1) Can NK-33/AJ-26 be built in the US rather than the Ukraine? Even if it is still a foreign design, construction, testing and integration in the US will make a lot of people happier.
But it seems that the Russian high-pressure kerolox staged combusion, in multiple thrust classes (and even staged-combustion hypergolics) are not so bad after all. Kerosene -- of all substances! -- is apparently coming back, partly because cost is now more important than performance, and because we can leverage past Russian and Soviet investments.
Quote from: Ben the Space Brit on 07/28/2010 09:17 pm1) Can NK-33/AJ-26 be built in the US rather than the Ukraine? Even if it is still a foreign design, construction, testing and integration in the US will make a lot of people happier.Aerojet has the rights to US production, but it's unlikely the economic case would close compared to restarting production in Russia. (As Ed says, it is not and never was Ukrainian. It also hasn't been produced since the Soviets canceled the N1 in the 70s)If the government were going to pay for US production of a Russian engine, it might be better to bite the bullet and do the RD-180 (for which US production rights also exists.)
2 NK-33s also have a disadvantage: two turbopump sets instead of one. Which wouldn't be bad in itself except vehicle controllability depends on both engines running. All other things equal (not that they likely *are*), that would increase chances of a LOM.
They still haven't got an RL-10 -- how primitive!
Quote from: alexw on 07/28/2010 09:48 pmThey still haven't got an RL-10 -- how primitive!You are gravely mistaken. KBKhA officially acquired the RL-10 know-how (in the process of collaboration with P&WR) and produced a "Red RL-10" called RD-0146. It sports some improvements and RW&R is marketing it outside of Russia. It is also baselined in the SPKG "Rus-M" (or was until RKKE's Zenit-based alternative was submitted last month). So, although it haven't taken the flight, they've got an RL-10 all right.
Russia produce staged combustion cryogenic engine KVD-1 for GSLV upper stage.
Yes it is.
Its isp is no better than RL-10B-2, but it's a lot better than early RL-10's of comparable thrust. Impressive. -Alex
AJ-10 doesn't develop enough thrust. It is also a pressure fed engine, which would result in a heavier, less capable upper stage. For this application, the only reasonable U.S. option would have been RL-10, but that would have added the expense of hydrogen fuel infrastructure. - Ed Kyle
Did they choose not to use the expander cycle deliberately for performance? Its isp is no better than RL-10B-2, but it's a lot better than early RL-10's of comparable thrust.
If I understand correctly, Russia has never placed into operation a hydrolox upper stage, certainly nothing with both the thrust and isp of RL-10B-2. In that sense, Russian rockets seem "primitive", technologically, compared to the conspicuous US investment in liquid hydrogen. Yet e.g. Proton still has very good performance and low cost, and for non-escape-velocity missions, the Russian choices in kerosene seem to have led to better value across most of the rocket spectrum. SpaceX (and Orbital) seem to be validating that proposition. -Alex
Those Isp and thrust results are as expected. There's no physical reason for Isp to be higher on staged combustion vs expander of the same mixture ratio. Expander is not good for a high thrust application, due to vehicle mass, but staged is.
Wow. Is this among the smallest staged-combustion engine built? -Alex
Orbital spaceship ( + 2nd stage with RD-0124) :
There's no physical reason for Isp to be higher on staged combustion vs expander of the same mixture ratio. Expander is not good for a high thrust application, due to vehicle mass, but staged is.