Chair Force Engineer

Wednesday, May 30, 2007

The Sky Must Be Falling

Michael Griffin has made a statement that I completely agree with. However, the subject matter is the question of human-induced climate change.

On the subject of getting NASA back on track, I'm afraid that the Administrator and I are still worlds apart from agreement.

Friday, May 25, 2007

Running Down a Dream

Benson Space and SpaceDev have unveiled the third design for their "Dream Chaser" manned spacecraft since the concept was announced in 2004. First they started with a clone of the X-34, as recommended in a paper by Marti Sarigul-Klijn. In November 2005 they changed to the HL-20, which was better suited for orbital spaceflights. They even went as far as negotiations with United Launch Alliance for use of the Atlas V 431 rocket. Yesterday, they unveiled this version of Dream Chaser, based on the X-1 and X-15 rocket planes.

I must say I was a bit disappointed to see the HL-20 design discarded. To be honest, I think Benson/SpaceDev's current design would be better for suborbital space missions, but the HL-20 clone would be better for orbital flights. If Benson Space succeeds in breaking into the suborbital tourism business, they should commission SpaceDev to design an all-new craft by the time they're ready to get into the orbital spaceflight market.

It's all a question of what direction Benson Space wants to go with its space tourism efforts. Do they want to go suborbital first, then get into orbital flights as the technology improves? Or do they want to leapfrog over the competition and go straight to orbit? While the latter strategy could play out in the long run, it would appear that the jump straight to orbital flights would be "a bridge too far" for most new-space companies.

In a way, the decisions facing the New-Space firms are similar to the choices made by US and Soviet space officials in the late 50's. The US committed to a brief suborbital program using the Mercury Redstone. The Soviets had planned on suborbital manned flights with a V-2 variant, but cancelled that program based on the success of the R-7 and Vostok rockets.

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Wednesday, May 23, 2007

What's Up, Dock?

It's recently been announced that the James Webb Space Telescope will be equipped with a docking ring for the Orion spacecraft. While the news brought me some initial excitement, I'm now scratching my head as to what's really going on within NASA.

The rationale for the Orion docking ring is simple: what happens if the spindly telescope fails to deploy properly? Before today's announcement, the answer would have been, "Say goodbye to $4.5 billion." The addition of the docking ring means that a human crew would have a fighting chance of manually correcting any deployment problems--or does it?

According to current schedules, JWST will launch in June 2013; a manned Orion/Ares I flight won't occur until two years later, according to current budgets and schedules. Further, Ares I will have nowhere near the delta-V to get Orion to the L2 point where JWST will reside. An Orion mission would likely have to wait until Ares IV (the hybrid of Ares I&V) is ready, which would probably be a few years beyond the projected 2015 flight of Orion with her first crew.

A bit closer to earth, a similar solution might make sense for the Hubble Space Telescope. During the projected 2008 Hubble Servicing Mission, Hubble will receive a low-impact docking system. While NASA's plan is to eventually de-orbit Hubble, a future Orion servicing mission shouldn't be ruled out.

If Orion docked with Hubble, the crew would be at a bit of a disadvantage using the stock Orion capsule. Without an airlock, the crew would have to vent the cabin every time an EVA was conducted. Crew members would also lack a platform to stand on while performing repairs.

The solution to these problems is an airlock module that was also equipped with a smaller version of the shuttle's CanadArm. The module would be stored in the spacecraft adaptor during launch; Orion would dock with it after reaching orbit. The airlock, in turn, would have a LIDS on its free end for docking with Hubble.

The airlock module is out-of-the-question for Orion flights on Ares I. There's no margin on that launcher, and the Orion service module acts as a third stage. However, if Orion was launched on a Jupiter 120, there would be up to 20 metric tons of payload margin that could be used for an airlock module, or even additional payload (replacement parts and upgrades for Hubble) mounted to Orion's service module. Even better, it's possible for Jupiter 120 to support a 2012 Hubble Servicing Mission.

It's possible that a Jupiter derivative could also reach JWST, but such a mission wouldn't occur by 2013 either. The Jupiter derivative for this mission would also require an upper stage to take Orion to L2 and back.

