DIRECT v3.0 - Thread 1

[firehauck]

MLAS was another waste of NASA's cash..Stick to the tower..The Russians have been using that system before some of you were even born.....

[Nathan]

The reason I said look at LOR-LOR and EML1/2 is that I believe that John Shannon's "Not Shuttle - C" LOR architecture is not a coincidence. I think that post Griffin NASA is looking at the whole EOR thing. Why else would you go with a hypergolic lander and lose even more performance.

Having a time pressure on the launch crew is just not a good idea IMO. Again Please correct me if I am wrong.

I agree. LOR-LOR is safer despite the performance advantage in other methods.
I'd happily accept nsc with lor-lor. I'd happily take nsc as it is following DIRECT principles even though, again, it is lower performance. I wold assume that the Basic version is the best we will get though - perhaps with 5 seg booster upgrade.
Direct is fantastic - NSC is fantastic for the same reasons.

Direct is better for future growth but future growth needs to be paid for.

[tamarack]

Just wondering, on the shuttle if one SRB goes, won't both go? Is this debris cloud calculation done assuming both SRBs explode, or are we assuming just 1. Ares I only has one SRB albeit a larger one, so I would guess it's debris cloud is smaller.

OT-
Granted, almost anything can explode under the right circumstances (even a tub of water), solid fuel like the SRBs aren't the explosion risk - liquid fuel is. When a stack goes (like Challenger) the risk from the SRBs is not in the explosion, but the dispersion of burning fuel pieces.

[tamarack]

There are three Jupiter 130 test flights planned, are there any ideas on how to use them? Obviously you could just launch non-functional dummy payloads, but that seems wasteful. Would something like a prototype propellant depot make a good payload?

OT-
I'd vote for dirt, fertilizer and seeds with a thruster. Very cheap and almost no risk if it doesn't reach orbit / Good ISS experiment and infrastructure if it does.

[simon-th]

Direct is better for future growth but future growth needs to be paid for.

An in-line SD vehicle offers more advantages over a side-mounted SD vehicle than just more future growth options.Lower safety, potentially higher operation costs, complexity and lower payload to orbit and TLI as well as constrained volume (diameter wise) are all matters that should not be disregarded when we talk about NSC.

Let's assume for a second that NSC is really cheaper to develop, in the grand scheme of things are 2 billion more for a DIRECT style in-line design really what we need to worry about when an in-line design provides advantages that NSC just doesn't have?

I think we all need to step back for second and look at the bigger picture. Which engineer in his right mind would design a side-mounted vehicle instead of an in-line vehicle on a clean-slate? Year, noone unless the payload doesn't fit on top of the rocket (like the Shuttle orbiter).

[ar-phanad]

Direct is better for future growth but future growth needs to be paid for.

An in-line SD vehicle offers more advantages over a side-mounted SD vehicle than just more future growth options.Lower safety, potentially higher operation costs, complexity and lower payload to orbit and TLI as well as constrained volume (diameter wise) are all matters that should not be disregarded when we talk about NSC.

Let's assume for a second that NSC is really cheaper to develop, in the grand scheme of things are 2 billion more for a DIRECT style in-line design really what we need to worry about when an in-line design provides advantages that NSC just doesn't have?

I think we all need to step back for second and look at the bigger picture. Which engineer in his right mind would design a side-mounted vehicle instead of an in-line vehicle on a clean-slate? Year, noone unless the payload doesn't fit on top of the rocket (like the Shuttle orbiter).

And wasn't it mentioned somewhere around here that the LAS abort motors would tear into the ET during an abort sequence of the NSC?

If not, what was that show-stopper that Ross mentioned?

And if there is a show-stopper, why is NSC still under serious consideration? Shouldn't we be factoring that into our comparisons?

Jesse

[simon-th]

And wasn't it mentioned somewhere around here that the LAS abort motors would tear into the ET during an abort sequence of the NSC?

If not, what was that show-stopper that Ross mentioned?

And if there is a show-stopper, why is NSC still under serious consideration? Shouldn't we be factoring that into our comparisons?

1. A preliminary abort mode assessment has already been done for NSC. There is a link to it on the dedicated NSC thread. It was determined there is enough margin between the ET and Orion so that an abort would not mean that Orion would touch the ET.

