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Northrop Grumman test fires first GEM-63XL motor for ULA’s Vulcan
by
Chris Bergin
on 13 Aug, 2020 23:50
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#1
by
Chris Bergin
on 13 Aug, 2020 23:50
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Vid:
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#2
by
spacenut
on 14 Aug, 2020 03:09
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If they can put 6 of those on a Vulcan, that is over 5 million lbs thrust just from the solids. They will really need a larger upper stage to increase payload capability. The original Atlas Centaur is not really big enough.
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#3
by
sdsds
on 14 Aug, 2020 03:59
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If they can put 6 of those on a Vulcan
There isn't really an
if in that. ULA has consistently said Vulcan is — indeed even defined Vulcan as — a system that can use up to six solids.
You weren't intending to create any uncertainty about that?
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#4
by
Redclaws
on 14 Aug, 2020 04:14
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If they can put 6 of those on a Vulcan, that is over 5 million lbs thrust just from the solids. They will really need a larger upper stage to increase payload capability. The original Atlas Centaur is not really big enough.
Well, they’re doing a bigger Centaur for Vulcan:
https://en.wikipedia.org/wiki/Centaur_(rocket_stage)#Centaur_V
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#5
by
jacqmans
on 14 Aug, 2020 12:54
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Northrop Grumman Successfully Completes First Qualification Test of New Rocket Motor for United Launch Alliance
News Releases
New graphite epoxy motors will help launch ULA’s Vulcan Centaur rocket beginning in 2021
August 13, 2020
PROMONTORY, Utah – Aug. 13, 2020 – Northrop Grumman Corporation (NYSE: NOC) conducted its first ground test of an extended length 63-inch-diameter Graphite Epoxy Motor (GEM 63XL) today in Promontory, Utah. This variation of the company’s GEM 63 strap-on booster was developed in partnership with United Launch Alliance (ULA) to provide additional lift capability to the Vulcan Centaur vehicle.
“Our new GEM 63XL motors leverage its flight-proven heritage while utilizing state-of-the-art manufacturing technology to enhance launch vehicle heavy-lift capabilities,” said Charlie Precourt, vice president, propulsion systems, Northrop Grumman. “The GEM 63XL increases thrust and performance by 15-20 percent compared to a standard GEM 63.”
During today’s static test, the motor fired for approximately 90 seconds, producing nearly 449,000 pounds of thrust to qualify the motor’s internal insulation, propellant grain, ballistics and nozzle in a cold-conditioned environment. This test demonstrated materials and technologies similar to the GEM 63 rocket motor that qualified for flight in October 2019.
Northrop Grumman has supplied rocket propulsion to ULA and its heritage companies for a variety of launch vehicles since 1964. The GEM family of strap-on motors was developed starting in the early 1980s with the GEM 40 to support the Delta II launch vehicle. The company then followed with the GEM 46 for the Delta II Heavy, and the GEM 60, which flew 86 motors over 26 Delta IV launches before retiring in 2019 with 100 percent success. The first flight of the GEM 63 motors will be on a ULA Atlas V launch vehicle planned for fourth quarter 2020, and GEM 63XL motors will support the Vulcan rocket in 2021.
https://news.northropgrumman.com/news/releases/northrop-grumman-successfully-completes-first-qualification-test-of-new-rocket-motor-for-united-launch-alliance
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#6
by
spacenut
on 14 Aug, 2020 14:07
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Could they put 8 of these Gem-63L's on a Vulcan? If so they would be getting into FH's range of LEO payloads. With 8 and a throttle down of BE-4's (if possible), until solids burn out, then throttle up to full power, they could get a very heavy payload to LEO or to the moon.
I multiplied in my head, it is not 5 million lbs of thrust for the solids, but 2,640,000 lbs thrust, and with two BE-4's, it would be 3,740,000 million. Hope they make connections for 8 solids.
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#7
by
PahTo
on 15 Aug, 2020 16:21
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I noted in the article that the 63XL cold tested has a non-steerable nozzle (no TVC). Is this going to be true of all 63XL or will there be a variant that has TVC? If control authority of a vehicle can be done via the liquid main engines, that's a big cost and performance savings for the solids (to have no TVC).
