Tag : spacebridge

Time flies like an arrow; fruit flies like a banana. 2010-03-27 10:48:00

10am: the designated meeting time. Noisebridge is empty. Camera battery on table with a plaintive note requesting someone to find a charger. I find the charger in the adjacent box.

10.27am: Chris arrives with a tiny video camera that arrived overnight for the launch. Nils and Ariel have also showed up in the meantime.

10.47am: donut run. Everybody is here. Assembly and final checks begin. Progress hampered by Saturday morning cartoons playing on the projector and PyCon preparations going on around.

11.27am: vox mode on ham radio working; we think both beacons should be visible. Setting up radio end-to-end test. In parallel, payload has been stencilled, trial assembly under way for final weighing. Cast up to 9 people, with at least three more to join on location.

11.47am: my updates are coming with creepy regularity. Still at Noisebridge; assembly of the multipart, multiplane payload is proving more challenging than expected. No APRS beacons have made it out yet, though this may be due to the poor radio permeability of the building.

12.00pm: the PyCon attendees are being very tolerant of our bellowing back and forth across the room while they’re trying to run talks. I’m alternating between shushing people and hiding behind the nearest pillar. Final weight comes in at 4 lbs 5 oz; sadly the stabilizing arms can’t take the weight without bowing alarmingly. Rapid replanning of support structure ensues. Still haven’t tested the radio gear.

12.21pm: packing up for departure. Drift trajectory estimate looks reasonable for our Alpha launch site.

12.56pm: all three cars on the road, connecting inverters and chargers in the car to top up batteries en route.

1.26pm: stuck in traffic near Livermore. So glamorous.

2pm: arrived at the California Qanat Aqueduct site, waiting for traffic-scattered posse. Made a foursquare location.

2.29pm: wind is blowing in an unfortunate direction. Condoms Meteorological

2.45pm: checking skyvector.com confirms that all the local airfields are reporting winds blowing north or north-east. Ozzy uses his pilot contacts to confirm that high-level winds are still blowing towards the east, so we only need to worry about the lowest 15,000 feet of ascent and descent. We decide to get another 10-15 miles east/south-east before launching.

2.59pm: confusion ensues due to phones redirecting to voicemail and partially meshed radio contact between vehicles – cavalcade count now up to 5, and uncertainty if all heads found seats.

3.02pm – interlude: we’re running very late, once again, and although none of the reasons are exactly the same as they were last time, the general problem is that too many individual tasks are still being tweaked, refined (or in some cases started) in the few days before launch. We’re deadline driven, but not very good at planning back from the deadline.

4pm: we spot an airstrip on our way south, and decide to try our luck. After a long and frustrating wait while attempts to contact the airstrip owner via friends of friends are made, the BATF (Bar of Alcohol, Tobacco and Firearms) point out that since they have permission to shoot automatic weapons at the airstrip, they feel entitled to grant us permission to launch a balloon. It’s on.

4.20pm: …or is it? The helium cylinder turns out to have been less than half-full. Perhaps a leaky valve that vented gas over the past month? We have the balloon at approximately neutral buoyancy. So… if we remove the skirt from the balloon, we might be able to cobble together a light enough payload to lift, by duct-taping together a G1, radio and camera. Drama!

4.48pm: Snatching victory from the jaws of defeat, Blake returns from a foraging expedition with a 73 cu ft cylinder of helium, acquired from a local party balloon filling place. The balloon has lift – next we assemble the entire payload string and see how much excess lift we have. If not enough, we’ll have to shave the payload down.

5.09pm: And I thought we launched late last time :P Balloon is filled with all the helium we can get. Electronics are all on, text messages with GPS co-ordinates are coming in; both APRS beacons are being received. Last zip-ties being attached now.

5.24pm: Not enough lift. Luckily, the heaviest camera doesn’t work with the lithium batteries that we bought anyway, so we can remove that. The balloon skirt is also being removed. In worse news, after the first few SMSes, the Android fell silent.

