Now, the part I completely don't buy is the hydrolox US. OA has no experience with LH - they chickened out of it before with Antares (which was wise in retrospect), and I can't see them outsourcing this need, much less having the launch frequency to "keep alive" a hydrolox US in house.Best I could see is sharing it with Antares, but once you'd have two LV (Antares LV + solid LV), there would be enormous pressure to have just one LV, so one would be back to all the same problems as before, which is why they didn't do a solid Antares nor a LH US for it.
Quote from: Space Ghost 1962 on 03/06/2016 11:03 pmNow, the part I completely don't buy is the hydrolox US. OA has no experience with LH - they chickened out of it before with Antares (which was wise in retrospect), and I can't see them outsourcing this need, much less having the launch frequency to "keep alive" a hydrolox US in house.Best I could see is sharing it with Antares, but once you'd have two LV (Antares LV + solid LV), there would be enormous pressure to have just one LV, so one would be back to all the same problems as before, which is why they didn't do a solid Antares nor a LH US for it.Do you think it's possible they could use a common US with the Blue orbital LV?
I must ask again When will Orbital ATK present all the details about this new launch vehicle?Anyone?
Now, the part I completely don't buy is the hydrolox US. OA has no experience with LH - they chickened out of it before with Antares (which was wise in retrospect), and I can't see them outsourcing this need, much less having the launch frequency to "keep alive" a hydrolox US in house.
Orbital ATK also supplied a combined eighteen Delta IV and GEM-60 key composite structures, which provide lower weight and higher performance. The largest composite structures are four to five meters in diameter, range from one to eight meters in length, and are produced using either advanced wet winding or hand layup, machining and inspection techniques at Orbital ATK’s manufacturing facilities in Iuka, Mississippi, and Clearfield, Utah.Additionally, Orbital ATK manufactured the propellant tank for the Delta IV upper stage roll control system at the company’s Commerce, California, facility, and it designed and manufactured the nozzle for Delta IV's RS-68A engine at its Promontory, Utah, facility. Orbital ATK also designed and produced the nozzle's thermal protection material, which is capable of shielding the nozzle from the extreme heat of launch, when external temperatures can exceed 4,000 degrees Fahrenheit.
Yes, but I don't think any of the things OA makes for the Delta 4 are in contact with LH2. To the extent that propellants are involved, I think they are all solid or hypergolic.
Quote from: Sam Ho on 03/26/2016 04:30 pmYes, but I don't think any of the things OA makes for the Delta 4 are in contact with LH2. To the extent that propellants are involved, I think they are all solid or hypergolic.Actually yes there are some parts (tubing) within RS-68A leading to and then across the nozzle extension and back that are in contact with LH2 and LO2
He spoke of the various options (including certain Russian and American engines) for kerolox/hydrolox stages. The key reason they went with a solid US was that they were taking enough of a gamble on the LRE first stage and didn't want to risk more.
I also expect Antares 200 to be replaced soon by Antares 300 with a AR-1 as first stage engine. Because the RD-181 (Export version of the RD-191) will be banned just like the RD-180.
Quote from: Space Ghost 1962 on 03/26/2016 10:28 pmHe spoke of the various options (including certain Russian and American engines) for kerolox/hydrolox stages. The key reason they went with a solid US was that they were taking enough of a gamble on the LRE first stage and didn't want to risk more.I wouldn't necessarily read that to mean they didn't think they could do it.
At the time Orbital was competing in a very crowded field so by using an existing option on the US the perceived development risk, and possibly more likely the perceived schedule risk was reduced making their bid more attractive to NASA.
Commercial crew is a good example of this. Any major space company could probably manage (and how many proposed) spaceplanes, but in the end capsules presented less risk from NASA's POV.
For Antares I think there wasn't an HyLox engine that matched their needs. The upperstage would need about 200kN (45 000 lbf) engine. So Orbital choose for an cheap solution they could offer themselfs, castor 30 (xl). BE-3U can trottle down and meets te requirements. I also expect Antares 200 to be replaced soon by Antares 300 with a AR-1 as first stage engine. Because the RD-181 (Export version of the RD-191) will be banned just like the RD-180.
There has been considerable discussion on what liquid engine we would select for the Enhanced configuration liquid upper stage. Having lost my own personal battle for an RL10-based upper stage (probably for good reason...) I am happy to report that we are negotiation with the Russian government for usage approval of the RD-0124, the current (relatively new) Soyuz upper stage engine.
Does anyone have a sketch of what this rocket might look like?