Orion (CEV / SM) - status

cIclops · 2008-03-13 17:00:36

Having said that, is there any good reason to have an SM with a smaller diameter than the CM?

It saves mass.

GCNRevenger · 2008-03-13 17:03:40

Well, since they are never technically suppose to be exposed to anything until reentry, it would appear on the surface to mitigate the flaws.
Having said that, is there any good reason to have an SM with a smaller diameter than the CM?

That and the area of the shield is much smaller. And the shape is much simpler. Oh, and its not upside down like Shuttle.

As far as the SM size, it was reduced because of the higher density of hypergolic fuels hence making the SM lighter. Instead of making a "stubbier" SM of the same diameter as the CM would limit the size of big efficient spherical fuel tanks plus make it harder to stow the solar arrays/communications antenna.

gaetanomarano · 2008-03-13 18:36:43

It saves mass.

no, it don't have to be as long as the version with less diameter, also, the fairing for the current version is much longer and heavier

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gaetanomarano · 2008-03-13 18:44:48

...big efficient spherical fuel tanks...

the tanks seen in the current version are not perfect sphere, also, two tanks needs a larger but unused structure ... it's better to have a larger SM with four smaller spherical tanks a lighter structure and a smaller faring

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cIclops · 2008-03-14 04:46:18

It saves mass.
no, it don't have to be as long as the version with less diameter, also, the fairing for the current version is much longer and heavier.

The size and mass of the external fairing does not change, what changes is the size of the internal structures. These structures are smaller and therefore have less mass. AFAIK the length of the SM is determined by the engine. The fuel tanks are in the full width 5m top section of the SM. Anyway the external fairing is jettisoned before Orion reaches orbit. It's important to eliminate any unnecessary mass of the on orbit spacecraft and reducing the diameter of the lower part of the SM accomplishes this.

gaetanomarano · 2008-03-14 05:18:11

The size and mass of the external fairing does not change, what changes is the size of the internal structures.

while the SM mass remains similar with both designs, the fairing could be (at least) 50% longer and heavier if it must cover the entire SM rather than only the SM engine

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cIclops · 2008-03-14 05:34:58

The size and mass of the external fairing does not change, what changes is the size of the internal structures.
while the SM mass remains similar with both designs, the fairing could be (at least) 50% longer and heavier if it must cover the entire SM rather than only the SM engine
.

The fairing extends the full length of the SM, it's not structural, it's for the aerodynamics.

gaetanomarano · 2008-03-14 15:57:53

The fairing extends the full length of the SM, it's not structural, it's for the aerodynamics.

with the current design SM the fairing will be up to twice the dimension and the weight:

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cIclops · 2008-03-14 17:26:31

This latest Ares I concept image shows the LAS adapter fairing meeting the SM fairing, below that is the Instrument unit.
It's fairing all the way from the base of the LAS to the upper stage.

this drawing also shows that the CM/SM is smaller in diameter than the LAS adapter, see how the 5m width of the top section of the SM fits inside the LAS adapter. Therefore there must be an outer fairing the full length of the SM minus that part under the adapter. This is the advantage of the new adapter, it pulls the CM from the base thus making the CM structure lighter.

gaetanomarano · 2008-03-14 17:40:03

...this drawing also shows that the CM/SM is smaller in diameter than the LAS adapter...

nothing change if the extra-fairing is under the SM or part of the BPC ... its total will be bigger, longer, larger and heavier than the simpler structure I suggest (that was the same of Apollo)

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cIclops · 2008-03-14 17:43:46

The outer wall of the SM is not part of the fairing.

