Rick Swift & Apple & Embedded I make things. Sometimes, I’ll talk about it here.

Filed Under #Space

High Altitude Balloon Flight

High Altitude Balloon Flight featured image

Vandenberg Shuttle Launch Complex

Not many people know that once upon a time, NASA built a Space Shuttle Launch Complex at Vandenberg Air Force Base in California, 1985. It was later dismantled, and no Shuttle was ever launched. Oh, how I wish they had kept it! I would've seen so many more launches, not having to travel across the country for each one.

Spaceflight Now has posted a series of articles with lots of photos from the era. Really great stuff.

Looks fake, doesn't it? It's not. It was built.

Each of these articles has a whole slew of images:

Balloon Controller

I'm probably just procrastinating a bit before getting into writing firmware for this thing, but I though I'd post a picture of the Balloon Controller with nearly everything populated. I'm still waiting for the barometric pressure sensor and GPS connector to arrive, but everything else is installed.

Balloon Controller

I've verified that everything powers up, but beyond that, I have no idea if anything works. I was able to flash the MC with a blinky LED program, though, so that's a good start.

UPDATE (15:38): Got the DBGU serial port work. Note that this board has two USB ports. One for the MC proper, and one for an FTDI chip attached to the SAM7X's DBGU port. This was easier than writing a Mac OS X virtual serial port driver against the MC's USB port.

DBGU Port Working

UPDATE (18:27): Got the battery voltage being measured, and also got the radio link working!

It's a little cumbersome to flash the MC when you have an external power source, because it needs to power cycle to re-enumerate the USB and set up for download. So I pulled the fuse that USB bus power goes through, which means that I only have to disconnect the main power supply to power cycle it, rather than disconnect that and unplug the USB cable.

18 km Range Test a Success

Darren and I tried an 18 km range test today with the n920. Amazingly, we had success with just the rubber ducky antennas, and down to 250 mW transmit power on both ends! He was up near this winery, and I was on the fifth floor of Yahoo! building D.

At first we tried the new Yagi, but it didn't seem to work (at all). We were astonished to get a link with just the whip antennas. They didn't even have a proper ground plane, just being stuck out the side of the plastic boxes I had put the gear in (and pointing upward).

Using the ATS123? command to query the receive signal strength, Darren had -88 dBm, I had -105 dBm (measurements varied, but I think that was at 250 mW). I tried sending a file to myself via loopback, < 1 KB in length, which failed the first time and succeeded the second. A 131 KB file failed, and I didn't try it a second time. I could see it dropped stuff from within the file. We'll have to investigate exactly what went on. Are the radios full duplex? How big are their buffers? It seemed to send the entire file before receiving anything, but that could've been an artifact of PortTermX.

Interestingly, the Yagi didn't seem to offer much. It was also nearly impossible to hold while operating the computer. Next time, we need to put it on a stand of some kind.

Hopefully this weekend we'll try a much longer range test, from the winery to Coyote Hills.

New 900 MHz Yagi Arrived

Our balloon experiment is using a 920 MHz frequency-hopping radio link (we also have 2.4 GHz radios, but will probably stick to 920 MHz). The balloon will carry a dipole or vertical bazooka tuned for 920 MHz, but it will be rotating and squirrelly. It will also be 30 - 50 km away. So I decided a good Yagi on the ground will help ensure we maintain our fade margin.

I looked at a couple options from L-Com. The best 900 MHz Yagi they had offered 14 dBi in 109 cm, but was $120. The next best offered 13 dBi for $44, so I bought it. I didn't realize until it arrived that it was 145 cm long!

900 MHz 13 dBi Yagi

So, this will prove to be unwieldy, at best, especially from a moving car. We might decide to have a fixed ground tracking station, but that approach will need investigation.

Radio Link Test 2

I put the n920 slave in a box and left it with a co-worker on the fifth floor of my office building. I took my laptop and the master radio over to our other building, 5 km away, and set up on the sixth floor. My co-worker was on the balcony outside the building, and I was in a conference room inside.

After we powered up the radios, and after I dealt with my radio coming loose from its dev board, we established a link and I was able to send a few characters to the slave. It was set up with a loopback connector, so those bytes came right back.

A query of the master's receive signal strength returned -91 dBm.

Hopefully this weekend we can do a 20 km test.

