BY JUSTIN RAY

Follow the countdown and launch of the Boeing Delta 2 rocket with five replacement satellites for the Iridium communications system. Reload this page for the very latest on the mission. Use our text only page for faster downloads.

SUNDAY, FEBRUARY 10, 2002
2000 GMT (3:00 p.m. EST)

Engineers are troubleshooting the fuel sensor on the Boeing Delta 2 rocket's first stage propellant tank to determine what caused the erroneous reading during this morning's countdown. A company spokesman said no decision has been made on whether the sensor will have to be replaced.

The sensor in question is one of three that detect when the fuel tank is drained of its RP-1 kerosene, thereby telling the rocket's onboard flight computer when to shut down the main engine during launch.

There is still the potential of a Monday launch attempt if the sensor trouble can be resolved in time. The five-second launch window opens at 1743:44 GMT (12:43:44 p.m. EST; 9:43:44 a.m. PST). The weather forecast calls for a 90 percent chance of acceptable conditions.

The irony today was the fact that the weather -- specifically the winds -- ended up being favorable despite the pessimistic forecast issued Saturday. But in the end a technical bug scrubbed the launch.

1539 GMT (10:39 a.m. EST)

SCRUB! A faulty sensor found as the launch team was preparing to load the Delta 2 rocket's first stage fuel tank has forced Boeing to scrub today's launch attempt.

There are three sensors, two were indicating "dry" and the malfunctioning one was showing "wet" conditions inside the rocket's tank. Since fuel had not begun to flow into the tank, the sensor was obviously found to be in error. All three sensors must be working correctly in order for fueling and the countdown to continue.

Troubleshooting will be performed today on the sensor system. There is no word yet on when another launch attempt will be made.

It is the third straight day that a problem has postponed this launch of five Iridium mobile communications satellites. High winds were to blame Friday and mechanical problems with a downrange telemetry aircraft scrubbed Saturday's try.

1533 GMT (10:33 a.m. EST)

The troubleshooting of a sensor malfunction continues. No decisions have been made. It appears this sensor is one of three, and all three are required to be operating for launch.

1520 GMT (10:20 a.m. EST)

A sensor problem was uncovered as the launch team was readying to load RP-1 kerosene into the first stage. Troubleshooting is underway.

1509 GMT (10:09 a.m. EST)

The launch team is now beginning preparations to load the Delta 2 rocket's first stage fuel tank with a 10,000 gallons of RP-1 kerosene.

1449 GMT (9:49 a.m. EST)

The Terminal Countdown has begun for today's launch of Boeing Delta 2 rocket with five replacement satellites for the orbiting Iridium mobile communications network. Liftoff remains scheduled for 1749:19 GMT (12:49:19 p.m. EST; 9:49:19 a.m. PST) from Space Launch Complex-2 West at Vandenberg Air Force Base in California.

The weather is currently acceptable at the launch site with winds at just 8 knots. Air Force forecasters had worried about winds gusting up to 34 knots today, and as such gave an 80 percent chance weather would prohibit launch.

The countdown is being controlled from the "soft blockhouse" located about 8 miles from the Space Launch Complex 2-West pad. Senior launch officials are stationed in the Mission Directors Center located on South Base of Vandenberg, a good distance from the pad.

With the countdown underway, the activities planned over the next hour include verifying the hazard danger area is cleared, activating the rocket's Redundant Inertial Flight Control Assembly guidance computer, pressurizing the first and second stage helium and nitrogen systems and second stage fuel tanks and checking the C-band tracking beacon on the rocket.

The loading of RP-1 kersone fuel into the rocket's first stage will begin in about 20 minutes.

1349 GMT (8:49 a.m. EST)

A third attempt to launch a Boeing Delta 2 rocket and five Iridium satellites is underway this morning at Vandenberg Air Force Base in California. The countdown just entered a one-hour planned built-in hold in advance of Terminal Count, which begins at 1449:19 GMT.

Overnight, the 177-foot tall mobile service tower at the Space Launch Complex 2-West pad was wheeled back from around the rocket. The gantry is used to stack the vehicle and provides the primary weather protection and access to the rocket during its stay on the oceanside complex.

Liftoff remains scheduled for 1749:19 GMT (12:49:19 p.m. EST; 9:49:19 a.m. PST) today, weather permitting.

