Successful Launch!

In my last post I talked about building a rocket. This past weekend I actually flew it! I went out to the middle of nowhere in Eastern Oregon for Oregon Rocketry's “Summer Skies” launch. My plan was to launch with an H motor and then a J to get my level 1 and level 2 TRA certifications. I was also there to help Portland State Aerospace Society launch their much larger rocket. Both rockets were a success, though each with their own caveat. Regardless I had a blast!

Setting up

The night before I prepared my rocket, getting the chute folded and all the parts put into place. I also calculated the stability using OpenRocket and decided to add some weight to the nose to offset all the weight of all the epoxy in the tail.

Rocket and its components laid out.

The rocket and its components laid out.

Then it was off to Brothers Oregon, or at least some empty piece of desert nearby. I discovered upon arriving that the different altitude/temperature/humidity/something had changed the nosecone fit. I ended up spending an hour sanding it down so it fit better. But after that all I had to do was load the first engine and fly!

All loaded and ready to go

All loaded and ready to go

On the pad waiting to launch

On the pad waiting to launch.

Liftoff!

Liftoff!

Safe back on the ground

Safe back on the ground.

The first flight was nearly perfect! My delay charge was a little too long and so the chute opened a little after apogee. But otherwise it was did exactly what it should have done: go up about 1000 feet and land a little ways away unharmed. Level 1 achieved!

I'm pretty happy that it flew well!

I'm pretty happy that it flew well!

Level 2

Level 2 requires taking a test and flying a rocket on a larger motor. The test was no problem, but a larger motor means bigger forces, more speed and more things that can go wrong. After checking over my rocket I decided that it was still in prime condition so I loaded up the larger J335 motor (75 lbs of thrust for 2 seconds) and flew it again. This time the rocket would go to an altitude of about 3000 feet.

Liftoff for level 2 flight

Liftoff for the second time in a day!

The takeoff was beautiful! If you're wondering, the launch rail was tilted to compensate for wind. 10 seconds later I was expecting to see a chute, but for the second time it was late! In fact a bunch of people that day had the same problem. We are beginning to suspect that some our motor delays were mislabeled. At any rate the chute did open and I could see it come down in binoculars.

Falling on drogue.

Falling on drogue.

But when I got to it (this time it came down over half a mile away) I found out that the top had “zippered”. What happened is that the since the chute didn't open at apogee the rocket started to fall and had picket up so much speed that when the chute opened the chord yanked the cardboard body tube around and cut into it.

Oh no!

Oh no!

Oh well, it turns out that it's still flyable, all I have to do is trim the tube a little. And because it's still flyable I still got my level 2 certification!

PSAS

By this point I was pretty tired so I called it a night. Unfortunately there was a full moon that night so there wasn't much to see star-wise. Someone brought a telescope and we looked at Saturn which was beautiful. The next morning everyone got up and worked on the main even: Portland State Aerospace Society's LV2c rocket. Equipped with cameras, flight computers, an electronic roll control system and a massive N2000 motor this 70 pound behemoth blasted 15,700 feet into the air. A lot more info can be found on their launch data page. Here is a video of the launch from about a mile away on a nearby hill:

More Rockets

I plan to continue working with PSAS and hopefully launch another big rocket in September in Black Rock Desert, Nevada. Until then I work on understanding the complex interaction between roll control canards and rear fins, which turned out to be more problematic than anticipated (on PSAS's rocket). I don't know if I'll fix up and fly mine again. Maybe someday.

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Rocket Build Log

Until the weather turned ugly I was planning on flying a rocket big enough to get level 1 and level 2 TRA certification this weekend. While it looks like I will have to hold off until next month, I can at least share a short build log.

The rocket is a kit from Giant-leap rocketry. It comes with a nose cone, body tube, motor retainer and centering rings, and fins all cut out and ready to assemble. It also comes with a parachute and shock cord, Kevlar wadding, and launch lugs. In other words it comes with everything except fuel, epoxy, and patience.

The kit the way it arrived.

The kit the way it arrived.

