Author Topic: DIRECT v3.0 - Thread 1  (Read 1293333 times)

Offline dlapine

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Re: DIRECT v3.0 - Thread 1
« Reply #3360 on: 07/27/2009 08:34 pm »
Ah, that explains the concept rather simply.

Hmmm, wouldn't deceleration require that the vehicle be in a retrograde orientation? For that matter wouldn't landing require a tail-first burn and a rather abrupt attitude change? Sounds like something out of Doc E. E. Smith's Lensman.

That's assuming the under-thrusters were rather anemic.


Offline ChuckC

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Re: DIRECT v3.0 - Thread 1
« Reply #3361 on: 07/27/2009 09:00 pm »
Okay, sorry about this being a graphics- and sound-heavy fansite but this is the only pictures I could find in a rush. 

Space: 1999 Eagle

You see the basic horizontal lander concept here with some of its most obvious applications: pressurised crew/cargo carrier, unpressurised cargo carrier (including fuel transport) and mobile laboratory for surveys far from the outpost.

I have also attached a PDF of the NASA proposals (as leaked to NASAWatch), which look remarkably similar.  I usually refer to their idea as the 'Altair-X'.

The Altair-X looks like it was definitely inspired by Space: 1999 Eagle. My guess is that who ever came up with this design was Space: 1999 fan.

Offline ar-phanad

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Re: DIRECT v3.0 - Thread 1
« Reply #3362 on: 07/27/2009 09:03 pm »
I think I've found the horizontal lander http://www.nasaspaceflight.com/2006/09/lockheed-martin-lunar-landers-revealed/

When I was a kid, I sketched out in detail, several pages, a lander that could be stowed in the shuttle's cargo bay that looked almost exactly like that. I called it the Locust Lander, since it looked vaguely insectoid.

Aside from the obvious, it's amusing to see that I may have been onto something.

Offline ChuckC

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Re: DIRECT v3.0 - Thread 1
« Reply #3363 on: 07/27/2009 09:10 pm »
Ah, that explains the concept rather simply.

Hmmm, wouldn't deceleration require that the vehicle be in a retrograde orientation? For that matter wouldn't landing require a tail-first burn and a rather abrupt attitude change? Sounds like something out of Doc E. E. Smith's Lensman.

That's assuming the under-thrusters were rather anemic.



The best way to decelerator such a lander is belly first while in orbit and then rotate the lander’s tilt and the swiveling the decent engines as you approach landing,  I used that technique in orbiter and it woks well.

Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #3364 on: 07/27/2009 09:21 pm »
Sorry if this was answered already or somewhere else, but I'll post it again in case it wasn't.

The hardware for the avionics for the J-130 is deployed on which part of the vehicle? The core? The capsule? Interstage?

Same question for the J-246.

Just wondering how the second stage of the J-246 maintains coordination with the avionics package on the J-130.

There is a common "Instrumentation Unit" ring which is always fitted just below the Payload Fairing.

That way, the same hardware unit can be mounted on top of either the Jupiter Core Stage or the Jupiter Upper Stage and can control all the stages below it.

Essentially its the same approach as Saturn.

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
-Robert A. Heinlein

Offline dlapine

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Re: DIRECT v3.0 - Thread 1
« Reply #3365 on: 07/27/2009 09:23 pm »
Ah, that explains the concept rather simply.

Hmmm, wouldn't deceleration require that the vehicle be in a retrograde orientation? For that matter wouldn't landing require a tail-first burn and a rather abrupt attitude change? Sounds like something out of Doc E. E. Smith's Lensman.

That's assuming the under-thrusters were rather anemic.



The best way to decelerator such a lander is belly first while in orbit and then rotate the lander’s tilt and the swiveling the decent engines as you approach landing,  I used that technique in orbiter and it woks well.

Um, that kinda looks like the engines are fixed and at the rear of the vehicle.

To have the engines on swivel mounts and get a reasonably equal thrust axis through the bottom of the craft, you'd almost have to move one to the front of the craft, located near the cockpit. See the design for the Russian yak-38, a vertical takeoff design.

