Launch vehicle, Atlas V Options

[Redstone]

NASA has decided to use the Atlas V, with 4 strap-on solid rocket boosters to launch MSL. This is the same rocket that launched MRO (no solids) and New Horizons (5 solids).

Cost: $194.7 million, less than half the price of the Titan IV which would have been needed a few years ago.

Rocky Mountain News article

NASA press release

[dvandorn]

This just points out another truth behind the funding levels required for planetary missions. If you let your scientific goals dictate the mass of the spacecraft, you have to accept the additional cost of a larger booster to get you there. If you let the cost of the booster drive your total mass budget, then you have to sacrifice some of your science objectives in order to "afford the ride."

A fifth of a billion dollars just to get yourself on a path to Mars... no wonder there are so few missions that can fit under the Discovery mission cost caps.

-the other Doug

[Jim from NSF.com]

NASA has decided to use the Atlas V, with 4 strap-on solid rocket boosters to launch MSL. This is the same rocket that launched MRO (no solids) and New Horizons (5 solids).

Cost: $194.7 million, less than half the price of the Titan IV which would have been needed a few years ago.

The amount is not the price of the rocket. Asthe news release says "That cost includes NASA launch services and mission integration requirements" which includes many things like payload processing facility costs, down range telemetry support, KSC contractor support, KSC support, mission unique modifications to the launch vehicle (NASA never orders a "stock" vehicle and this spacecraft uses special power sources) etc.

[Guest_BruceMoomaw_*]

The Discovery missions are all supposed to use Delta 2 (or smaller boosters) for precisely that reason -- although even that has been complicated by the fact that Delta 2's use as a commercial launcher is about to cease, which makes it a lot less cost-effective for Boeing to keep the assembly line going, which in turn has caused a big jump in the price that Boeing demands from NASA for Delta 2s. *sigh*

Couple this with the fact that the important Solar System exploration goals that can be achieved at this point with little spacecraft are decreasing in number, and the case becomes very strong for considerably slowing down the pace at which Discovery missions are launched -- maybe to about one every 4 years, as with the New Frontiers missions -- at the same time that we raise their cost cap. (By contrast, it still looks as though there are a lot of worthwhile scientific goals, of greatly varied type, that can be met with small Explorers.)

[RNeuhaus]

I would like to learn about the what are limit of mission cost for every type of Discovery Class. I have heard that Discovery has three or four levels, I (smaller mission), II (Scout mission), III (Enterprise aka mission) or IV (Complex Enterprise mission).

Now, about the cost to launch a Atlas V for MSL which is about 200 millions dollars. I would like to know about the structure of costs. I suppose that the material cost would be cheaper about 1/3 and the support service would account at 2/3, isn't?

Then, I have the impression that the material cost will drop every year with the improvement of technology, reusing material and continuity of production. But, on the service side, as the general rule, everything is growing every year.

Maybe, it would be the best of the worlds is that the developed countries build technology, infrastructure support and laboratories and the less developed countries with cheaper labor cost will operate, the work that is not highly specialized such as monitoring, checking, programmed works and so on of the same style during the mission exploration.

It would be ideal, as it will lower costs for any solar system exploration but hope that the business of space will be look for the best price for consumer.

Rodolfo

[Jim from NSF.com]

The "other items" of the launch service costs are 1/3 to 1/5 of the overall costs.

[Guest_PhilCo126_*]

A reminder to point out that the Atlas V is not the most powerfull non-man-rated launch-vehicle
Titan IV : 2 X 600 + 240 = 1440 kdaN
Ariane 5: 2 X 525 + 90 = 1140 kdaN
Atlas V/511: 1111 kdaN

...

[Bob Shaw]

A reminder to point out that the Atlas V is not the most powerfull non-man-rated launch-vehicle
Titan IV : 2 X 600 + 240 = 1440 kdaN
Ariane 5: 2 X 525 + 90 = 1140 kdaN
Atlas V/511: 1111 kdaN

...

Hmmm... ...anyone know what the final outcome was for the Ariane 5 man-rating? The core vehicle was meant to launch Hermes, after all. Obviously, the new upper stage wasn't specifically linked to any manned use, but...

Bob Shaw

[ugordan]

A reminder to point out that the Atlas V is not the most powerfull non-man-rated launch-vehicle
Titan IV : 2 X 600 + 240 = 1440 kdaN
Ariane 5: 2 X 525 + 90 = 1140 kdaN
Atlas V/511: 1111 kdaN

What's a kdaN? It looks to be a measure of thrust of some sort?
Also, Titan IV is no more in service so no point in including it.