In short, outfitting JWST for an Orion repair mission doesn't make sense, unless significant delays are expected on JWST. Frankly, I wouldn't be surprised if big delays were in store for the next-generation telescope. An Orion mission to the venerable Hubble telescope would make a lot more sense, but NASA doesn't have a launcher that will be ready in time to perform the mission.

Sunday, May 13, 2007

Out of Gas

Every time I log onto Facebook (the popular social network website,) I see that several more of my friends have joined a group stating that they're not buying gas on May 15. The idea is that if people boycott the gas companies for one day, the prices will drop. Ideas like this indicate a poor understanding of economics; if left uncorrected, it will lead people to believe in rubbish like Marxism.

I'm somewhat amazed to see how poorly people understand the concept of supply & demand when it comes to gas. Because our demand is high, relative to the world's petroleum output, gas companies can get away with charging prices that are now reaching $4.00/gallon in some cities.

As Peter Parker says in Spider-Man 3, "we all have a choice." In the case of rising gas prices, we can choose to consume less gas, hence we choose to buy less gas. What effect will the May 15 gas boycott have? A small fraction of the nation's drivers will have an immediate need to fill up on May 15. Most boycotters who would have normally filled their tanks up on May 15 will instead do it on May 14 or May 16. As long as driving habits don't change, consumption will remain the same.

Here's a modest proposal: why don't we have a day where, instead of boycotting the oft-villainized oil companies, we decide to boycott the consumption of gas? Even better yet, why can't every American make a commitment to burning 20% less gasoline than they used to? After all, 20% of our petroleum resources come from the middle east. Isn't it a sad irony that American petrodollars flow to the oil sheiks, who give the petrodollars to terrorists, who turn around and kill Americans? Hopefully the asshole who leisurely cruises around in his Ford Excursion thinks about the blood of American service personnel next time he looks in the mirror.

All Americans need to examine their driving habits to determine how they can contribute to our energy independence. I get burned up every time I see some dickhead driving to work alone in a truck or minivan or SUV. These vehicles have their purpose, but they should be left in the driveway when they're not absolutely necessary for hauling people or cargo. Virtually every household should have at least one four-cylinder compact car that's used as a "daily driver" for the commute to work and back.

Adopting "daily drivers" is a good start towards a future free of middle eastern oil, but it's not the only simple thing we can do. Short trips can be accomplished on foot or on bike. Errands that aren't time critical can be pushed aside until they can be combined with another trip in the same direction. It's not going to take ethanol or hydrogen to alleviate the short-term energy crisis. It takes a little bit of critical thinking and discipline, so we can make a conscious effort to reduce the amount of gasoline we use.

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Thursday, May 10, 2007

Return-to-Flight

Direct Launcher is back in action.

After taking some lumps from NASA's Doug Stanley back in December, the Direct Launcher proposal has been updated. Version 2 is now online at the Direct Launcher website.

The revised proposal was the product of a small but dedicated team, combining the efforts of the original DIRECT team plus TeamVision. The resulting launch vehicle is named "Jupiter" and comes in several variants. Important revisions to Jupiter include:
--The tried-and-true RS-68 (in quantities of two or three) provides the first stage propulsion, instead of a regen-cooled variant that doesn't yet exist. The change is more consistent with the DIRECT philosophy of "Let's use what we have today instead of reinventing the wheel."
--The Earth Departure Stage is defined in greater detail, using two near-term J-2XD engines instead of the definitive J-2X.
--The new architecture allows for the Orion service module to perform the LOI burn instead of the LSAM. This is a more efficient use of system mass than NASA's baseline.
--As more confidence is established after several lunar sorties, DIRECT can evolve into an LOR-LOR architecture instead of EOR-LOR.

The important thing to remember is that DIRECT is the guiding approach/philosophy, while Jupiter is the family of launch vehicles. Noting that this is a family of vehicles is important, as Jupiter can evolve with a stretched first stage and five-segment SRB's once more money is available.