cIclops · 2008-03-17 05:13:25

NASA Readies Hardware for Test of Astronaut Escape System - 12 Mar 2008

The pad abort test will simulate an emergency on the launch pad. Upon command from a nearby control center, a dummy Orion crew module -- which would sit on top of a rocket for an actual launch -- will be ejected directly from the launch pad by its rocket-propelled launch abort system to about one mile in altitude and nearly one mile downrange.
That is why engineers and technicians at NASA's Langley Research Center in Hampton, Va., NASA's Dryden Flight Research Center in Edwards, Calif., and industry partners on the Orion Project are taking particular care to fabricate and equip the first flight test articles with extreme precision.
Engineers and technicians at Langley designed and fabricated the structural shell of the simulated crew module for the first pad abort test and now are conducting a series of ground checks on the structure. The "crew module simulator," as it is called, accurately replicates the size, outer shape and mass characteristics of the Orion crew module.
Orion crew module flight test article build-up
"The next step is to ship the completed crew module simulator to Dryden, where they will outfit it with the smarts -- the computers, the electronics, the instrumentation -- all the systems that need to work in conjunction with the structure," said Phil Brown, manager of the Langley Orion Flight Test Article Project.
After the instrumented dummy crew module is delivered to White Sands this summer, it will be integrated with the PA-1 launch abort system flight test article, a vertical tower containing the escape rocket motor and a guiding rocket motor currently under construction at Orbital Sciences, Inc. in Dulles, Va. The combined crew module and launch abort system will be placed on the launch pad being constructed especially for the abort flight test series.
During the pad abort test sequence, the escape system's main abort motor will fire for several seconds, rapidly lifting the simulated crew module from the test launch pad, after which the escape system will detach, and three 116-foot-diameter parachutes will deploy to slow the module for landing.
The test will provide early data for design reviews to follow and will be followed by an ascent abort test in 2009 and a second pad abort test scheduled for 2010, both at White Sands. A parallel series of higher-altitude launch tests will commence at NASA's Kennedy Space Center in Florida in 2009.
"These flight tests will either confirm that our system works or help us identify and correct any defects that surface," said Greg Stover, manager of the Orion Launch Abort System Project Office, located at Langley. "Our goal is that on every manned mission the launch abort system will be the most reliable system that we hopefully never have to use."

cIclops · 2008-03-28 13:17:34

The 9,071 kg Orion crew module simulator is loaded on a C-17 airplane - 27 Mar 2008

Late in the evening of March 27, the Orion crew module simulator was loaded on a C-17 aircraft. Next stop -- NASA's Dryden Flight Research Center in Edwards, California, for more flight test work -- including the installation of flight computers, instruments and other electronics.
Late this year, the full-size structural model will be propelled off a simulated launch pad at the U.S. Army's White Sands Missile Range in New Mexico to test Orion's astronaut escape system, which will ensure a safe, reliable escape for astronauts in case of an emergency.

cIclops · 2008-04-06 12:46:45

Freshly painted Orion mass simulator at Dryden - imaged 1 Apr 2008

A full-scale flight-test mockup of the Constellation program's Orion crew vehicle has arrived at NASA's Dryden Flight Research Center to undergo preparations for the first short-range flight test of the spacecraft's astronaut escape system late this year.
Engineers and technicians at NASA's Langley Research Center fabricated the structure, which precisely represents the size, outer shape and mass characteristics of the Orion space capsule.
The Orion crew module mockup arrived on an Air Force C-17 at NASA Dryden March 28. After painting in the Edwards Air Force Base paint hangar, the conical capsule was taken to Dryden for installation of flight computers, instrumentation and other electronics.

Module Mockup Arrives at Dryden for Test Preparations - 4 Apr 2008

RedStreak · 2008-04-07 13:21:02

LAS for Orion Has Successful test

I'm suprised Cyclops or SpaceNut didn't spot this link first!

Aerojet, a GenCorp (NYSE: GY) company and Orbital Sciences Corporation (NYSE: ORB) announced today that together the two companies successfully conducted a static firing of the jettison motor, a key component of the Launch Abort System (LAS) for NASA's Orion next generation human spaceflight program.

With LAS and the dummy module cyclops posted about previously it looks like the abort test planned for end of year will be well-prepared. What'll come out of it will be another story naturally but taken together this and cyclops' post are promising preludes.

cIclops · 2008-04-07 13:33:06

Yes, this is an important step, the first firing of one of the three new rockets motors for LAS. A successful test is always good news. The big all up LAS test with the dummy command module will be even more important.

cIclops · 2008-04-15 04:06:21

Diagram of the internal structure of the LAS - from Marshall Star (PDF) - 20 Mar 2008

Nicely shows how the LAS provides load support externally to the capsule thus reducing its mass.

gaetanomarano · 2008-04-15 19:28:51

.

NASA will soon realize that its tower-LAS is big and heavy like the Tour Eiffel... and will adopt something like MY underside-LAS...

RedStreak · 2008-04-15 23:28:32

NASA will soon realize that its tower-LAS is big and heavy like the Tour Eiffel... and will adopt something like MY underside-LAS...

*bonks gaetanomarano on the head with a model of the Eiffel Tower for just insulting the nation of France*

Unless you want excessive wind tunnel tests, I suggest you stow that underside booster idea.

RedStreak · 2008-04-15 23:32:49

Looking at the aerodynamics of the LAS shroud, I think it is a logical step-up from Apollo. As the article says they are essentially using Apollo knowledge but applying tools and data Apollo didn't have available for its era.

cIclops · 2008-04-16 03:45:01

Just to take this totally OT, there's a competition to redesign the Eiffel Tower to increase its capacity - they'll never get it off the ground with this design

Yes the new shroud is very cleverly designed and the Orion LAS is far more capable than the Apollo or the Soyuz system. The Soyuz LAS is ejected before the first stage stops firing, so there's no abort capability afterwards. Orion has a full abort capability through upper stage ignition.

cIclops · 2008-04-16 08:46:06

A few more details and video ...

