ULA Atlas V news!
 

Hello All,

On the day when John Glenn, the first man to ride an Atlas, turned 90 (see: http://www.space.com/12328-astronau...ican-orbit.html ), NASA has (belatedly, but better late than never...) gotten together with United Launch Alliance (see:
http://www.space.com/12331-nasa-pri...naut-crews.html ) to look into human-rating the Atlas V so that it could safely carry crewed spacecraft such as those being developed by Blue Origin, Boeing, and Sierra Nevada. I guess SpaceX's steady (if sometimes slow) progress has finally lit a fire under NASA--but it's a shame that they couldn't have started the Atlas V human-rating process pro-actively when the end of the Shuttle program was decided several years ago. At least now that Aerojet has finally ironed out the metallurgy of the Atlas V's oxidizer-rich AJ-26 first stage engine, we wouldn't be dependent on the Russian-made engines for the vehicles.

Think you got your spurs tangled up there a bit...

Aerojet is working with Energomash on the NK-33, which has been 'rebranded' as the AJ-26. Supposedly they're developing a US manufacturing capability, but the engines are supposed to come from Russia (cheaper). The AJ-26 is to be used on their Taurus II booster, Orbital Science Corps. entry in the COTS commercial cargo service contract to ISS.

The Lockheed/ULA Atlas V, on the other hand, is powered by the Russian RD-180 kerolox engine. These are SUPPOSEDLY capable of being manufactured by Pratt & Whitney/Rocketdyne (PWR) but are all currently purchased directly from Russia... (cheaper). I say "supposedly" because that was part of the condition of the deal, being a USAF/DOD national security asset launcher, was the capability to produce the engine domestically if necessary. The metallurgy of the Russian kerolox engines is substantially more advanced than the US engine capabilities, allowing them to run oxidizer-rich for higher efficiency, something which would melt most US rocket engines like a blowtorch...

Back on topic, this IS good news... IMHO it should have been done about, oh SEVEN FLIPPIN' YEARS AGO! If it had, along with finishing Atlas V heavy, we'd have a US launcher capable of lofting manned Orions as soon as they were ready, and be facing a MUCH shorter gap after shuttle retirement. As it is, the program will still probably not have an Atlas ready to launch humans for another few years at least, which means a substantial gap. Even though Orion is "too expensive" to use as an ISS crew transport, it WOULD have been a nice 'fallback' position in case we have a spat with the Russians, or the Russians have a problem with their spacecraft, or US "commercial crew" efforts falter (by SpaceX, etc.) or the like.

Also, a man-rated Atlas V carries two important benefits-- 1) the Atlas V would make a VERY good LRB to replace the SRB... the RD-180 is available now, ready to go, as is Atlas, and four of them clustered around an SLS core vehicle made from an ET tankage with a thrust structure housing 3-4 SSME's gets you 70 tons to LE0. Cluster 6-8 Atlas V first stages around such an SLS core, and you have 130 metric tons in orbit, as required by the Congressional mandate on SLS, WITHOUT AN UPPER STAGE! Throw in a new upper stage, and presto, you have an EXTREMELY capable deep space launch vehicle for Orion and whatever cargo you want to put on it! Once the Atlas LRB is manrated, it would be on an equal footing with SRB, and would just beat SRB all to pieces on performance, upgradability, and cost (SRB costs are borne by NASA ALONE, while Atlas V costs would be shared with the Air Force/DOD, just as they are for NASA science mission launches).

The second thing that Atlas manrating brings to the table is, RL-10 gets manrated as well for the upper stage. RL-10 is about the most efficient hydrogen engine we have (next to SSME) and it's pretty darn cheap to boot. The main drawback is it's pretty low thrust, requiring large clusters for sufficient performance for stages burning on ascent. For SLS type vehicles like the AJAX vehicle which would use a 3-4 SSME powered ET derived core vehicle lifted by 4-6 Atlas V LRB's, the upper stage would use a cluster of 6 RL-10's (of course this arrangement is perfectly acceptable-- it worked VERY well on the Saturn I Block II vehicles which all flew with the S-IV stage, powered by a cluster of 6 RL-10s, until it was replaced with the S-IVB stage on the Saturn IB, powered by a single J-2 engine). An SLS powered by 4 SSME's on a shuttle ET derived core, lifted by SRB's, could also use an RL-10 powered upper stage in the 6 engine cluster, which provides greater efficiency (though lower thrust and therefore greater gravity losses on ascent, though if your core vehicle first stage is designed right it's not an issue-- the ISP and lower upper stage engine cluster dry weight means more payload than the higher thrust but lower ISP and higher stage dry weight of the J-2X powered stage).