0045 GMT (7:45 p.m. EST Sat.)

Boeing officials have decided to make an attempt to launch the Delta 2 rocket on Sunday despite a less-than-optimistic weather forecast that calls for an 80 percent chance high winds will scrub the 1749:19 GMT (12:49:19 p.m. EST; 9:49:19 a.m. PST) liftoff. The available launch window on Sunday extends for just five seconds.

Technicians will roll the protective mobile service tower away from the rocket at Vandenberg Air Force Base's Space Launch Complex 2-West overnight. The Terminal Countdown will begin exactly three hours before launch time.

We will update this page Sunday with countdown status reports and a live play-by-play call of the launch.

SATURDAY, FEBRUARY 9, 2002
1800 GMT (1:00 p.m. EST)

Launch of the Boeing Delta 2 rocket with five Iridium satellites from Vandenberg Air Force Base in California could occur as early as Sunday, but strong winds might again delay liftoff.

The problems with a telemetry relay aircraft that scrubbed today's launch opportunity will be resolved by Sunday, Boeing spokesman Glen Golightly said.

Boeing will receive a weather update from Air Force meteorologists at 4 p.m. PST (7 p.m. EST; 0000 GMT) today to help officials decide whether or not to press ahead for a Sunday launch attempt.

The current weather forecast calls for an 80 percent of weather prohibiting launch on Sunday because of 22-knot winds and gusts to 34 knots.

"A very strong area of high pressure has moved into the Great Basin, bringing clear skies and warmer temperatures to Vandenberg. As the high increases in strength, we will enter into a Santa Ana type wind scenario, winds will be shifting to the southeast and increasing overnight. This presents a problem for tower roll as well as launch drift wind constraints. Increasing winds after T-0 will also cause concern for post-scrub procedures," the latest weather forecast issued to the launch team said.

If officials decide to continue with launch preparations following the 4 p.m. PST meeting, another weather briefing will occur at 10 p.m. PST (1 a.m. EST; 0600 GMT). The second meeting would again give Boeing the opportunity to either scrub or decide to move forward with the countdown.

Sunday's five-second launch window opens at 1749:19 GMT (12:49:19 p.m. EST; 9:49:19 a.m. PST). See a chart of launch windows for the next few days.

The forecast for Monday is a bit better, with a 40 percent chance of unacceptable winds.

"Clear skies and warm temperatures will remain for Monday, with winds staying from the southwest and slightly decreasing in speed. Winds will remain very close to constraints, but the decreasing speeds increase the possibility of a launch attempt."

1415 GMT (9:15 a.m. EST)

SCRUB! Officials have called off an attempt to launch the Boeing Delta 2 rocket today from Vandenberg Air Force Base in California. Liftoff had been scheduled for 1754:55 GMT (12:54:55 p.m. EST; 9:54:55 a.m. PST). The first try at launching this mission on Friday was scrubbed due to winds.

Today's postponement was caused by mechanical problems with an instrumented P-3 aircraft that is needed to receive live data from the Delta 2 and relay the information back to engineers at Vandenberg as the rocket travels beyond the coverage zone of ground tracking stations.

A telemetry plane is routinely used for approximately ten minutes during Delta missions from Vandenberg beginning at around T+plus 6 minutes. A map of the ground track for this launch shows the aircraft's coverage area.

The tracking station at Vandenberg provides coverage of the rocket's initial ascent -- through the first stage burn and ignition of the second stage. But the rocket travels over Vandenberg's horizon as it streaks southward during the second stage burn, making a telemetry aircraft necessary to monitor the rest of the stage firing and to determine a successful arrival in orbit.

After the second stage engine shuts down about 11 1/2 minutes after launch, the vehicle enters a long coast period. Little activity occurs aboard the rocket during that time, so no telemetry relay coverage is required.

Ground stations in South Africa, Kenya, Sweden, Greenland, Alaska and Hawaii will be used in addition to Vandenberg and the P-3 aircraft to cover this launch and deployment of the five Iridium satellites.

Boeing will decide later today when to make the next launch attempt.

FRIDAY, FEBRUARY 8, 2002

Boeing will try again Saturday to launch its Delta 2 rocket with five Iridium mobile communications satellites into low-Earth orbit from Vandenberg Air Force Base in California.

Friday's attempt was thwarted by a 22-knot gust of wind at the seaside launch pad just before liftoff time. The launch team aborted the countdown at T-minus 55 seconds.

