Samizdata

I am sure many of you have by now heard the coverage about the airplane crash into waters off of La Guardia airport in New York.

What I have not heard yet are comments on the fine piloting it took to grease a rather good size metal bird into the water. The pilot could not have had many minutes to think about his options, and yet as far as I can see, he did everything flawlessly.

I just want you all to ponder what it takes to bring a commercial transport of that size down on the water, in one piece, floating and with all your passengers alive.

The pilot and co-pilot of this flight deserve all of the applause we can give them and a heart felt thank you from all the passengers and their families.

I have been informed that Majel Barrett Roddenberry has died. She is best known to many as Nurse Chapel aboard the original Starship Enterprise. Despite being a major celebrity, she was perfectly at ease joining the rest of us in the hospitality suites until all hours of the night.

Somewhere I have a photo of her behind the suite’s ‘bar’ counter chatting with Buzz Aldrin, Lori Garver and another close friend of mine, Beverly Freed at once of our International Space Development Conferences.

She and her husband Gene Roddenberry, who died in the early 1990’s, were strong supporters of the National Space Society’s goal of a solar system wide human civilization.

Here are a few links to photos of Majel I took at the 1993 ISDC in Huntsville, Alabama.

Majel accepting posthumous award on behalf of Gene Roddenberry.

Majel accepting posthumous award on behalf of Gene Roddenberry

Majel with Lori Garver (currently member of the Obama transition team for space policy)

Majel with Buzz Aldrin

Meanwhile, the band played on… Home on Lagrange anyone?

Note: the dates on the files are the dates on which the rolls were developed, not the dates they were taken. Photos were scanned from prints and thus the quality is not wonderful.

Jane’s reports the following:

Thales aims directed-energy weapon at ground, naval applications. Thales Air Systems Division is working on a joint development project with the Ecole Polytechnique engineering school in Orsay, France, to develop a directed-energy weapon (DEW) for ground and naval applications. Project Director Philippe Antier of Weapon Systems, Thales Air Systems Division, told Jane’s that the aim of the project is to provide a capability against missiles, aircraft and unmanned aerial vehicles (UAVs) to a range of up to 10 km as a complement to very-short-range air-defence (VSHORAD) systems, with the goal of having the system operational by 2015

When it is steam boat time, you steam…

SpaceX tested the Falcon 9 a few days ago, November 22nd, on their giant test stand in McGregor Texas. I have reported previously as SpaceX increased the numbers of engines by a few at a time each test and am happy to report they have now succeeded in firing the nine Merlin engines in a sequence and for a period of time identical to that of a real mission.

Nine engines fired for 160 seconds; two were then shutdown and the remaining seven burned until the 178 second mark. The two engine shutdowns are done in the later stages of flight when much of the fuel mass has been burned off and the ‘G forces’ climb. This spare ‘oomph’ means a Falcon 9 can lose two engines and still reach the required orbit.

The stage developed 855,000 pounds of thrust at sea level. This will increase to about 1 million in vacuum. The Falcon 9 is not a little rocket.

A first flight attempt is expected from their Cape Canaveral pad during the first half of the coming year. I am not betting on a successful first flight, although it is a possibility. While the Merlin is now a fairly well understood engine, there are complex dynamic interactions between engines when you fly with more than one. I am sure Elon’s team has modeled and tested to the best of their ability, but simulations and ground tests are still ‘theory’ relative to real live flight.

I have no doubts whatever that the SpaceX team will have Falcon 9 flying for hire within the next two years.

You can watch the test here

The people at ISRO, the Indian Space Research Organization, have scheduled their first lunar probe for October 22nd.

You can read the Times of India and The Hindu for more information.

I sometimes wonder if we will see a second ‘Race To The Moon’, this time betwixt India and China for pretty much the same reasons as the first. If so, I hope to be sitting in the lounge watching the news with a Guinness in hand after flying Virgin Galactic to the Bigelow Luna.

Speaking of tourism… Richard Garriot flies to the space station today. There is no bar there, but hopefully the Russians keep a little stash of vodka for ‘medicinal purposes’.

Richard’s aunch occurred successfully at 3am EDT. Docking will happen Tuesday and there will be live coverage on NASA Select starting at 0530 EDT.

Over the last week I kept running across articles and video about a heavy weight couple who lost weight after the embarrassment of being asked to move to a different seat so the airplane could take off safely. On one Fox News show the talking heads went on about the times they were asked to move. None of them were particularly large so they talked overly long about how a jumbo jet could be unsafe to fly because a mere wisp of a talking headess was in the wrong seat.

This riled me a bit and has been roiling about in the back of my mind for some days. The people who write or talk about these things are supposedly educated, but the level of ignorance shown makes me very worried about what schools are actually requiring students to learn, even at the university level.

In hopes some of these ignorant but otherwise intelligent folk happen to drop by Samizdata, I will provide a bit of a remedial lesson in basic physics and a bit on aeroplanes as well.

I am hoping everyone is at least familiar with what a lever is, or at the very least a childhood teeter-totter. If two children sit on a board on opposite ends, they can find a balance point regardless of how fat or skinny the two are. One can move closer to the fulcrum, the thing upon which the board rests, or farther away. A child of a given weight at a given distance from the fulcrum creates what is known as a torque. The two children can balance these torques: Mass of child 1 times distance from fulcrum = Mass of child 2 times distance from fulcrum. In more typical notation: m1 * d1 = m2 * d2.

If you understand a teeter-totter, you can understand everything else I have to say.

An aeroplane has a number of points that are of interest. The most important to this discussion are the ‘center of lift’ and the ‘center of gravity’. If you had a very hefty jack and the underside of your 747 could handle it without a requirement for body work afterwards, a single point at which the aircraft could balance like a toy on a pencil is the center of gravity. This is just like the balance point of the children, but with the entire class and their teddy bears instead.

The fulcrum is the center of lift. This is a balance point created by the airflow over the surfaces of the plane in flight. Ideally, and in the simple case, the center of lift should be near the center of mass and both should be on the center line of the aeroplane. If one wing were longer than the other, the center of lift would shift away from the center line. This would not be a good thing unless you are Burt Rutan and know how to do tricky things which no normal mortal would think of doing.

In practice it is impossible to get the two exactly together. If the center of lift is forward of the cg the airplane will want to pitch up. If it is aft of the cg it will try to pitch down. Similarly if it is to the right or left of the cg. the airplane will want to roll right or left.

You can control the attitude of the aeroplane by neutralizing these forces. If you have a pitch up tendency, you dial in a bit of pitch down on the elevator trim tabs. Likewise for the other directions. In worst case you can use the control column and use deflection of the elevator or ailerons themselves to counteract the problem. It is not wise to fly like this under normal circumstances. If you run out of trim you have either not done your weight and balance papers properly or you are flying a Lancaster to Europe in WWII with a max bomb and fuel load and expect you are going to die anyway.

Airplanes have a bunch of numbers which pilots have to know. Among them are the ‘aft cg limit’ and the ‘forward cg limit’. Basically these mean you are too tail heavy or nose heavy to fly with enough of a safety margin to deal with the unexpected. They are not absolute limits. You are not going to reach the ‘my god we are all going to die!’ limit unless everyone piles into the tail and the pilot can not keep the nose down even with full downward elevator deflection.

Inside the cabin the pilot has readings off the landing gear that tell him what the weight and balance looks like after all the luggage, consumables and passengers are on board. If those indicators show the aeroplane is approaching the aft limit he or she will have a flight attendant pick someone from far aft and move them as far forward as possible.

That is all this whole storm in a teacup story was about. It is standard aviation practice that goes back to the first time Wilbur took Orville along with him.