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#260
by
FinalFrontier
on 06 Dec, 2009 15:13
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Was very pleased to see the launch live last night. The rocket looked great and it looks like everything went off without a hitch. Excellent to see a new delta rocket setup fly for the first time. Also: If the "commercial hsf option to bridge the gap between shuttle and new vehicle" option is chosen, and if the delta 4 was selected to be the main provider, would this new architecture that flew last night be better to use for a manned capsule then older versions (or older setups)?
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#261
by
ugordan
on 06 Dec, 2009 15:17
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would this new architecture that flew last night be better to use for a manned capsule then older versions (or older setups)?
Unlikely as you wouldn't want solids on a manned capsule. Both Orion and/or commercial LEO taxis would preferably use all-liquid EELV versions.
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#262
by
HIPAR
on 06 Dec, 2009 15:25
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According to an article at Spaceflight Now, the WGS-3 satellite orbit will be circularized using a combination of on-board rocket motors and ion propulsion engines. Then it will go into a temporary orbital position in range of a Boeing command station for contractor checkout. Finally it will be moved to it's operational location at 12 degrees west serving US forces operating in Europe, Africa and the Eastern Atlantic Ocean. Commissioning will require many months.
--- CHAS
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#263
by
FinalFrontier
on 06 Dec, 2009 15:29
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would this new architecture that flew last night be better to use for a manned capsule then older versions (or older setups)?
Unlikely as you wouldn't want solids on a manned capsule. Both Orion and/or commercial LEO taxis would preferably use all-liquid EELV versions.
Makes sense since they probably want to avoid unnessecary g loading (or worse).
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#264
by
Jim
on 06 Dec, 2009 15:42
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Makes sense since they probably want to avoid unnessecary g loading (or worse).
Has nothing to do with g-loading but reliability of solids
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#265
by
JosephB
on 06 Dec, 2009 15:54
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ULA has been like a machine this year with the launches.
Keep those great highlight video's coming!
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#266
by
Ben the Space Brit
on 06 Dec, 2009 15:55
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Does anyone have the RocketCam video all the way to 2nd stage ignition? Purely a matter of curiosity for me - I've always wondered if the RL-10 would generate a visible exhaust bloom like the SSME.
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#267
by
FinalFrontier
on 06 Dec, 2009 15:58
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Jim:
I did say "or worse".....
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#268
by
ugordan
on 06 Dec, 2009 15:59
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I've always wondered if the RL-10 would generate a visible exhaust bloom like the SSME.
In vacuum, not really. Unless there's some vapor or particulate stuff moving by the nozzle, nothing is visible - the chamber acts like a flashlight during nighttime launches. There's one old Atlas night launch video where the booster is falling away and is illuminated when RL-10 kicks in.
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#269
by
Art LeBrun
on 06 Dec, 2009 16:17
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Interesting that the first stage looks to be "falling away" when it is merely slowing.
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#270
by
the_roche_lobe
on 06 Dec, 2009 20:21
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A question about this version of the Delta IV. Over in the Direct forums there has been lots of talk about the problems of the RS-68 ablative nozzle when surrounded by shuttle type SRBs - hence the return to the RS-25. Yet the RS-68s this version of the Delta IV operates for one an a half minutes in close proximity to 4 fairly large SRMs with no problems.
What gives? Is the thermal/gas recirculation environment at the back of the Delta IV significantly different to the Direct designs? Was the problem with Direct the size and duration of the SRMs or was it the presence of multiple other RS-68s?
P
Edit: just noticed the same question being asked in the Delta IV Q&A section! I'll see if an answer eventuates there...
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#271
by
Ben the Space Brit
on 06 Dec, 2009 20:43
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A question about this version of the Delta IV. Over in the Direct forums there has been lots of talk about the problems of the RS-68 ablative nozzle when surrounded by shuttle type SRBs - hence the return to the RS-25. Yet the RS-68s this version of the Delta IV operates for one an a half minutes in close proximity to 4 fairly large SRMs with no problems.
What gives? Is the thermal/gas recirculation environment at the back of the Delta IV significantly different to the Direct designs? Was the problem with Direct the size and duration of the SRMs or was it the presence of multiple other RS-68s?