Unfortunately, for reasons that are too complicated to explain here, I was not able to take photographs of the first few steps. So I pick up after having put the motor retainer and centering rings in the base of the tube and tacking the fins in with a little bit of epoxy. The next step is to really glue the fins in. And I mean really glue them in.

Epoxy everywhere

Epoxy everywhere

This involves adding thick epoxy fillets to each fin interface. The outside is actually the least important in terms of strength, but a sharp transition is bad for aerodynamics. So I added a fillet made of epoxy mixed with millions of micro-balloons—microscopic, vacuum-filled plastic spheres. This keeps the mixture light, but add lots of volume.

Masking around a fillet that is ready to be poured.

Masking around a fillet that is ready to be poured.

A finished fillet.

A finished fillet.

The next step is to put the final centering ring in the base. I used JB weld instead of standard epoxy because this part can get very hot from rocket exhaust. Most epoxies are destroyed by heat, so be sure to use something heat tolerant.

The bottom centering ring.

The bottom centering ring.

After that construction is pretty much complete. All that's left to do is paint. I started with a couple of coats of primer followed by three coats of flat white.

Ready to paint

Ready to paint

Flat white

Finished coat of white paint

Then I did some personalizing. I channeled a Mercury Redstone and added some test pattern checkerboards in black. I also painted the nose cone black at this point.

Masked for black paint

Masked for black paint

All that was left was to add the launch lugs and add some stickers.

The finished rocket

The finished rocket

When I go to launch I'll slide the motor in and stuff the parachute and wadding in the top. Then hopefully it'll fly straight up 3,000 feet! I will follow up with a post with pictures, and possibly even a video of the launch—which at the moment looks like will happen the last weekend in June.

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Open Source Bridge

I'm speaking at Open Source Bridge, June 1-4 2010 This year I'm lucky enough to be speaking at Open Source Bridge. OSBridge started in 2009 when the popular OSCON conference was held in San Jose instead of Portland. A bunch of local programmer types wanted something local to fill the gap left by OSCON. So, thus, OSBridge was formed. It's run entirely by volunteers, true to the open source spirit. This year there are a ton of great speakers on topics ranging from writing faster PHP to how to run a business based on open source software.

Open Source Rockets

What am I going to be talking about? Rockets of course! Andrew Greenberg, the sort-of project manager of Portland State Aerospace Society, and I are going to be giving an overview of the work PSAS has done in the last few years to design and build an advanced amateur rocket. In fact we are planning a launch next weekend (May 22–23, 2010) at Oregon Rocketry's Brothers launch site.

If you're in Portland or nearby and interested in open source software issues you should come to Open Source Bridge. And don't forget, if you can't afford the full price you can always volunteer. I hope to see you there!

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Drawing Stream Graphs

The concept of “stream graphs” were widely popularized by the New York Times when they published a now famous graphic of box office numbers over time using a stream graph, which is a stacked area graph that is displaced around the x-axis to make an organic flowing shape.

A stream graph

A simple, example stream graph

I think I first saw a stream graph that Amber Case was showing off after coming back from a conference. She was using a web based app that someone had wrote that graphed the most used words on twitter about a particular search term.

Use Case: Twitter

Another place where there is lots of volatile data is twitter. In fact several years ago someone wrote a program to search the last 1000 tweets containing some search term and then draw a graph showing words inside those tweets popularity over time. The result was surprisingly effective at showing conferences because the graph would grow and shrink roughly in proportion with how good a speaker was, and what he or she said that was most interesting.

Twitter data

A stream graph of the tweets during one morning of the recent Emerging Communications Conference

In general stream graphs are good for any kind of bin-able data that evolves complexly over time.

The Problem

The problem with the web app Amber was using is that it's pretty limited. There is no way to go further back than the last 1000 tweets and any data that is collected is immediately graphed, instead of being saved for further breaking down and analysis. Plus there is no way to change the colors or scaling.

I wanted to help. It took me a while to figure out where to start. Eventually I found a paper filled with wonderful mathematical descriptions of how to draw stream graphs. And at the same time I discovered how easy it is to write in python. So I wrote a simple python class that would take some arbitrary set of data (a list of a list of points) and draw a pretty stream graph in SVG.

