ANN REALTIME REPORTING 03.19.07 2010 EDT: "We have scrubbed for the day." With that statement, launch controllers at Kwajalein Atoll nixed any chance the Falcon 1 rocket would launch Monday, as crews work to get a handle on a reported communications glitch.

No word yet when SpaceX will try again. The current launch window extends through March 23.

Previous Reports

2005 EDT: Gwynne Shotwell, vice president of business development for SpaceX, states a possible communications glitch may be behind the abort of Monday's launch of the Falcon 1 rocket.

In a webcast teleconference with reporters, Shotwell said it appears the glitch developed during a switchover in communications at the T-minus 1:30 mark. At that point, communications with the launchpad were changed over from landline, to the range RF... and it's possible the signal wasn't picked up.

Shotwell added several abort modes are built into the vehicle, in the wake of last year's failed launch, to insure the vehicle is as well-prepared for launch as possible.

There remains a chance the vehicle may still be launched today.

1945: At T-minus 1:03, launch controllers aborted Monday's planned launch of the SpaceX Falcon 1 rocket. ANN is still awaiting word on what occurred -- and if this abort means the launch has been scrubbed for the day.

1855 EDT: Problems with sending telemetry information from Omalek Island on Kwajelein Atoll to SpaceX headquarters in El Segundo, CA delayed the countdown somewhat for today's planned "DemoFlight 2" launch of the Falcon 1 rocket, but the good news is the problem appears to have been worked out.

The countdown has been held since the telemetry problem reared its head, but the vehicle is now fueling. Launch is now scheduled for 1945 EDT.

1810 EDT: We are at T-minus 29 seconds and under a planned hold for the launch of the second SpaceX Falcon 1 rocket, expected to occur approximately 50 minutes from now.

According to SpaceX, during this "Demo-2 mission" the vehicle will carry ~50 kg of experiments and associated hardware from the launch site at Omelek into a 685 km circular orbit with 9° inclination. The payload consists of the Autonomous Flight Safety System (AFSS) and the Low Cost Tracking and Data Relay Satellite System (TDRSS) Transmitter (LCT2), developed by National Aeronautics and Space Administration (NASA) and the mechanical adapter hardware required to interface the payload with the launch vehicle.

The AFSS and LCT2 payloads are not deployed, but there will be a separation demonstration of an inert payload immediately after second stage 1st burn main engine shutdown.

The primary DARPA objective for this mission is to gather flight data on the Falcon 1 launch vehicle and supporting systems. A secondary objective is to separate a payload into LEO, to place the second stage into the planned final orbit, and demonstratiing AFSS using the LCT2 for telemetering data back to Kwajalein and to Wallops Flight Facility. The AFSS and LCT2 represent early steps in providing low-cost space-based range services for communications, tracking, and on-board autonomous flight termination. The AFSS is operating in a shadow mode for this mission.

1500 EDT: SpaceX founder Elon Musk says conditions are optimal for launch later today of the company's Falcon I booster rocket.

"The flight readiness review conducted last night shows all systems are go for a launch attempt at 4pm California time (11pm GMT) today (Monday)," Musk wrote, adding "the launch will be postponed if we have even the tiniest concern."

That concern stems from the outcome of the company's inaugural Falcon launch attempt almost one year ago. As ANN reported, that Falcon I was destroyed after a fuel leak led to shutdown of the rocket's main engine approximately 30 seconds after launch on March 24, 2006.

Undaunted, SpaceX pressed ahead with its program... and was awarded a commercial orbital transportation services (COTS) contract by NASA, to develop methods to launch and deliver crew and cargo to the International Space Station, along with rival commercial space launch outfit Rocketplane-Kistler.

Now, the time has come to see if SpaceX can make good on its promise of affordable, reliable launch service. Stay tuned, ANN will bring you continuous updates throughout the day.

FMI: www.spacex.com