As an aside, and purely thinking out loud here, the majestically slow lift-off of Antares did make me wonder if there would be a case for gaining performance through small strap-on SRMs. The gravity losses in early flight must be pretty large in this vehicle.
if there would be a case for gaining performance through small strap-on SRMs.
They are very different companies. Not everyone is out to colonise another planet, you know.An upper stage upgrade (Castol 30XL) is in the works to loft the planned enlarged Cygnus.As an aside, and purely thinking out loud here, the majestically slow lift-off of Antares did make me wonder if there would be a case for gaining performance through small strap-on SRMs. The gravity losses in early flight must be pretty large in this vehicle.
How about qualifying the NK... I mean, AJ-26 for a few more % max thrust??? That would do wonders for performance, given the low initial T/W...
I'm just curious about any news relating to any improvements or follow-on's to the Orbital Antares Launcher. Any plan for engine upgrades?Any plan for multiple engines?Any plans for a Antares Heavy?It seems that Orbital is pursuing a much more conservative strategy than SpaceX.
Orbital is evaluating development of a west coast launch site for Antares.
I guess ask Russians to improve it - I'm sure they would be able to come up with a trick or two to extract more performance.
Huh? what makes you think that is possible?
And if you add NK-43 (hmm AJ26-60? ) in the second stage I think performance will be even better - I couldn't find Castor's specs but I'm pretty sure NK-43 has better Isp...
It does have a very nice Isp. However, it would be a little like putting a V10 in a motorcycle. It'd be a fun ride, but you're unlikely to survive it. If you dig back, Antonio mentions the work done on a high energy liquid upper stage powered by an RD-0124. That's a 70,000lbf engine (which is pretty close to the thrust output of a Castor 30) Contrast that with about 400,000 lbf for the NK-43. The Antares first stage won't lift an upper stage large enough to justify that, so if you were silly enough to build such a thing, you'd have a small-ish upper stage with a big honking engine, topped by what would rapidly become a very flat payload.
Quote from: Jim on 04/23/2013 12:46 amHuh? what makes you think that is possible?Well they are the ones that were working with KeroLOX SC engines for decades, plus they have a successful history of iterative improvements with other engines. For one, NK-33 has much lower chamber pressure than RD-1xx family, so maybe this can be increased to raise Isp and thrust. I'm not a rocket engines designer to be more specific, I'm just saying that if anyone can improve these engines, it would be the Russians... And their design philosophy has always been to build a baseline engine, and then gradually improve on that. NK-33 did not have a chance to go through this improvement process, so I'm fairly certain there is a room for improvements. Also they could use improved materials that are lighter/stronger, as there have been improvements in materials as well during all these years.