PARIS — It is a question that has been asked over and again since March 2011, when satellite fleet operator SES of Luxembourg, historically managed with the conservatism of a Luxembourg bank, contracted for a launch with Space Exploration Technologies Corp. (SpaceX).
How could SES agree to launch a satellite on a rocket that had never flown to geostationary transfer orbit (GTO) and never demonstrated its ability to do so?
The Falcon 9, after a scrubbed launch attempt Nov. 25, was slated to make another attempt Nov. 28.
SpaceX Chairman Elon Musk, while addressing another question during a Nov. 24 press briefing, made the case for why a rocket that has flown only once should be trusted to launch a commercial satellite insured for $200 million.
By turns humble and confident, Musk laid out the Falcon 9 defense:
“We should still view this launch with the perspective that there is still a bit of remaining risk because it’s only the second flight of the new design of Falcon 9,” Musk said. “Even rockets that have been flying a long time … still have failures.”
SpaceX said the Aerospace Corp. of El Segundo, Calif., a nonprofit, federally funded research and development center, conducted a 20-year study of rocket failures between 1980 and 1999 and concluded that almost all were the result of engine or stage-separation malfunctions.
Musk said the new Falcon 9 v1.1 deals with both those issues by using the same Merlin 1D engine to power both the first and second stage, and flying with only two stages that need to separate.
“The higher the production rate of engines, the better the quality because you are able to iron out different things,” Musk said — a statement that would find no disagreement among other launch service providers.
“The flight history that we gain with each mission is an order of magnitude greater than a rocket that is flying one of a particular type of engine per flight.
“Having flown the last flight of Falcon 9, we effectively got 10 missions’ worth of flight data on the Merlin engine — because there were 10 [engines]. So you get a much better statistical reliability, much faster. And you see issues with an engine at an order-of-magnitude greater pace than you would otherwise.”
These characteristics, plus the fact that Falcon 9 is capable of completing its mission even if it loses one of the nine first-stage engines, gives the vehicle an inherent reliability far beyond its actual flight heritage, Musk said.
To maximize the power available to place the SES-8 telecommunications satellite into a supersynchronous transfer orbit, SpaceX will not to try to recover the rocket’s first stage.
“Just to be sure that we can complete the mission with the maximum likelihood, even if there is an engine out or multiple engines out, we will not be trying to recover the stage,” Musk said. “We are going to gather data on the stage as it re-enters and apply that information to future launches, but we’re not going to try to recover it.”