Inmarsat 5-F2 - Proton-M Launch Updates
Launch Vehicle Overview, Countdown Timeline, Russian Archive
Inmarsat 5-F2 Comsat arrives in Orbit after successful Proton/Briz-M Mission
February 1/2, 2015
About eight hours before T-0, non-essential personnel evacuated the launch pad for propellant loading. Proton-M was powered up approximately six hours prior to T-0 to begin checkouts of the Guidance System and Spacecraft Abort Unit.
The Russian State Commission met to discuss the status of launch preparations, providing the formal approval for propellant loading operations that commenced at about T-6 hours. The three-hour operation saw the first, second and third stage of the Proton receiving a total of 622,075 Kilograms of toxic Unsymmetrical Dimethylhydrazine fuel and Dinitrogen Tetroxide oxidizer.
The six RD-275M engines came to life 2.5 seconds ahead of liftoff - igniting and throttling up to an initial thrust stage before ramping up to a full liftoff thrust of 1,014 metric ton-force. Proton-M does not use a hold-down system and started rising from its pad once the engines reached their launch thrust, pulling up the main umbilical located at the base of the rocket until it separated which triggered the Contact Liftoff Command.
The main engine of Proton's third stage shut down nine minutes and 31 seconds after liftoff with the smaller vernier continuing operation for another 10 seconds to finish Proton's mission of boosting the orbital unit to a sub-orbital trajectory. Nine minutes and 41 seconds into the mission, the Orbital Unit was separated - being sent on its way after a successful Proton flight.
After its separation, the Briz-M Upper Stage assumed control of the first, entering a stable attitude and beginning a 95-second coast phase ahead of the first of five main engine burns. The short coast allowed the vehicle to reach a point near the apogee of the trajectory so that the burn could circularize the orbit. Main engine start was preceded by the usual ten-second propellant settling burn of the high-pressure thrusters that ensure the main engine only receives liquid propellant and does not ingest any gas bubbles.
The S5.98 engine of the Briz-M ignited as planned at T+11:16 and fired for 4 minutes and 23 seconds, its burn time was automatically adjusted by the Briz-M's Flight Control System based on data gathered during ascent in order to correct minor insertion inaccuracies of Proton-M. The first burn targeted a circular Parking Orbit of 173 Kilometers inclined 51.5 degrees.
The fifth burn started at T+15:15:05 and lasted for 3 minutes and 27 seconds targeting an insertion orbit of 4,341 by 65,000 Kilometers. Burning out of plane, the Briz-M used this last burn to reduce the inclination of the orbit to 26.75 degrees. According to information from the Guidance System of Briz-M, the satellite was delivered to an orbit of 4,310 by 64,954 Kilometers at the planned inclination, marking a successful orbital insertion by the Briz-M Upper Stage.
Separation of the Inmarsat 5-F2 satellite confirmed at T+15 hours, 30 minutes and 41 seconds after liftoff, at 4:01 UTC on Monday morning. After separation, the satellite was planned to establish attitude control and communications with the ground for its initial set of operations including a series of propulsive maneuvers occurring in the coming days as well as the deployment of the solar arrays and communication antennas.
Briz-M was tasked with two disposal burns, the first a 15-second maneuver at 7:11 UTC and the second a 100-second burn at 8:21 UTC.
Sunday's launch marked the 402nd Proton-M flight since its inauguration in 1965. 2015 will be a busy year for Proton with at least 11 launches on the manifest - nine of the 11 payloads to be launched by Proton in 2015 are communications satellites including three Russian Ekspress satellites. The other two missions will loft the classified military communications satellite known as Garpun and a triplet of Glonass navigation satellites marking the comeback of the Block DM-03 upper stage.
Data Source: ILS/Khrunichev
To deliver the Inmarsat-5 F2 Spacecraft to an optimized Supersynchronous Transfer Orbit, the Proton-M Rocket will perform a nominal ascent mission and deliver the Orbital Unit consisting of the Briz-M Upper Stage and the Payload to a sub-orbital trajectory. Separating after 9 Minutes and 42 Seconds, the Orbital Unit will start powered flight by igniting the Briz-M Main Engine to place itself in a Low-Earth Parking Orbit. In total, the Briz-M Upper Stage will make five Main Engine Burns separated by coast phases to increase its orbital altitude. After all burns are complete, the Satellite will be separated 15 Hours and 31 Minutes after Liftoff and starts its own mission lasting for at least 15 years.