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#8
by
ugordan
on 15 Aug, 2020 16:42
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I noted in the article that the 63XL cold tested has a non-steerable nozzle (no TVC). Is this going to be true of all 63XL or will there be a variant that has TVC? If control authority of a vehicle can be done via the liquid main engines, that's a big cost and performance savings for the solids (to have no TVC).
The AJ-60A boosters currently used on the Atlas don't have TVC, either. I would expect the new boosters to retain the fixed nozzles as well. Not only is it a cost savings, it's a reliability improvement - eliminating moving parts and points of failure.
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#9
by
lrk
on 15 Aug, 2020 16:49
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I noted in the article that the 63XL cold tested has a non-steerable nozzle (no TVC). Is this going to be true of all 63XL or will there be a variant that has TVC? If control authority of a vehicle can be done via the liquid main engines, that's a big cost and performance savings for the solids (to have no TVC).
The GEM-63XLT variant for OmegA (if that ever flies) will have TVC.
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#10
by
baldusi
on 15 Aug, 2020 17:51
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I noted in the article that the 63XL cold tested has a non-steerable nozzle (no TVC). Is this going to be true of all 63XL or will there be a variant that has TVC? If control authority of a vehicle can be done via the liquid main engines, that's a big cost and performance savings for the solids (to have no TVC).
Atlas (the 63 user) has enough control authority with its dual nozzles, that it can simply use the lighter and more reliable fixed nozzle. Vulcan, which has two engines, I would assume has even grater control authority.
Delta IV, no the other hand, have a single nozzle (I don't think the gas generator exhaust can be used to control rotational moments). So it needed the TVC boosters.
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#11
by
ugordan
on 15 Aug, 2020 18:14
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Atlas (the 63 user) has enough control authority with its dual nozzles, that it can simply use the lighter and more reliable fixed nozzle. Vulcan, which has two engines, I would assume has even grater control authority.
I wouldn't claim 2 BE-4 engines have a particularly
greater control authority than a single RD-180. Compared to the Delta IV and its roll control nozzle, Vulcan/Atlas certainly have a much greater
roll control authority on account of 2 vectorable main chambers.
Delta IV, no the other hand, have a single nozzle (I don't think the gas generator exhaust can be used to control rotational moments)
I believe that's precisely what was used for roll control on RS-68. Delta IV could technically fly with no solids, just that it rarely did due to perfomance reasons.
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#12
by
baldusi
on 16 Aug, 2020 02:51
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Atlas (the 63 user) has enough control authority with its dual nozzles, that it can simply use the lighter and more reliable fixed nozzle. Vulcan, which has two engines, I would assume has even grater control authority.
I wouldn't claim 2 BE-4 engines have a particularly greater control authority than a single RD-180. Compared to the Delta IV and its roll control nozzle, Vulcan/Atlas certainly have a much greater roll control authority on account of 2 vectorable main chambers.
Well, two BE-4 have 4.8MN vs 3.8MN or the RD-180, and they will be further apart, so I assumed greater control authority. But I failed to check gimballing, and BE-4 is apparently just 5 deg. vs RD-180 8. So, it's undefined, I would guess.
Delta IV, no the other hand, have a single nozzle (I don't think the gas generator exhaust can be used to control rotational moments)
I believe that's precisely what was used for roll control on RS-68. Delta IV could technically fly with no solids, just that it rarely did due to perfomance reasons.
You are right. My lousy memory thought that Merlin 1C used the GG exhaust and RD-68 was fixed. My mistake.
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#13
by
sdsds
on 16 Nov, 2023 00:19
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Does the GEM 63 XL retain "heritage" from the GEM 46 that would let NG offer an air-ignited variant?
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#14
by
FutureSpaceTourist
on 21 Dec, 2023 17:33
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Measuring more than 72-feet-long, the GEM 63XL is the longest monolithic, single-cast solid rocket motor ever produced — a designation previously held by the GEM 63.
