Jupiter vs. Ares

[Lunar_Lander]

Hi everybody,

yesterday I downloaded the 2006 AIAA paper made by TeamVision Inc., which is all about their approach for the CEV, it's launcher and the missions to Moon and Mars.

I have to say, that I think their arguments are quite reasonable, for instance they mention how much Ares I has changed from using stock STS components to components which have to be developed (like the 5-segment SRB or the J2-X instead of the SSME). Another point of them is that the CEV for ISS travel doensn't need to have lunar capability, but that the current CEV development wants to have a lunar capable craft also for Earth Orbit only flights.
They suggest to construct three versions of the CEV, the first only for Earth orbit, the second for Lunar Orbit and the third for a direct ascent lunar landing (thereby eliminating the LM).

As for the rocket they suggest to build a two-stage rocket using the original SRBs and the ET with two engines plus a second stage. The whole setup would be called "Jupiter I", having a LEO payload of 80 tons.
For the ISS missions they suggest the Delta IV Heavy for Cargo and the Atlas V for people.
Jupiter II would then be used to launch the lunar landing, therefore also delaying the need for a new launch tower, the J2-X and the 5-segment booster until the time where the landing missions are planned (which they call Era 3, while Era 1 is the ISS transfer and Era 2 the Lunar Orbit missions).

What is your opinion? I think that the plan sounds good and would be worth pursuing.

 

[Urwumpe]

I quite like the Jupiter concept, but don't fall prone to the argument, it needs less development time as it reuses more components of the Shuttle. While it is true, it will still be a new launch vehicle.

What makes Jupiter better is the fact, that it forms a useful basic infrastructure for exploration. You can launch it more often and find more missions for the launchers, as they have a more balanced approach as the Ares architecture.

 

[Kyle]

Don't care what they use as long as it gets the job done!

 

[tori]

I feel that Jupiter philosophy is a little bit off. Come on, we don't do manned space exploration to actually explore space, we do it to better ourselves and our technology. Freezing the research by just hacking some old junk off a rocket built by our grandfathers and jamming it up our own is not how we're gonna move to the next techlevel.

Also, using the SSME on an expendable vehicle would increase the per-launch cost dramatically (unit cost over 80M USD). It's a ground-start engine, so heavy modification would be required anyway. The J-2X is an order of magnitude cheaper (around 12M), a good ton lighter, and already comes with air/vacuum-start and restart capability. The development cost is probably going to overshadow the manufacturing cost greatly (you know, the NASA way), but at least it's new technology.

 

[joiz]

one question: could jupiter launch mars direct? and what tori said.

 

[Lunar_Lander]

Don't care what they use as long as it gets the job done!

I won't say so, because I think it is important to consider cost, development time and so on.

@tori: Your arguments are good too. I also would rather think about developing the J-2X than modifying the SSME (also when the price per piece is higher for the latter). But I'd say that the Jupiter uses some proven technology. Urwumpe correctly stated that it would need development time, but in case of Ares we would have to start from scratch! For Jupiter we have at least some bits of tech we already have proven and tested.

@joiz: I don't know all about Mars Direct, but I think that one of the later Jupiters (e.g. Jupiter-II or -III could lift Mars Direct to Mars). Oh, I just see that you need Saturn V-class rockets. In that case you could even use several Jupiter-I (80 tons to LEO per shot).

 

[RisingFury]

Taking SSME and reconfiguring them for Jupiter would be a big waste.

SSME are optimized for a SSTO, but a better solution is to have two different engines - one for low altitude and one for vacuum of space. That way you optimize your Isp and get way more out of your fuel.

Besides, they're not made for restart capability and NASA study revealed it would be damn difficult to restart them...

Developing J-2X is a good idea.

 

[tl8]

I won't say so, because I think it is important to consider cost, development time and so on.

I am going to jump in here and disagree. If the vehicle chosen doesn't do what it is meant to do all that money and time will be wasted.

I would prefer having to spend an extra year getting the vehicle perfect than launch something that can't actually do what we want it to.

 

[Hielor]

Freezing the research by just hacking some old junk off a rocket built by our grandfathers and jamming it up our own is not how we're gonna move to the next techlevel.