The RL-10 is a valuable addition and this is basically cost-sharing anyway, because if we develop any kind of in-space cryogenic propulstion capability, or cryogenically powered lander, it will be an RL-10 or RL-10 derivative (CECE) type engine powering it. SO the RL-10 will HAVE to be manrated anyway sooner or later. This way you're killing two birds with one stone...

This is really good news... shame it didn't come earlier...

Later! OL JR :)

PS... have you heard about the new AJ-500 engine that's supposed to be mfg'd in Huntsville, Alabama?? Supposed to be a new US F-1 class kerolox engine, presumably again based on Russian design?? This would be an EXCELLENT development for HLV use in the US... be it LRB's or dedicated kerolox first stage...

No. I had read earlier (although I can't find the reference at the moment) that there was a proposal to re-engine the Atlas V first stage with Aerojet-made AJ-26 engines (perhaps uprated versions) in order to avoid potential supply problems with Russian-made ones. This proposal had nothing to do with the Atlas V's potential use for launching manned spacecraft (the Air Force wouldn't want to be without the Atlas V for want of Russian-supplied engines), but an "All-American" Atlas V would certainly be more attractive to NASA for the same reason.

Vaguely. Is it based on the four-chamber, 1.7 million lb. thrust engine that powers the Zenit's first stage? If so, its four smaller (than the F-1) thrust chambers should be less susceptible to combustion instability. Also:

I'd love to see the RL-10 be human-rated via the Atlas V. It could be used for numerous manned and unmanned space flight applications, as you mentioned above. Being inherently reusable, it also has possibilities for powering reusable spacecraft. For example: The late Len Cormier's "Space Van" 747-launched orbital space plane was designed to be powered by 8 RL-10s. Its performance to orbit by itself was marginal (it also had a "booster mode" in which it would have released an orbital injection stage with a payload) with the original 15,000 lb. thrust RL-10s. The new 22,000 lb. thrust RL-10s should give air-launched spacecraft similar to the "Space Van" more comfortable mass margins.

I read that they had originally LOOKED at powering Atlas V with the NK-33/AJ-26, but chose the RD-180 instead. IIRC it was said that it was POSSIBLE to power the Atlas with the AJ-26. But surely it would involve more than a few changes, and changes cost money.

Still, anything's possible (with enough money!)

Later! OL JR :)

That could be what it was, as the article I read was from several years ago. I can see why NASA might prefer AJ-26s for engine-out capability later during ascent, as the RD-180 is a two-nozzle engine (like the early Rocketdyne Atlas booster engines--one turbopump set feeding the two booster chambers). But since losing one RD-180 chamber (or one AJ-26 engine) just after liftoff would mean "game over" anyway and would automatically trigger an abort, it would make financial sense to keep the RD-180 in the Atlas V and get Pratt & Whitney to "get on the ball" about producing an all-US RD-180, as it's a darn fine engine to have. (There is a precedent in the US for adopting foreign-designed powerplants. The A-7 Corsair II used an Allison-built version of the Rolls-Royce Spey turbofan that was called the TF-41 in the US, and Teledyne Continental's small aircraft and drone turbojet and turboprop engines [the most famous is probably the J-69 that powers the T-37 "Tweet" jet trainer] are all derived from the French Marbore centrifugal-flow turbojet engine made by Turbomeca.)

Yeah, about like a "domestic" vehicle-- there IS no such animal anymore... 3/4 of the parts in ANYTHING now comes from "overseas" (no matter which side of the ocean you happen to be on).

The J-2X has a European built nozzle IIRC and of course we know about the Russian engines previously mentioned.

I'd be kinda curious to know more about this AJ-500 engine they're talking about... any idea what THAT one is??

Later! OL JR :)