Not to mention the weight penalty the vehicle would incur in structure for having thrust located 90 degrees off-axis. Ouch.


Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #3366 on: 07/27/2009 09:23 pm »
There are already plenty of dedicated threads for discussing the vertical vs. horizontal Lander design.

Please take the discussions of those to their correct locations as this thread is NOT the right place for them.

Thank-you.

Ross.
« Last Edit: 07/27/2009 09:25 pm by kraisee »
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Offline dlapine

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Re: DIRECT v3.0 - Thread 1
« Reply #3367 on: 07/27/2009 09:28 pm »
Sorry if this was answered already or somewhere else, but I'll post it again in case it wasn't.

The hardware for the avionics for the J-130 is deployed on which part of the vehicle? The core? The capsule? Interstage?

Same question for the J-246.

Just wondering how the second stage of the J-246 maintains coordination with the avionics package on the J-130.

There is a common "Instrumentation Unit" ring which is always fitted just below the Payload Fairing.

That way, the same hardware unit can be mounted on top of either the Jupiter Core Stage or the Jupiter Upper Stage and can control all the stages below it.

Essentially its the same approach as Saturn.

Ross.

Ah, that's what I was asking about.

Thanks. Makes sense not to reinvent the wheel

Offline Nathan

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Re: DIRECT v3.0 - Thread 1
« Reply #3368 on: 07/27/2009 09:52 pm »
My work (?) here is done.

So Long, and Thanks for All the Fish.  :)

All shiny! I'd have focused on a 12MW reactor as an initial step before going to the full 200MW version but there's nothing wrong with being bold.
Looks good - easy to read - abstract was very useful. I'd get behind this. DOE could fund the reactor development...
Given finite cash, if we want to go to Mars then we should go to Mars.

Offline cro-magnon gramps

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Re: DIRECT v3.0 - Thread 1
« Reply #3369 on: 07/27/2009 10:33 pm »

This is what DIRECT is trying to propose:   "Everyone Remain Where You Are" instead of "All Change Please".

But still, lets take advantage of the fact that a fair number (15-20%) of current Shuttle workforce are almost at retirement age.   Lets allow these good people to retire from NASA (with their dignity intact) and lets save a bit of money in the process by simply not back-filling most of their positions.   Over the next 5 years, we simply accept the natural ~3-4% retirement "attrition rate" and trim the total number of staff that way in order to save money.


Now, don't be under any illusion that this is a "simple" solution -- it isn't.   Frankly, the details are a complete *&^*% to work out and it will NOT be a painless process for everyone.   But, generally speaking, it *IS* a viable approach.

Ross.

Ross, Remain Calm and Carry On! that sums up the first quoted paragraph..
   but there is a problem in your assumption that retirement exits of staff w/no replacements is a good thing... sadly, the longer you take the agency down that road, the more hide bound the management and staff are going to get, without that infusion of young and inovative techs and managers... the agency is not going to be as flexible... quick to accept a new opportunity or way of doing things... say you take the top age bracket of 55-65 out of the calculation, can you tell me the average age of the engineering department, or the management team... think about it... you don't need to post the results...

as well, you are going to find that when you do need those young minds, they will have either gone to commercial endeavours, (not necessarily in space or aeronautics) or because of lack of opportunity, perhaps decided not to persue higher education...
   
Gramps "Earthling by Birth, Martian by the grace of The Elon." ~ "Hate, it has caused a lot of problems in the world, but it has not solved one yet." Maya Angelou ~ Tony Benn: "Hope is the fuel of progress and fear is the prison in which you put yourself."

Offline tamarack

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Re: DIRECT v3.0 - Thread 1
« Reply #3370 on: 07/27/2009 10:46 pm »
...
It really boils down to this:   Any mission currently considering a launcher in the cost range of Delta-IV Heavy, could fly on a Jupiter-130 instead with fewer weight & size restrictions.   That *IS* of interest to many people within the science community -- more than a few have contacted us to say so!

Now, the number of missions considering such a cost is very low -- typically only the flagship missions can afford to even consider it.   But they *DO* exist.