I agree. In order to get to the next tech level we need two buildings of the current tech level and a large stockpile of materials. Stuff from the old tech level won't help us.

 

[Eagle]

I am going to jump in here and disagree. If the vehicle chosen doesn't do what it is meant to do all that money and time will be wasted.

I would prefer having to spend an extra year getting the vehicle perfect than launch something that can't actually do what we want it to.

That's the kind of thinking that gives you nothing, not even a prototype for 30 years or research and design. Eventually you need to settle for 'good enough' (for now) or you'll never get anything.

 

[Urwumpe]

That's the kind of thinking that gives you nothing, not even a prototype for 30 years or research and design. Eventually you need to settle for 'good enough' (for now) or you'll never get anything.

Yes. But it has to meet the requirements, and you don't fit the requirements to the launcher you have now. Because this kind of thinking does not even get you closer.

Ares does not meet the original requirements, and Jupiter does not meet the current requirements - because the current requirements are designed as such, that the launcher has to be Ares.

The only way out would be strict project management, including a proper identification of the best technical solution. But this never happened and will never happen.

 

[tblaxland]

I agree. Requirements should fit goals, and solutions fit requirements, not the other way around. Requirements do change. That is part of any project but there a good reasons for changing requirements and bad reasons.

Examples of good:
1. The goals have changed (generally client driven).
2. The new requirements fit the goals better (better cost, better time, etc).

Examples of bad:
1. Sunk cost fallacy (eg, we can't do something different now, we've already gone so far down this road).

 

[Andy44]

The whole manned space program is a case of "sunk cost fallacy", if you ask me (you're probably not asking me, but I'll offer my opinion, anyway).

Take the Space Shuttle. By the time it was realized that it wasn't going to measure up to expectations of low cost launches and airliner-style safe operation, it was too late for NASA to turn back. Too much money (and political clout) had been spent, so the only course of action was to keep BS'ing Congress into believing it would pay off someday if they just stayed the course and dumped more money into it.

Ares is no different. It was sold as a cost-effective way to get us past the shuttle years, back into LEO, to the Moon "and beyond". That was typical bureaucratic nonsense. The new launcher isn't measuring up, so NASA is dumbing down the requirements and shedding promised features like skip re-entries, land recovery and reusability for the capsule. And it will still cost more than promised. But we can't stop now! We've sunk too much money into it.

Apollo on steroids? Yeah, steroids make you bigger, but not healthier.

 

[Linguofreak]

The new launcher isn't measuring up, so NASA is dumbing down the requirements and shedding promised features like skip re-entries, land recovery and reusability for the capsule.

IMHO, land recovery is a bug, not a feature, in a capsule.

 

[Urwumpe]

IMHO, land recovery is a bug, not a feature, in a capsule.

Actually it is opposite. Ocean landing is always the worst place you want to be.

 

[Andy44]

IMHO, land recovery is a bug, not a feature, in a capsule.

Okay, assume you're correct about this (I disagree, but that's a capsule argument, not a rocket one). But the weight you save from eliminating the bigger chutes and landing bags and the skip-capable heat shield could be used for something more useful.

If the rocket was powerful enough.

Which it's not. So you just lose the mass altogether. Getting rid of a "bug" by using a weaker rocket isn't a good way to fix a bug.

Stick to the process: figure out how much you want your spacecraft to mass, then design a launcher that can lift it, and build-in margin from the get-go. Von Braun asked NASA how much Apollo would weigh, and then designed the Saturns to lift that mass plus a healthy margin, knowing the mass would grow. It did, and his rockets were up to the task. NASA is now doing it backwards. Trying to make the capsule fit the launcher, which can't be made bigger without scrapping the SRB segments and going to a fatter diameter or going liquid.

 

[tblaxland]

I'll offer my opinion, anyway

Always welcome

Ares is no different. It was sold as a cost-effective way to get us past the shuttle years, back into LEO, to the Moon "and beyond".

Because "let's develop technology by building cool spaceships" or "lets develop technology so that we can build a viable commercial space sector" is not sufficient motivation for your politicians to part with your tax dollars? (They are real questions, not some cheap shot rhetorical question) There is great resistance to aerospace applied research in this country, so I am genuinely curious.