Faced with just a five-second window in which to launch the rocket each day, managers had no choice but to scrub the liftoff for 24 hours.

Delta 2 rockets are not bolted to the launch pad. They sit atop a mount and are allowed to sway back and forth in the wind. However, the sudden gust during Friday's countdown caused the rocket to violate a rule that governs how far the vehicle is allowed to move in the wind during the final moments before launch.

The limit is one-degree of motion and the gust forced the rocket to one-and-a-half degrees, Boeing spokesman Glen Golightly said.

The vehicle's motion is a concern because the main engine nozzle could hit the launch mount during liftoff if the rocket sways too far in high winds. Also, the movement can cause errors in the rocket's guidance computer, Golightly said.

A new launch countdown will begin at 1454:55 GMT (9:54:55 a.m. EST; 6:54:55 a.m. PST) Saturday leading to liftoff exactly three hours later.

The weather forecast for Saturday calls for an 80 percent chance of acceptable conditions. Winds are the main threat.

Meteorologists had called for a 90 percent of acceptable weather on Friday with winds the only concern.

We will have live updates during Saturday's countdown and throughout the 85-minute flight of the Delta 2 to deliver its Iridium cargo to space.

1805 GMT (1:05 p.m. EST)

Today's launch attempt was aborted by a wind gust at the pad. The Delta 2 rocket is not bolted down to the launch pad and the vehicle sways back and forth in the wind. The sudden gust caused to the rocket to exceed the allowable movements for the onboard guidance computer during the final countdown, Boeing said.

With just a five-second window to launch today, officials were forced to scrub the liftoff for the day.

Launch has been rescheduled for Saturday at 1754:55 GMT (9:54:55 a.m. PST; 12:54:55 p.m. EST). A five-second window also will be available.

1800 GMT (1:00 p.m. EST)

We're still waiting for word from Boeing on what caused today's countdown abort and scrub of the launch.

1800 GMT (1:00 p.m. EST)

The countdown was halted at T-minus 55 seconds due to a problem. This effectively scrubs today's launch since there was just a five-second window in which to get the rocket airborne.

1759 GMT (12:59 p.m. EST)

ABORT! The countdown has been stopped.

1759:31 GMT (12:59:31 p.m. EST)

T-minus 1 minute. The Range has given its final clear-to-launch. The Delta 2 rocket's second stage hydraulic pump has gone to internal power after its pressures were verified acceptable.

1759:01 GMT (12:59:01 p.m. EST)

T-minus 90 seconds. At the telemetry receiving areas where data from the rocket will be transmitted the data recording charts have gone to high speed.

1758:31 GMT (12:58:31 p.m. EST)

T-minus 2 minutes. The first stage liquid oxygen vents are now being closed so the LOX tank can be pressurized for launch. Puffs of vapor from a relief valve on the rocket will be seen in the remainder of the countdown as the tank pressure stabilizes.

1758:01 GMT (12:58:01 p.m. EST)

T-minus 2 minutes, 30 seconds and counting. The five Iridium satellites atop the Delta 2 rocket have switched to internal power. And the final "go for launch" has been received from the spacecraft management team.

1757:31 GMT (12:57:31 p.m. EST)

T-minus 3 minutes and counting. The safety destruct safe and arm devices are being armed.

1756:31 GMT (12:56:31 p.m. EST)

T-minus 4 minutes and counting. Now in the final phase of the countdown the Delta 2 rocket's systems begin transferring to internal power for launch.

Launch of the Iridium spacecraft remains set to occur at 1800:31 GMT from SLC-2 West at Vandenberg Air Force Base in California. There are no problems standing in the way of the 290th Delta rocket launch, the 101st for a Delta 2 and first of 2002.

1755:31 GMT (12:55:31 p.m. EST)

Now five minutes from launch! Standing by for release of the hold in one minute. All the polling has been completed with the decision made to resume the countdown for an on-time launch today.

1751:31 GMT (12:51:31 p.m. EST)

Now half-way through this 10-minute built-in hold.

1749 GMT (12:49 p.m. EST)

Boeing reports there are no problems being addressed and liftoff remains set to occur at 1800:31 GMT today. There is just a five-second launch window available today.

