Author Topic: AJAX Lite or AJAX 120  (Read 5507 times)

Online spacenut

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AJAX Lite or AJAX 120
« on: 04/01/2011 08:10 pm »
I like the AJAX rocket that Downix has developed.  I was thinking, what about an AJAX lite or AJAX 120.  If you could take a core Delta IV and use one RS-25 engine instead of the RS-68, then add two strap on Atlas V's, (thus the 120 designation). 

Could this get to orbit without a second stage?

Could it launch Orion with a service module?

Could it launch Orion to L1 or L2? 

Would it be quicker and easier to develop than one of the commercial or the larger SD just to service the space staton? 

« Last Edit: 04/01/2011 08:20 pm by spacenut »

Offline sdsds

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Re: AJAX Lite or AJAX 210
« Reply #1 on: 04/01/2011 08:17 pm »
That's an AJAX-120, not a -210.
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Online spacenut

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Re: AJAX Lite or AJAX 120
« Reply #2 on: 04/01/2011 08:21 pm »
Corrected.  Is this a good idea?

Offline Downix

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Re: AJAX Lite or AJAX 120
« Reply #3 on: 04/01/2011 08:45 pm »
Corrected.  Is this a good idea?
Best I've gotten was about 25mT, not much different than the Delta IV Heavy, although with one less stage.
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Online spacenut

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Re: AJAX Lite or AJAX 120
« Reply #4 on: 04/01/2011 08:51 pm »
Would that be less expensive than DIV heavy?  I know it would be easier to man-rate. 

Also, if you added a few solids to the Atlas boosters could it deliver a cargo somewhere between the 25 tons to 70 ton AJAX? 
« Last Edit: 04/01/2011 08:53 pm by spacenut »

Offline Downix

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Re: AJAX Lite or AJAX 120
« Reply #5 on: 04/01/2011 08:52 pm »
Would that be less expensive than DIV heavy?  I know it would be easier to man-rate. 
A bit more expensive, actually. 
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline sdsds

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Re: AJAX Lite or AJAX 120
« Reply #6 on: 04/01/2011 08:53 pm »
Best I've gotten was about 25mT, not much different than the Delta IV Heavy, although with one less stage.

I only get 20t using a core with a dry mass of 73t (i.e. a Delta IV CBC), loaded with 190t of propellant.  That doesn't fill the CBC, but that's because filling the CBC would make for an unacceptable thrust/weight ratio at lift-off.

Clearly because the core goes all the way to orbit, every ton of dry mass you shave off the core is an added ton of payload capability....
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Re: AJAX Lite or AJAX 120
« Reply #7 on: 04/01/2011 08:54 pm »
So it would be better to develop the Atlas V phase II? 

Offline Downix

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Re: AJAX Lite or AJAX 120
« Reply #8 on: 04/01/2011 08:59 pm »
Best I've gotten was about 25mT, not much different than the Delta IV Heavy, although with one less stage.

I only get 20t using a core with a dry mass of 73t (i.e. a Delta IV CBC), loaded with 190t of propellant.  That doesn't fill the CBC, but that's because filling the CBC would make for an unacceptable thrust/weight ratio at lift-off.

Clearly because the core goes all the way to orbit, every ton of dry mass you shave off the core is an added ton of payload capability....
73t is for  the entire Delta IV dry, not for the CBC.  The CBC itself has a dry mass of 26,760 kg.  And it holds 199,640 kg of propellant.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Offline Downix

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Re: AJAX Lite or AJAX 120
« Reply #9 on: 04/01/2011 09:00 pm »
So it would be better to develop the Atlas V phase II? 
No, it would be best to just launch the Atlas V HLV as/is.  Low development cost, soonest result, lowest cost.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

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Re: AJAX Lite or AJAX 120
« Reply #10 on: 04/01/2011 09:03 pm »
Do you think ULA will ever develop Atlas V heavy?  Or ACES?

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Re: AJAX Lite or AJAX 120
« Reply #11 on: 04/01/2011 09:08 pm »
So it would be better to develop the Atlas V phase II? 

AJAX-120 is a useful thought experiment.  It shows the flexibility of pairing SSME and RD-180.  SSME is awesome for a ground-lit stage that goes all the way to orbit.  You can't get that with a kerolox stage.

In terms of what "would be better," how worried are you about lighting your second stage at altitude?
« Last Edit: 04/01/2011 09:08 pm by sdsds »
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Online spacenut

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Re: AJAX Lite or AJAX 120
« Reply #12 on: 04/01/2011 09:15 pm »
Not worried, just want to get going with something to launch manrated spacecraft as quickly as possible to replace shuttle.  I have been watching these forums for 5-6 years now, and NASA is slow and foot dragging getting something accomplished.  It was on my 16th birthday that they landed on the moon.  July 20, 1969.  I thought we would be on Mars by now.  Now that we have lost my parents WWII generation, we seem to have no leadership in this country anymore, from politics to CEO's of corporations.  We used to be the leader, developer, and mover of the free world.  Now we seem to have become complacent, hedonistic, and who cares about anything except what is mine generation.  From welfare greed to corporate greed.  It seems as if only small business and small corporations are leading today. 

Sorry for the ranting.  Just want America to be America again. 
« Last Edit: 04/01/2011 09:18 pm by spacenut »

Offline Downix

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Re: AJAX Lite or AJAX 120
« Reply #13 on: 04/01/2011 09:24 pm »
Do you think ULA will ever develop Atlas V heavy?  Or ACES?
AVH is an option for you to order from ULA already, so it is more than likely someone, someday will have a payload which can use it.  ACES, that will need NASA support due to the full nature of it.  Without NASA, expect the Common Centaur instead.
chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

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