On an enormous electronic map of the globe in the modernist headquarters of a satellite company here, two green hexagons the size of dinner plates hovered off the west coast of Australia, revealing signals from an armada of ships and planes converged in the hunt for any remains of Malaysia Airlines Flight 370.
The searchers were there in large part because the company, Inmarsat, had produced an innovative analysis of a series of fleeting radio signals from the plane — picked up by one of its satellites in the hours after the jet, carrying 239 people, disappeared from radar screens March 8.
Investigators say Inmarsat's findings were critical to establishing that the Boeing 777-200 almost certainly crashed into the southern Indian Ocean. And more than a month since the flight took off, they remain among the few clues that investigators have as they try to piece together what happened.
This week, the search vessels moved to an area hundreds of miles northwest of Perth, where Australian and Chinese ships have detected multiple "pings" consistent with those of a plane's underwater locater beacons — not far from where Inmarsat's calculations helped narrow estimates of the plane's last location. The most recent of those signals were detected on Wednesday, prompting Australian officials leading the search to suggest that remains of the plane could be found soon.
Through it all, the staff in Inmarsat's east London control room have kept constant tabs on the global flow of mobile voice and data transmissions carried by its network of 11 satellites orbiting 22,000 miles above the earth. Superimposed upon the 21-foot-long map dominating a wall is a color-coded mosaic of cells, each spanning several hundred square miles.
"The nature of our system is such that we can direct communications capacity very quickly to anywhere on the globe," said Ruy Pinto, Inmarsat's chief technology officer. "We are designed for that," he added. "So when there is an event that we feel is going to require additional capacity or resources, we have a group of people that gets together and starts diverting resources to provide terminals, radio frequency and power."
Inmarsat, a communications company with $1.25 billion in revenue and 1,900 employees in more than 60 locations, has grown accustomed to playing a vital supporting role in world events, including conflicts and disaster relief. But in the case of the missing Malaysian jet, the company has found itself thrust, somewhat uncomfortably, into the spotlight.
On a recent day, the cells over geopolitical hot spots like Crimea, Syria and Afghanistan were lit up in pink or yellow. They reflected a heavy concentration of satellite phones and portable broadband terminals in use by various military, media and relief organizations. Busy sea lanes near the English Channel, the Persian Gulf and the Straits of Malacca were tinted a deep green.
Mr. Pinto pointed out the patch of activity off the Australian coast. But he and the handful of engineers who did the Flight 370 analysis maintained a stoic reserve.
"There is no sense of a job well done quite yet, but that will probably come later," said Mr. Pinto, 54, a Brazilian who joined Inmarsat as a software engineer in 1990. "There is a strong feeling that why we're doing this is to help the investigation and try to help the families. We are very sure that our emotions, whatever they are, are nothing compared to their emotions, and we are very conscious that the story isn't about us."
Known originally as the International Maritime Satellite Organization, Inmarsat was created in 1979 by the 88-member International Maritime Organization, an arm of the United Nations, and charged with providing a seamless global network for basic ship-to-shore voice and data communications, including free emergency services for ships in distress.
Over the next 30 years, its offering expanded to include hand-held satellite phones and other land-based mobile services as well as air-to-ground technology that today is installed on roughly 90 percent of the world's fleet of transoceanic wide-body jets.
Unlike employees of better-known tenants of an area of east London known as the "Silicon Roundabout" —Amazon, Google, Facebook and Intel all have offices nearby — Inmarsat's workers are less accustomed to seeing their company's name in the headlines. Instead of beanbag chairs and Foosball tables, its common areas are decorated with scale models of satellites and multistage rockets.
Inmarsat was converted into a private company in 1999, and member states were granted shares that many quickly sold or transferred to national telecom operators. Several attempts at a public share offering failed after the global dot-com bubble burst in 2000, and the company was eventually bought by Apax Partners and Permira, two European private equity firms, for an estimated $1.5 billion. Inmarsat was listed on the London Stock Exchange in 2005 in an initial public offering that valued the company at more than 1.3 billion pounds, or $2.4 billion, at the time.
Inmarsat's market capitalization has since nearly tripled, to about £3.4 billion. Maritime communications still generate more than half of sales, while land-based services and bandwidth leasing — activities heavily dependent on government and military contracts — together represent about 30 percent of revenues. With a 48 percent share of the world's mobile satellite communications market, Inmarsat is twice the size of its nearest competitor, Iridium of the United States.
Aeronautical services are Inmarsat's smallest, but fastest growing, business; they generate revenues of $114 million in 2013, up 13 percent from 2012.
Even as the recent economic downturn has slowed international shipping traffic and many government contracts have dried up because of budget constraints, Inmarsat has been investing $1.6 billion in upgrading its satellite network to provide even greater capacity and higher data transmission speeds.
The first of this new generation of satellites, called Global Express, was launched into orbit in December, and it will be joined by two more this year. Capable of running 100 times faster than its current systems, Global Express could enable new services like airborne videoconferencing or 3-D in-flight movies — as well as real-time streaming of location and performance information from a plane.
It is the disappearance of Flight 370, of course, that has revived debate in the aviation industry about the feasibility of continuous tracking of the nearly 100,000 flights that crisscross the skies each day.
Most airlines have until now been reluctant, though, to assume the costs of using even the scaled-down satellite tracking technology that Inmarsat and some other companies already offer. And air safety authorities have been slow to consider requiring airlines to install such equipment.
The latest version of Inmarsat's aircraft broadband system is already capable of sending intermittent positioning and other cockpit data alongside the in-flight Internet and satellite phone services sold to passengers. Roughly 5,000 planes are fitted with the technology, Mr. Pinto said. But because the system has not yet been certified by regulators as a safety feature — that is expected late next year — many airlines continue to rely on older, cheaper technology.
The lack of positioning data from Flight 370 led to Inmarsat's laborious attempt to estimate the plane's trajectory, an analysis that had never been done before. One of the most surprising elements of Inmarsat's contribution to the search, according to investigators, was that satellite links — which are used mainly for transmitting maintenance data, not for navigation or even to communicate with air traffic control — could even be used to tease out the plane's last known location.
Inmarsat's engineers say they have extracted as much information as possible from the plane's final messages. As they continued to follow developments in the search, Mr. Pinto and his colleagues said they were pleased to have been able to contribute their expertise. But the loss of Flight 370 has also spurred a sense of mission to join with other industry players to press for change.
"It has galvanized us internally to advertise what the technology can do, with the right sort of regulatory environment and willingness from stakeholders," Mr. Pinto said. "The technology is there to prevent the uncertainty that we face in this event from being repeated."