Friday, September 23, 2005

Sky rockets in flight, after-dark delight

When it comes to launching spacecraft, the U.S. federal government has two main installations. The Eastern Range is comprised of the launch pads at Cape Canaveral Air Force Station and Kennedy Space Center in Cocoa Beach, Florida. This is where they launch the space shuttle and all other manned spacecraft. Also, all interplanetary spacecraft and any Earth-orbiting satellite with an inclination (angle the satellite's trajectory makes with the equator) less than 57 degrees launches from the Eastern Range. These spacecraft take off toward the east or northeast, taking advantage of the fact that the Earth already rotates in that direction, giving the satellite a boost of angular momentum. The 57 degree limit (which at least applies to space shuttle launches) comes from the fact that, if a satellite launched in a direction that is more than 57 degrees toward the north, it would be launching over populated areas of the east coast. People don't appreciate it when debris from spacecraft (or the shuttle's solid rocket boosters) fall on them from the sky. The ascent stages of these rockets need to occur over unpopulated areas, and the Atlantic Ocean fits that bill. Note: not all countries have that luxury in their spaceport location. Russian rockets taking off from Plesetsk Cosmodrome in Russia, or Baikonour Cosmodrome in Kazakhstan, have been known to rain debris down over the rural plains. Farmers have been known to sell pieces of Russian spacecraft to supplement their income.

The Western Range is located at Vandenberg Air Force Base near Point Arguello, north of Santa Barbara, California. This launch site is less talked about, probably since no manned spaceflights are launched there, and no interplanetary missions either. This site specializes in polar orbitting satellites. The Eastern range can't deliver polar orbits, since there are populated areas both due north (east coast) and due south (islands of the Carribean, and South America). The Western Range, however, has a clear path over the Pacific Ocean to the south. Vandenberg also is the launch site for various military launches, including Minuteman ICBM's, which it launches (without armed warheads, of course) toward the South Pacific for test purposes.

Launches from Vandenberg can be visible by residents of much of the southwest United States, depending on the lighting conditions. Last night, Thursday September 22nd, there was an especially cool launch. At 7:24 pm Pacific Daylight Time, not long after sunset, a Minotaur rocket launched the "Streak" satellite (a DARPA - Defense Advanced Research Projects Agency project) into a polar orbit. Since the sun had set for southern California, it was nice and dark on the ground. As the rocket gained altitude, it re-entered sunlight. This resulted in the rocket's exhaust being illuminated by the sun, while the rest of the sky was dark. A beautiful sight. I took a few snapshots from the roof of my apartment building in Sherman Oaks. You can see the other snapshots at: While Vandenberg launches something once every month or so, a nice, visible, dusk launch like this is a bit more rare, occurring every few years or so.

Having grown up in San Diego, I had seen the remnant exhaust trails of such launches before, but I'd never watched one while it was actually happening. It was beautiful! It looked like a giant comet shooting skyward.
For more infor on Vandenberg's rocket launches, and other space events relevant to the southern California area, check out SpaceArchive:

Friday, September 09, 2005

David Galvan and the Half-Blood Donation

I think Samuel L. Jackson said it best in the fine piece of film de cinema, The Negotiator, when he screamed at the police helicopters, "You want my blood?! TAKE MY BLOOD!"

In the spirit of Mr. Jackson's enthusiastic endorsement of blood donation, I headed down to the UCLA Blood and Platelet Center in Westwood this morning to make one myself. A little background is in order here. The first time I donated blood was a little less than a year ago. It arose from two motivations: 1.) guilt for not having donated before, and 2.) the desire to overcome fear.

As to the first motivation, I do not mean that anyone should be meant to feel guilty for not donating blood. Such a donation is a very personal and heartfelt act (so to speak), and each person has their own reasons for doing it or not. Everybody certainly has the right to decide what to do with their own body, afterall. But, for me personally, I felt a little guilty. Many times in college, when working in Houston, and now in grad school, I had seen advertisements and solicitations to participate in blood drives. I had watched others come back from giving blood, knowing that there was no physical reason why I could not do the same. I also knew that blood donations were essential to helping people in need.

The reason I didn't donate is because I felt an aversion to the actual process. I don't have a problem with needles used for injection. Give me a tetanus shot or an innoculation any time. But there is something about sliding a needle into one of my veins and seeing my lifeblood flow slowly out of my body through a winding tube that gives me the creeps, even though I know it is completely safe for me. The fact that I felt this psychological aversion to the process, and that it was keeping me from doing something that could help other people, led me to feel guilty. That, in turn, led me to the second motivation.

Back in my days as a Boy Scout, I learned a definition for bravery, which is a part of the Scout Law. ("A Scout is trustworthy, loyal, helpful, friendly, courteous, kind, obedient, cheerful, thrifty, brave, clean, and reverent.”) Bravery is not the lack of fear. It is the ability to take action and do what is right, despite the fear. I felt that the fear I had of donating blood was not well founded, and even a little selfish. So I decided to make a blood donation in order to overcome that fear.

My first donation went fine. I was sort of nervous going in, I tried not to look at my blood flowing through the tube, and I felt a little light headed afterwards, but other than that it was a success. I walked out feeling triumphant and manly. (. . . while munching my cookie. . . and sipping my Juicy Juice. . . out of a bendy straw. Ahem.)