The DIRECT V2 proposal is quite short in comparison with DIRECT V1. It reads more like an addendum to the V1 proposal, rather than a stand-alone document. It's important to remember some of the V1 proposal's key points, like the re-use of shuttle launch pads and facilities, and the problems with Ares I that will prevent it from being safe, simple or soon. While some of DIRECT V1's criticisms of Ares were unfounded, it's still true that the Ares I-Orion stack has extremely thin performance margins, and requires multiple burns of the same engine that will be used for the return from lunar orbit.

At the risk of sounding like a cheerleader, DIRECT V2 is the only way that NASA can achieve its goals of going back to the moon "safe, simple & soon" in the current budgetary climate. It's pleasing to Congress because it preserves shuttle jobs/votes, it closes the manned spaceflight gap after the shuttle retires, and it will probably be cheaper to develop than Ares I.

Sunday, May 06, 2007

Regrets

Two years ago today, I commissioned as an officer in the United States Air Force. By this point in my life, I realize that this was the wrong decision. The military lifestyle is not suited for my natural abilities and aptitudes, and I feel that I am doing the nation a disservice by being here and consuming taxpayer dollars.

I bear half the responsibility for this situation, by not realizing sooner that this life was not suitable for me. I had inklings of this long before I commissioned; I never felt like I fit in with the other cadets. At the same time, I had friends who genuinely cared about me and genuinely thought I could do some good if I stuck with it. Yet I didn't have any mentors to tell me that if I really wanted to be a good engineer (as opposed to being a manager,) I should forget about commissioning in the Air Force, spend my free time learning the computer and machine shop skills I'd need to thrive in the industry, and work on internships during my summers. Then again, I probably wouldn't have had the patience or drive to do any of those things, either.

At the same time, the Air Force has to examine itself and ask how they can let such poor cadets pass through the cracks in the system to get their commissions. The "Kinder, gentler" Air Force is more reluctant to give cadets the boot, although that has changed recently as a result of force-shaping. I don't think the Air Force is very forthcoming in presenting a realistic picture of what the acquisition career fields look like when cadets are going through their training. And for cadets who are on scholarship, the Air Force only grants them one year to change course and leave the ROTC program before the threat of recouping scholarship money comes into play.

I may seem like a dead-ender, but I'm still motivated by the fact that my reputation is tied to my work. If my program is delayed because of something I did (or failed to do,) that weighs very heavily on my conscience. In the end, when beauty and material wealth have escaped us, all we have is our reputations.

Based on listening to me rant, one might get the impression that I was only in this for the scholarship money. While the money was nice, I can honestly say that I used to believe in what I was doing. That changed after about six months on active duty. I realized that my aptitudes were being wasted, and that I'd make a more valuable contribution to society in a different capacity. I don't think that the system ever made an effort to understand me. As much as I tried, I never seemed to understand the system, either.

My hope is that I can serve out the last two years of my commitment without getting my nose any dirtier, and without giving the Air Force an excuse to make me pay my scholarship back. Hopefully I can emerge from this experience a little wiser, and with a little more clarity on what I should be doing with my life.

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Saturday, May 05, 2007

Russian to the moon?

The head of Russia's space agency claims that NASA has spurned offers of Russian assistance for manned lunar missions, and that the US plans on monopolizing Helium-3 resources on the moon. The story is consistent with Russian government talking points which condemn "American unilateralism." While the claims reek of absurdity, it creates a point for more intelligent debate on important issues facing NASA's future lunar efforts.

I don't know of what, if any, overtures have been made between the US and Russia regarding lunar exploration. Nevertheless, NASA must ask itself if the American taxpayers will benefit from Russia's assistance. Assuming that the Russians could refurbish the facilities for manufacturing and launching the Energia heavy lifter, it could serve as a welcome alternative to the kludge that we call "Ares." However, the cost and time associated with getting Energia flying again is probably so prohibitive that it makes Ares look good by comparison. If Russia is willing to contribute resources that will save money and not delay the schedule, it will benefit the American taxpayers. But the ISS experience doesn't give us much reason to hope that this will play out.

The theme of Helium-3 monopolization is a common meme for moonbats who think that "George Bush is going to send Halliburton to the moon and strip its resources." There may be a day when Helium-3 is an important power source for earth. But until that day comes (and I don't expect to see it in my lifetime,) Helium-3 mining will be pointless. There are many obstacles that must be overcome before controlled fusion can be a viable power source. There are also plenty of reasons why Helium-3 fusion will be even harder to achieve than deuterium-tritium fusion. At this point, Robert Bussard's controversial research could be an equally-valid alternative to the traditional fusion approaches which have yet to achieve an ignition of the plasma.


