NASA's Bad Engine Habits
As NASA discards reusable engines, Blue Origin and SpaceX push new frontiers, Ars Techinca
“On the Monday before Thanksgiving NASA made what it deemed a momentous announcement: the space agency had awarded $1.16 billion to Aerojet Rocketdyne for rocket engines that would power its “Journey to Mars.” By contrast, a few hours earlier, the private space company Blue Origin secretly launched a rocket into space and safely landed it. The contrast between the deal struck in corridors of Washington D.C. and what had happened in the desert of West Texas could not have been more stark.”
How the new SLS engine contract is a step in the wrong direction, Space Review
“Blue Origin is not the only company in hot pursuit of reusable rockets. SpaceX has come close to succeeding in two attempts to land the first stage of the Falcon 9 orbital launch vehicle on an ocean platform. In the near future, SpaceX will also attempt to touch down the first stage of the Falcon 9 on land close to the launch site. Sooner or later, SpaceX will succeed and will be nailing these landings, just like Blue Origin did. Other companies and countries are working on reusable rockets and spacecraft as well. Those working on reusable suborbital vehicles include Virgin Galactic with their SpaceShipTwo, XCOR Aerospace with their Lynx rocketplane, and Masten Space Systems with their vertical takeoff and landing rockets.”
Keith’s note: This is not the first time in recent memory that NASA has made decisions to revisit old technology as part of bad habits it just can’t shake. The agency spent over a billion dollars on J-2X and then changed its mind. Meanwhile everyone outside of NASA who is spending their own money on rocketships is striving toward reusability for economic reasons. But NASA doesn’t do economical things in-house, now does it?
This needs to get much wider attention. NASA is going to be building complete Space Shuttle main engines and going to be using them only once. I cannot find the words to describe how wrong this is.
Doesn’t reusability only make sense with a reasonable flight rate.
Launchers only make sense with a reasonable flight rate.
It’s more than just the money, Keith, although of course you are right that the costs are part of the picture.
We see NASA following, not leading. I expect NASA to break new ground with new tech. I don’t mind when money is spent on something that turns out to be a dead end- that’s the nature of research (and I don’t have the expertise to assess J-2X in this context).
But I do know enough about space that tossing those marvelous engines designed for reuse into the Atlantic is just wrong.
Throwing away hardware on each flight deprives the engineers the opportunity to inspect it after flight. The space shuttle program was expensive, but inspecting, rebuilding, and reusing the SSMEs almost certainly had a positive impact on safety and reliability over the life of the program. This new version of the RS-25 will not have that luxury, so safety and reliability could suffer as a result.
See this as paying Aerojet/R-dyne X dollars a year, rather steadily, flying or not, Shuttle or not, Cx or not, and now SLS and so on.
NASA does love to pay people to paint. It’s that fear that if I don’t pay someone to paint the house a little every day they won’t be there, like when I need the house painted.
Payment for results? To have the house painted? To finish painting the house? God forbid.
The total that went to AR/R-dyne since Cx started in 2005 – there’s an excellent FOIA request. An even better question – the data by year. You’d find that slow but constant trickle of $…or should I say bleeding.
How about we build a totally reusable spacecraft system, let’s call it the Space Transportation System (STS). It flies into space and then comes back to earth. It is mostly reusable. What should we call the spacecraft?
Overpriced, inefficient and obsolete?
Not if done right. Not if designed using everything we know now that we didn’t know the first time.
What you describe is not SLS. From the space shuttle we learned that SSMEs can be reused over and over. We also learned that large segmented solids may have lower development costs, but have quite high reoccurring costs even when “reused”.
The lesson NASA unfortunately “learned” from SLS is that reuse is “hard”, so why bother? Defeatist, if you ask me.
“SLS Won” by one severely flawed assumption. The 2005 ESAS assumed a loss of crew during a rendezvous event was 1000 times riskier than experience and the goal became to eliminate all “3-launch solutions”. A 120mT lunar sortie divided by one or two is the source of the 70 and 130mT ‘requirement’. SLS/Orion have compromised all paths forward, with latest bar lowering called ‘distributed launch’.
Max Faget, Shuttle designer, “We really need to get behind a really sensible first stage that’s completely reusable and piggyback off that till you get the capability to have a two-stage reuseable vehicle.”
There are now dozens of limitations in the architecture and hardware in terms of cost, performance, and schedule, and worse, the inability to have innovation and creativity provide a foundation to the economy.
The lowering of the bar continues…..
https://www.youtube.com/wat…
You mean they ignored the fact that ISS was being built and serviced using dozens upon dozens of flights, each requiring rendezvous and docking (excepting of course the launch of the FGB, which was the first element).
“The 2005 ESAS assumed a loss of crew during a rendezvous event was 1000 times riskier than experience”
I was not aware of this, but it would explain the odd aversion to modular on-orbit construction for BEO missions. Was this just an unfortunate overestimation or a case of adopting the estimates required to get the desired answer?
In my opinion, it was the then NASA Administrator’s obsession with very large launch vehicles. CEV never needed to be as big as it was specified. Its bloated size was explicitly chosen to disqualify launching it on EELVs, despite their proven reliability. Instead, it “required” Ares I.
But, Ares I was little more than a thinly veiled development effort for some of the hardware to be used on Ares V (e.g. five segment SRBs). SLS is the descendant of Ares V and has the same flaws.
An HLV may not be required at all for beyond earth orbit missions if you assume in orbit assembly and refueling.
Going to single use engine has its benefits. The engine can be built with cheaper materials and less mass, or built the same and operated beyond the normal reusable engine limits. With Shuttle, NASA realized that rebuilding every engine between launches turns out to be more expensive than single use throw away.
