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#100
by
DanielW
on 05 Nov, 2014 01:17
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I am not an expert on rockets or foreign policy, but I think the fact that these engines are Russian is over-blown. It certainly makes some sense to have an all US fall-back for DoD payloads, but the fact of the matter is that the Russians make some good engines.
I personally prefer to have some mutually beneficial economic ties for lower impact vehicles like Antares. It may give governments leverage but it also serves to add some pressure to play nice.
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#101
by
robertross
on 05 Nov, 2014 01:31
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I am not an expert on rockets or foreign policy, but I think the fact that these engines are Russian is over-blown. It certainly makes some sense to have an all US fall-back for DoD payloads, but the fact of the matter is that the Russians make some good engines.
I personally prefer to have some mutually beneficial economic ties for lower impact vehicles like Antares. It may give governments leverage but it also serves to add some pressure to play nice.
If (heaven forbid) we were to have a major invasion overseas, or a war, precipitated by Russia then the sanctions we have seen so far will ultimately lead to a total ban by one side, then the other, on imports & exports. That's a worst case scenario, and leverage would not be the biggest factor on the world stage.
In this case, the spaceflight companies (and American Government/military) have the most to lose by not gaining access to a necessary part to their rocket or putting a payload to orbit. For Russia, it's only money that they can disperse for compensation.
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#102
by
DanielW
on 05 Nov, 2014 01:41
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I am not an expert on rockets or foreign policy, but I think the fact that these engines are Russian is over-blown. It certainly makes some sense to have an all US fall-back for DoD payloads, but the fact of the matter is that the Russians make some good engines.
I personally prefer to have some mutually beneficial economic ties for lower impact vehicles like Antares. It may give governments leverage but it also serves to add some pressure to play nice.
If (heaven forbid) we were to have a major invasion overseas, or a war, precipitated by Russia then the sanctions we have seen so far will ultimately lead to a total ban by one side, then the other, on imports & exports. That's a worst case scenario, and leverage would not be the biggest factor on the world stage.
In this case, the spaceflight companies (and American Government/military) have the most to lose by not gaining access to a necessary part to their rocket or putting a payload to orbit. For Russia, it's only money that they can disperse for compensation.
This is why we should have some systems that use all American parts. But some does not need to be all. Also I think that it is probably easier to find a supplier if you have money than it is to find a buyer if you have engines. Loss of a revenue stream can have pretty far ranging impacts on an economy. (or so I am told by political ads decrying plant closures that are somehow related to a candidate from wrong party.)
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#103
by
nimbostratus
on 05 Nov, 2014 02:41
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I think he means Oxidiser/Fuel ratio, i.e. the AJ-26 runs oxidiser-rich, while the Merlin 1D runs fuel-rich. As a result, they'd have to move the bulkhead so as to carry more fuel and less oxidiser.
All engines runs fuel rich, and the difference lies in preburner/gas generator mixture ratio.
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#104
by
pippin
on 05 Nov, 2014 02:55
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Cygnus is also meant to supply the ISS. If the state of affairs with Russia deteriorates to a degree where Russia no longer supplies engines for this purpose me somehow thinks the purpose itself will fall away, too.
If it happened now, after all, the US could not even send astronauts to ISS anymore, after all.
This is an international project depending heavily on Russia. You no longer want to play with Russia? No need for CRS/Cygnus anymore so no need to secure any "all US" (nonsense anyway, you always have _some_ stuff coming from abroad) supply of engines.
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#105
by
nimbostratus
on 05 Nov, 2014 03:00
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Guyz we are drifting off the topic of a changeover to another engine 
"On October 19, 2012, NPO Energomash announced that three days earlier, an experimental RD-193 engine completed its fifth live firing without leaving test bench No. 2 at the company's NIK-751 test facility. During five tests, the engine burned for a total of 678 seconds. Following the tests, the engine was to be disassembled and checked for any defects to clear it for further tests, NPO Energomash said."
http://www.russianspaceweb.com/rd193.html
maybe someone can focus on the history and see if this engine has a flight history?
RD-193 is the youngest sibling from the RD-191 Subfamily. RD-191 is gimbaled variant and RD-193,intended for Soyuz core stage, is fixed variant and is surround by the four nozzles of the Soyuz core stage steering engine. RD-193 has not been flown to date as it was in development cycles.
Fixed nozzle sorrounded by 4 steerng nozzles?
Dont' the 4 steering nozzles share the same turbopump with the main nozzles， which means the steering nozzles are part of the main engine?
And as far as I know, Rd193 is a downgraded version of Rd191, with lower thrust.
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#106
by
pippin
on 05 Nov, 2014 03:02
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Dont' the 4 steering nozzles share the same turbopump with the main nozzles， which means the steering nozzles are part of the main engine?
No. It's a separate engine with four nozzles, RD-0110
IIRC Soyuz-2-1v doesn't even have enough thrust to leave the ground without it (using NK-33)
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#107
by
nimbostratus
on 05 Nov, 2014 03:15
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Dont' the 4 steering nozzles share the same turbopump with the main nozzles， which means the steering nozzles are part of the main engine?
No. It's a separate engine with four nozzles, RD-0110
IIRC Soyuz-2-1v doesn't even have enough thrust to leave the ground without it (using NK-33)
Are you sure?
Perhaps Rd-0110 was adopted for suyuz 2.1v, not for other soyuzs.
And russians seems to be good at complicating things.
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#108
by
pippin
on 05 Nov, 2014 03:20
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Are you sure?
That's neither an RD-193 nor an NK-33 but an RD-108. With that engine Soyuz is definitely not getting off the ground but needs four boosters
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#109
by
nimbostratus
on 05 Nov, 2014 04:32
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Dont' the 4 steering nozzles share the same turbopump with the main nozzles， which means the steering nozzles are part of the main engine?
