SpaceBlogging

Sounds like my in-house Rocket Scientist/Super Model is busy this afternoon, so I’ll put up the space updates.

First, the mysterious X-37B is also taking along a not so hush-hush experiment. The METIS is similar to other tests such as LDF and MISSE on the reaction of various materials exposed to space for varying durations.

Building on more than a decade of data from International Space Station (ISS) research, NASA is expanding its materials science research by flying an experiment on the U.S. Air Force X-37B space plane.

By flying the Materials Exposure and Technology Innovation in Space (METIS) investigation on the X-37B, materials scientists have the opportunity to expose almost 100 different materials samples to the space environment for more than 200 days. METIS is building on data acquired during the Materials on International Space Station Experiment (MISSE), which flew more than 4,000 samples in space from 2001 to 2013.

“By exposing materials to space and returning the samples to Earth, we gain valuable data about how the materials hold up in the environment in which they will have to operate,” said Miria Finckenor, the co-investigator on the MISSE experiment and principal investigator for METIS at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “Spacecraft designers can use this information to choose the best material for specific applications, such as thermal protection or antennas or any other space hardware.”

We’re curious about something not mentioned in the release. How different is the orbit of the X-37B from the ISS, in terms of both altitude and inclination, and what effects might that have on the exposed materials?

Next up, Space-X. We’ve all enjoyed watching Elon Musk’s Falcon 9 attempt to safely land after orbital launch missions. Looks like they’ll try again in June. But the other major endeavor underway at Space-X is to crew certify a manned spacecraft. And one of the key tests for that is the pad abort. We’ve all seen the escape tower atop Mercury and Apollo capsules. Space-X uses a rather different approach with their manned variant of the Dragon spacecraft.

[youtube https://www.youtube.com/watch?v=5bhW2h08zhY]

That’s an unmanned test, but I’m thinking Space-X could make some money selling that as a carnival ride.

Dragon Guided Missile

Test firing a Dragon

[vodpod id=Groupvideo.1572793&w=425&h=350&fv=]

more about “LiveLeak.com – Firing A Dragon“, posted with vodpod
The dragon has been removed from service and replaced by the Javelin, but I have fond memories of being a Dragon gunner. Mostly I wanted to test my vodpod skills at posting a liveleak video.

Dragon Tales

One of the jobs I had when I was a young troop was Dragon Gunner. By the time I was a Dragon Gunner, they were pretty long in the tooth and not very highly thought of. But think about this: back before you could buy a pocket calculator, the Army had fielded a guided missile that could reach out and destroy a tank over half a mile away, and yet was small enough and light enough for one man to carry.

The Dragon, or M47 Medium Anti-Armor/Assualt Weapon, was first issued in 1975. It was a man portable guided missile that used wire guidance technology called SACLOS-Semi-Automatic Command Line of Sight. Basically, when the missile was launched, it trailed to very thin coppper wires behind it. It also had a flare in the rear of the missile. The sight unit tracked the flare and saw if the flare was in the crosshairs or not. If the missile was not in the cross hairs, the sight sent a signal by way of the wires for the missile to go up, down, left, or right. All you had to do to guide the missile was keep the crosshairs on the target. But that is easier said than done. Dragon gunners spent a lot of time practicing this skill. Since the missile cost about $10,000, they didn’t let us shoot all that many for practice. Usually, a device that fired a powerful blank cartridge was used. One of the other things that made it tough to aim was the launch itself. The missile used a small rocket to propel itself out of the launch tube.

[youtube=http://youtube.com/watch?v=xu7HjKR4I3U]

That’s a missile being shot from a test stand. In real life, it looks pretty much the same and it takes practicee to avoid flinching. If you flinch, you tend to point the sights at the dirt. The missile quickly obeys and flies right into the dirt. That’s not what you want.

If you look closely at the photo above, you’ll see a bunch of dimples on the side of the missile. These are the rocket motors that fly it to the target. Since the back end of the missile is taken up by the wire spool, the flare and the starter motor, the engineers had to put the sustainer motors somewhere else. Also, they had to figure out a way to control the missile in flight. They came up with an unusual method. There are 32 pairs of motors on the missile. While the Dragon is flying, it is spinning like a bullet. Pairs of motors will fire, sounding like a “pop” to boost it on its way. If the missile is not in the crosshairs, other pairs of motors will fire to push it back onto the right path.

Here’s a video that demonstrates the launch and if you listen closely, you’ll hear the pop-pop-pop.

While the Dragon was a pretty impressive weapon for its day, it had its problems. Its range was only 1000 meters. That’s right about the maximum range of the machine guns mounted on all the vehicles it was shooting at. Since it took 10 seconds  for the missile to fly that far, the bad guys had a fair chance of spotting you and shooting quite a few bullets at you while you tried to guide the missile. They didn’t even have to hit you. If they made you flinch, you’d miss the target. That was the other big problem. You had to keep the crosshairs on an often moving target. Even heavy breathing was enough to make this difficult. Getting shot at didn’t help. Still, it was better than no anti-tank weapon at all.

With these shortcomings in mind, the Army developed the replacement for the Dragon. The Javelin has twice the range, is faster, has a better warhead, and has a fire and forget capability. Once the Javelin gunner fires, he can duck for cover or start reloading while the missile guides itself to the target.

[youtube=http://www.youtube.com/watch?v=8VdRnY-TUb4]