Inmarsat 5-F2 is a commercial communications satellite built by Boeing Satellite Systems for operation by the British satellite telecommunications company Inmarsat. Three identical satellites were ordered from Boeing in August 2010 with a fourth ordered as a spare in 2013 - all flying under the Inmarsat-5 designation.
The Inmarsat-5 satellites are based on Boeing's 702HP High-Power Satellite Platform that is capable of hosting powerful communications payloads with payload power of up to 18kW with state of the art onboard systems including precise pointing capability and the use of flight-proven components and built-in redundancy to ensure the satellite meets its in-orbit lifetime of 15 years.
In the stowed launch configuration with the antennas and solar arrays stowed against the satellite body, the spacecraft measures 6.98 meters (height) by 3.59m (width) by 3.27m (length). Once in orbit, the two solar arrays are deployed creating a span of 33.80 meters. With the communication antennas and two external radiators deployed, the satellite measures 8.08 meters from side to side. The spacecraft has a launch mass of 6,100 Kilograms and weighs 3,750kg when beginning its life in Geostationary Orbit.
The two deployable solar arrays each have five wings that are covered with ultra triple-junction gallium-arsenide solar cells that deliver a beginning of life power of 15 Kilowatts decreasing to 13.8kW at the end of the satellite's service life.
Power is stored in dual Lithium-Ion batteries and dedicated avionics regulate the main power bus of the spacecraft to provide power to all subsystems of the satellite bus and the communications payload.
Inmarsat-5 F2 is equipped with a 445-Newton bipropellant Liquid Apogee Engine that is used for the initial climb to Geostationary Orbit. In addition, the satellite uses four axial 22-Newton Thrusters and four radial 10-Newton thrusters for smaller orbit adjustments, drifting in Geostationary Orbit and attitude maneuvers. Inmarsat-5 F2 also uses an xenon ion propulsion system (XIPS). XIPS-25 provides a thrust of 165 Millinewtons. This system can be used for Stationkeeping or drifting in Geostationary Orbit and for satellite momentum control. Using ion thrusters is more efficient in terms of fuel consumption and can extend a satellite's lifetime beyond its limited storable fuel supply.
The spacecraft facilitates a total of 89 Ka-Band transponders that create 89 user beams that are generated by 2 transmit and 4 receive apertures. Six steerable spot beams are used to provide flexible communication services. The high-capacity spot beams are fed by twelve 130-Watt traveling-wave tube amplifiers while the regular communication beams use bent-pipe repeaters and 60:48 TWTAs.
The communications payload provides flexible global coverage and also includes a hosted Ka- and L-Band payload for use by the US Government.
The Inmarsat-5 satellites will provide global mobile satellite services, including mobile broadband communications for deep-sea vessels, in-flight connectivity for airline passengers and streaming high-resolution video, voice and data. Secure communications can also be provided for government or commercial users.
Inmarsat 5-F2 is planned to operate from a position of 55 degrees west in Geostationary Orbit, joining the F1 satellite that is located at 63 degrees east.
Proton Rocket rolls to Launch Pad to open busy Year of Russian Launches
January 29, 2015
The first Proton rocket to fly in 2015 has been rolled out to the launch pad at the Baikonur Cosmodrome to begin final preparations for liftoff set for 12:31 UTC on Sunday to begin a long Super-Synchronous Transfer Mission lofting the Inmarsat 5-F2 communications satellite.
After a few difficult years and several stand-downs caused by failed missions, the Proton launcher is looking forward to a busy year with up to a dozen missions, the majority being launches of commercial communications satellites contracted through International Launch Services. A number of government-operated missions are on the schedule including the launch of the Garpun military communications satellites and the launch of thee Glonass navigation satellites marking the comeback of the Block DM-03 upper stage to be used atop Proton after the first two such missions ended in failure. In 2015, Proton will introduce its Phase IV upgrade that includes the latest mass reduction achievements using new materials and manufacturing techniques on certain components which will allow Proton to loft 150kg of additional payload mass into a standard Geostationary Transfer Orbit.