We think there might be two, perhaps three, a decade.   But our current cost profile increases SMD's top-line budget to approximately twice its current level and that would allow for quite a few more small, some extra medium and one or two new large-scale missions to be funded.


One of the missions we really would like to see is a series of Hubble-like large space telescopes supporting 8.2m diameter mirrors.   There are some fairly good arguments to be made for developing a fairly sizable 'batch' of such telescopes all at the same time and using them in parallel to look at lots of different parts of the sky at the same time.   There's also the (admittedly remote) possibility that DoD might be interested in a very similar technology too and *might* consider sharing some of the costs for developing the new platform too.   But we'll just have to see.

Ross.

You just highlighted one of the reasons against DIRECT/Ares IV: The incredibly small number of foreseeable science missions such a vehicle would cater to. Almost all currently planned missions can fit in available heavy launch systems and as technology progresses, even more will fit.

The purpose of a super-heavy launch system is to add capability to what won't be shrinking as technology progresses - humans. If two or three science missions come along per decade (like Hubble) that don't fit in available vehicles, they could easily buy space on a launch of a vehicle specifically designed for human infrastructure like the Ares V.

PS - I completely agree with increasing the number and size of orbiting telescopes, but don't think DIRECT/Ares IV is nessisary to accomplish this. Low-cost (relative term) heavy launch vehicles, like Falcon9, have the possibility of putting up large numbers of conventional telescopes. James Webb will give us a great view fairly soon and if a massive telescope is desired - Current technology limits its size not by weight or primary mirror, but the diameter of the secondary mirror. Available heavy launch vehicles could send a telescope a couple dozen meters across to the ISS.

Offline Lobo

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Re: DIRECT v3.0 - Thread 1
« Reply #3371 on: 07/28/2009 12:15 am »
The critical things, right now, seem to be determining just how big the lander can actually be, and how stable it will be when trying to land on rough, uneven, terrain when its tanks are almost dry.   Those are turning into real challenges at present.   But they can be solved and there are plenty of options still available.

Ross.

My *personal* favorite option is to go toward a horizontal lander design. It solves a LOT of problems, not the least of which is a tall, thin lander with empty tanks trying to set down on uneven ground without tipping over. Couple that with both the crew and any cargo that accompanies them, or the cargo on a cargo flight, are all close to the ground, not many meters up and nearly inaccessable.

Yea,
Make them look the “Eagles” from “Space 1999”.
;-)

Actually, I’ve seen some concepts for horizontal cargo landers.  Looks a bit like the Eagles from Space 1999.  A main engine to the rear does all the braking, then the RCS/OMS thruster pods at the 4 corners are designed to be able to produce enough down thrust for the final landing.  Then all of your cargo is inline and close to the ground.  Since you don’t have to design for an ascent stage, you can make it very cargo-friendly for offloading and maximizing landed volume.

I’ve been leaning towards really liking that coupled with a small (relatively) reusable crew lander.  It’d be refueled by Orion with a service module that would have large enough hypergolic tanks to both refuel the RLL, and take Orion back through TEI.  (Both the RLL and service module would use the same hypergolic fuel, so the RLL refill is “tanked” off the main tanks in the SM).  The lander would be one piece rather than two, and instead of two, with two redundant engines that could be switched back and forth in case of any engine problems on descent or ascent.  Since it’s one piece and relatively small (not designed for crew habitation on the surface per se, just for transits, dockings, and autonomous station keeping in lunar parking orbit.  Design focus on that and longevity.  The crew habitats would be on the cargo lander.

I don’t really think it’s that pie in the sky either.  I mean, why not reuse the hardware?  Would there have really been any reason the LEM couldn’t have been reused if it was one piece, and could have been refueled? (and had solar panels to keep it powered while parked in orbit and on the surface).  Per Direct, the EDS does LOI not the LSAM anyway, so once you have a Cargo lander down, and the RLL on station, you can do a single J-246 launch with the large “tanker” service module and Orion.  The only real obstacle is hypergolic propellant transfer in lunar orbit, but Apollo had obstacles too that they worked out with Apollo 9 and 10.  The LEM had never been tested, nor had LOR.  So you’d similarly have “practice” missions to be sure the technologies for transferring propellants and consumables to the RLL all worked as designed.  You’d have a cargo lander with your supplies and equipment before any attempt was made to land on the surface. 