2. Personally I'd say there aren't any show-stoppers for NSC that mean you can't develop the vehicle and fly it. There ARE however issues that need to be worked out and that might mean schedule delays and more development costs.

3. NSC is under consideration. No doubt. We shouldn't fall in the trap that right now any option has been discarded - e.g. Ares I is still the baseline CLV and is NOT dead, even if most people around here think so.

[ar-phanad]

And wasn't it mentioned somewhere around here that the LAS abort motors would tear into the ET during an abort sequence of the NSC?

If not, what was that show-stopper that Ross mentioned?

And if there is a show-stopper, why is NSC still under serious consideration? Shouldn't we be factoring that into our comparisons?

1. A preliminary abort mode assessment has already been done for NSC. There is a link to it on the dedicated NSC thread. It was determined there is enough margin between the ET and Orion so that an abort would not mean that Orion would touch the ET.

2. Personally I'd say there aren't any show-stoppers for NSC that mean you can't develop the vehicle and fly it. There ARE however issues that need to be worked out and that might mean schedule delays and more development costs.

3. NSC is under consideration. No doubt. We shouldn't fall in the trap that right now any option has been discarded - e.g. Ares I is still the baseline CLV and is NOT dead, even if most people around here think so.

I'm not falling into that trap. I just thought that a critical problem was being overlooked, that's all. Not overlooked by Shannon or the NSC proposal itself (I have no knowledge of that), just our collective brainstorming here in regards to DIRECT.

If it works, it works. I just want to get out of LEO, same as the rest of you.

Jesse

[Ben the Space Brit]

2020 for the Moon is still doable.

Moon 2020? With DIRECT? That's probably worse than the current NASA plan. There must be a mistake. Maybe I haven't understood something?

Why should that be a mistake? I still think that this is a pretty good target for a poorly-funded project (which is what return-to-the-Moon is).  Remember, as things are going, it looks like funds are going to have to be shared with ISS up until 2020.  That is going to slow things down a lot.

I also think that I should point out that the current NASA plan is talking about return to the Moon by about 2028.

Please, don't say that there was a multiyear margin and the 2017 was the "never-going-to-happen-optimistic" scenario. Please, say, that I am just having a nightmare and we are still going to the Moon by 2017 (or earlier).

2017 was the estimated date before Aerospace Corp pointed out that DIRECT hadn't included the MSFC's ability to make mountains out of molehills.  The IOC has been moved to 2018 to absorb the civil service inefficiency coefficient.

[Ben the Space Brit]

Just a couple of days ago things were different. To the Moon by 2017. Now, it is 2020. Soon it is 2025? 2030? See?

No, it was never 2017, not for J-241.  It was 2017 for the J-246 (with the 6 x RL-10B-2 upper stage).  However, the J-241 uses the J-2X engine, which still needs to be developed.  That adds time onto the process straight away.

So, we will NEVER see the first manned mission to Mars... I rest my case.

Well, given that latest research suggests that humans can only survive 200 days (~7 months) outside of Earth's magnetosphere, we're obviously going to have to look again at propulsion and shielding for Mars anyway.  So Mars slips back.  The mid-2030s, optimistically.

Please, do whatever is needed to keep up with the original Moon 2017 plan...no...this is pointless. I just lost all the enthusiasm towards manned spaceflights.

You need to keep faith. 

This isn't the Apollo era anymore - miracles are not possible because the money tap is not turned on so high.  If we want the stars, we are going to have to slowly and patiently claw our way up against the odds.  That means compromising with politicians and doing with less. 

[ah_mini]

No, it was never 2017, not for J-241.  It was 2017 for the J-246 (with the 6 x RL-10B-2 upper stage).  However, the J-241 uses the J-2X engine, which still needs to be developed.  That adds time onto the process straight away.

Can't they just stick to the J-246 or whatever allows the earliest mission to the Moon? Maybe they can develop the J-241 later (if it is even needed).

My two cents: Stick to the option that allows the earliest mission (2017?) to the Moon (including landing).