5.57pm: Heartache and angst as people’s favourite projects are ruthlessly culled to reduce weight. Stand-by Android with old SMS code resurrected in the hope that it will send reliably.

6.53pm: not enough lift to clear the trees with even the most minimal payload. We scrub, clean up, and retire to the nearest hotel for food and consolatory champagne.

Categories: Spacebridge, Syndicated

Time flies like an arrow; fruit flies like a banana. 2010-03-26 22:32:00

Friday night before launch, and once again we start from having no working radio beacons. But unlike last time, we have some seriously impressive looking Sputnik-like payload. One of the major worries from the previous launch was the internal temperature, reported at -21C at one point.

This time, we have a solid block of styrofoam with voids carved into it for individual pieces of equipment, some of which are further wrapped in aluminized mylar for additional insulation; some of which have active heating internally in the form of a power resistor across a 9V battery.

We’re optimistic.

Similarly exciting, although we’re flying the same APRS tracker as last time, we also have new APRS softmodem code for the Android, meaning that it will alternate transmitting position updates from its internal GPS with the known-working tracker.

That’s assuming that we can make it work together sensibly by 10am tomorrow, of course.

Other than that, we have extra cameras, including an IR experiment, and random updated bits and pieces. We may even manage to charge the batteries this time.

Categories: Spacebridge, Syndicated

Time flies like an arrow; fruit flies like a banana. 2010-02-08 22:19:00

Declaring a week’s advance notice of a balloon launch to the edge of space when we hadn’t even bought most of the equipment, let alone built it, was probably an act of pique, if not madness. Remarkable how well it worked out, though – just look at the pictures!

The plan was simple: a ham radio broadcasting an APRS position beacon, a GPS that was known to work at high altitudes, a camera hacked for time-lapse photography, and an Android cellphone that we’d program to scream out its own GPS co-ordinates via SMS whenever it caught a glimpse of a cellphone network.

We were buoyed by the unexpected help from all three members of another Space Balloon Project, one of whom Christie had met in line for the checkout at a Ham Radio Outlet, who then showed up at the fateful meeting when the timeline was decided. They’d done it before in style, and even – very bravely! – volunteered their camera and parachute (a donation from rocketchutes.com) for the experiment.

So the work began.
12 hours before our planned launch, Icarus, as Andrew’s phone-home code for the Android had been dubbed, was working beautifully. Everything else was a shambles.
The APRS beacon seemed to be sending, but it wasn’t being received by either our own radios or the public repeaters. Our receiving radios couldn’t pick up either our own or any other APRS beacons. The weather forecast for the Central Valley was miserable, and the FAA says you can’t launch balloons into more than 50% cloud coverage. We hadn’t worked out how to pack the payload safely, nor how to rig it and the parachute to the balloon. Not even the known-working camera was working!
But by 3am of the launch day, the electronics seemed to be functional, and since we had an extra tank of helium and two spare balloons, there was enough of a margin for error to make the rest of it up as we went along.
On arriving in a largely overcast Central Valley in the early afternoon, I rechecked the FAA regulations and found that the 50% cloud cover restriction didn’t apply to payloads as light as ours, so our initial gas station rendezvous point instantly turned into our first launch location.

The gas station was well equipped with many things that we’d forgotten to bring, including miniature weather balloons for testing before the real launch (available in packs of 3, with optional lubrication). The staff were also related to the people who owned the adjacent field, and told us that although they weren’t giving us permission to enter, they also weren’t going to call the police immediately. We were committed.

More problems soon showed up – the radios hadn’t taken a charge overnight, and were dangerously low on battery. The ground station battery failed altogether after receiving a single APRS packet. Our attempt to use expandable foam to hold the components in place in the cooler also failed, leaving us with a soggy mass in a plastic bag with no rigidity. We broke the attachment points on the cooler.

