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NASA, France Skeptical of SpaceX Reusable Rocket Project
MarkWhittington writes: "The drive by SpaceX to make the first stage of its Falcon 9 launch vehicle reusable has attracted the attention of both the media and the commercial space world. It recently tested a first stage which 'soft landed' successfully in the Atlantic Ocean. However both NASA and the French space agency CNES have cast doubt that this kind of reusability could ever be made practical, according to a Monday story in Aviation Week. SpaceX is basing its plan on the idea that its Merlin 1D engines could be reused 40 times. However, citing their own experience in trying to reuse engines, both NASA and the CNES have suggested that the technical challenges and the economics work against SpaceX being able to reuse all or part of their rockets. NASA found that it was not worth trying to reuse the space shuttle main engines after every flight without extensive refurbishment. The CNES studied reusing its Ariane 5 solid rocket boosters liquid fueled and reusable but soon scrapped the idea."
No doubt that SpaceX has put a whole lot of effort into making this work, but it amazes me that people who are otherwise knowledgeable about this kind of stuff can't stand looking at actual results rather than assuming this is just random musings. One of the ways SpaceX knows how many potential launches they can get out of their engines is because they have put some of these Merlin-1 engines on their test stand in Texas and have fired them for full mission duration burns 40-50 times. SpaceX definitely doesn't make up these numbers out of their hind end but rather from experience and actually using this equipment.
Again reality sort of bites these guys hard because SpaceX has been able to bring the 1st stage down to a soft landing. With the most recent launch, SpaceX was denied the opportunity to do more because both the FAA and the USAF folks at Cape Canaveral didn't really want that return stage going anywhere near the launch pad until SpaceX has proven they have control of the vehicle. Regardless, SpaceX has done the really hard part of actually getting the spacecraft to return in a recoverable condition.... something these "experts" in this article are denying is even possible in a theoretical sense.
The 2nd stage recovery is going to be a whole lot harder, and it is something that even SpaceX themselves have said may not be successful. Still, I wouldn't categorically write off SpaceX either and it is just stupid to dismiss something like this as impossible without even making an attempt to see if it could be done.
Beyond stating the obvious, these quotes from the NASA engineers don't really seem to fly with me.
I get that building rocket engines is a tough challenge, as can be clearly demonstrated by how few new rocket engine designs ever get completed.n All of the complaints about the RD-180 engine with its manufacturing being done in Russia center around the fact that trying to get even just a rough equivalent would require building a brand new engine from scratch. For large engines that can launch payloads of several metric tones into orbit, typically only one or two ever get designed each decade by anybody around the world. This past decade one of those engines was the Merlin engine designed by SpaceX.
What makes the Merlin engine so interesting is precisely because it is bland. SpaceX hasn't been trying to push the envelope in a hardcore sense with exotic fuels or pushing the limits of specific impulse (the efficiency rating of a rocket engine). Instead they are using rather mundane fuels (Kerosene and Liquid Oxygen.... stuff used in rockets for decades) and instead are trying to simplify the design of the rocket every chance they get. Also unlike the SSME, the #1 consideration on building the Merlin has been saving money and not trying to improve performance.
I'll also note that SpaceX does not intend to do sea recovery of these rockets, so doing any consideration of salt water besides general ocean spray into the launch environment (still a problem at KSC) is not really an issue. A problem facing the managers at KSC, or rather the Cape Canaveral Air Station, is trying to find a place for these stages to land. Both the Cape Canaveral Staff and the FAA-AST want to make sure that SpaceX doesn't land their rockets on top of other facilities (like taking out pad 39B), but that is a traffic control problem and not anything to do with the technical capability of getting the rockets to a recoverable location.
As for the economics argument, a company driven by profits rather than a government agency who gets billions of dollars to extend failed programs is somebody who I expect to understand if something is going to be economically feasible or not. I'm sure SpaceX has done all of the number crunching a long time ago as they don't have the sugar daddies in the U.S. Senate to bail them out if it doesn't work.
The idea that NASA has been poo-pooing SpaceX is mostly a myth. NASA has been urging caution and realism, but NASA has been on SpaceX's side from the early days. However people really get into the narrative of hip young capitalists taking on the stogy old government and shoe horn an adversarial narrative in.