” she said. “But I think it would be safe to say thousands more are probably needed given the scope of the disaster in the region, and the extent to which relief organizations are deploying to the area.”

Inmarsat of London said in a Sept. 6 press release that it was offering free use of its mini-M mobile satellite communications devices within the disaster zones until Sept. 11. The company saw call minutes on its satellite system jump more than 50 percent Sept. 3-4 and opened up additional channels to accommodate the increase, the release said.

Traditional fixed satellite service providers also are lending a hand. PanAmSat of Wilton, Conn., for example, gave the Red Cross six months of free capacity for communications purposes, company spokeswoman Jennifer Gill said. PanAmSat also deployed an inflatable antenna to transmit and receive messages at a Red Cross relief center in Biloxi, Miss, Gill said. The company set up a Wi-Max Internet system to be used by the Red Cross in New Orleans as well, she said.

Companies providing relatively new services such as satellite radio, television and Internet also have been busy.

XM Satellite Radio of Washington on Sept. 7 launched Red Cross Radio, a station dedicated to broadcasting disaster-related information to Red Cross staff and volunteers. The station is broadcasting from XM’s Washington headquarters and from the nearby Red Cross headquarters, and will operate for as long as necessary, company spokesman David Butler said. XM is providing the channel to the Red Cross as a public service, Butler said.

By the time Katrina hit, the Red Cross already was equipped with some 800 satellite radios donated by XM and rival Sirius Satellite Radio in anticipation of such disasters.

Jim Collins, a spokesman for Sirius, said his company arranged to donate 1,000 radios about a year ago . Some 500 of those radios have been delivered, and another 500 are available if the Red Cross needs them, he said.

Sirius set up an emergency channel dedicated to Katrina-related news during the heat of the crisis, Collins said.

Satellite television companies, meanwhile, helped to spread hurricane-related news to both relief workers and the general public.

DirecTV Group of El Segundo, Calif., launched a Hurricane Katrina Information channel which provided information such as road closures, locations of relief centers and shelters , and contact information for relief agencies and insurance companies, the company said in a Sept. 2 press release. The station also lets individuals communicate with family and friends by sending text and email messages directly to the company, which then displays the messages across the bottom of the TV screen.

Echostar Communications Corp. of Englewood, Colo., meanwhile, has set up satellite TV services in nine shelters receiving refugees, according to a company press release.

Satellite Internet services have proved useful for helping those stranded by the storm to communicate with others. Members of the National Rural Telecommunications Cooperative are making WildBlue satellite Internet service available in areas affected by the storm, setting up terminals so victims can contact their families, according to a news release issued by the organization. The National Rural Telecommunications Cooperative provides products and services to more than 1,200 rural telecommunications providers in 47 states.

Other companies have pitched in to provide devices to aid coordination efforts. Global Relief Technologies and Telenor Satellite services have teamed up to provide satellite services to the U.S. Marines and the Federal Emergency Management Agency .

The equipment provided by Rockville, Md.-based Telenor and Oslo, Norway-based Global Relief, enables relief workers in the field to transmit and receive GPS coordinates and other information on area conditions and logistics using specially adapted personal digital assistants.

“One of the lessons learned is that we hope [this equipment] will be included in fly-away kits in the future,” Telenor spokesman Thomas Surface said.

Mike Beavin, director of government relations for the Satellite Industry Association, said the Katrina experience demonstrates the critical role satellite communications play in disaster response and recovery, and that the relevant authorities need to be properly equipped beforehand.

“Maybe there are some new requirements needed legislatively,” Beavin said. “It may be the most critical communication infrastructures need to be backed up by something that doesn’t rely on an existing terrestrial network.”