DIRECT v2.0 - Thread 2

[renclod]

Nathan - 8/4/2008  12:35 AM

Yes.   A single Jupiter-232 has approximately 80% of the "throw" capability of Ares-V.   It can do almost everything Ares-V is planned to do, and if there's a shortfall you can fly one extra flight every four to make up the difference.

One extra flight every few years is a lot more economically sound than spending $15bn extra in development and another $1.2bn every year.

And once we do get the Propellant Depot architecture up and running it raises the theoretical limit for each Lunar Lander (lifted dry on a single J-232) to around 180-200mT!   The real limit is ultimately defined by how much fuel you can afford to lift.

Ross.

Hi Ross,
Would the same upper stage be used for single lauch cargo only as it would for dual launch? developing multiple upper stages would increase development cost and would provide a reason not to support direct. I've seen graphics of Diret with a large number of upper stage varieties. this worries me a bit.

Nathan.

The same question goes for LSAM/Altair. Would a unique lander design lend itself to triple uses ? (single launch - dual launch - re-fuel at depot)

ESAS's 1.5 architecture is flexible. Single Ares V - Altair - cargo only. Dual launch Ares I/V for manned mission. Both types of mission use a single unique lander design- just the payload is different: ascent module plus single digit tonnes cargo (I/V), or double digit tonnes cargo only (V).

IMHO.

[Jim]

alexterrell - 8/4/2008  6:50 PM

1.  If the USA prefers that NASA be first and foremost an employment agency, then that's the choice of the USA. A European country on the other hand would not have this choice, being bound by supra-national laws.

2. There are no facts on costs yet, so we can't use them. What would Boeing charge in a competitive tender for 24 Delta IV launches over a 2 year period?

.

1,  Again, it is the US gov't (DOD, NRO, NOAA, etc) and not just NASA that can't use Zenith and Proton.

2.  It doesn't matter because spacex can't launch that many

[kraisee]

renclod - 9/4/2008  9:39 AM

The same question goes for LSAM/Altair. Would a unique lander design lend itself to triple uses ? (single launch - dual launch - re-fuel at depot)

For DIRECT there are a few options.

The Dual launch (w/ CEV) is the default.   The closest pure cargo option would actually be a dual launch solution still.

A single J-232 launch would be about 80% that of an Ares-V in all aspects including mass on the lunar surface.   The LSAM would need to be scaled to suit to get optimum performance though, so this would no longer be ideal for the 2-launch solution...

There are a number of options.   An LSAM suitable for both missions could be designed with optional tanks and optional engines - but that would be an expensive option to pursue.

One approach we've been looking at is the Crasher Stage though.   Both missions could be supported by simply varying the size of the Crasher element.   Barrel stretches to the tanking would be the only required changes to support virtually any realistic configuration.

This approach actually allows for a fairly huge variance in LSAM size.   It can theoretically support both single and dual launch options, perhaps even three-launch for *really* big payloads.   The key to making that work would be having an engine with deep cycle capability able to support the largest planned mission.   The same engines would be operated below max for many instances, but operating an engine below maximum stress levels is not a bad thing!

I'll try to get some drawings and numbers put together soon, but I've got my hands full with other things right now so please be patient.

Ross.

[kraisee]

renclod - 9/4/2008  9:17 AM

The Mars Society is pleased to announce the addition of Dr. Scott Horowitz ... to our Board of Directors.

Great.   Just the right person to be advising Zubrin.

Ross.

[alexterrell]

kraisee - 9/4/2008  11:10 PM

This approach actually allows for a fairly huge variance in LSAM size.   It can theoretically support both single and dual launch options, perhaps even three-launch for *really* big payloads.   The key to making that work would be having an engine with deep cycle capability able to support the largest planned mission.   The same engines would be operated below max for many instances, but operating an engine below maximum stress levels is not a bad thing!

I'll try to get some drawings and numbers put together soon, but I've got my hands full with other things right now so please be patient.

Ross.

I suppose the limit is a fully fueled LSAM plus cargo needs to mass less than the J-232 launch load, which would imply 50 tons of cargo at least.