1746:31 GMT (12:46:31 p.m. EST)

T-minus 4 minutes and holding. The countdown has entered the final planned hold. This is a planned 10-minute hold leading to today's liftoff time of 1800:31 GMT (1:00:31 p.m. EST).

During the hold officials will poll the various team members behind the scenes, in the "soft blockhouse", Range Operations Control Center and Mission Directors Center.

At this point there are no technical problems being reported and weather remains "go" for launch, although it is still foggy at Vandenberg and the view of liftoff could be hampered for spectators. We're still waiting to get a final update on the Range Safety constraints.

1744 GMT (12:44 p.m. EST)

The vent of the first stage RP-1 fuel tank is being closed and the tank is being pressurized for launch.

1740:31 GMT (12:40:31 p.m. EST)

T-minus 10 minutes and counting. The countdown is heading to T-minus 4 minutes for a 10-minute hold. Liftoff the Boeing Delta 2 rocket from Vandenberg Air Force Base is still slated to occur at 1800:30.5 GMT with five satellites to serve as orbiting spares for the Iridium mobile communications network, which provides telephone, data and paging services to subcribers anywhere on the planet.

For this launch, Boeing is using a model 7920-10 Delta 2 rocket. The expendable launch vehicle consists of two stages, nine strap-on solid rocket boosters and a 10-foot diameter payload fairing. The rocket stands 127 feet tall. See our rocket fact sheet for more.

1737 GMT (12:37 p.m. EST)

Inhibited checks are beginning for the Range Safety command destruct receivers that would be used in destroying the Delta rocket should the vehicle veer off course and malfunction during the launch.

1730:31 GMT (12:30:31 p.m. EST)

T-minus 20 minutes and counting. Countdown clocks are running again following the planned 20-minute hold. The count will continue to the T-minus 4 minute mark where another hold is scheduled. Launch remains set for 1800:30.5 GMT.

1726 GMT (12:26 p.m. EST)

The Boeing Launch Conductor has polled the launch team for a "go" to pick up the countdown as planned. No problems were announced. Clocks are set to resume in four minutes.

1720 GMT (12:20 p.m. EST)

Now half-way through this 20-minute built-in hold in the countdown.

1710:31 GMT (12:10:31 p.m. EST)

T-minus 20 minutes and holding. The countdown has entered into the first of two planned hold periods during the last 20 minutes of the Terminal Count for today's precise 1800:31 GMT launch time. This pause will last 20 minutes in duration.

These holds are designed to give the launch team a chance to deal with any problems and catch up on work that could be running behind schedule. At this point, the countdown is reported to be going well with no significant technical problems with the rocket or spacecraft.

Engineers have just completed gimbal checks of the nozzles on the first stage main engine and twin vernier engines and second stage engine. This test is performed to ensure the engines will be able to steer the rocket during launch.

1700 GMT (12:00 p.m. EST)

Now exactly one hour from the scheduled liftoff time for the Boeing Delta 2 rocket from Space Launch Complex 2-West at Vandenberg Air Force Base along the central coastline of California. The base is located about half-way between Los Angeles and San Francisco.

Over the next few minutes, the "slew" or steering checks of the first and second stage engines will be performed. Also RF link tests between the Range and rocket are scheduled.

1650 GMT (11:50 a.m. EST)

T-minus 40 minutes and counting. Countdown clocks are continuing to the T-minus 20 minute mark where a 20-minute built-in hold is planned. A final 10-minute hold at T-minus 4 minutes will lead to the target liftoff time of 1800:30.5 GMT today for the Boeing Delta 2 rocket.

1641 GMT (11:41 a.m. EST)

The launch team reports the loading of the Delta 2 rocket's first stage liquid oxygen tank was completed at 1640:53 GMT for a duration for 24 minutes and 3 seconds. The tank will be replenished through the remainder of the countdown to replace the liquid oxygen that naturally boils away.

The rocket is now fully fueled for launch today at 1800:30.5 GMT (10:00:30.5 a.m. PST; 1:00:30.5 p.m. EST) from Vandenberg Air Force Base in California to deliver five Iridium replacement satellite payloads into space.

The vehicle's first stage was successfully loaded with RP-1 kerosene fuel along with the liquid oxygen this morning. The second stage was loaded with its storable nitrogen tetroxide and Aerozine 50 fuels on Tuesday; and the nine strap-on booster rockets are solid-propellant.