LAS jettison motor test - video - 40 secs

Orion Launch Abort System Jettison Motor Test - 14 Apr 2008

NASA successfully tested the Launch Abort System jettison motor, the first full-scale test for the Constellation Program's Orion crew exploration vehicle. The jettison motor is a solid rocket motor designed to separate the Launch Abort System from the crew module on a normal launch and to safely propel the abort system away from the crew module during an emergency.
The static test firing was conducted by Aerojet Corporation in Sacramento, Calif. NASA has partnered with Lockheed Martin Corporation, Orbital Sciences Corporation, and Aerojet Corporation to supply the jettison motor.
"This was a major success for the Orion Launch Abort System team," said Mark Cooper, NASA's integrated product team lead for LAS Propulsion at Marshall Space Flight Center in Huntsville, Ala. "The test provided valuable data on motor performance that will allow design and analytical refinements by our contactor team. The test is the culmination of intense and focused work by the entire jettison motor team."
Demonstrating the jettison motor performance is critical to the development of the crew module's launch abort system, which will offer a safe escape in the event of an emergency on the launch pad or during the climb to a low Earth orbit. The jettison motor test was a critical demonstration milestone in the Orion Project's preparations for the first of a series of flight tests of the Launch Abort System currently scheduled for late 2008.

gaetanomarano · 2008-04-16 08:48:35

Looking at the aerodynamics of the LAS shroud, I think it is a logical step-up from Apollo.

no, it's too big and heavy, so, its aerodynamic advantage is small if compared with the extra-mass the rocket must lift

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gaetanomarano · 2008-04-16 08:50:36

Unless you want excessive wind tunnel tests, I suggest you stow that underside booster idea.

why? ...my LAS design is the absolute BEST and it needs LESS wind tunnel tests

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GCNRevenger · 2008-04-16 09:29:52

No they won't gaetano, the LAS faring may be larger, but the reduced aerodynamic strain on the Orion capsule allows the capsule itself to be lighter. Every pound that can be transferred from capsule to LAS saves several pounds of capsule mass. This is because the LAS is discarded well before reaching orbit.

The capsule then only needs to resist compressive force along the axis during reentry instead of compressive force against the walls of the capsule during launch. Viola'

And nobody is ever going to use the "underside LAS" because bolting anything to the heat shield is a terrible idea, and there would be too much equipment protruding into the service module.

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#301 2008-03-13 17:00:36

Re: Orion (CEV / SM) - status

#302 2008-03-13 17:03:40

Re: Orion (CEV / SM) - status

#303 2008-03-13 18:36:43

Re: Orion (CEV / SM) - status

#304 2008-03-13 18:44:48

Re: Orion (CEV / SM) - status

#305 2008-03-14 04:46:18

Re: Orion (CEV / SM) - status

#306 2008-03-14 05:18:11

Re: Orion (CEV / SM) - status

#307 2008-03-14 05:34:58

Re: Orion (CEV / SM) - status

#308 2008-03-14 15:57:53

Re: Orion (CEV / SM) - status

#309 2008-03-14 17:26:31

Re: Orion (CEV / SM) - status

#310 2008-03-14 17:40:03

Re: Orion (CEV / SM) - status

#311 2008-03-14 17:43:46

Re: Orion (CEV / SM) - status

#312 2008-03-17 05:13:25

Re: Orion (CEV / SM) - status

#313 2008-03-28 13:17:34

Re: Orion (CEV / SM) - status

#314 2008-04-06 12:46:45

Re: Orion (CEV / SM) - status

#315 2008-04-07 13:21:02

Re: Orion (CEV / SM) - status

#316 2008-04-07 13:33:06

Re: Orion (CEV / SM) - status

#317 2008-04-15 04:06:21

Re: Orion (CEV / SM) - status

#318 2008-04-15 19:28:51

Re: Orion (CEV / SM) - status

#319 2008-04-15 23:28:32

Re: Orion (CEV / SM) - status

#320 2008-04-15 23:32:49

Re: Orion (CEV / SM) - status

#321 2008-04-16 03:45:01

Re: Orion (CEV / SM) - status

#322 2008-04-16 08:46:06

Re: Orion (CEV / SM) - status

#323 2008-04-16 08:48:35

Re: Orion (CEV / SM) - status

#324 2008-04-16 08:50:36

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#325 2008-04-16 09:29:52

Re: Orion (CEV / SM) - status

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