I look forward to the figures / drawings.

Cargo is very important if the aim is a lunar base. If however, the aim is to undertake Apollo 18, 19, 20 etc, then cargo is relatively unimportant. I'm still not sure what the aim is.

[rsp1202]

kraisee - 9/4/2008  9:20 PM

renclod - 9/4/2008  9:17 AM

The Mars Society is pleased to announce the addition of Dr. Scott Horowitz ... to our Board of Directors.

Great.   Just the right person to be advising Zubrin.

If there was only some way to get him on board the Chinese program.

[Pheogh]

Chuck asked me to move this question about the Commercial Ares-1 vehicle to this thread:

Ok, ok, This not conspiracy talk, and I am not attempting to change this into a DIRECT thread,.. buuuuut, If you will just bear with me because I honestly don't know the answer. Would ATK stand to make more money with the 5, 5,5, 6 Segment SRB R&D development through the Ares program, plus the Commercial launch market,.. OR ... Would they be more profitable with the published Jupiter Series flight rate of the Standard 4-Segment SRB?

[clongton]

Pheogh - 10/4/2008  5:01 PM

Chuck asked me to move this question about the Commercial Ares-1 vehicle to this thread:

Ok, ok, This not conspiracy talk, and I am not attempting to change this into a DIRECT thread,.. buuuuut, If you will just bear with me because I honestly don't know the answer. Would ATK stand to make more money with the 5, 5,5, 6 Segment SRB R&D development through the Ares program, plus the Commercial launch market,.. OR ... Would they be more profitable with the published Jupiter Series flight rate of the Standard 4-Segment SRB?

We have actually looked at this and over the long haul, because of the anticipated flight rate based on using Jupiter in lieu of Ares-I, ATK would make more money servicing the 4-segment RSRB for the Jupiter than they would on the 5-segment RSRB for Ares-I. Of course, the ATK executives would need to be willing to set aside their big bonus for developing the 5-segment booster if it were actually halted. But there remains the possibility that the 5-segment development effort could get so far down the line that it becomes more appropriate for DIRECT to incorporate it instead of shutting it down. That decision would be based entirely on political concerns and ATK's development schedule. If that were to happen, ATK would make even more money with the Jupiter than with the Ares.

[kraisee]

alexterrell - 10/4/2008  3:29 AM

I suppose the limit is a fully fueled LSAM plus cargo needs to mass less than the J-232 launch load, which would imply 50 tons of cargo at least.

Works best with Propellant Depot.

That limit becomes 108mT *dry* spacecraft mass then.

Ross.

[kraisee]

alexterrell - 10/4/2008  3:29 AM

Cargo is very important if the aim is a lunar base. If however, the aim is to undertake Apollo 18, 19, 20 etc, then cargo is relatively unimportant. I'm still not sure what the aim is.

Yes, it does seem pretty hazy right now.

I can't speak for NASA, but here is what we propose:   Starting around 2018 we begin a 5-year concerted effort to try to land as many cargo modules as we can, in order to build a viable habitat on the Lunar surface.   DIRECT can afford 6 Lunar missions per year for Ares' cost of just 2 missions.   That's about 20 Cargo-only missions (full 2-launch size) plus 10 Crew/Cargo missions in that 5 year period - that's an awful lot of hardware and exploration we can do relatively quickly.

20 Cargo-only missions should be more than sufficient to build a fairly descent outpost.   As soon as that is completed, we would begin to scale-back the Lunar efforts by re-directing all the experienced Lunar hardware development teams to the Mars effort - aiming for a Mars Mission attempt around 2031.

During the 'scale-back', we would assume Lunar flight rate would reduce to 2 crew rotations to the Lunar surface per year, with 1-2 cargo missions to support them.   Hopefully we can encourage International Partnerships to help offset some of the costs too, but we aren't banking upon it - just to be safe.

Somewhere around 2031 we send our first crewed Mars mission - while continuing our exploration of the moon - albeit at a slower pace for a time.