As the newest members of Northrop Grumman’s Graphite Epoxy Motor (GEM) family of motors, both boosters build on the company’s extensive history of successful GEM 40, GEM 46 and GEM 60 motors and leverage the company’s industry-leading expertise in composite large solid rocket motor development and manufacturing to provide customers with a cost-effective, reliable, flexible and on-time system.
Learn how these unprecedented motors are manufactured and more about all of our commercial solid rocket motors here: http://ms.spr.ly/6054ibM7p.
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#15
by
PahTo
on 21 Dec, 2023 19:58
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Does the GEM 63 XL retain "heritage" from the GEM 46 that would let NG offer an air-ignited variant?
My perception of the GEM 63XL, based on various discussions and info (granted, some seen in wiki) is that the motor is designed for sea-level lift--that is, to get the LV out of the dense lower atmosphere. Considering Vulcan employs BE-4, which has better specific impulse performance, especially in near-vac and vac environments, would tend to obviate the desire/need for air-start capability in this application.
On a side note: I find it interesting the burn time for the XL is (apparently) a bit shorter than the GEM63. Given the longer casing provides increased thrust (read: internal pressures and temps) while the external diameter is the same ("63"), I infer the casing has thicker walls to handle the increased thrust, decreasing burn time accordingly. This also indicates a design preferring low-altitude performance.
EDIT: it occurs to me the launch mount/launch pad may be a constraint for the heavy variant (6x GEM63XL) of Vulcan. It may well be that to have six of those powerful SRMs, two have to air start. ??
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#16
by
sdsds
on 21 Dec, 2023 21:15
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Does the GEM 63 XL retain "heritage" from the GEM 46 that would let NG offer an air-ignited variant?
[...] the motor is designed for sea-level lift--that is, to get the LV out of the dense lower atmosphere. Considering Vulcan employs BE-4, which has better specific impulse performance, especially in near-vac and vac environments, would tend to obviate the desire/need for air-start capability in this application.
Some of my interest involves mission-specific or at least non-standard ascent profiles targeting unusual payload deployment trajectories. Equatorial LEO is an easy example.... (Yes, using a pad at the equator is better; those are in limited supply and ELEO is just one example.)
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#17
by
sdsds
on 04 Feb, 2024 21:01
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Looking at the 'heritage' of the GEM-63XL, there's a notable claim at
https://www.northropgrumman.com/space/sentinel/icbm-over-65-years-of-technical-leadership stating Thiokol produced the world’s first solid-fuel missile. I don't doubt the existence of the TX-18 missile; is there any available technical information about it? And maybe it's obvious from context but this excludes powered solids, right? (Chinese use of gunpowder rockets in 1232, etc. etc.)
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#18
by
edkyle99
on 05 Feb, 2024 14:55
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Looking at the 'heritage' of the GEM-63XL, there's a notable claim at https://www.northropgrumman.com/space/sentinel/icbm-over-65-years-of-technical-leadership stating Thiokol produced the world’s first solid-fuel missile. I don't doubt the existence of the TX-18 missile; is there any available technical information about it? And maybe it's obvious from context but this excludes powered solids, right? (Chinese use of gunpowder rockets in 1232, etc. etc.)
Perhaps they mean
guided solid propellant missiles, though the AIM-4, a heat-seeker, didn't "guide" very well. (Thiokol only made the motor. Hughes made the missile.)
- Ed Kyle
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#19
by
Steven Pietrobon
on 06 Feb, 2024 06:01
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Perhaps they mean guided solid propellant missiles, though the AIM-4, a heat-seeker, didn't "guide" very well. (Thiokol only made the motor. Hughes made the missile.)
Yes, I think that's what they meant. The GAR-1 (later AIM-4) was the world's first guided air to air missile. It wasn't the world's first guided solid propellant missile though. The WWII German solid propellant Rheintochter was a guided surface to air missile. Guidance was by radio remote control.
https://en.wikipedia.org/wiki/Rheintochter