The more I ponder it, the more I like it.  Makes sense, is not really any more complicated than the fully disposable Altair, and would save the cost of a new Altair every mission.   Your cargo landers could be made as inexpensively and “cheaply” as possible as no human life depends on it.

Offline Lampyridae

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Re: DIRECT v3.0 - Thread 1
« Reply #3372 on: 07/28/2009 12:29 am »
Can we stick to the topic at hand, ie DIRECT 3.0? There are plenty of other threads for lander discussion.

Ross, I was wanting to make a comment to the Augustine Commission about the flexible path option. I'd like to advocate it, but I'd also like to show that DIRECT 3.0 is the best choice for this option over something like NSC and especially EELV.

Have you any thoughts how payload, economies of scale etc. would be applicable to the DIRECT case? I'm thinking for example that having 6 RL-10Bs would a key safety factor out there. Unfortunately J-246 could squeeze a NEO mission into one launch... impacting economies of scale, especially if there's only 1 or 2 missions a year (possible).

Offline HIP2BSQRE

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Re: DIRECT v3.0 - Thread 1
« Reply #3373 on: 07/28/2009 12:50 am »
...
It really boils down to this:   Any mission currently considering a launcher in the cost range of Delta-IV Heavy, could fly on a Jupiter-130 instead with fewer weight & size restrictions.   That *IS* of interest to many people within the science community -- more than a few have contacted us to say so!

Now, the number of missions considering such a cost is very low -- typically only the flagship missions can afford to even consider it.   But they *DO* exist.

We think there might be two, perhaps three, a decade.   But our current cost profile increases SMD's top-line budget to approximately twice its current level and that would allow for quite a few more small, some extra medium and one or two new large-scale missions to be funded.


One of the missions we really would like to see is a series of Hubble-like large space telescopes supporting 8.2m diameter mirrors.   There are some fairly good arguments to be made for developing a fairly sizable 'batch' of such telescopes all at the same time and using them in parallel to look at lots of different parts of the sky at the same time.   There's also the (admittedly remote) possibility that DoD might be interested in a very similar technology too and *might* consider sharing some of the costs for developing the new platform too.   But we'll just have to see.

Ross.

You just highlighted one of the reasons against DIRECT/Ares IV: The incredibly small number of foreseeable science missions such a vehicle would cater to. Almost all currently planned missions can fit in available heavy launch systems and as technology progresses, even more will fit.

The purpose of a super-heavy launch system is to add capability to what won't be shrinking as technology progresses - humans. If two or three science missions come along per decade (like Hubble) that don't fit in available vehicles, they could easily buy space on a launch of a vehicle specifically designed for human infrastructure like the Ares V.

PS - I completely agree with increasing the number and size of orbiting telescopes, but don't think DIRECT/Ares IV is nessisary to accomplish this. Low-cost (relative term) heavy launch vehicles, like Falcon9, have the possibility of putting up large numbers of conventional telescopes. James Webb will give us a great view fairly soon and if a massive telescope is desired - Current technology limits its size not by weight or primary mirror, but the diameter of the secondary mirror. Available heavy launch vehicles could send a telescope a couple dozen meters across to the ISS.

How much do you think 1 Ares V flight is going to cost???

Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #3374 on: 07/28/2009 01:00 am »
How much do you think 1 Ares V flight is going to cost???

CxP's own internal estimate is $1.4 billion for each Ares-V.

Ross.
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Offline Jim

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Re: DIRECT v3.0 - Thread 1
« Reply #3375 on: 07/28/2009 01:03 am »

1.  Low-cost (relative term) heavy launch vehicles, like Falcon9, have the possibility of putting up large numbers of conventional telescopes

2. Available heavy launch vehicles could send a telescope a couple dozen meters across to the ISS.

1.  More like a proven and higher performance vehicle like Delta IV heavy

2.  The ISS is the wrong place for a telescope

Offline Marsman

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Re: DIRECT v3.0 - Thread 1
« Reply #3376 on: 07/28/2009 01:16 am »
How much do you think 1 Ares V flight is going to cost???