The Mars technologies also allow us to explore other targets too - such as NEO's.   We can then begin a regular (1 per year or so) long-duration mission program over time visiting lots of interesting sites.

But essentially once all the development work is finally scaled back (mid 2030's), having achieved the realistic goals of the VSE, we would then have sufficient monies to be able to sustain a very robust human exploration program regularly visiting the moon, Mars and a good number of NEO's all at the same time.

This, to me, seems to be an effective way to create mankind's first-generation "highway network" infrastructure enabling robust human expansion beyond this biosphere to a variety of useful destinations.

The development monies, now free'd up after creating the Mars/NEO capability, could then be turned to a variety of possible purposes around 2035-40.   My personal preference would be to seriously begin utilizing the vast resources then made available to us in all *three* destination programs.

That's what our budget forecasts allow DIRECT to do with only an inflationary increase to NASA's budget every year.   I've seen NASA's costings, and I'm 100% convinced the Ares solution couldn't possibly hope to afford anything like the same though.   DIRECT allows this effort to encompass the Moon and Mars and NEO's - not "or".

Ross.

[Lampyridae]

Hmm, this gets more and more interesting. I wonder what a Jupiter mission launched by Jupiter rockets could be like? Ironically it would directly leverage off a lot of lunar experience, and ISRU on Callisto would be a doddle.

[clongton]

Just for S&G’s I took a few minutes yesterday to go back and listen to President Bush’s speech on January 14, 2004, when he announced the VSE. He very specifically spoke about spacecraft for planetary missions being “assembled on and launched from” the moon in order to avoid the expense of climbing up earth’s gravity well every time for every mission. But I have seen nothing of this in CxP releases. I bring this up because the last few posts have nibbled around the edges of transitioning from a lunar to a Mars centric architecture in terms of how many lunar missions per year considering Jupiter vs. Ares launches.

[mike robel]

Chuck,

If the objective is to build an industrial base on the moon capable of assembling and launching large complex spacecraft from the moon, then it will be in the next century before we get to mars and not in current year + 30.  Of course, perhaps I am misinterpeting this as "building", but in either case we will have to lift components, tools, etc from earth to the moon, so I don't see the short term value.  Long term perhaps.  But in the short term, its easier to launch from earth and go DIRECT to Mars.  

[clongton]

mike robel - 11/4/2008  11:49 AM

Chuck,

If the objective is to build an industrial base on the moon capable of assembling and launching large complex spacecraft from the moon, then it will be in the next century before we get to mars and not in current year + 30.  Of course, perhaps I am misinterpeting this as "building", but in either case we will have to lift components, tools, etc from earth to the moon, so I don't see the short term value.  Long term perhaps.  But in the short term, its easier to launch from earth and go DIRECT to Mars.  

Mike,
I’m not suggesting that is what we should do. All I am saying is that is what the President actually said. I only mentioned it because of the direction the conversation was heading and wanted to see if anyone else had noticed that and was wondering how others viewed his statement in light of the desire to use the moon as a way-stop vs. an assembly and launching location. Personally, I do not support such a scheme in the near term.

[alexterrell]

mike robel - 11/4/2008  10:49 AM

Chuck,

If the objective is to build an industrial base on the moon capable of assembling and launching large complex spacecraft from the moon, then it will be in the next century before we get to mars and not in current year + 30.  Of course, perhaps I am misinterpeting this as "building", but in either case we will have to lift components, tools, etc from earth to the moon, so I don't see the short term value.  Long term perhaps.  But in the short term, its easier to launch from earth and go DIRECT to Mars.  

I assume whoever wrote that speach knows that. What I suspect he means is a middle ground of launching LOx, and maybe Hydrogen, to L1 and then staging the mission at L1.

I'd actually argue that even in its almost literal sense (build an industrial base on the moon capable of supporting the creation of large Mars ships in Earth orbit), this would be a faster way to Mars colonisation than Mars Direct, based on Directs v2.0 architecture.

Of course, for Mars flags and footprints, the moon is a waste of time.