---------- Post added at 12:38 ---------- Previous post was at 12:35 ----------

Actually it is opposite. Ocean landing is always the worst place you want to be.

For reusability? Salt water damage, etc? I image that could be quite nasty for an RCS engine for example. Otherwise, I expect that water-based recovery fleets are not cheap either compared with their land-based alternatives.

 

[Andy44]

Because "let's develop technology by building cool spaceships" or "lets develop technology so that we can build a viable commercial space sector" is not sufficient motivation for your politicians to part with your tax dollars? (They are real questions, not some cheap shot rhetorical question) There is great resistance to aerospace applied research in this country, so I am genuinely curious.

Well, I'm the wrong person to ask about this, being a wackjob libertarian who thinks that letting government do commercial space stuff is wasteful in principle to begin with.

Note that the United States (and other spacefaring nations) has two "space programs", the high-profile civil one known as NASA, and the lower-profile one run by the USAF which includes defense-related satellites and launch vehicles such as the Atlas and Delta families. The military space program has a well-defined mission which is a real government function, and as a result it is adequately funded and mostly succesfull in its tasks, despite the occasional setback. NASA really serves no practical function for a government; it makes scientists and dreamers happy but won't warn us when someone is getting ready to start a war or deploying nukes on Cuba, as a result it is always scrounging not only for funds, but for a well-defined reason to exist.

There is a third "space program" in the U.S., the commercial sector, which owns and operates communications satellites for telecom, television, and satellite radio. Nobody has to force their shareholders into paying for space technology, they are trying to make money. Without NASA/USAF, would they have developed and flown their own launch vehicles?

Hard to say, but maybe there is an Australian Elon Musk out there somewhere. The easy availability of Russian, American, and ESA government-funded launch services, however, makes it difficult for a private party to get market share in the launch business, methinks.

 

[tblaxland]

Well, I'm the wrong person to ask about this, being a wackjob libertarian who thinks that letting government do commercial space stuff is wasteful in principle to begin with.

Oh well, I guess I'm a wack job centrist who happens to agree with you

Without NASA/USAF, would they have developed and flown their own launch vehicles?

Possibly not. Related question: would we have a thriving commercial aviation sector without NACA/NASA(Aeronautics)?

Hard to say, but maybe there is an Australian Elon Musk out there somewhere. The easy availability of Russian, American, and ESA government-funded launch services, however, makes it difficult for a private party to get market share in the launch business, methinks.

When you buy a Delta IV launch, it is not govt subsidised is it? Just the development was govt sponsored?

 

[Andy44]

Related question: would we have a thriving commercial aviation sector without NACA/NASA(Aeronautics)?

Yes, in fact we did have one long before NACA was thought of. (Although WWI provided military-funded advances, too.)

But the commercial possibilities of aviation were apparent early on. Making money with airplanes is fairly easy to do, compared with spaceflight. If I could transport 20 businessmen to a large city on the moon for the cost of a DC-3 then commercial space would be a snap. But there's no cheap means of spaceflight and no business on the moon.

Government cannot create commerce artificially by pouring money into space tech development; if there's no real, natural, market then it'll always be little more than a tax boondoggle.

When you buy a Delta IV launch, it is not govt subsidised is it? Just the development was govt sponsored?

The cost of the hardware is probably not subsidized, but I'm fairly certain the launch team is USAF or civilian government employees. Maybe the private party compensates the government for this, I don't know.

But the development costs are considerable, especially if you look to the 1950s when nobody had done it before. Atlas, Titan, and Delta all started off as ballistic missile programs, of course. And don't forget the launch facilities, such as Cape Canaveral Air Force Station, are government-owned as well.

Anyway, maybe we should start a seperate thread, as this is getting away from the Jupiter-Ares topic. To comment on the topic, I would say that neither Jupiter not Ares is really cost-effective, but one may have wasted less money than the other and been perhaps more capable and flexible. The idea to use Atlas and Delta for LEO missions, for example, makes alot of sense because these vehicles are already in service and are useful for more than just one purpose; they serve defense, civil and commercial needs, and they are mostly the products of Lockheed Martin and Boeing, which makes them "more commercial". Ares I will probably never be used for anything but Orion, and it's an in-house NASA design, which doesn't do much for promoting the private sector, which NASA is supposedly trying to do.