You can too!

Amber's friend Aaron Parecki is a Portland based developer who took my stream graph class and, using his twitter API key and database skills, finally fix Amber's conference graphing woes. I open sourced my code at github where you too can start making stream graphs of your own out of any data you want.

Amber, Aaron and I presented an overview of our work at the Portland DataViz users group in Portland, Oregon on April 29th. You can see the slides to my part of the talk here:

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Space at SXSW

I was lucky enough this past week to be a part of the South by Southwest (SXSW) Interactive conference in Austin TX. For the uninitiated SXSW is a film and music festival plus a conference about internet business and culture. It's a mecca for all things cool and new on the web. There is so much that goes on there that it's impossible to attend any more than a small fraction of the planned events. This year included some panel talks that directly involved space and science. In my opinion the best one was Moon 2.0: The Outer Limits of Lunar Exploration.

To the Moon

The panel was made up of 5 people representing the diversity of ways that both NASA and private space companies have used social media to reach out to the public and generate interest in space travel. They also talked about the future of space travel — both manned and unmanned — and their thoughts about private space ventures taking the lead in innovation while allowing more people than ever to be involved directly in, and getting to, space.

There were two people on the panel who represented NASA and how they have embraced services like twitter and facebook to try and rekindle the public's love of space travel. Veronica McGregor works for NASA JPL and got the ball rolling in 2008 by creating a twitter account for the mars lander Pheonix. She gave the lander a personality by tweeting about the science it was doing in an engaging and often humorous fashion. It was so successful in getting the public's attention that NASA started creating similar accounts for all it's robotic interplanetary missions. We also heard from Nick Skytland — a project manager in Houston who works with the manned spaceflight missions. He showed how the Astronauts have been able to use twitter to directly connect with people and not just while they are on the ground training, but in space too thanks to a real time internet downlink added to the ISS in January of this year.

Astro_Mike tweets about readjusting to gravity

Astro_Mike tweets about readjusting to gravity

NASA isn't the only player in space anymore. We now have several private space companies developing both manned and unmanned missions. One such group is Masten Space Systems based in Mojave California. The company is headed up by David Masten who was also on the panel. He talked about his company's involvement in one of the many challenge prizes that have popped up recently in an attempt to kick-start the private space industry. Masten won the million dollar level two lunar lander challenge this past year.

Speaking of challenge prizes another panelist was Amanda Stiles who works for the Google Lunar X Prize, a $20 million dollar prize for the first team who can land a robot on the Moon that can move at least 500 meters and send back at least 1 Gigabyte of HD image data. This is just one prize in a long history of prizes that have spurred on innovation and even created entirely new markets. There are currently at least 20 teams competing for the prize.

The final speaker Cariann Higginbotham is co-owner and co-host of spacevidcast.com, a popular podcast that covers all things space. She and her husband formed spacevidcast and share videos of shuttle launches and other important events live on the web. She talked about how NASA and the major media outlets have made space commonplace, but not in a good way. She has worked hard to remind us that launching something into space is an amazing achievement even if it happens fairly often. And people have been listening, the web has proven a great place for like-minded people to get together and talk about a subject they are excited about.

To Infinity and Beyond

It used to be [that we thought in the future] that an astronaut wouldn't be a job, but a certification to do some other, normal job.
David Maston - SXSW 2010

The one thing all the panelists have in common is the belief that space will play a big part of the future and that it will be more collaborative, more international, and more participatory. Dave Masten pointed out that during the Apollo years we thought we could do anything, and that everyone who wanted to could live space, even if all they did a normal job. There would be a place for the accountants and the janitors in space too. But during Apollo our investment in NASA was about 5% of the national budget, while now it's less than 1% percent. Somewhere in between we won the space race, but lost interest. Now we are entering a new era of private space and renewed public interest.

Technology has now come far enough that smart, dedicated people can start building advanced rockets in their garages. In fact that's what I do. We no longer have to rely on large institutionalized space programs to get to space. It's a very exciting time to be a rocket scientist.

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    I'm speaking at Open Source Bridge - June 1–4, 2010 - Portland, OR