The Delta-IV has one engine behind every core tank. The Direct 2.0 J-23x had
three behind a much larger tank and also had much larger SRMs that burn for 30 seconds longer. The 'hole' in the air punched by the 8.4m-diameter shuttle ET-derived core prevents the cooling air circulation that is possible with the 5m-diameter Delta-IV core.
As you can imagine, this effect gets even worse with Ares-V. That has
six RS-68As behind a
10m-diameter core, so the area under the tank gets even hotter.
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#272
by
Antares
on 06 Dec, 2009 22:13
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The radiant thermal power of the GEM-60 pales in comparison to that of the "SSM-151".
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#273
by
sdsds
on 06 Dec, 2009 22:22
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The radiant thermal power of the GEM-60 pales in comparison to that of the "SSM-151".
80% ?
(4 * 6) / (2 * 15) = 0.8
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#274
by
ugordan
on 06 Dec, 2009 22:31
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(4 * 6) / (2 * 15) = 0.8
Huh? What metric are you using? What's 6 and 15?
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#275
by
Antares
on 06 Dec, 2009 22:39
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Geometrically, it's going to scale with the surface area of the plume. 6 and 15, which need to be squared anyway, is oversimplified.
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#276
by
Nick L.
on 07 Dec, 2009 01:46
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#277
by
jacqmans
on 08 Dec, 2009 09:52
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Boeing's 3rd WGS Satellite Sends 1st Signals From Space
CAPE CANAVERAL, Fla., Dec. 6, 2009 -- Boeing [NYSE: BA] has acquired the first on-orbit signals from the third of six Wideband Global SATCOM (WGS) satellites. The signals indicate that the spacecraft is healthy and ready to begin orbital maneuvers and operational testing. WGS is the latest U.S. Department of Defense satellite communications system.
A United Launch Alliance Delta IV rocket launched the WGS-3 satellite at 8:47 p.m. Eastern time on Dec. 5 from Cape Canaveral Air Force Station. A ground station in Dongara, Australia, received the satellite's first signals 58 minutes later at 9:45 p.m. Eastern time. Boeing's Mission Control Center in El Segundo, Calif., confirmed that the satellite is functioning normally.
"This mission marks another important advancement in the communications capabilities that our advanced satellites provide to U.S. military personnel around the world," said Craig Cooning, vice president and general manager, Boeing Space and Intelligence Systems. "The nation's warfighters rely on satellites like this one to help them execute difficult missions safely and effectively, and the Air Force-Boeing team is committed to coming through for them."
Following a series of orbital maneuvers and on-orbit tests over the West Coast of the United States, WGS-3 will be placed into geosynchronous Earth orbit over the Atlantic Ocean. The satellite joins WGS-1, which entered service over the Pacific Ocean in April 2008, and WGS-2, which began operations over the Middle East in August 2009. The WGS-1 and WGS-2 satellites meet and, in some cases, exceed Air Force mission requirements. Together, the three WGS satellites will provide assured access to high-data-rate communications for U.S. forces and allies around the world.
WGS is the Department of Defense's highest-capacity communications satellite system. The satellites are built on the proven Boeing 702 platform with 13 kilowatts of power. The payload provides reconfigurable coverage areas and the ability to connect X-band and Ka-band users anywhere within their field of view via an onboard digital channelizer -- features not available on any other communications satellite.
Boeing is building three more WGS satellites for the Air Force with enhancements that include a radio frequency bypass designed to support airborne intelligence, surveillance and reconnaissance platforms requiring additional bandwidth. Satellites four through six are planned for launch in 2011 and 2013.
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#278
by
charlieb
on 13 Dec, 2009 20:49
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Would have been nice of Boeing to mention 'who' acquired the signal from Dongoura... And it wasn't Boeing.
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#279
by
HIPAR
on 29 Jun, 2010 22:02
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Was very pleased to see the launch live last night. The rocket looked great and it looks like everything went off without a hitch. Excellent to see a new delta rocket setup fly for the first time. Also: If the "commercial hsf option to bridge the gap between shuttle and new vehicle" option is chosen, and if the delta 4 was selected to be the main provider, would this new architecture that flew last night be better to use for a manned capsule then older versions (or older setups)?
