x
measure the temperature of the cosmic background radiation at wavelengths from
about 0.5 mm to 5 mm if we were lucky. It would have to be immersed in a bath
of liquid helium, it would have to fly to an altitude of 40 km, and it would have a
window that would open up after the payload had reached the target altitude. It
had all the ingredients of a satellite, except it wasn’t going to really be in outer
space. It had a big battery (although no solar cells, it wouldn’t operate in the daytime), a radio transmitter and receiver, some command processors, a magnetometer so that we would know which way we were pointing, electronics boxes to
operate the motors and detectors, and a big rotating momentum wheel to control
the orientation. It fit inside a 2 m cubical frame made of aluminum. We built it up
and tested it in the lab at Berkeley until it seemed to work the way we hoped and
expected. David Woody and I were now the lab partners working on it, so we
loaded it into a big yellow university truck and drove it to the National Scientific
Balloon Facility at Palestine, TX.
This place was chosen because it was very flat and not very populated, and at
the right latitude so that once in a while the high altitude winds would die down
and we could get a very long flight. It’s a beautiful place in its own way. Many
of the neighbors and staff at the base were watermelon farmers in real life, and
those melons sure are juicy and sweet! At any rate we got there, set up our
equipment, and got ready for the flight. We’d never seen anything like it before.
The balloon is a gigantic bag of very thin polyethylene, and there is a method to
unroll it and fill it partially with helium while our part, the payload, is suspended
from a huge modified earthmoving machine called Tiny Tim with jaws 7 m in
the air to hold the payload, until the balloon was ready to pull it up. The launch
is done at dusk so the equipment will reach altitude just after dark. After a lot of
fiddling and fussing, and discovering that the antenna had fallen off the payload
because I’d made a bad solder joint, finally we were all ready, and up it went. It’s
an extraordinary sight, rising slowly and then faster, going not quite straight up,
and almost out of sight.
But alas, the helium gods were not appeased. We used to keep a little Buddha
in the lab and rub his tummy for good luck, but that wasn’t enough. By the time
our equipment reached the planned altitude, the motor turning the screw in the
interferometer wouldn’t go, and the preamp for the detector was sending out a big
signal even though it shouldn’t. We got zero scientific data and I wondered what I
would do next. We got the payload back – it comes down on a parachute if we’re
lucky. We drove back to Berkeley with it and set to work. David thought of a way
to build a test chamber to find out what was the matter, using Styrofoam boards
and dry ice, which would get our big cubical frame down to the right temperature,
about minus 70°C. He found out that we had three different reasons for failure.
Two would have been found with the dry ice test, but the third we would have
Foreword
measure the temperature of the cosmic background radiation at wavelengths from
about 0.5 mm to 5 mm if we were lucky. It would have to be immersed in a bath
of liquid helium, it would have to fly to an altitude of 40 km, and it would have a
window that would open up after the payload had reached the target altitude. It
had all the ingredients of a satellite, except it wasn’t going to really be in outer
space. It had a big battery (although no solar cells, it wouldn’t operate in the daytime), a radio transmitter and receiver, some command processors, a magnetometer so that we would know which way we were pointing, electronics boxes to
operate the motors and detectors, and a big rotating momentum wheel to control
the orientation. It fit inside a 2 m cubical frame made of aluminum. We built it up
and tested it in the lab at Berkeley until it seemed to work the way we hoped and
expected. David Woody and I were now the lab partners working on it, so we
loaded it into a big yellow university truck and drove it to the National Scientific
Balloon Facility at Palestine, TX.
This place was chosen because it was very flat and not very populated, and at
the right latitude so that once in a while the high altitude winds would die down
and we could get a very long flight. It’s a beautiful place in its own way. Many
of the neighbors and staff at the base were watermelon farmers in real life, and
those melons sure are juicy and sweet! At any rate we got there, set up our
equipment, and got ready for the flight. We’d never seen anything like it before.
The balloon is a gigantic bag of very thin polyethylene, and there is a method to
unroll it and fill it partially with helium while our part, the payload, is suspended
from a huge modified earthmoving machine called Tiny Tim with jaws 7 m in
the air to hold the payload, until the balloon was ready to pull it up. The launch
is done at dusk so the equipment will reach altitude just after dark. After a lot of
fiddling and fussing, and discovering that the antenna had fallen off the payload
because I’d made a bad solder joint, finally we were all ready, and up it went. It’s
an extraordinary sight, rising slowly and then faster, going not quite straight up,
and almost out of sight.
But alas, the helium gods were not appeased. We used to keep a little Buddha
in the lab and rub his tummy for good luck, but that wasn’t enough. By the time
our equipment reached the planned altitude, the motor turning the screw in the
interferometer wouldn’t go, and the preamp for the detector was sending out a big
signal even though it shouldn’t. We got zero scientific data and I wondered what I
would do next. We got the payload back – it comes down on a parachute if we’re
lucky. We drove back to Berkeley with it and set to work. David thought of a way
to build a test chamber to find out what was the matter, using Styrofoam boards
and dry ice, which would get our big cubical frame down to the right temperature,
about minus 70°C. He found out that we had three different reasons for failure.
Two would have been found with the dry ice test, but the third we would have
Foreword