kraisee - 7/4/2008 10:15 PMQuoteLampyridae - 6/4/2008 8:45 PM
Bienvenu au NSF, René!
I'm not part of DIRECT but these are commonly asked questions so I'll just answer them for you as best I can (apologies for assumptions and mistakes...)...(SNIP)
All correct as far as I can tell, thanks for the summary while I was away.
Although I would alter the Obama/Clinton thing.
I'm not writing either of them off as potential DIRECT supporters yet. We are beginning to make inroads to both their campaigns and I think they're both quite open to realistic options for reducing the cost and schedule for Shuttle's replacement as long as it also protects the voting workforce. 9,000 votes has to be worth a few seconds sound-bite!
Ross.
By all accounts ATK are really trying to make a commercial launcher out of Ares-I.
Cale - 7/4/2008 8:35 PM
Dear Ross & Chuck,
Having been a big fan of Orbiter Space Simulator for a few years, I stumbled upon Antonio's Direct v.01 addon and was very impressed....(SNIP)
Antonio has previously done quite a few "Beta-Test" profiles for the team using Orbiter. It's a pretty good simulator for early testing of the practicality of ideas like this.osiris - 7/4/2008 9:32 PM
Ross & others,
Thank you for taking the time to answer my questions.
kraisee - 8/4/2008 3:17 AM
We know the configuration can achieve at least a highly elliptical Lunar Orbit with this, but we're still fine-tuning whether we can get it down into circular, or even near-circular Low Lunar Orbit.
Jim - 7/4/2008 7:55 PMQuotealexterrell - 7/4/2008 5:22 PM
A J-232 can deliver a tether system of about 130 tons (including ET as counter mass). Assuming the same ratio, we have about a 15 ton capability. That makes Falcon 9 a bit light weight at 10.5 tons, especially given the need for a plane change to an equatorial orbit. (So would be launched from Kwajein or Kouranu, or both).
A Zenith sea launch might also be an option, though the launch rate would be difficult.
Though of course, if a J-232 really can deliver 100 tons of fuel to LEO for $200 million, then a tether may not be financially viable. (A SEP reusable upper stage might still be).
Zenith is not viable. US gov't can't use it.
Question still stands, why just Spacex? They haven't even launched one yet. They haven't proven capable of doing the mission
)alexterrell - 8/4/2008 2:57 AM
At the moment, Zenith, Proton are the lowest cost operators. Spacex is expected to join them. Based on the costs of Directs, even with a tether, Atlas and Delta are probably too expensive.
US Government can use them all. Just won't.
It's a bit like some Westerner who only buys products made in his country. His choice to pay double, his stupidity.
Jim - 8/4/2008 6:54 AMQuotealexterrell - 8/4/2008 2:57 AM
At the moment, Zenith, Proton are the lowest cost operators. Spacex is expected to join them. Based on the costs of Directs, even with a tether, Atlas and Delta are probably too expensive.
US Government can use them all. Just won't.
It's a bit like some Westerner who only buys products made in his country. His choice to pay double, his stupidity.
Wrong. US Gov't (not just NASA) can't use Zeniths or Proton. It is against the Commercial Space Act (a law). Know what you are talking about before making statements.
"Probably too expensive" That doesn't cut it. Use factsbefore making statements.
Spacex is "expected" to join them. Spacex is not pregnant. It is not a sure thing. Why isn't the same thing said the Tesla electric car. Isn't it going to take out Ford and GM?
Look in the mirror first before calling "some" Westerns stupid. There are reasons for such laws.
kraisee - 7/4/2008 6:55 AM
iii) Oh boy. *Big* subject this. And complicated by "1-vehicle, 2-launch" solution we're employing compatred to the "2-vehicle, 2 launch" solution employed by Ares. Ours shares a lot more of its operational costs between our two configurations of the same vehicle compared to Ares' two completely different vehicles - so we're always going to be cheaper. Here are the details:
Ares-I:
Development: ~$14,400m
Fixed: $800m/year.
Variable: $130m/flight @ 1 per year, $105m/flight @ 4 per year.
Ares-V:
Development: ~$15,000m
Fixed: $2,000m/year.
Variable: $240m+90m (for the EDS)/flight @ 1 per year, $194m+$73m/flight @ 4 per year
Jupiter-120:
Development: ~$9,500m
Fixed: $900m/year.
Variable: $140m/flight @ 1 per year, $113m/flight @ 4 per year, $102m/flight @ 8 per year
Jupiter-232: (J-120 has already paid Fixed Costs for SRB + Core, so just add EDS + 1 more RS-68):
Development: ~$4,000m
Fixed: $800m/year
Variable: $110m/flight @ 1 per year, $93m/flight @ 4 per year
Thus the baseline of: 2 ISS per year + 2 Lunar Crew per year + 2 Lunar Cargo per year total up to:-
Ares: $29.4bn Development (non-recurring). $2,800m Fixed, $1,488m Variable = $4,288m per year (recurring).
DIRECT: $13.5bn Development (non-recurring). $1,700m Fixed, $1,374m Variable = $3,074m per year (recurring).
Difference: $15.9bn Development (non-recurring). $1.214bn per year (recurring).
Ross.
kraisee - 7/4/2008 4:49 PM
I would *LOVE* to engage Dr. Zubrin in a deep discussion of how to make our systems viable with his, but given that we're a bit of a hot potato currently I understand if he wishes to keep out of this for now.
But something behind the scenes would be well worthwhile for our 2008 AIAA paper - which is already well underway. It going to focus upon Mars and the reverse-engineered architecture for the moon which will act as an "analogue" for those later missions.
Zubrin's skills and the whole Mars Society skill-base would be *amazingly* valuable if we can put it together with a 100mT launch system along with Propellant Depot facilities in LEO (at least).
Ross.
Nathan - 8/4/2008 12:35 AMQuote
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.
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?
.
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)

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.
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.
kraisee - 9/4/2008 9:20 PMQuoterenclod - 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.
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?
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.
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.