The Inmarsat 5-F2 spacecraft was delivered to the Baikonur Cosmodrome just before the holidays to begin processing at the launch site to get ready for its mission. Unpacked from its transport container and placed in a test stand, the spacecraft went through stand-alone testing and detailed inspections to ensure it made its journey from its manufacturer Boeing to the Kazakh launch site without suffering any damage.
In early January, the satellite was loaded with propellants and pressurant for consumption during its transfer into Geostationary Orbit and for orbit maintenance over the course of its mission.
The launcher and Briz-M Upper Stage were also delivered to Baikonur in the old year. At the 111 Launch Vehicle Integration Building, the three-stages of the Proton-M were integrated and went through electrical and pneumatic testing in the first two weeks of January.
At Site 101, the Briz-M was placed in a test stand for a series of electrical testing before being moved to a dedicated hazardous processing facility where it received helium tank pressurant and propellants that were loaded into the smaller high-pressure tanks of the upper stage that feed the propellant settling thrusters and attitude control thruster system while the main engine receives propellants from the low-pressure tanks loaded at a dedicated fueling station once Proton-M is fully assembled.
With all components passing their processing campaigns as planned, the stage was set for the various elements to come together - starting with the Briz-M and the satellite that were joined in Hall 101 where the satellite was installed atop the Upper Stage on January 20. After a final set of inspections and reconfigurations, the orbital unit was encapsulated in the protective payload fairing of the Proton-M rocket. Proton’s fairing is 4.35 meters in diameter and comes at lengths of 13.3 and 15.3 meters to accommodate a number of different payloads. Afterwards, the upper composite was moved to the Launcher Integration Facility where Proton-M was waiting for its payload. Once attached to the third stage of the Proton, the lengthy integration process was complete and a number of tests were run.
On Tuesday morning, the assembled Proton-M rocket was rolled out to the Briz-M fueling Station for a two-night stay to facilitate the propellant loading procedure on the upper stage. Over the course of the two-day operation, Briz-M received 19,800 Kilograms of storable propellants, Unsymmetrical Dimethylhydrazine and Nitrogen Tetroxide.
Fueling was completed on Wednesday to set the stage for rollout to the launch pad on Thursday after the State Commission had given the official approval after reviewing the status of launch preparations.
Early in the morning on Thursday, the Proton departed the fueling station en-route to the launch pad at Site 200/39. Once arriving at the pad, the Proton was moved to its vertical launch position and the Mobile Service Structure was rolled up to the vehicle to provide access platforms for workers and protect the rocket.
Over the next two days, teams will be busy performing a number of tests on the launch vehicle and the upper stage. Also, final close-outs of launch vehicle systems are performed to get ready for the launch countdown. The satellite team will be watching over the spacecraft and perform final battery charging ahead of the countdown.
Countdown Operations will get underway on Sunday, 11 hours and 30 minutes ahead of liftoff at 12:31 UTC. Thundering off, Proton will complete a standard ascent mission, burning its six RD-275M engines for two minutes, delivering a total thrust of 1,014 metric-ton force before the second stage cuts in for a burn of three minutes and 27 seconds using its cluster of four engines. The third stage fires its engines until T+9 minutes and 42 seconds. Immediately after cutoff, the orbital unit consisting of Briz-M and the Inmarsat satellite will be separated into a sub-orbital trajectory.
Beginning a five-burn mission, Briz-M will conduct an initial burn of its S5.98 main engine to boost the stack into a circular Low Earth Parking Orbit for a coast phase of over one orbit to target the descending node of the orbit for the long second burn that will be over 19 minutes in duration to raise the apogee of the orbit to 6,000 Kilometers to set up for another coast of nearly an entire lap around Earth so that the next burns can finish the apogee-raising. The third and fourth burn are performed as a pair on the descending node of the orbit, thus occurring on perigee which enables Briz-M to raise its apogee to a supersynchronous altitude of 65,000 Kilometers. The two burns are separated by the jettisoning of the Auxiliary Propellant Tank of Briz-M.
Next will be a coast phase of over ten hours during which Briz-M climbs all the way up to the apogee of the orbit at 65,000 Kilometers where the fifth burn will take place, aiming to raise the perigee to over 4,300 Kilometers and reduce the orbital inclination which decreases the amount of propellant needed by the spacecraft to transfer into its final Geostationary Orbit above the equator. Spacecraft separation occurs 15 hours and 31 minutes after liftoff. (See detailed Flight Profile Overview below.)