Balloon Controller v1

I've been hard at work this week on the Balloon Controller. It's an ARM-based embedded system with a bunch of sensors, intended to be flown as a payload on a high-altitude balloon. I'm very nearly finished with the PCB layout, but I thought I'd post a picture of it anyway:


The board features:

  • MakingThings Make Controller
  • Microhard Corp n920 radio comm link
  • GPS
  • Compass
  • Digital altimeter, 10 - 1300 mBar
  • Internal and external temperature sensors (internal is on the altimeter, external is a thermistor)
  • SD Card
  • System battery voltage sensing
  • Two USB ports, one for downloading new code, the other with an FTDI to access the debug serial port
  • Wide supply voltage range, 9 - 28 V (we'll probably use an 11.1V LiPoly pack for R/C cars

This is just a prototype. The next version will feature an Atmel SAM3S MCU instead of the Make Controller, some GPIO, and more refinement. It might even have an image sensor interface and be able to downlink images in real-time. And they'll be available for purchase, although we'll look at alternatives for the communications link, because the n920 radios are fairly expensive.

Stay tuned for updates.

Jumping into Astrophotography with Both Feet

Before you take anything in this post too seriously and drop $5000 (or more) on astronomy gear, know that I have yet to take a really good picture of anything. Partly, this is because I don't have all the stuff I'm going to suggest you get below.
You may find the suggestions below expensive. That's part of why I haven't gotten it all yet. You should know that I don't like to start small. I like to get equipment that makes my life as easy as possible. You may prefer a different approach. Don't let this post discourage you from trying. It's likely you have more patience than I do.
Astrophotography is hard. Shooting bright objects like the moon is easy. Shooting any kind of "deep sky" object, like a nebula, is hard. There is a lot to learn, and a lot of equipment to buy, and you can really go whole-hog. When I was trying to figure this stuff out, I didn't really want to know everything, just the specifics for the kind of equipment I had already bought (a Celestron NexStar 6SE).
So, here's a partial list of stuff to buy to get started. I'm sure you can do better, and I haven't even tried all of these things myself, but it's what I have or will buy next. Note that I assume you're using a Cassegrain telescope.

Okay, I there's more stuff to put on this list, but I'm finding it hard to be specific enough in the short time I want to take to write this. A couple of notes:


The telescope suggested above is both a mount and an optical tube (OTA). I'd probably recommend getting a different OTA, one with the capability of accepting 2" optics on the back. The Sirius EQ-G mount worked well for me for the short time I had it, although I didn't like the computer as much as on the NexStar 6SE mount. However, it will work fine with any number of OTAs. It's often cheaper to buy one of their pre-made combinations, but it might not really be what you want. The actual OTA you get is (in my inexperienced opinion) less important than the mount, the focuser, and the camera. But the more serious accessories are 2", and you can always add an adaptor to get down to the 1.25" stuff.
Oh, and get the GPS accessory to save you time and reduce errors when setting up.


The focuser mentioned above seems like a first-rate device, but I don't have one yet. Ideally, you want electric, computer-controlled focusing. Focusing is the single hardest part of shooting images, and I can't stress enough how much frustration I've encountered with it. I very much want computer-controlled focusing, and as a beginning step, I would get a focuser that at least has an electric motor on it that I can control manually. This keeps you from touching the telescope and making it shake.
There is so much backlash in the worm gear on the built-in focus in the SCT OTA, it's very hard to use it to focus. Adding the Crayford-style focuser should vastly improve your ability to focus, and I won't try to take pictures again until I have one.
Buying a focuser from those guys requires knowing exactly what telescope you have. There are like three different things to order: the focuser itself, the adaptor for your specific telescope, and the remote focus motor and electronics. After you settle on a telescope, call them and they should be helpful in getting you the right focuser.
Before buying the focuser, try shooting without it on your scope, and see what your results are. Pretty soon, you'll be wanting one.


There are many choices in cameras. If you have a nice DSLR, you'll probably want to use that. I borrowed a friend's for a while, but finally bought a low-res video camera from The Imaging Source. His DSLR was a little too old to be well-controlled by the computer. The key is to be able to have the computer see what the camera sees, with rapid frame updates, to make it easier to focus. Once that's done, you want the computer to be able to control the camera's shutter and exposure, so that you can remotely trigger it, and not shake the OTA.


