BY JUSTIN RAY

June 30, 2000 -- Follow the countdown and launch of the Proton rocket launching the Sirius 1 spacecraft for Sirius Satellite Radio. Reload this page for the very latest on the mission.

0057 GMT (8:57 p.m. EDT)

SPACECRAFT SEPARATION CONFIRMED! The first Sirius Satellite Radio spacecraft was successfully launched into orbit tonight by a Russian Proton rocket. International Launch Service, which managed the mission, confirms the Block DM performed two scheduled firings and then deployed the Sirius 1 satellite into the correct highly elliptical, highly inclined orbit around Earth. In addition, ground controllers have established contact with the new satellite, verifying its good health following launch.

Read our full story for complete details on the launch and Sirius Satellite Radio.

This marks the 14th successful Proton launch by ILS, an international venture between Lockheed Martin, Khrunichev and Energia to globally mark the Proton and American Atlas rocket fleets.

The next Proton launch is scheduled for 2340 GMT (7:40 p.m. EDT) on July 4 when a Russian military communications satellite will be hauled into space. That Proton will be outfitted with the Phase 2 second and third stage engines, serving as the second of two required qualification flights for the RD-0210 powerplant before use aboard the Proton to launch the International Space Station's Zvezda service module on July 12.

Meanwhile, Sirius Satellite Radio plans to deploy its other two spacecraft using Proton rockets in September and October. The three Space Systems/Loral-built satellites will operate as a constellation to provide coast-to-coast, commercial-free digital radio directly to American motorists.

2228:47 GMT (6:28:47 p.m. EDT)

T+plus 20 minutes. We will pause our coverage at this time. But check back later this evening as we provide updates after the Block DM upper stage fires to boost Sirius 1 into its highly elliptical, highly inclined orbit.

2219:47 GMT (6:19:47 p.m. EDT)

T+plus 11 minutes. The aerodynamic shroud around the Block DM upper stage has been jettisoned. The stage and Sirius 1 will now coast in the low-altitude parking orbit for the next 32 minutes.

At T+plus 43 minutes, 50 seconds the first of two firings by the Block DM is scheduled to boost Sirius 1 to toward its final perch above Earth. The second firing is planned at T+plus 2 hours, 3 minutes and 17 seconds.

Separation of Sirius 1 to complete this launch is expected at T+plus 2 hours, 25 minutes and 10 seconds, or 0033:57 GMT (8:33:57 p.m. EDT).

2218:47 GMT (6:18:47 p.m. EDT)

T+plus 10 minutes. The Proton core vehicle has completed its job today by carrying the Block DM upper stage and attached Sirius 1 satellite into a parking orbit around Earth. Third stage engine shutdown and stage separation has been confirmed.

2217:47 GMT (6:17:47 p.m. EDT)

T+plus 9 minutes. Less than one minute remaining in the third stage firing.

2216:47 GMT (6:16:47 p.m. EDT)

T+plus 8 minutes. Third stage engine combustion chamber pressure is normal. Altitude is 182.3 km, downrange distance is 1298 km.

2215:47 GMT (6:15:47 p.m. EDT)

T+plus 7 minutes. The third stage and control systems are working normally. Altitude is 175 km, downrange distance is 880 km.

2214:47 GMT (6:14:47 p.m. EDT)

T+plus 6 minutes. The second stage has completed its firing and separated. The third stage engine ignition confirmed. Also the payload fairing has been jettisoned.

2213:47 GMT (6:13:47 p.m. EDT)

T+plus 5 minutes. Altitude is 132 km, downrange distance 431 km. Standing by for ignition of the third stage.

2212:47 GMT (6:12:47 p.m. EDT)

T+plus 4 minutes. About 90 seconds remaining in the second stage burn today. Altitude over 100 km, downrange distance 214 km.

2211:47 GMT (6:11:47 p.m. EDT)

T+plus 3 minutes. The four second stage engines continue to fire. Altitude is 70 km.

2211:17 GMT (6:11:17 p.m. EDT)

T+plus 2 minutes, 30 seconds. The second stage engines have ignited and the spent first stage has dropped away.

2210:17 GMT (6:10:17 p.m. EDT)

T+plus 90 seconds. Engine combustion chamber pressures look nominal.