No. It's a separate engine with four nozzles, RD-0110
IIRC Soyuz-2-1v doesn't even have enough thrust to leave the ground without it (using NK-33)
And it occurs to me that RD-0110 was an upper stage engine for early soyuz LV. Perhas some modification has been made for use in atmosphere.
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#110
by
nimbostratus
on 05 Nov, 2014 05:22
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Cygnus is also meant to supply the ISS. If the state of affairs with Russia deteriorates to a degree where Russia no longer supplies engines for this purpose me somehow thinks the purpose itself will fall away, too.
If it happened now, after all, the US could not even send astronauts to ISS anymore, after all.
This is an international project depending heavily on Russia. You no longer want to play with Russia? No need for CRS/Cygnus anymore so no need to secure any "all US" (nonsense anyway, you always have _some_ stuff coming from abroad) supply of engines.
OSC can buy enough engines at a or 2 times, so there will be no need for follow-on procurement.
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#111
by
nimbostratus
on 05 Nov, 2014 05:24
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RD151 is developed for Naro use only?
Why bother develope so many new engines?
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#112
by
GClark
on 05 Nov, 2014 06:43
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And it occurs to me that RD-0110 was an upper stage engine for early soyuz LV. Perhas some modification has been made for use in atmosphere.
For info on the RD-0110R, see here:
http://russianspaceweb.com/rd0110r.html
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#113
by
GClark
on 05 Nov, 2014 06:44
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RD151 is developed for Naro use only?
Why bother develope so many new engines?
AIUI, RD-151 was developed in such a way as to comply with MTCR.
For info on KSLV/Naro, see:
http://russianspaceweb.com/kslv.html
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#114
by
nimbostratus
on 05 Nov, 2014 07:36
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RD151 is developed for Naro use only?
Why bother develope so many new engines?
AIUI, RD-151 was developed in such a way as to comply with MTCR.
For info on KSLV/Naro, see:
http://russianspaceweb.com/kslv.html
Thanks for your infomation.
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#115
by
nimbostratus
on 05 Nov, 2014 08:50
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RD151 is developed for Naro use only?
Why bother develope so many new engines?
AIUI, RD-151 was developed in such a way as to comply with MTCR.
For info on KSLV/Naro, see:
http://russianspaceweb.com/kslv.html
No matter how Rd-151 was born, it is a working engine. It can replace NK-33 on soyuz 2.1v and Antares, and perhaps other engines.
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#116
by
baldusi
on 05 Nov, 2014 13:50
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Don't know if someone already mentioned this, but in looking at the specs for the AJ-26 and Merlin 1D it looks like you could replace two AJ-26 with five Merlin 1D. It's an almost exact match, with a little more sea level thrust and a little less vacuum thrust.
Different O/F, different isp, different cycle (you have to deal with the gas generator output), different TVC, different diameters... etc. Save for the thrust nothing similar.
Same oxidizer and fuel - LOX/RP-1 - otherwise I wouldn't have mentioned it as a possibility.
Same propellant (LOX/RP-1), different oxidizer to fuel ratio. Merlin's are about 2.35, while RD-180/193 are about 2.73. That requires different tanks, and since it changes the density, it might require longer tanks. This impacts GSO, Pad, erector, etc.
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#117
by
rusty
on 06 Nov, 2014 06:33
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Wouldn't it just be easier to go with a solid ATK first stage? They are already using or will use a ATK 30XL for the second. ATK has a good track record.
The launch safety criteria for solids violate overpressure in case of failure at the MARS pad IIRC, and would most likely never be given a waiver by FAA, NASA or anyone else. That means a new pad, probably not at MARS.
Minotaur V already launches next to the Antares pad. What makes you think a Castor 120-based rocket, like AthernaII or an Orbital/ATK equivalent, wouldn't be allowed? If a RSRM Castor 900 or single-segment Dark Knight was proposed (AthenaIII) I could see an argument, but not these.
-snips-
Athena 2cS with six boosters would lift 4.19 tonnes to a 500 km x 28.5 deg LEO ...
It is a number that bumps up close to Delta 2 and Antares capability. ...
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#118
by
russianhalo117
on 06 Nov, 2014 15:26
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Wouldn't it just be easier to go with a solid ATK first stage? They are already using or will use a ATK 30XL for the second. ATK has a good track record.
The launch safety criteria for solids violate overpressure in case of failure at the MARS pad IIRC, and would most likely never be given a waiver by FAA, NASA or anyone else. That means a new pad, probably not at MARS.
Minotaur V already launches next to the Antares pad. What makes you think a Castor 120-based rocket, like AthernaII or an Orbital/ATK equivalent, wouldn't be allowed? If a RSRM Castor 900 or single-segment Dark Knight was proposed (AthenaIII) I could see an argument, but not these.
-snips-
Athena 2cS with six boosters would lift 4.19 tonnes to a 500 km x 28.5 deg LEO ...
It is a number that bumps up close to Delta 2 and Antares capability. ...
Minotaur family excluding Minotaur-C versions are not subject to FAA because they are government launchers (managed through USAF; DoD, not FAA/NASA; DoC) . Since Antares is a civilian launcher it is subject to stricter criteria to ensure enforced safety. I will let other people like Jim provide the details as I'm at work right now.
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#119
by
CT Space Guy
on 06 Nov, 2014 23:38
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How about as a short term solution. Use a recovered F9 first stage (provided SpaceX gets one back soon).
Use the Antares second stage. Let Orbital provide any adapter and they could process all their stuff elsewhere at the cape then shortly before flight integrate both sections at LC40.
SpaceX could have an anchor user for used F9 boosters and by just selling the booster and launch they could give Orbital some great pricing.