By this point, I have little faith in the truthfulness of any press release issued by the Russian space agency. The American people have no reason to expect fruitful results from a space alliance with the Russians, unless Russia can guarantee an alternative to the Ares rockets (or if the Atlas V, with a Russian-made engine, becomes part of Project Constellation.) And the next time you hear anybody mention the near-term mining of Helium-3, ask where you can buy some of the crack they are smoking.

Wednesday, May 02, 2007

Scotty Doesn't Know

According to sources, legendary astronaut John Young claims that Ares I won't work. He says that NASA knows this, but will not announce this conclusion until May 23.

As much as I think the "Scotty Rocket" is a foolish idea, I don't think it's totally unworkable. The problem is that there's a distinct mismatch between the Orion spacecraft's mass and the Ares I's capabilities.

Orion is a train-wreck in slow motion, because NASA is trying to reconcile two very different sets of requirements. NASA wants a six-man ISS capsule and a four-man lunar capsule. Seeing as how COTS is supposed to dock with ISS, why should the same requirement burden Orion? The Orion command module should be no more than 33% heavier than the Apollo CM, due to the 33% increase in crew size. Significant mass savings can be achieved through lightweight alloys, composites, and miniaturized avionics that weren't available in the mid 60's. The Orion SM should be less massive than the Apollo SM, because there's no requirement for a lunar-orbit insertion burn, and the fuel cells of Apollo were replaced with solar arrays.

Alternately, if NASA stubbornly sticks to its "Sumo Capsule" named Orion, there are several fixes that can enhance Ares I's performance. These would include:
--Changes to the engine nozzle's expansion ratio, sacrificing thrust for specific impulse
--Changes to the solid propellant formulation in the first stage to increase specific impulse
--Filament-wound casings for some SRB segments, and deletion of first-stage recovery system

None of these changes are free of negative consequences.
--Reducing the SRB's thrust negates one of "Scotty Rocket"'s advantages, which is the depressed trajectory that allows for aborts during all flight regimes. Then again, I find NASA's original logic to be specious; the Saturn IB only had a thrust-weight ratio of ~ 1.26
--Changes to the propellant formulation will snowball into changes in the SRB casting process and machinery, and result in an all-new fuel grain design.
--Filament-wound SRB's that are expended will negate another advantage of the SRB, which is the confidence that is gained from reusing flight-proven hardware.

The biggest problem with "Scotty Rocket" is that the first stage is inherently inflexible. Solid fuel rockets can't easily be widened or lengthened like liquid-fuel stages can. The Challenger disaster and the current disaster that's called "Ares I" only vindicate Wernher von Braun's opposition to using solid rockets in manned launchers.

I am very skeptical of any unverified reports that NASA is throwing away "The Stick." NASA has blindly stuck with this monstrosity and worked through previous problems that have developed, rather than changing gears. If NASA truly is giving up on "Scotty Rocket," they will likely adopt something like "Ares IV" or its SRB-less cousin, "Ares III," to replace it. That way, NASA will be able to get money for its lunar/Mars rocket instead of putting its development off until future presidential administrations. However, Ares IV is definitely overkill for the crew launch mission. Nevertheless, NASA's reaction to more practical ideas like Atlas V and Direct Launcher has been cool at best (at times, it's been vicious and mean-spirited.)

In short, it's premature to declare the death of Ares I and celebrate. Just because it's a dumb idea doesn't mean that it will never work. It just means that it will require an inordinate amount of work and money to fix the problem; it will also lead to a system that is inferior over the life of NASA's lunar program. At this point in the program, it appears that the Orion spacecraft is in just as much trouble due to conflicting design requirements and excessive weight. At this stage in the game, it's not too late to change Orion. For the SRB-based Ares I, fixes will be much harder to make. The only way NASA can survive the crisis is through clarity of its mission and responsibility in the way it spends taxpayer dollars.