Chair Force Engineer

Sunday, July 31, 2005

Making Rockets Like Airplanes

I'm thinking back to Elon Musk on Friday and some of his aircraft analogies for his rocket. He wants to build as much of the rocket in the factory instead of stacking it on the pad. This is akin to building an airplane in a factory instead of on the runway. This makes a lot of sense.

It makes less sense to run up the rocket's first stage engines before lifting off, as an airliner does before it takes off. This isn't a big deal with an airliner because it doesn't take a lot of fuel to run up the airliners engines momentarily before takeoff. Yet this is critical for a rocket because you're wasting the finite amount of oxidizer onboard (while the oxidizer is free in an aircraft.) The fuel expended prior to liftoff is wasted mass; the rocket works on the principle that about 90% of its mass is expended as useful propellant.

Friday, July 29, 2005

Rocket Booster

The guest of honor on base today was Elon Musk, brainchild of the SpaceX company. He immediately came off as a person with infectious enthusiasm and a desire to leave his positive mark on the world. I must admit that his zeal for space was infectious. He was so bold to declare that exploring space was more important than curing cancer. He explained that most cancers are already treatable, and that the majority of terminal cancer patients would only see a few more years added to their lives if their cancer were cured, due to their advanced age.

Elon's ultimate vision is to make mankind a multi-planet species. Part of that vision is a self-sustaining colony on Mars. That's the kind of rhetoric that gets me excited.

The real excitement came later, when Musk made the first public comments on his Falcon IX launcher. It's essentially a Falcon V with four more engines on the first stage, plus a larger 5 meter payload shroud. Robert Bigelow (Space Gigolo) originally wanted to launch his "Nautilus" space hotel on a Falcon V, but development delays caused him to turn to the Russian "Dnepr" instead. Musk was able to get Bigelow to agree to a Falcon IX launch for his next space hotel module in 2007.

If Falcon V is Musk's replacement for the Delta II, Falcon IX is the competitor to Delta IV and Atlas V. The Falcon IX can also be clustered into a "heavy" variant, akin to the Delta IV Heavy. Space station resupply ships and space tourist capsules are also in the cards.

At this stage, I can't tell if Musk is the savior of the space launch industry, or just another smooth-talking crackpot like we have seen too many times in this industry. For instance, details on the recovery scheme for the Falcon I first stage are very sketchy. Where are the recovery ship and divers? Is there a way of keeping the sea water out of the engine (or, as my supervisor suspects, is the engine thrown away with only the tankage reused?)

A lot is riding on the inaugural launch of Falcon I this fall (aside from the Air Force Academy's satellite.) My hope of hopes is that it successfully achieves orbit. The proof will be in the (orbital) pudding.

Tuesday, July 26, 2005

The Meeting that Refused to Die

I had to miss the highlight of the day, the televised launch of Discovery, because I was in a meeting that started at 8 AM. We had expected it to last until noon. Instead, we took a lunch break then and were back in the meeting by 1:30. I left before 2 PM to attend a claims briefing, and the meeting was still going when I returned around 3 PM.

During the course of the meeting, it felt like I was trying to drink from a fire hose. There was just way too much information to digest, and a lot of the technical issues were foreign to me.

Perhaps the worst part of military life is the moving process, the reason why I was being briefed by the claims department. The Air Force hires movers who are about as smart as grilled cheese sandwiches. They break your items, lose them, and steal them. The moving process is the epitome of incompetence.

Saturday, July 16, 2005

Golden CAV

One of the civilians in the office was bashing the idea of a "comman aero vehicle," or CAV, the other day. His point was that a CAV would only be useful against rare, deeply-buried targets. After hearing him out, I have to concede that a CAV would be an expensive system that could not presently be deployed in large numbers, but it does have utility right now as a silver-bullet weapon.

It is first necessary to understand what a CAV is. Imagine a ballistic missile, topped with a delta-winged glider. The glider would re-enter the earth's atmosphere at hypersonic speed, approach a target, then release several GPS-guided bombs.

The CAV's most visible strength is its responsiveness. When Osama bin Laden attacked the US on the morning of Sept. 11, several CAV's could have attacked terrorist targets by the afternoon of the same day (assuming that specific targets had been selected and programmed into the CAVs' bombs.)

The 9/11 scenario brings up another excellent advantage of the CAV: force projection from the continental US. In order to invade Afghanistan, the US had to spend weeks establishing diplomatic relations with unsavory governments like the one in Uzbekistan in order to gain bases close to the theatre of battle. The wasted time and political liabilities would be a thing of the past with CAV.

CAV also provides survivability benefits over conventional cruise missiles and ballistic missile warheads. Ballistic warheads follow a predictable track and can theoretically be intercepted, as tests of our missile defense system have shown. Cruise missiles are slow moving and follow a pre-programmed path. Although they incorporate stealth features amd fly below radar coverage, cruise missiles can be easily shot down by manned aircraft and anti-aircraft gunners once they are visually detected. A CAV has the ability not only to outrun most anti-aircraft missiles, but to maneuver out of the path of high-speed interceptors like the American missile defense system.

The "deeply-buried target" scenario, the greatest strength of the CAV, might be more common than we think. The scenario usually presumes an enemy leader like Saddam Hussein who has taken refuge in an underground bunker. However, the Iraqi experience at Osirak has convinced many rogue states (particularly Iran and North Korea) that their nuclear facilities are only safe if they are buried underground. Our increasing reliance on spy satellites has also given potential enemies another reason to bury their military equipment and facilities: to conceal it from our prying eyes.

There is no doubt that a CAV mission would be much more expensive than one launched by a land- or sea-based aircraft. Then again, the ICBM-boosters for the CAV were bought and paid for back during the Cold War. It wouldn't be practical to mount an entire air campaign with CAV's, but they make sense for time-sensitive, highly-defended, or deeply-buried targets. It also gives us leverage when negotiating with other countries for basing and overflight rights. The CAV is a perfect fit with the Rumsfeld vision of transformational defense systems.