My second attempt at a donation didn’t go as well. Five minutes or so into the donation, the nurse noticed that my blood was flowing rather slowly. This could be a problem since, the slower the blood moves, the more likely it is to clot at the needle, which would slow it down even more. She told me to clench the squeezy toy in my hand more often, to help pump the blood out, but it was no use. After a short time, the blood had essentially slowed to a stop. What’s more, they told me they would not be able to use the blood already in the collection bag. I asked why, and this is the answer I got: the collection bags have a certain amount of anti-coagulant in them to keep the blood from clotting while it’s being collected (the bag is rocked back and forth on a machine, to help with this as well.) The amount of anti-coagulant is based on the volume of blood the bag can hold (these ones expect a donation of ~400- 450 mL). If there is not enough blood in the bag, the ratio of anti-coagulant to blood will be off, which will somehow render the blood unusable for donation purposes. The nurse suggested that perhaps I had not been hydrated enough, making my blood was unusually thick. She said I should try to drink a lot of water next time. I left disappointed, but determined to try again.

Which brings us to this morning. I spent all week making sure I was drinking ~8 glasses of water a day, loaded up on fluids this morning, and walked into the donation center to make my great comeback. I warned my nurse about what happened last time, told her how I’d been drinking lots of water, and she made preparations to better coax out my blood. If you’ve ever held my hands, you know that they are typically pretty cold. I think I have poor circulation in my extremities due to low blood pressure, small arteries/veins, or something. Heat should help keep the veins from constricting too much, so I’m told, so the nurse gave me a microwaved bag of fluid to hold in my hand, instead of a squeezy toy. Aside from hydration, blood pressure (mine is a tad lower than average, but not by all that much), and heat, another factor that could affect the flow rate is the placement of the IV needle. My nurse clearly had many years of experience doing this, and she expertly slid the needle in place. It was quick and almost painless. She monitored the flow closely.

Things were going fine for a while. Then, about halfway through the donation, my blood decided to slack off again. She piled on more warm bags of fluid, did something to the tube that was supposed to help move the blood along, rubbed my arm, even gently changed the needle’s orientation a little, all to no avail. A couple of other nurses came over and puzzled over the problem, suggesting different things to one another as to how to get my blood flowing better. Everything seemed to have been tried. Again, we had to abort. I had not quite filled the collection bag halfway. The nurses shrugged and apologized that my donation hadn’t worked out, and I apologized that my blood was so lazy. The only other thing they could think to suggest is that I try to use a vein in my other arm (all three attempts so far have been using my left arm). As I walked out, nurses were still shaking their heads: “. . . never seen that happen two times in a row!” Great.

It occurs to me that I am not a physically impressive specimen of humankind. My visual acuity is 20/400, I recently learned that I have flat feet, and apparently I can’t even bleed right. What am I, some sort of mummy? At least I know I’m not very likely to bleed to death.

I do intend to try again. This is something small I can do to try and help other people. Besides, its personal now. What, my blood isn’t good enough for you? You want my blood? TAKE MY BLOOD!

Wednesday, September 07, 2005

The answer, my friend, is blowin in the (solar) wind. . .

One of the challenges of being a graduate student in science is developing the skill to communicate your research to people of varying backgrounds. If a space physicist from another university asks me about what I'm working on, they get a fairly different answer than would a scientist in a different field, let alone another grad student, a non-scientist, a friend, a family member, or a barber. As many of my professors have told me: effective communication is all about knowing your audience. What are they really asking when they ask what you're doing, and what level of detail will allow them to understand, instead of just boring them enough to make them change the subject?

This is a skill I don't think I've mastered yet, and I'm trying to get better at it. Teachers and media spokesmen (news reporters, for example) have mastered this skill, and I admire them for it. What good is science (or information, for that matter) if you can't disperse the knowledge among many people?

Today, my friend Dave (sits in the cubicle next to mine, has the same advisor, and is a much better teacher than I am) forwarded me this link:


  • It has several little Flash games about space physics and space weather. You can have the Sun fire a coronal mass ejection (CME) at the Earth, and see what sort of damage it causes. You can play a neat mini-golf game that teaches you how charged particles move in electric and magnetic fields. I swear, you don't have to be a nerd to enjoy these things (but it helps).

    Explaining something so the person understands it is one thing, doing it well enough that they get interested is another, and making something fun. . . well, that's priceless. See, you can learn something from a computer game!

    Monday, September 05, 2005

    Messenger of the Gods

    MESSENGER is a NASA spacecraft whose mission is to study the planet Mercury from orbit. It should make its first flyby of the planet in 2008, and eventually enter a stable orbit in 2011. In the mean time, it has to get there, and it does so by making “gravitational assist” maneuvers near Earth and Venus. Because the spacecraft has to lose energy to go from Earth’s orbit to Mercury’s, it flies by Earth and Venus on their interior sides; that is, on the sides facing the sun. By doing this, it loses a little bit of its angular momentum to the planet, resulting in a lower energy orbit that brings it closer to the Sun, and hence closer to Mercury. (Note: spacecraft headed toward the outer solar system will do just the opposite, flying by the exterior side of Earth, Mars, or Jupiter in order to steal some of the planet’s angular momentum, and gain a higher radius, higher energy orbit. Since the ratio of spacecraft mass to planet mass is extremely small, the change in the planet’s orbit is not significant.) This clever way of navigating the solar system saves propellant, and likewise a little bit of taxpayer money. (the mission costs < $300 million, a bargain for an interplanetary mission)

    Last month, while we were busying ourselves with our hectic lives involving family, friends, work, food, driving on the freeway, and television, the MESSENGER spacecraft was making just such a maneuver near the Earth. While it was leaving the vicinity of our planet, it took a series of photographs with its wide angle camera. These images have been strung together to form a little movie of the Earth as seen by the spacecraft, as it goes from near the orbit of geosynchronous satellites to past the orbit of the Moon, in a little less than 24 hours time.

    Views like this are one of the reasons I love space exploration.