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#480
by
hop
on 10 Feb, 2011 06:01
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I think Russia had restarted production on engines such as the RD-170 after a more longer hiatus.
This is not correct. The RD-170 family has been flying more or less continuously since it became operational.
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#481
by
Antares
on 10 Feb, 2011 17:01
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Nothing before February 2010 on PWR engines is valid now. When the SSME contract was given an end date, the question of who bears the fixed costs of PWR became unknown. I wouldn't believe anything south of $50M, and I start getting confident around $80M given the costs of other PWR engines. 'Course, it's all dependent on how many engines are built each year.
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#482
by
baldusi
on 21 Feb, 2011 16:19
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I know that ULA has been working on a "fuel densification" technologies. I understand that this means to keep the cryogenic hydrogen at higher temperature/pressure. Or does it means to still use the same temperature at a higher pressure?
On a related note, what temperature could you keep the hydrogen if you used 400Bar pressure vessels? All public data that I've found on hydrogen is on the 1~12Bar range. In fact, I'd love to know what pressure would keep the hydrogen liquid at 20C.
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#483
by
Jim
on 21 Feb, 2011 16:32
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I know that ULA has been working on a "fuel densification" technologies. I understand that this means to keep the cryogenic hydrogen at higher temperature/pressure. Or does it means to still use the same temperature at a higher pressure?
Actually it is to make it colder.
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#484
by
Nate_Trost
on 21 Feb, 2011 17:15
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What are the chances of Delta 4 medium picking up additional missions over the next several years? If it isn't on NLS2, and it's more expensive than Atlas V, it seems like the only reason a non-heavy Delta 4 would be flying is DoD/NRO working around current Atlas flight rate constraints.
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#485
by
Jim
on 21 Feb, 2011 17:37
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What are the chances of Delta 4 medium picking up additional missions over the next several years? If it isn't on NLS2, and it's more expensive than Atlas V, it seems like the only reason a non-heavy Delta 4 would be flying is DoD/NRO working around current Atlas flight rate constraints.
Delta IV will be flying approx 4 missions per year.
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#486
by
baldusi
on 21 Feb, 2011 17:47
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What are the chances of Delta 4 medium picking up additional missions over the next several years? If it isn't on NLS2, and it's more expensive than Atlas V, it seems like the only reason a non-heavy Delta 4 would be flying is DoD/NRO working around current Atlas flight rate constraints.
Delta IV will be flying approx 4 missions per year.
As it stands now, leaving D4H out, what profiles are better covered by D4 and which by A5? Being from the same company I'd think they would be sort of LV agnostic. But as an economist, I would think that until they truly merge at every level, there would be an amount of launches for each vehicle that would require further investment, and thus be cheaper to cover with the other LV. So, the question is:
Are some profiles better for one and some for the other or are they using the A5 at maximum capacity and filling the rest with Delta 4?
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#487
by
Jim
on 21 Feb, 2011 17:49
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NRO for DIV
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#488
by
alexw
on 21 Feb, 2011 20:45
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NRO for DIV
Future policy or past? NROL-41 was on AV-501 last year, plus three others on 401/411.
-Alex
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#489
by
pathfinder_01
on 21 Feb, 2011 22:24
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As it stands now, leaving D4H out, what profiles are better covered by D4 and which by A5? Being from the same company I'd think they would be sort of LV agnostic. But as an economist, I would think that until they truly merge at every level, there would be an amount of launches for each vehicle that would require further investment, and thus be cheaper to cover with the other LV. So, the question is:
Are some profiles better for one and some for the other or are they using the A5 at maximum capacity and filling the rest with Delta 4?
Delta and Atlas are still owned by Beoing and lockhead Martin. ULA just builds and launches them. Getting rid of Delta is probably not easy as Both Lockhead Martin and Boeing are on ULA board.
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#490
by
baldusi
on 22 Feb, 2011 00:23
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NRO for DIV
I have to understand that for the general orbits and payloads that the NROL needs, Delta 4 is better optimized? I still don't parse Jim that easily.
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#491
by
Jim
on 22 Feb, 2011 00:40
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No, just less Russians
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#492
by
baldusi
on 22 Feb, 2011 01:26
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No, just less Russians
See? That was short and clear. Thank you.
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#493
by
Robotbeat
on 25 Mar, 2011 20:33
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What is the current status of Delta IV (Heavy) upgrades other than RS-68A? Is there a real need for the upgrades? Are they planned to actually happen, or just powerpoint right now?
Also, what's the status of RS-68A? What performance will this enable to LEO for Delta IV Heavy? To C3=0?
Thanks!
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#494
by
baldusi
on 25 Mar, 2011 23:42
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Apparently they have passed the first acceptance test of the first engine for the Delta 4 Heavy mission.
You can read the
Press Release
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#495
by
kevin-rf
on 31 Mar, 2011 02:04
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Quick Thor, aka delta question. Something Jim recently mentioned had me thinking. Are there any good pics. of the flamey side of the old Thor IRBM. I am now a little curious how the Thor/Delta/Delta II Verniers evolved with time. I had never given it much thought.
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#496
by
Jim
on 31 Mar, 2011 02:09
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They never changed
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#497
by
kevin-rf
on 31 Mar, 2011 12:55
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Now that is an answer I did not expect ...
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#498
by
sdsds
on 03 Aug, 2011 16:00
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This is a question about Delta Mariner, the ship that transports Delta (and now Atlas) cores from the assembly plant to the launch site. What facilities are needed at the receiving end of those shipments? Could cores be delivered to the same location where Shuttle ET cores were delivered? Could cores be delivered to Michoud and then be transported on from there?
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#499
by
Jim
on 03 Aug, 2011 16:43
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This is a question about Delta Mariner, the ship that transports Delta (and now Atlas) cores from the assembly plant to the launch site. What facilities are needed at the receiving end of those shipments? Could cores be delivered to the same location where Shuttle ET cores were delivered? Could cores be delivered to Michoud and then be transported on from there?
The Delta Mariner uses the dock at VAFB that was intended for shuttle ET's.
The Delta Mariner is a RO RO (like the ET Barge) and only a Delta IV EPT (transporter) is needed to remove the core for Delta. The Atlas core had its tractor with it.
Why would cores be delivered to Michoud?