That’s not how you launch a balloon

That’s not how you launch a balloon

Aug 25

A balloon is supposed to be at rest in the air mass and anything attached to the balloon had better be at rest in the air mass as well or there’ll be trouble.

This is how you launch a balloon.
Turn up at Mildura Airport. The stars are hard and bright and it’s perishing cold. The professionals look like Americans, but they aren’t, they are Australians. They bought their cold-weather gear when they were in America, training. They’re locals, they know what it’s like out here at five o’clock in the morning.

The Met boys would call the wind `Calm’, but when they launched their four o’clock met balloon they noted very carefully which way it drifted. The launch vehicle is parked out in the field facing what might laughingly be called downwind.

The launch vehicle is an ordinary flat-bed truck. There’s a frame mounted on the front above the windscreen and the rig is tied to the frame with rope. On the back of the truck is a wooden crate and a large tarpaulin. Two men unroll it and a third follows them sweeping it. Two more men park a giant scale on wheels at the other end of the tarpaulin. A semi-trailer backs up to it carrying a couple of dozen gas bottles running the length of the tray.

On the launch vehicle the crate is opened and the balloon taken out and carefully unfolded along the tarpaulin. The far end is threaded through the rollers on the scale and the rollers closed. The near end is attached with rope to the top of an unfurled parachute which, in turn, is attached to the top of the rig. On that rope is a, what, I don’t know what its proper name is, I call it a squib. It’s an electrically detonated explosive that shoots a knife through the rope. There’s more of these on the ropes holding the rig to the frame.

A fat tube connects the gas bottles to the top of the balloon. An initial hiss turns into a shriek that goes on for half an hour. The professionals wear ear muffs the rest of us stand well away. People watch the scale as the bubble at the top of the balloon inflates. When the bubble is around ten meters diameter the scale shows that the total lift is enough. The gas is cut off.

In the sudden hush the driver of the launch vehicle starts his engine. A command is given and with a great crash the top roller of the scales is flung back. Flapping and fluttering the bubble starts to rise and the vehicle moves off slowly downwind. The driver man oeuvres to keep the bubble over the payload, until the balloon is stretched at full length vertically above the vehicle, like a giant exclamation mark in the morning twilight. Balloon, payload and launch vehicle are all at rest in the air mass. The squibs on the ropes are fired, the vehicle brakes and the balloon serenely moves away, beginning its hour-long journey to the edge of space.

That’s how you launch a balloon.

Everyone busy, the airport has to be cleared and open for the seven thirty Melbourne flight.

You watch the balloon until it is out of sight, then wait a little longer and it blazes forth, golden, as it enters sunlight.

A bit of breakfast in the project’s tea room, with the telemetry jangling the background. Eight o’clock and it’s a beautiful day, sun shining, sky blue and the balloon still visible through a telescope, no longer an exclamation mark, more like a rounded, inverted delta. There isn’t much wind at altitude today, so the recovery crew hasn’t left yet. They tell tales of previous recoveries, how once the rig landed on an island in the middle of the Murray river and they had to find a boat to get it back, of the time the balloon went south-west into the Sunset country where wind-blown sand hones mallee roots to razor sharpness and they had to drop four sets of tires from the air before they could get it out, of the occasion the cut-down command didn’t work and they thought the mechanical timer would bring it down in Canberra but that didn’t work either and it drifted into restricted airspace over Newcastle where the spotter plane couldn’t follow it and it was washed up on the shore at New Zealand months later, of the day when there was no wind at all and the spotter pilot spent the day in a deckchair looking straight up and it came down less than mile away.

Early afternoon, and the chill from this morning still hasn’t left you. They send the cutdown command on a telephone dial. On the third try it works. The squibs on the rope attaching the balloon to the parachute fire, the rig drops away and a line from the top of the parachute to the top of the balloon pulls open a rip panel and the balloon falls away. The spotter pilot follows the rig under its brightly colored parachute to the ground and guides the recovery crew to collect it. They are back by half past five, everything is packed away and down to the pub to celebrate a successful day.