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DIRECT Post-Shuttle Plan Pitched To Obama Team
FleaPlus writes "Popular Mechanics reports that a 'renegade' group including NASA engineers has met with President-Elect Obama's space transition team to present information on the DIRECT architecture for launching NASA missions after the Space Shuttle is retired. According to the group, DIRECT's Jupiter launch system will be safer, less expensive, better-performing, and be ready sooner than the Ares launch system NASA is currently developing, while still providing jobs for much of the existing shuttle workforce. Meanwhile, it's expected that current NASA head and adamant Ares supporter Michael Griffin will be replaced by a new NASA administrator."
Then comes the Columbia disaster and the subsequent investigation which recommended that shuttle be retired by 2010.
In 2004 Bush announces the Vision for Space Exploration clearly defining our country's goal to resume our manned exploration of the moon and Mars.
NASA conducts an extremely detailed study into literally hundreds of architecture design alternatives known as the Exploration Systems Architecture Study. It is a fantastic report - read it here. The study rejects using EELVs (due primarily to safety concerns)and recommends a shuttle-derived re-using shuttle and Apollo technology across the two launch vehicles (then called CLV and CaLV). The recommended architecture becomes the basis of the Constellation architecture. (Which later replaces Space Shuttle Main Engines (SSMEs) on the CaLV with RS-68 engines and extends teh CLV from 4-seg to 5-seg (which was actually in the original trade space). This configuration was chosen as it was both the safest configuration as well as having one of the lowest O&M costs (particularly compared with alternatives that leveraged SSMEs more heavily.) NASA is finally on a path to returning to a capability beyond LEO as well as dramatically reducing its workforce with the looming retirement of shuttle a somewhat simpler to maintain replacement
Therein lies the problem... as retirement looms and irreversible decisions begin to be made (reconfiguring pads, not-ordering certain long-lead items for shuttle, etc..) that huge workforce of shuttle support finally realize what Constellation means to their job security. Without shuttle and its extremely complex reusable sub-systems, many of these people will be out of a job and their pet projects in jeopardy.
Not surprisingly, there becomes no shortage of personnel at Shuttle-oriented NASA sites who begin advocating against Constellation and for an extension of Shuttle. Adding to the detractors are of course the disgruntled "establishment" consortium of launch providers, ULA, advocating using EELVs. Then there are the Direct guys who are brilliant NASA engineers but this concept was in essence already considered in the ESAS study and deemed less favorable than the CLV approach.
Add to the mix the political baggage that comes with the program's genesis stemming from an unpopular president and the oncoming president's commitment to "change" at all levels of government and you have a perfect storm of opposition - much of it which has absolutely nothing to do with the actual merits of the current design.
People who have not worked on Constellation simply don't understand how much work has gone into it compared with any of the above mentioned alternatives. Of course they look good now. They have been studied by small groups of engineers for months. Compare with the thousands who have been working on Constellation for years. Despite what anyone says about their program being cheaper or faster - any change at this point will result in
"It takes considerable knowledge just to realize the extent of your own ignorance." - Thomas Sowell
While not a NASA engineer, I am a rocket engineer, and I've worked indirectly with NASA. I've also been following Ares and the DIRECT plan in some detail. I believe I'm qualified to say that the DIRECT plan looks better now than Ares did at a similar point in its development. Even including sunk costs on Ares, it seems quite likely to me that DIRECT is cheaper, quicker, more reliable, and more capable. Ares is already overweight and behind schedule; I would rather bet that it will become more so rather than less so before development is done. DIRECT is not immune to the same effects, but it is a much wiser plan in that it has *much* more margin to work with at a comparable stage in development. Its engineers understand that rockets always get heavier as they get closer to completion, never lighter.
Oddly enough, the only way to compare the two projects is to actually look at the details. The fact that one is further along in development than the other does not automatically make it better, any more than it automatically makes it worse. It may take a little bit of effort to make a reasonable apples-to-apples comparison between the two programs, but it is by no means impossible. AFAICT, comparisons of that sort appear to either be products of bureaucratic inertia ("we've already decided on Ares, therefore it must be right") or they conclude that DIRECT appears to be faster, cheaper, safer, and more capable.
Of course I can't make a perfect judgment on the matter. However, I think that for someone not directly involved in the projects in question, I'm quite well qualified. And yes, I'm aware that paper projects always look better. The thing is, Ares never looked all that good -- even on paper. The idea that an extended SRB is anything other than a new large solid is a fantasy; it was obvious to everyone with technical knowledge on the matter from the beginning that any nontrivial changes to the SRBs lost most of the advantages of keeping Shuttle hardware involved. Changes to the main fuel tank are less problematic, but still not wonderful. Using only a single (extended, and therefore new) SRB as the first stage of Ares I obviously had problems -- the performance characteristics meant it was being used in a highly suboptimal manner in that application.
To an observer who hasn't been paying attention since the early Ares proposals, I can see how this would look like jumping ship as soon as the paper project met reality, only to start a new paper project. However, that is not an apt description. Ares was based on a set of highly optimistic assumptions -- basically, that the designers knew how heavy the payloads would be, and could design to those targets. Unsurprisingly, the Orion capsule grew in mass and Ares I had to find extra performance to make up for it. In contrast, the Jupiter 120 has 40t of throw capability to LEO for a 20t capsule. The extra 20t is allocated to "extra payload." In the event that Orion gets heavier still (which it probably will do, though a lot of the weight gain has likely already happened), it's far, far easier to reallocate a few tons from "extra payload" to "capsule" than it is to pull those tons out of a hat. That sort of planning is what makes DIRECT better, even when comparing apples to apples. Any aerospace engineer who looked at early Ares proposals should have had warning flags going up in their mind as soon as they saw how small the gap between the target capsule mass and the lift capability of the booster was.
For the record, I think there is a lot less wrong with Ares V than there is with Ares I. The Jupiter is still a better choice, I believe, but the difference is less drastic. There is a middle ground that would cancel Ares I, and use Ares V to launch the capsule -- I think this would be an improvement over the current plan, but that the DIRECT plan would be better still. None of these are how I think the rocket *should* be designed, given ample time and budget -- but replacing the Shuttle is a project that doesn't have ample time. If NASA is to get anything flying soon, it will have to be a suboptimal design that has significant Shuttle heritage. Of such projects that I've seen proposed, DIRECT is the best compromise between doing the job well and something that could actually be built in time.