[Guest_DonPMitchell_*]

Let's look at some numbers. Here are some figures for vacuum and sea-level specific impulse, which measures engine efficiency (and thrust in metric tonnes). The F-1 was the biggest engine ever built, but it was based on an old-fashion gas-generator cycle:

F-1 (Saturn V) - 304 265 (790 tons)
YF-20B (Long March) - 289 259 (83 tons)

Staged compustion is the current state of the art, and this gives you significantly more thrust per kilogram of fuel. The Proton managed 316 sec. even using less efficient fuels (N2O4 + Dimethylhydrozine). At the time of the F-1, only the Russians had mastered staged combustion design:

RD-253 (Proton) - 316 285 (178 tons)
NK-15 (N-1) - 318 297 (157 tons)
RD-180 (Atlas V) - 338 311 (423 tons)
RD-701 (MAKS) - 415 330 (408 tons)

Today we see the benefits of both staged combustion and liquid hydrogen. The SSME was the groundbreaking technology here, the starting point for all the other cryogenic staged-combustion engines. In the RD-0120, the Russians made some improvements to the SSME which NASA has been studying. It is a simpler design, and is able to achieve combustion stability without complex anti-oscillation dampening chambers. The RS 68 is also a fine engine, designed to be cheap simple and disposable.

RS 68 (Delta IV) - 420 365 (338 tons)
Vulcain (Ariane) - 434 318 (110 tons)
SSME (Shuttle) - 453 363 (232 tons)
RD-0120 (Buran) - 455 359 (200 tons)

For orbital vehicles, it is better to look at the LEO payload, because that depends on the thrust of all the stages and how their sizes have been balanced against one another.

Super-heavy:
Saturn V: 118 tons
N-1: 95 tons (if it had worked)
Energiya: 88 tons

Heavy:
Shuttle: 27.5 tons
Delta 4-H: 25.8 tons
Proton: 21.0 tons
Atlas V: 20 tons (551 config.)
Titan 4: 17.8 tons
Ariane V: 16.0 tons
Atlas V: 12.5 (401 config.)

Long March 2E: 9.2 tons
Soyuz: 7.4 tons

[ugordan]

You're forgetting the engine RD-180 was derived from -- the RD-170 from the Energia strap-on boosters. With twice the thrust of an RD-180, it beats even the mighty F-1 at 800 tons of thrust. Its variant (RD-171) is being used on the Zenit rocket.
IIRC, the F-1 were actually closer to 700 tons of thrust than 800.

[Guest_DonPMitchell_*]

You're forgetting the engine RD-180 was derived from -- the RD-170 from the Energia strap-on boosters. With twice the thrust of an RD-180, it beats even the mighty F-1 at 800 tons of thrust. Its variant (RD-171) is being used on the Zenit rocket.
IIRC, the F-1 were actually closer to 700 tons of thrust than 800.

The RD-180 and RD-170 are clusters of 2 and 4 engines, respectively. The RD-701 is a dual engine. But nevertheless they are powerful and well designed.

[attachment=6054:attachment]

[Bob Shaw]

The RD-180 and RD-170 are clusters of 2 and 4 engines, respectively. The RD-701 is a dual engine. But nevertheless they are powerful and well designed.

Don:

I'd always thought that one of the particularly Soviet design threads was the way that they saw grouped nozzles as only part of a single engine, particularly when they shared turbopumps and other plumbing. The US designers would see four engines, but the Russian just one. Isn't this descriptive dichotomy what we're seeng with the RD-180 and RD-170?

Bob Shaw

[Guest_DonPMitchell_*]

Don:

I'd always thought that one of the particularly Soviet design threads was the way that they saw grouped nozzles as only part of a single engine, particularly when they shared turbopumps and other plumbing. The US designers would see four engines, but the Russian just one. Isn't this descriptive dichotomy what we're seeng with the RD-180 and RD-170?

Bob Shaw

Exactly, and the RD-108 on the Soyuz was also such a grouped design. The issue is combustion stability, an extremely difficult problem. Today the Russians are the masters, but in the 1960s, they just couldn't build large chambers. The N-1 had 30 1st-stage engines, at which point the increased probability of failure is a problem. I doubt anyone would ever attempt to build such a large single-chamber engine like the F-1 today, but it was an impressive engineering feat.

The Russians also like to simplify the pumping system, typically with a single-shaft multi-turbine design (like their RD-0120 vs. the multi-pump SSME).

[RNeuhaus]

A reminder to point out that the Atlas V is not the most powerfull non-man-rated launch-vehicle
Titan IV : 2 X 600 + 240 = 1440 kdaN
Ariane 5: 2 X 525 + 90 = 1140 kdaN
Atlas V/511: 1111 kdaN

...

What are these numbers? 2 (?) -I suppose: 2 rockets laterals- x 600 (?) - I suppose: propulsion force in KiloNewtons- = 1440 kdaN (?)

Thanks!

Rodolfo