Nonetheless, after jury-rigging a gas regulator out of high-school chemistry supplies (inexplicably present in Christie’s van), we started to fill the balloon. We turned on all the electronics, confirmed that we were receiving both SMS position updates every minute from Icarus and APRS position updates (via Brian’s APRS-capable radio) every 30 seconds, and then, with the balloon almost completely filled and yearning to fly, we proceeded to debate the best way to attach the payload, parachute and balloon together. After filling our quota of rope burns, we were ready to fly – and launch we did, complete with countdown!

Partying ensued, while we watched the balloon soar skywards at a furious pace, and was soon lost in the clouds. The ebullience muted a little when we discovered that the APRS data wasn’t being seen by any of the area digipeaters, although Brian’s radio was still receiving updates. Only one further position SMS was received after the balloon was released, and then Icarus fell silent. After a few minutes, the APRS beacon failed as well. The balloon was lost.

We cleaned up the site in a more somber mood, with the burners automatically falling into a line to scour for discarded trash, and decided to drive down to Los Banos, about 50 miles south, in the hope of being closer to the vicinity of any eventual landing. Almost an hour after launch, when halfway to our destination a single APRS packet appeared on the digipeaters, which told us we’d achieved our mission by ascending to 60,901 feet, but also spelled out the doom to which we’d sent our faithful electronic payload.

The automatic beacon reports not only GPS position, but also the temperature inside the cooler and input battery voltage. That single packet – the only one that APRS digipeaters received for the whole flight – told us that the temperature was critically low, at -21C – water vapour would have condensed onto the electronics and frozen, and the internal chemistry in the batteries would have slowed to the point of failure. We had a 9V lithium battery for power, and the tracker (which also powered the GPS) required a 6.8V minimum to maintain its internal voltage. The reported voltage was only 6.7V – and the balloon was still climbing.
We continued south, with each car’s occupants adding to their own ever-growing list of flaws with our process and equipment, desperately hoping for another update from the balloon, but to no avail.
Eventually we arrived at a Denny’s, and stopped. The sun was setting, and temperature falling quickly. We plugged in the depleted battery to charge in the hope that another working radio might help find a signal, and sat down to start listing all of the things that we’d need to fix for the next attempt. Just as the waitress came by to take our order, my phone beeped.
Icarus, amazingly, had survived our abysmal failure at providing environmental isolation, and reacquired a wireless signal. Its first SMS told us that the payload was plummeting through 5,500 feet, and less than 20 miles away. With rushed apologies to the staff, we tore outside and back into the cars, as Icarus kept us updated every minute with its slowing descent and final resting place.

Half an hour later, in pitch darkness, we were deep inside a goose farm, most of the team standing watch for farmers with shotguns while the intrepid few bravely ventured forth through fertile fields, ankle-deep mud, and throngs of potentially man-eating fowl to successfully retrieve the payload – in pristine condition.

So many things went wrong – the effort that we put into the APRS side vastly outweighed the results. The camera failed partway down due to ice melting inside the electronics. Nothing inside the cooler was secured, and only luck kept us out of turbulence sufficient to have components damage one another. But Icarus was a blinding success, and the sensor data, photographs and video that we captured are just amazing. Accelerometer readings indicate a peak altitude somewhere between 67,000 and 70,000 feet.

We’ll work out the insulation, and the APRS gear. Icarus will soon be in the Android Marketplace for others to use. Later, we’ll send up solar panels, model rockets and radiation detectors, control balloon altitude to steer across countries and oceans with prevailing winds, and descend to a specific spot with a UAV.

But right now we have another full tank of helium.

Next launch is mid-March.

Photos from Andrew, Christie, and Mikolaj; join the spacebridge mailing list to help out with future adventures. Also available is raw sensor data from the GPS, accelerometer and magnetometer on the G1, 180MB of photos taken by the camera (including the image above), and the KML track for use in Google Earth. The complete video taken by the downwards facing camera is also available.

Categories: Spacebridge, Syndicated