2209:47 GMT (6:09:47 p.m. EDT)

T+plus 60 seconds. Altitude is 10 km, downrange distance 3.7 km. All systems reported normal.

2209:17 GMT (6:09:17 p.m. EDT)

T+plus 30 seconds. Roll maneuver has started to place the rocket on the proper flight azimuth for Sirius 1.

2208:47 GMT (6:08:47 p.m. EDT)

LIFTOFF! Liftoff of the Russian Proton rocket launching a revolution in how Americans listen to the radio.

2207:47 GMT (6:07:47 p.m. EDT)

T-minus 1 minute. The engine start command will be issued by the launch sequencer at T-minus 2.5 seconds. The six first stage engines will be ignited at T-minus 1.6 seconds.

2206 GMT (6:06 p.m. EDT)

T-minus 2 minutes and counting. The Sirius 1 spacecraft, Proton rocket and Block DM upper stage have been declared ready for launch.

2204 GMT (6:04 p.m. EDT)

T-minus 4 minutes and counting. Today's launch will occur from the recently renovated pad 24 at Baikonur Cosmodrome.

2202 GMT (6:02 p.m. EDT)

T-minus 6 minutes and counting. The Proton rocket weighs 1,719,606 pounds as it sits on the launch pad. The Sirius 1 spacecraft accounts for 8,377 pounds. At launch the Proton's six first stage engines will fire together to lift the massive rocket skyward into the predawn skies at Baikonur.

2158 GMT (5:58 p.m. EDT)

Only ten minutes remain in the countdown to launch. There are no problems being worked and weather is not a factor for launch, officials report.

The Proton rocket's first three stages that make up the core vehicle will complete their mission in the first 9 minutes, 51 seconds of the launch. That is important to remember because these stages are the same design that will carry the Zevzda service module into orbit for the International Space Station in a couple of weeks.

The Proton third stage will deploy the Block DM upper stage and attached Sirius 1 spacecraft in a nearly elliptical 106-mile high parking orbit. The Block DM will conduct the first of two firings at T+plus 43 minutes, 50 seconds to begin the journey into the desired orbit for Sirius 1. The burn will last about six minutes.

A second burn is planned at T+plus 2 hours, 3 minutes, 17 seconds to completed the powered phase of today's launch. The second Block DM firing is expected to last just under two minutes.

Separation of Sirius 1 from the Block DM will occur 2 hours, 25 minutes, 10 seconds after launch.

2148 GMT (5:48 p.m. EDT)

T-minus 20 minutes and counting. All activities are on schedule at Complex 81's pad 24 at the Baikonur Cosmodrome for liftoff of the Proton rocket at 2208:47 GMT today.

The Sirius 1 spacecraft being launched today is the first spacecraft in Sirius Satellite Radio constellation. It will operate in a egg-shaped orbit ranging from 14,900 miles at the low point to 29,200 miles at the high end, inclined 63.4 degrees.

The craft will be joined by Sirius 2 and 3 in September and October respectively to provide 100 channels of digital radio to subcribers across the United States.

2142 GMT (5:42 p.m. EDT)

The countdown is proceeding smoothly for launch of the International Launch Services Proton rocket. The weather conditions at Baikonur are acceptable and no technical problems are being discussed.

In the past little while the launch team provided the final updates to the rocket's guidance computer and the sequencer is now controlling the countdown to liftoff.

2100 GMT (5:00 p.m. EDT)

Final preparations are underway at the Baikonur Cosmodrome in Kazakhstan for today's launch of a Russian Proton rocket carrying the Sirius 1 digital radio broadcasting spacecraft for Sirius Satellite Radio of New York City. Liftoff is scheduled for 2208:47 GMT (6:08:47 p.m. EDT), and there is a 12-second launch window.

The three-stage Proton rocket and its Block DM upper stage will need just shy of 2 1/2 hours to hurl the Space Systems/Loral-built Sirius 1 satellite into the planned highly elliptical, highly inclined orbit around Earth. See our timeline of the events to occur during launch.

Stay on this page for continuing live updates throughout the countdown and launch. Also, Spaceflight Now will be offering a live streaming video broadcast of the launch beginning at 2140 GMT.