You go to cheaper materials and less mass and you could adversely impact safety.
The way they’re going to make it cheaper is by using modern manufacturing methods. After all, the original SSME was designed in the 1970s, so there is a lot of room for improvement.
They did try that with the RS-68. It didn’t quite work as cheaply as they expected and the engine under-performed.
Actually, the original SSME was designed and built to cut out weight. RS-25 probably isn’t changing materials (i.e.: cheaper) because most materials used in aerospace are there for a specific purpose (strength, fatigue resistance, temperature, etc). AR & NASA have both touted reduced cost for the engine due to this redesign development, involving reduced fabrication time using SLM, eliminating welds, and using advanced manufacturing processes to lower overall cost. It’s likely the engine will gain a little weight to help save cost. Taking weight out of space components is the costly endeavour, putting weight back in often improves fatigue margins at the compromise of slightly reduced lift capacity. That said, the engine is slated to run at a higher power level than it did on shuttle, so it will actually have a greater thrust output – and they can run at higher power because the engine doesn’t have to be reusable and sustain through the higher stress of multiple launches.
First off, they are only “throwing away” heritage SSMEs that have already flown a number of times on shuttle missions; NASA plans to develop a cheaper RS-25 for SLS – presumably by getting rid of a lot of the margins and robustness needed for reusability. Secondly, SpaceX & Blue are commercial companies seeking to do a large number of launches annually – so reusability makes a lot of sense. Even though NASA should launch SLS more than once every few years for Exploration missions, its not clear that you’ll ever launch it often enough to make reusability make sense. Don’t forget – for over 30 years we reused ATK’s solid rocket booster metal segments and with all the costs associated with developing the capability, booster recovery and refurbishment, I recall the studies done later said they were at best breaking even!
Read the articles. The contract award is to develop these “cheaper” engines. The development contract is for $1.16 billion. SpaceX plans to sell Falcon Heavy launches for $90 million (from their website). So, $1.16 billion would buy you about 13 Falcon Heavy flights.
The contract actually does not include any fight hardware. That is a separate option to buy 6 (yes 6) RS-25E at additional cost.
I calculated the $1.16B for 6 engines comes to about $193M per engine in just development cost. About what a fully expendable Falcon Heavy flight with launch service and payload processing will cost.
The SpaceX price quote of $90M for a Falcon Heavy flight is for 6.4 metric tons to GTO orbit with what I am guessing with all 3 cores being recoverable.
That works out to 6 X 53 mT = 315mT IMLEO for $1.16B with Falcon Heavies. In comparison a SLS Block 1 flight can only do about 70 IMLEO for about same cost.
It would be absolutely impossible for SpaceX to develop a high energy upper stage if the demand was there?
For SpaceX a large part of the market is in LEO where thrust is more important.
Only if there is lots of payload that could not be serviced with the Falcon Heavy in the fully expendable mode. Like if you need to put something more than 53 metric tons in LEO or 21 metric tons in GTO orbits.
However in future the BFR (Big F** Rocket) with the MCT (Martian Colonial Transporter) upper stage with the Raptor full flow staged combustion engines with performance close to HydroLox engines. Both the BFR & MCT are reusable. The BFR will have IMLEO of more than a couple hundred metric tons.
So it is unlikely that the Falcon rocket family will get a high energy upper stage from SpaceX. But maybe something like the ULA ACES upper stage as a kick stage as part of the payload is possible.
Using a ULA kick (third) stage is probably the most expedient option. It could be considered part of the payload, with SpaceX simply putting the stage and spacecraft in a LEO parking orbit, and then the customer operating the mission from there. That is less efficient than a single, optimized trajectory, but easier to do.
But SpaceX would have to make some changes. On-pad support for cryogenic fuels (especially after a launch delay) would be one. Also, although I couldn’t find the planned dimensions for the ACES, but about the size of a Centaur or DCSS. That just barely fits in the current payload shroud of a Falcon. Since that’s what they are planning for the Falcon Heavy, you wouldn’t have much room left for the actual payload. Unless SpaceX developed a new, larger shroud.
First off, NASA is MANDATED to:
“(2) The improvement of the usefulness, performance, speed, safety, and efficiency of aeronautical and space vehicles;”
NASA is a taxpayer funded agency and their mandate is to first and foremost help americans and there businesses to prosper and improve the economic landscape of our Nation.
It is in the NATIONAL interest to have reusable launch vehicles and since NASA is also mandated to:
“(c) The Congress declares that the general welfare of the United States requires that the National Aeronautics and Space Administration (as established by title II of this Act) seek and encourage, to the maximum extent possible, the fullest commercial use of space.”
So any missions NASA wants to conduct they would fall on mandates A LOT FARTHER down the list than the ones I have shown.
ALL of NASA’s long term launches become cheaper if the Nation has reusablity. NASA will have more funding available for actual hardware the sooner America has reusability in the launch hardware.
http://history.nasa.gov/spa…
Feh. This of course has nothing to do with sending people to Mars, it’s about sending money to certain contractors and Congressional districts. NASA astronauts will go to Mars when SpaceX sells them tickets.
No doubt that’s part of the story and has been discussed here ad nausea.
But it is not the whole picture.
Maybe a silly question Keith..
Why not use the RS68? like with D IV H? Is this not almost as much thrust at a lower (disposable) Price Tag? btw love your stuff
The RS-68 is not compatible with large segment solids due to heat retention issues. Mainly cause by the cheaper ablative cooled exhaust nozzle that could not be test fire.
But it is moot. The production line for the RS-68 is ending soon. Just remaining open to roll out the last few RS-68As for about 5 more future Delta IV Heavy flights for the spooks.