The J-246 is still the official baseline of DIRECT. However, the DIRECT team (to which I have no links) decided to present the J-241 to the panel as a much more conservative design, to avoid baseless FUD attacks that have been levied at the J-246 upper stage figures. If DIRECT were to get the go-ahead from the panel and was developed by NASA unchanged (very unlikely, but possible), then the J-246 would be researched more thoroughly with full NASA resources, with the J-241 as a fall back position should any unforseen issues arise. That's the beauty of having an architecture with proper margins (unlike Ares I/V).

At least, I think that was the idea...

[firehauck]

After thinking a bit..with all the talk going on..as they say.." Talk Is Cheap ".Let's have some action ! All that is going on with the commission is just,in my perspective, a lead weight. If Obama wants to really get something started he could say " Look..we have to keep to a certaint budget here..We must re-invent ourselves to be again a space fairing nation as was back in the days of Apollo. Keeping to that budget I am authorizing Congress to allocate funding for a new rocket called DIRECT 3.0 that will allow us to do almost immediately what needs to be done and close the gap vacated by the Shuttle retirement.Also with the DIRECT  variants, the Moon,Mars and other destinations will be within our grasp"..................Obama has to take a leap of faith here....Sure it's a different time..but the time has come for a bold direction to be drawn out by our president. If it doesn't occur then the talking will continue without any major action !

[Arthur]

More important than 2017 or 2030 is the intent of the mission. I would much rather return to the moon to stay in 2030 (or even 2040) than plant a flag in 2017 as part of a program to plant a new flag on the moon every 50 years.

The flexibility of the DIRECT architecture leaves that door open in a way that Ares I with a shrinking payload does not.

[cixelsyD]

After thinking a bit..with all the talk going on..as they say.." Talk Is Cheap ".Let's have some action ! All that is going on with the commission is just,in my perspective, a lead weight. If Obama wants to really get something started he could say " Look..we have to keep to a certaint budget here..We must re-invent ourselves to be again a space fairing nation as was back in the days of Apollo. Keeping to that budget I am authorizing Congress to allocate funding for a new rocket called DIRECT 3.0 that will allow us to do almost immediately what needs to be done and close the gap vacated by the Shuttle retirement.Also with the DIRECT  variants, the Moon,Mars and other destinations will be within our grasp"..................Obama has to take a leap of faith here....Sure it's a different time..but the time has come for a bold direction to be drawn out by our president. If it doesn't occur then the talking will continue without any major action !

That'll really make the people at CxP upset, or at least it won't save any face for them. I'd rather see them bring up Direct behind the scenes and just get it done without any fanfare.

[MP99]

After thinking a bit..with all the talk going on..as they say.." Talk Is Cheap ".Let's have some action ! All that is going on with the commission is just,in my perspective, a lead weight.

NO! The commission is only spending 90 days, for goodness sake! That's fast, not slow.

NASA has just spent four years working on Ares I. Do you think it would have been wasted time to have spent 90 days at the beginning of the project, dropped it and done something better instead?

The commission needs to spend a bit of time working through the options, and even with 90 days they don't have time to go into any depth.

Let the commission do their work. It is conceivable that they may offer an option which is attractive enough to congress & the WH that they will stump up additional funds to achieve it.

If you want more money for HSF - persuade the commission, and they will try to persuade the govt on your behalf.

cheers, Martin

[clongton]

And wasn't it mentioned somewhere around here that the LAS abort motors would tear into the ET during an abort sequence of the NSC?

If not, what was that show-stopper that Ross mentioned?

And if there is a show-stopper, why is NSC still under serious consideration? Shouldn't we be factoring that into our comparisons?

1. A preliminary abort mode assessment has already been done for NSC. There is a link to it on the dedicated NSC thread. It was determined there is enough margin between the ET and Orion so that an abort would not mean that Orion would touch the ET.

2. Personally I'd say there aren't any show-stoppers for NSC that mean you can't develop the vehicle and fly it. There ARE however issues that need to be worked out and that might mean schedule delays and more development costs.

3. NSC is under consideration. No doubt. We shouldn't fall in the trap that right now any option has been discarded - e.g. Ares I is still the baseline CLV and is NOT dead, even if most people around here think so.

There is an extremely serious safety hazard for the NSC abort mode which is under investigation. Remember that the abort motors are less than 10 feet away from the LOX tank on the ET. Remember also that the LOX tank walls are very thin and very pressure sensitive. The safety issue is that at the very instant of ignition of the abort motor, the ignition *shock wave* will disintigrate the LOX tank before the explosive bolts that will free Orion from the SM have even completed their de-couple.That envelops Orion in a cloud of LOX and tank debris with abort motors burning before she even leaves the stack. It's being looked at. No official results yet.