There are no technical problems with the rocket being reported by Boeing and the weather forecast is favorable. However, at last check Range Safety was "no go" due to the prediction that the covers from the solid rocket motor nozzles ignited a minute into flight would land in populated areas, which is always a concern for Delta launches from Vandenberg. The Delta pad is positioned on the north part of the base and the rocket heads south to polar orbit along the Vandenberg coastline where the Titan, Atlas and SLC-6 pads are located.

The computer model that makes the nozzle cover impact prediction is loaded with today's winds and other weather factors, and will be re-run as the countdown continues with the hope the situation improves.

1630 GMT (11:30 a.m. EST)

Launch is just 90 minutes away.

1617 GMT (11:17 a.m. EST)

Now officially 10 minutes into this approximate 25-minute process to fill the first stage liquid oxygen tank.

1618 GMT (11:18 a.m. EST)

Cryogenic liquid oxygen, chilled to Minus-298 degrees F, is now flowing from a 28,000-gallon storage tank at Space Launch Complex 2-West, through plumbing and into the bottom of the Boeing Delta 2 rocket. The LOX will be consumed by the first stage main engine during the first four-and-a-half minutes of flight along with the nearly 10,000 gallons of RP-1 kerosene loaded aboard the vehicle earlier this morning.

Also in the countdown the launch team has completed the work to turn on the rocket's guidance computer.

1557 GMT (10:57 a.m. EST)

The Air Force launch weather officer has just briefed managers on current and forecast conditions for today's liftoff of the Boeing Delta 2 rocket. Everything is looking promising for acceptable weather today with just a 10 percent chance of ground winds posing a constraint.

Though there are low stratus clouds and fog hovering over Vandenberg this morning, but meteorologists predict that will burn off by launch time. The forecast calls for unrestricted visibility, no significant weather, a temperature in the 50s F and northwesterly winds from 10 to 15 knots.

Range Safety's initial checks of the computer models, based on today's wind conditions and other factors, show that the nozzle covers from the solid rocket boosters could fall in populated areas on the base, making that safety constraint "no go" for launch at the moment. However, the modeling will be re-computed as the countdown continues to see if the situation changes. The prediction on debris and toxics from a launch explosion shows safe conditions today.

1500:31 GMT (10:00:31 a.m. EST)

The Terminal Countdown has begun for today's launch of Boeing Delta 2 rocket with five replacement satellites for the orbiting Iridium mobile communications network. Liftoff remains scheduled for precisely 1800:30.5 GMT (1:00:30.5 p.m. EST; 10:00:30.5 a.m. PST) from Space Launch Complex-2 West at Vandenberg Air Force Base in California.

The countdown is being controlled from the "soft blockhouse" located about 8 miles from the Space Launch Complex 2-West pad. Senior launch officials are stationed in the Mission Directors Center located on South Base of Vandenberg, a good distance from the pad.

With the countdown underway, the activities planned over the next hour include verifying the hazard danger area is cleared, activating the rocket's Redundant Inertial Flight Control Assembly guidance computer, pressurizing the first and second stage helium and nitrogen systems and second stage fuel tanks and checking the C-band tracking beacon on the rocket.

The loading of RP-1 kersone fuel into the rocket's first stage will begin in about 20 minutes. This operation will be followed by loading of super-cold liquid oxygen at 1615 GMT (11:15 a.m. EST; 8:15 a.m. PST).

Overnight, the 177-foot tall mobile service tower was wheeled back from around the rocket and the fully assembled Delta 2 was exposed for launch. The gantry is used to stack the vehicle and provides the primary weather protection and access to the rocket during its stay on the oceanside complex.

1400 GMT (9:00 a.m. EST)

It is launch day for the first Boeing Delta rocket flight of 2002. The Terminal Countdown is scheduled to begin in one hour in preparation for liftoff today at 1800 GMT (1:00 p.m. EST; 10:00 a.m. PST) from Vandenberg Air Force Base in California.

THURSDAY, FEBRUARY 7, 2002
1800 GMT (1:00 p.m. EST)

All systems remain "go" for Friday's launch of five Iridium spacecraft aboard a Delta 2 rocket from Space Launch Complex 2-West at Vandenberg Air Force Base in California.

"We just completed the Launch Readiness Review and we're ready to give it a try tomorrow," Boeing Mission Director Rich Murphy said in an interview a short time ago.