Once you start taking pictures that need more than a few (10 - 30) seconds' exposure, you're going to need to autoguide your telescope. This requires a second camera. Fortunately, this camera can be cheaper and lower-quality, and ideally is black and white.
While your main imaging camera has its shutter open and is accumulating photons, it can't send back data to the computer. The second camera takes short exposures of brighter stars, and uses the movement of those stars to move the telescope while the main camera is still exposing. You can easily need to take several hour-long exposures to get a really good deep-sky image, and for this, autoguiding is a requirement (simple open-loop tracking isn't good enough, and you'll get smearing).
I have no recommendations for autoguiding, because I've never gotten good enough at focusing to even consider it. You'll need a little OTA attached to your main OTA for it, and you'll need a camera and software compatible with your computer (I use a Mac, and most of this stuff is designed for PCs).
But you can take some nice images with good focus and your mount's tracking before spending money on autoguiding.

More Stuff

There's so much more to learn. Get Ron Wodowski's The New CCD Astronomy to learn it all. For example, the best pictures are taken with very sensitive B&W cameras, and color filters are used. You shoot four separate images, three with RGB filters and one for luminance, and then combine them in software.
There's stuff about periodic error correction (PEC) and other elements of the tracking mount drive train to improve tracking.
There's stuff about cooling your imaging device to reduce thermal noise in the sensor.
There's stuff about shooting dark frames to remove noise from defects in your sensor (this you can do with any setup, and is fairly easy: just put the cover on your telescope, and shoot a frame, then subtract that from your results in software).

Tracking Antenna Mount

This weekend I'm working on a tracking antenna mount that we'll be using for our UAV and balloon tests in the next few weeks (months?).


Block diagram:


Here's what's inside. A MakeController and an alt-az gimbal mount that I don't think is available any longer.


The ports. Ethernet and USB (not sure which I'll implement) for the ground control computer to connect to, and power (may not be used either).


Here are the other parts. GPS (EM-408) , compass module (HMC6352), external GPS antenna (with a little MMCX to SMA pigtail):


Closeup of the GPS and compass module:


Getting all the stuff mounted in the enclosure has been a pain, and has taken much of the day (plus the Cal game, and other stuff). There's a lot of wiring to do still, and hopefully I'll actually get some code written this weekend. Stay tuned!

Launching a Balloon

I've seen a lot of reports lately of recent and past amateur balloon launches. People have been launching sounding balloons with payloads containing GPS and cameras, and have been very successful. I've wanted to do this for some time, and coming across all these reports has excited me about the idea again.
Really what I want to do is launch a satellite. So I've decided to expand the scope of the balloon launch in support of a future satellite launch. I've ordered the Microhard radio we'll be using on the satellite to test on the balloon.
We're going to build a payload with GPS, temperature, pressure, still pictures, and possibly video. Lots of work to do in the link budget calculation to see what we can do, and within the 1.8-kg payload FAA limit. We're also building a directional 2.4 GHz antenna to automatically point at the thing (a project I began a couple years ago for UAV use).
This is going to be fun. Check back for updates.

Watching NASA on Snow Leopard

UPDATED: 2009-10-19
I'm not sure for how long this little tip will work. I figure when Akamai & Apple catch on to the fact that people are watching a stream they intended for the iPhone, they'll put a stop to it.
But in the meantime, you can watch a very high quality stream of NASA TV in Snow Leopard's QuickTime X Player. Just launch QuickTime Player, go to the File menu and choose “Open URL…”. Then enter the following URI:


Old URI: http://qthttp.akamai.com.edgesuite.net/iphone_source/yahoo/nasa/nasa_all.m3u8

You can also follow along with STS-128 with MissionClock for iPhone and iPod Touch.
I've been watching for the past hour or so, and it's not without its problems. It's about 45 seconds behind Spacevidcast, which seems to be the lowest-latency stream available. Every now and again it will stop momentarily. Sometimes the window shrinks and turns black for a while, then comes back. But overall, it's a high-quality image that should work on a variety of connections, and doesn't suck down CPU like watching in a Flash player. However, it does cause the fans in my Aluminum MacBook Pro 2.5 GHz Core2Duo to run a little bit, and I suspect Apple could do some work to improve this.