CxP's own internal estimate is $1.4 billion for each Ares-V.

Ross.

That sounds a little extreme- where did you get that figure from? I've heard figures around $500-700 million variable per Ares V.

Offline kraisee

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Re: DIRECT v3.0 - Thread 1
« Reply #3377 on: 07/28/2009 01:22 am »
That sounds a little extreme- where did you get that figure from? I've heard figures around $500-700 million variable per Ares V.

Its a figure straight from CxP Documentation, dated October 2008, detailing the annual costs for operating the Lunar Program and the effect of adding or removing missions from the manifest.

Ross.
« Last Edit: 07/28/2009 01:23 am by kraisee »
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Offline agman25

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Re: DIRECT v3.0 - Thread 1
« Reply #3378 on: 07/28/2009 01:27 am »
I'd just like to make a couple of suggestions for the DIRECT guys

1. One of the advantages of the Ares I/V approach is that it lands a large mass on the moon in a single launch.
2. NASA will claim (justifiably I think) that a lot of money and time has been spend on the Ares I upper stage, J-2X and the 5 segment solid and individually they seem to work.

I just think you guys should do some calculations for how a 8.4 meter core would work with a Ares I upper stage with a J-2X and how much mass you can land on the moon in a single launch.

I am not qualified to judge whether an Ares I US with a 8.4 m core will work or if maximum mass landed per flight gives the most economical moonbase. I just think you should have the numbers ready.

Also please look at the LOR-LOR or EML-1/2 rendezvous situations. I understand that a lot of performance is lost if there are separate TLI's for Orion and the LSAM but it just seems to me that it is inviting trouble to expect two successful launches within a limited time period to do a lunar mission. Also you need two launch pads.

Just a few suggestions. Admire your hard work.
« Last Edit: 07/28/2009 01:38 am by agman25 »

Offline Mark S

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Re: DIRECT v3.0 - Thread 1
« Reply #3379 on: 07/28/2009 01:51 am »
I'd just like to make a couple of suggestions for the DIRECT guys
Speaking as an NSF reader, since I'm not on the DIRECT team, but here are my observations:

Quote
1. One of the advantages of the Ares I/V approach is that it lands a large mass on the moon in a single launch.
Only in theory.  In practice, Ares-V does not exist and if it did it would be too expensive to fly very often.

Quote
2. NASA will claim (justifiably I think) that a lot of money and time has been spend on the Ares I upper stage, J-2X and the 5 segment solid and individually they seem to work.
Sunk cost in a broken architecture should have no relevance on plans going forward.  What matters is cost/performance going forward, and DIRECT excels in that regard.

Quote
I just thing you guys should do some calculations for how a 8.4 meter core would work with a Ares I upper stage with a J-2X and how much mass you can land on the moon in a single launch.
AIUS does not fit well with the DIRECT architecture.  It is not needed for LEO operations, and is too small for Lunar/NEO operations.  J2X may be salvageable, as in the J-241 config, but it is heavy, underperformant, and gives the JUS/EDS no engine-out capability.

Quote
I am not qualified to judge whether an Ares I US with a 8.4 m core will work or if maximum mass landed per flight gives the most economical moonbase. I just think you should have the numbers ready.
DIRECT was not created to save Ares.  It was created to save NASA, or more specifically, the American HSF program.

Quote
Also please look at the LOR-LOR or EML-1/2 rendezvous situations. I understand that a lot of performance is lost if there are separate TLI's for Orion and the LSAM but it just seems to me that it is inviting trouble to expect two successful launches within a limited time period to do a lunar mission. Also you need two launch pads.
DIRECT would be playing into Ares hands if they were to propose an LOR-LOR baseline.  DIRECT has plenty of margins, but these scenarios would put DIRECT below the CxP targets and allow those still in power to automatically dismiss DIRECT.

Quote
Just a few suggestions. Admire your hard work.

Me too!

Mark S.

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