There are no technical issues being worked by the launch team and the weather forecast is generally favorable for the precise liftoff time of 1800:30.5 GMT (1:00:30.5 p.m. EST; 10:00:30.5 a.m. PST). There is a five-second launch window available.

Air Force meteorologists are giving an 80 percent chance of meeting the launch weather rules. The only concern could be layered clouds becoming too thick for the rocket to safely fly through.

Tonight technicians will begin countdown activities at the launch pad with work to retract the mobile service tower from around the Delta 2 rocket. The rollback is scheduled to occur between 12 and 1 a.m. local time (3-4 a.m. EST; 0800-0900 GMT).

Pad securing work will continue overnight in preparation for starting the Terminal Countdown at 7:00 a.m. PST (10:00 a.m. EST; 1500 GMT) from the T-minus 150 minute mark. Two built-in holds are planned during count. The first will occur at T-minus 20 minutes for a duration of 20 minutes; the second happens at T-minus 4 minutes and should last 10 minutes.

During Terminal Count, the rocket's first stage will be loaded with a highly refined kerosene fuel, called RP-1, and super-cold liquid oxygen. Other routine pre-launch events during the three-hour countdown include activating the rocket's guidance computer, pressurizing the fuel and oxidizer tanks of the second stage, which were loaded with storable propellants on Tuesday, performing engine steering checks and switching onboard systems to internal power.

Watch this page for live coverage of Friday's countdown and launch with play-by-play updates.

WEDNESDAY, FEBRUARY 6, 2002

A Boeing Delta 2 rocket is set for launch Friday from Vandenberg Air Force Base in California to deliver into space five satellites that will serve as orbiting replacements for the Iridium mobile communications constellation.

The launch team will have just five seconds to get the rocket airborne or else wait until another day. Friday's opportunity begins at 1800:30 GMT (1:00:30 p.m. EST; 10:00:30 a.m. PST).

The two-stage rocket, fitted with nine solid-fueled strap-on boosters, will fly on a southerly track from the Central California launch pad, located 140 miles northwest of Los Angeles.

About an hour into the flight the rocket will settle into an orbit 345 nautical miles above Earth and begin deploying the five Iridium satellites one at a time. The final craft is scheduled to be released one hour, 25 minutes after liftoff.

This will be the 12th time a Delta 2 rocket has launched satellites for the Iridium network, which provides global voice, data and paging services to subscribers around the world. From May 1997 through November 1998, 11 Delta 2s successfully launched 55 Iridium spacecraft.

"The mission is similar to the other Iridium missions that we have launched," Jay Witzling, Boeing's vice president and deputy program manager for Delta, said in an interview. "Obviously there are five (satellites) onboard the rocket, we are flying to a similar trajectory that we have before...the separation events and timing as we go around the world are pretty much similar to the previous launches."

In all, 88 spacecraft have been launched on Delta 2, Chinese Long March and Russian Proton rockets. Sixty-six of the satellites serve as the primary orbiting network to cover virtually the entire planet. Seven others are orbiting spares, ready to replace any of the 66 primary satellites when one fails. Eleven satellites have malfunctioned in space and four have fallen from orbit, according to Iridium.

With Friday's launch and one planned in June from Russia using a Eurockot booster with two satellites the Iridium armada will have 14 orbiting spares, which engineers believe will keep the constellation healthy through 2010.

The original Iridium company rolled out commercial service in November 1998, but failed to attract a sufficient number of subscribers due to the pricey $3,000 phone and $7 per minute airtime fees.

Iridium LLC lapsed into bankruptcy protection in August 1999 and by spring 2000, without a suitable buyer found, it appeared the satellite fleet would be driven into Earth's atmosphere to burn up.

The $5 billion system was rescued in December 2000 when Dan Colussy, an aviation industry veteran, purchased the assets of Iridium LLC, including the satellite constellation and the terrestrial network for about $25 million.

The miracle resurrection of Iridium was completed in March 2001 when commercial service was relaunched. The new company -- Iridium Satellite LLC -- debuted with cheaper prices and set out to target specific industries that it believed would subscribe to the system for communications to remote areas of the planet where terrestrial telephone networks do not exist, like construction, emergency services, maritime, mining, forestry, oil and gas and aviation. The U.S. Department of Defense is an existing Iridium customer under a multi-year contract for unlimited airtime for up to 20,000 government users.