Stream overload during LRO/LCROSS launch

I'm sitting here suddenly overwhelmed at the utter coolness of what I'm doing. I'm sitting at my desk in my home office, "working from home," as NASA's LRO/LCROSS mission prepares for launch in a few hours. In front of me is a 22" Apple Cinema Display attached to a 15" Aluminum MacBook Pro (Core 2 Duo, 2.5 GHz).
Thanks to NASA and Spacevidcast, playing on my desktop I have no less than six video streams, some with multiple angles, showing me the rocket and various other video. Thanks to ScanAmerica, I'm listening to the Kennedy Space Center ground loops via iTunes internet radio streaming. A NASA Java applet shows the Atlas countdown information. I'm chatting with friends via AIM, Yahoo! Messenger, and GTalk, as well as Spacevidcast's chat room. I'm following NASA agencies and employees via Twitter. And I have my as-yet-unfinished iPhone app MissionClock counting down to LRO. It looks like this:

Stream overload 1

This is all cool by itself, but every now and again I get a tweet like this one from Andy, who works cryogenics (fuel) and other things on the launch pad:

Been on the tower for the last 5 hrs. Finally got down and now they are kicking us out for the Atlas launch.

They just started the go/no-go poll. Time to do some real work while I listen/watch. Weather is a bit of a concern, here's hoping it holds!
One last bit of commentary: this ULA/Atlas launch has a lot more transparency/awesome geek factor than NASA Shuttle launches. I get to see a lot more info, and hear a lot more. I hope the Shuttle public outreach can surpass that of the Atlas someday soon. There aren't many opportunities left!

University Satellite Delfi-C3 Successfully Deployed

The Delft University of Technology in the Netherlands successfully launched and deployed a 3U Cubesat called "Delfi-C3", into polar low-Earth orbit. Because it carries no batteries, it only operates when not in eclipse. We on the West coast of the United States, and those in Alaska, were the first ones able to hear it. I was unable to hear it on its first pass at around 0455 UTC (2155 local), but they encouraged me to try again for the second pass, at around 0631 UTC. I finally heard it at 06:39:08 (give or take a second or two). (Pictures of the satellite.)
I had almost given up, when I remembered to try the backup frequency, and voilà! There it was! I was able record audio (received by an ICOM IC-R1500 connected to my Mac via USB, recording into QuickTime Player at the device-native format) and send it to the team.
And I just got off the phone with Wouter! He called me to thank me for sending them the audio file, and to tell me that it was, in fact, Delfi-C3, and that I am the first person to hear it. He says this confirms that it is operating in Science mode on the backup frequency. Sadly, it appears that my recording was too noisy to allow any telemetry to be decoded.
What a rush! I'm so thrilled for those guys, and thrilled to have suddenly been a real, if small, part. Wouter tells me they are all very happy to hear that their satellite is alive and well.
Congrats, guys!

iPhotos of Saturn

I snapped these by holding my iPhone, with its crummy, scratched-up lens, up to the eyepiece of my little telescope. The cold wind was shaking the scope and making me shiver. The actual view was much better, but I was surprised enough to get these that I decided to post them here.
I tried with my digicam, but gave up too soon; I couldn't get it to show up at all.

IMG_0108.JPG IMG_0109.JPG IMG_0110.JPG

My first amateur radio contact ever, with Astronaut Dan Tani aboard the International Space Station

On February 6, 2008, I had the great honor of making radio contact with Astronaut Daniel Tani, as he flew overhead aboard the International Space Station (ISS). This was one of the most exciting and awesomely cool things I've ever gotten to do. It was my first voice ham radio contact ever, and after a great deal of help from the tireless Kenneth Ransom, Dan and I finally managed to schedule a time to chat.
Today I received permission to post publicly a photo, taken by Cosmonaut Yuri Malenchenko, of Dan while he was talking to me:

Dan Tani floating sideways in microgravity aboard ISS

Almost as cool was the email I got from space when I was first trying to schedule the contact with Dan. It was a bit of a challenge, because you need line-of-sight in order to establish radio communications at the frequencies we were using (144 MHz, also known as 2 meter). This means that the contact has to occur during a pass. Since ISS orbits the Earth once every 90 minutes, and the Earth itself rotates during that time, it's only overhead during certain times of the day, and those times are different every day.
Add to that the fact that Dan is an incredibly busy person up there, so we had to find a time when he was both off duty and ISS was in sight. Around 1600 PST on February 6th that finally happened (I think Dan stayed up late to make it happen, and for that I thank him). We were able to chat for about 9 minutes, and it was great fun.
Thanks again to Kenneth Ransom, Yuri Malenchenko, and Mike Kobb (who assisted on the ground as my antenna tracker).
I had the privilege to go to Florida to see Dan's first shuttle mission launch (STS-108). I lack the words to express my extreme appreciation of Dan, for making that possible, and for taking the time to do this with me. From the bottom of my heart, thank you, Dan!

Uh...Windoze in Space?

I’ve been watching a lot of NASA TV lately (always do when the Shuttle visits the ISS, although probably more this time than previously).
One thing I’ve noticed a lot more this trip than any other: lots of stupid issues with Microsoft Windoze software. Problems getting email, problems getting printers to print, etc.
Now, I’ve seen lots of Macs in use at NASA. You can see them in Mission Control on NASA TV. You can see them in photos of the various labs all over the country.
Why aren’t they using Macs in orbit? I know Macs have their share of problems, too, but seriously. Email, word documents, printing…this kind of stuff works much, much better on a Mac than it does on Windows (if you don’t think so, you’re a fucking moron and should be sterilized to keep you from reproducing). Plus, you get the benefits of a virus-free OS. I know if I were in space, that’s what I’d want.

Boo. SpaceX Scrubbed for the Day

As of 1712, they are beginning scrub procedures. This means they will not launch today, and it sounds like they may not launch for 24-48 hours. They will begin de-tanking (removing fuel) shortly. Sigh.

Damn. SpaceX Abort

Demo Flight 2 has been aborted with less than 3 minutes to go. The rocket was secured (a pretty exciting process to watch and listen to), and the countdown stopped at T -00:01:02. I'm still waiting to see what the outcome is.
They're just now saying they're going to spend the next 10 minutes to assess why they aborted.

SpaceX Launch in 5 Minutes

This is very exciting. I'm watching the webcast right now. I hope it goes well...

SpaceX Experiences Setback

The coolest company around made their first launch attempt today, but flight lasted only a minute. Nevertheless, I hope they succeed on their next attempt, and I sent them a small note of encouragement.
Coolest thing? I got a personal response (from the PR person, to whom I sent the note):

Thanks so much for your kind words of support. The entire team at
SpaceX greatly appreciates it.

Best regards,

Awesome. I want to work there.

Coolest R/C plane ever

I thought the A-10 was cool, but this beats it: An R/C A380, with four microturbine engines.

Welcome Home, Discovery!

Beautiful landing, Cmdr. Collins! Welcome home. Congratulations to all!

NASA Flies Again

A stunning and awesome return to flight liftoff at 7:39 AM, PDT. STS-114 couldn't have asked for a more beautiful day for a more perfect launch. Plus, the new cameras made for some kickass views!
Congratulations to NASA and to the thousands of people who helped make it a success!

Nice to know NASA's well on its way to stupidity

In this Reuters article, NASA's new administrator talks about how we won't get to the moon 'til 2015 at the earliest, and that that mission will likely be followed by a multinational space station on the moon.

There's nothing on the moon worth the money and the time. It would make much more sense to go straight to Mars, skipping the Moon entirely. We could land humans on Mars by 2015, and have a regular rotating mission every two years, for about a tenth of the cost of the proposed Moon missions.

Bush fucks everything up.

I Always Thought the Japanese Were Smarter than We Americans

But not I'm not so confident of the assessment. Sure, they've got some wacky cultural surprises (Japscat? Eeesh), but generally the Japanese employ wisdom and elegance in their endeavors. So, why would they jump on the same wasteful space exploration initiative as the U.S.? Why take two decades to go to the moon, when they could go straight to Mars in half that time?

Our political leaders need to recognize the merits of a human Mars exploration program, and they need to set the goal of accomplishing serious scientific research on Mars.

Aaron Sorkin on Why We Should Go to Mars

In the episode of West Wing entitled "Galileo," one of the plot lines centers around an unmanned probe, sent to Mars, with which NASA has lost contact. Mallory and Sam are standing beside a limo outside a concert hall, and they have this exchange:

Mallory: "I spoke to my dad. I'm sorry about Galileo."