[tamarack]

...though NASA will probably ruin everything and add years to those estimates...

OT -
When we wanted to break the sound barrier - civilian agencies couldn't get results. When we wanted men in space - we almost lost the best minds moving them to a civilian agency. NASA, like its predecessor, isn't built for results. It's built to create jobs and that takes more time and money...then more time and money...then more time and money...etc.

DIRECT is a great example of the indecisive merry-go-round, myopic 'vision' and political waffling of NASA. After billions of dollars, years of studies and design; The plan is a dusted-off, 30yr-old architecture with half the originally desired capacity. :facepalm: Only 10% reaches orbit and if we're going to pursue space with earnest, the systemic stagnation that makes up 90% of NASA must be dumped. Ad astra per aspera.

$0.02

[simon-th]

There is an extremely serious safety hazard for the NSC abort mode which is under investigation. Remember that the abort motors are less than 10 feet away from the LOX tank on the ET. Remember also that the LOX tank walls are very thin and very pressure sensitive. The safety issue is that at the very instant of ignition of the abort motor, the ignition *shock wave* will disintigrate the LOX tank before the explosive bolts that will free Orion from the SM have even completed their de-couple.That envelops Orion in a cloud of LOX and tank debris with abort motors burning before she even leaves the stack. It's being looked at. No official results yet.

The HLV Crew Abort Assessment (preliminary report - headed by Doug Whitehead) does not mention that. Actually they mention that there are no recontact issue with the ET (page 32). Of course the assessment mentions there is a lot more work to do including "more detailed work on thermal and pressure effects in connection with plume interactions on ET". I however didn't see much on the issue of "shock interactions" other than that in the assessment.

[mike robel]

And wasn't it mentioned somewhere around here that the LAS abort motors would tear into the ET during an abort sequence of the NSC?

If not, what was that show-stopper that Ross mentioned?

And if there is a show-stopper, why is NSC still under serious consideration? Shouldn't we be factoring that into our comparisons?

1. A preliminary abort mode assessment has already been done for NSC. There is a link to it on the dedicated NSC thread. It was determined there is enough margin between the ET and Orion so that an abort would not mean that Orion would touch the ET.

2. Personally I'd say there aren't any show-stoppers for NSC that mean you can't develop the vehicle and fly it. There ARE however issues that need to be worked out and that might mean schedule delays and more development costs.

3. NSC is under consideration. No doubt. We shouldn't fall in the trap that right now any option has been discarded - e.g. Ares I is still the baseline CLV and is NOT dead, even if most people around here think so.

There is an extremely serious safety hazard for the NSC abort mode which is under investigation. Remember that the abort motors are less than 10 feet away from the LOX tank on the ET. Remember also that the LOX tank walls are very thin and very pressure sensitive. The safety issue is that at the very instant of ignition of the abort motor, the ignition *shock wave* will disintigrate the LOX tank before the explosive bolts that will free Orion from the SM have even completed their de-couple.That envelops Orion in a cloud of LOX and tank debris with abort motors burning before she even leaves the stack. It's being looked at. No official results yet.

Well, I am just a layman, though very interested, but it appears to me any vehicle with large diameter solids that depends upon parachutes to land the crew in the event of an abort is going to have a problem with that big F****** Radiant Cloud.

Better break out the F-1 engine again...

[Danny Dot]

snip

There is an extremely serious safety hazard for the NSC abort mode which is under investigation. Remember that the abort motors are less than 10 feet away from the LOX tank on the ET. Remember also that the LOX tank walls are very thin and very pressure sensitive. The safety issue is that at the very instant of ignition of the abort motor, the ignition *shock wave* will disintigrate the LOX tank before the explosive bolts that will free Orion from the SM have even completed their de-couple.That envelops Orion in a cloud of LOX and tank debris with abort motors burning before she even leaves the stack. It's being looked at. No official results yet.

Thank goodness.  Plume impingement is a very real threat to the ET.  Protecting the CM for Apollo was a lot of work.

Danny Deger