New Day, New Play: SpaceX Counting Down to Falcon 9 Launch, Possible Landing

SES Falcon 9 Full Thrust Credit: SpaceX

SES Falcon 9 Full Thrust
Credit: SpaceX

After delaying the launch for 24 hours to allow the maximum possible densification of super chilled liquid oxygen propellant, SpaceX is once again counting down to the launch of the SES-9 mission to geostationary orbit.

The launch window opens at 6:46 PM Eastern, with the launch broadcast beginning approximately 20 minutes earlier.

This will be the first geostationary comsat mission for the upgraded Falcon 9 Full Thrust, and its second flight overall. The first flight of the series, that of the Orbcomm OG-2 mission which took place on December 21st of last year, successfully demonstrated the second stage restart of the Merlin 1-D Vacuum engine, a capability which will be employed on this evening’s launch to send the 5,271 kg spacecraft on its way to a geostationary transfer orbit which will use a combination of chemical and electrical propulsion to reach its final position at 108.2 degrees East, some 36,000 km above the Equator.

SES-9, which will be co-located with the SES-7 spacecraft, has 81 high-powered Ku-band transponder equivalents, which will be used to serve Pay-TV, data and mobility customers in Asia and Indonesia. In addition to ground based customers, SES-9 will also provide maritime connectivity for some 26,000 vessels sailing through traffic congested areas such as the Suez Canal and the Strait of Malacca. It will also provide in-flight connectivity for airliners operating in western Pacific area.

More information on the Boeing built satellite is available here.

Although SpaceX has offered no further comment on the reasons which prompted it to delay yesterday’s planned launch beyond a brief web posting last night, it is possible that the pause may have been as much about maximizing the potential for a first stage recovery as it was about marshaling the reserve capacity for a successful launch. Densificaiton of the Falcon 9’s liquid oxygen through super chilling to near its absolute freezing point allows for more of the propellant to be loaded in the same tank space, resulting in a more energetic booster with increased margins. It is one of the defining features of the Full Thrust version of the booster which is now entering regular service.

After working through the failure analysis and return to flight follwoing last year’s loss of the NASA/CRS-7 mission, SpaceX worked with SES to alter the planned flight profile in order to reduce the time it will take to reach its final position and begin generating revenue. That change means less propellant will be available to slow the returning Falcon first stage, resulting in a highky energetic re-entry.

If the pause was in fact part of the effort to effect a first stage recovery, one which SpaceX says is highly unlikely due to today’s flight profile, the descending booster will at least find mostly favorable conditions waiting for in the Atlantic Ocean.

The latest weather buoy readings from NOAA station 41047 some 350 nautical miles ENE of Nassau, Bahamas, shows seas running around 5 feet. It is fairly windy however, with gusting between 19 and 23 knots.

Elsbeth III Screenshot:

Elsbeth III

According to, the tugboat Elsbeth III, which has accompanied the SpaceX Automated Spaceport Drone Ship in the past, was last recorded in the general area, although that reading is several days old.

SES has been a strong supporter of SpaceX’s recovery efforts, going so far as to state that it would very much like to be the first comsat customer to launch on a previously flown Falcon rocket. In a pre-launch press conference with reporters at Cape Canaveral, SES Chief Technology Officer Martin Halliwell suggested that assuming certain qualifications are met, the company might be willing to be on the first re-flight period, without requiring a demonstration flight.


The SpaceX technical webcast:

and SpaceX hosted webcast:

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