Sam: "They've got a lot of tests they can still try."

Mallory: "How much money is it going to cost to try them?"

Sam: "Don't start with me."

Mallory: "I'm asking as a taxpayer! It costs a hundred-sixty-five million to lose the thing, how much more money is it going to cost to make sure you're never going to find it?"

Sam: "I don't know, Mallory, but we certainly won't divert any municipal tax dollars which are always best spent on new hockey arenas." (Sam likes Mallory, Mallory is dating a hockey player.)

Mallory: "No, it's best spent feeding, housing and educating people."

Sam: "There are a lot of hungry people in the world Mal, and none of them are hungry because we went to the Moon. None of them are colder and certainly none of them are dumber because we went to the Moon."

Mallory: "And we went to the Moon. Do we really have to go to Mars?"

Sam: "Yes!"

Mallory: "Why?"

Sam: "'Cause it's next. 'Cause we came out of the cave, and we looked over the hill, and we saw fire. And we crossed the ocean, and we pioneered the west, and we took to the sky.…The history of man is on a timeline of exploration and this is what's next."

Mallory: "I know."

Sam: "People like you, who say tha—what?"

Mallory: "I said, 'I know.' We're supposed to be explorers."

Sam: "Then, what the hell?"

Mallory: "I just like hearing you talk about it."

Sam: "You know something—"

Mallory: "You get all puffed up."

Sam: "You're a pain in the ass."

Mallory: "Yes."

Like so many things of this nature, the impact is much greater when heard. To that end, I've provided an AAC file for it.
Later, CJ and the President are talking about the broader theme they had been trying to come up with. Earlier in the episode, they had arranged to have some sixty-thousand public school students join with the President in a televised classroom event, to watch the probe land. Throughout the course of the episode, the President decided he wanted to expand the theme of the event. At the end of the show, they still didn't know if Galileo Five was okay, but here was more argument for the exploration, in terms of how it captures imaginations and drives people to achieve. By the way, the President had been giving CJ a hard time for not getting into the spirit of exploration, teasing her about the way she said "Galileo Five."

CJ: "Mister President, about that televised classroom for tomorrow—"

The President: "I'm gonna wait up for a while, see if we hear anything. It's out there somewhere. So close."

CJ: "I think you should do the classroom either way."

Pres: "Yeah?"

CJ: "We have, at our disposal, a captive audience of schoolchildren. Some of them don't go to the blackboard or raise their hand 'cause they think they're gonna be wrong. I think you should say to these kids, 'You think you get it wrong sometimes? You should come down here and see how the big boys do it. I think you should tell them you haven't given up hope and that it may turn up, but in the meantime you want NASA to put its best people in the room and you want them to start building Galileo Six. Some of them will laugh, and most of them won't care, but for some, they might honestly see that it's about going to the blackboard and raising your hand. And that's the broader theme."

Pres: "I'll say."

CJ: "I'll be in my office, Mr. President."

Pres: "CJ."

CJ: "Yes, sir?"

Pres: "You said it right that time."

CJ: With a smile, "I'll be in my office."

Pres: After she leaves, looking up at the sky, "Talk to us."

And the audio file.

Mars Direct on West Wing

I think the actors who play the staff on the television show The West Wing should all just play their characters and do the jobs for real. (Too bad the incredible wealth of knowledge the characters possess is probably not available to the actors.)
In the episode entitled "Ghengis Kahn," Josh Lyman, the White House Deputy Chief of Staff, gains new respect for NASA and space exploration. A character goes so far as to mention Mars Direct by name, and Josh is intrigued enough to listen. He doesn't believe Congress would ever support it, but if someone like that was actually in the White House, Mars Direct could become a reality.
The argument hinged primarily on the incredible inspiration manned space exploration creates. At one point, Josh had to convince his assistant of it, and the dialogue was very nice.
All this from an episode not written by Aaron Sorkin.

Don’t Bother With the Moon

More and more people seem to be fawning over Bush’s ridiculous “vision.” It’s not a vision, it’s political strategery. It is nothing but a waste of money, and the negative impact is already being felt, as evidenced by the recent announcement to abandon Hubble. (I only reference one article referring to the announcement).