U2 Anisotropy Experiment in Peru:
U2 Anisotropy Experiment in Peru:
In order to see that our newly discovered CMB dipole anisotropy was not an artifact, a campaign was mounted to make observations from the southern hemisphere. If the same dipole pattern was also observed in the southern sky, that would confirm our observation and support the interpretation that was due to our motion in the Solar System's orbit around the Galaxy. Southern hemisphere data would also reduce our errors particularly in direction.
Northern Sky Coverage showing where observations were made
prior to the Peru campaign.
The experiment was flown aboard the NASA Ames U2 jet aircraft. It turned out to be extremely difficult to mount a campaign to the south. There was considerable physical and political risk to the aircraft. We would like to have gotten fairly far south - e.g. Australia or southern South America. The flight to Australia would be too long and thus risky. There were political issues important at the time other places. However, the Peru was pleased and supportive of our mounting flights from the Lima airport. One end of the Airport was the commerical & civilian Jorge Chavez (a famous pioneer aviator) International Airport and on the other end was a Naval Air Station. In between the US had a small building which was used for diplomatic mail station routing diplomatic mail to the various embassies and back to the US. The US building would be our home base for keeping our small equipment and tools, including our polarization experiment which operated on the roof for a month. The U2 was kept in a near-by hangar provided by our Peruvian hosts.
We were able to make a number of observations and they confirmed and improved our northern sky observations.
Some interesting photographs:
U2 in Lima Peru at Jorge Chavez airport.
Behind the U2 is an Aeronauves of Peru aircraft and barely visible
behing that is an Aeroflot plane. At the time this is probably the
closest an operating U2 and a USSR aircraft every were.
Aeroflot plane in the background.
We cleaned and dried the components and reassembled the apparatus.
It was working properly again and we could have our first flight
the next day - actually evening as we took our data after dark.
Check out and preparation for the flight began in the middle of the
day for an evening launch and a night flight.
Click here
for more photographs and information about the U2 DMR instruments.
Click here for information and photographs
of the U2 pilot and flight preparations.
George Smoot took these photographs during the campaign in Peru
so that there was ready access and difficult conditions.
U2, experiment, George Smoot and Phil Lubin working late
the night the U2 arrived to get the instruments working again.
When we checked the equipment as soon after the U2 landing as possible,
we noticed that the instruments were not operating properly.
We worked through the night taking it appart, standing on ladders,
leaning over the aircraft.
We eventually realized that the signal was not getting to the
electronic portion of the receiver.
We took apart the radiometers and found that there
was water in the waveguides carring the signal from the antennas
into the switch at the front of the receiver.
The U2 had flown from NASA Ames with the apparatus already installed.
The long flight at high altitude caused the unpowered apparatus
to get very cold.
Once the U2 descended in Peru, the high coastal humidity was condensed
in the equipment.
It is especially cold at high altitudes in the tropics.
We had worried and made sure that the equipment heaters
had the extra capacity needed to maintain temperature there.
The decision had been made not to operate the instrument on the flight down
both for the safety of the instrument and since the data were unlikely
to be useful. We could not have two flight legs in opposite directions
close together to be sure that there was no effect from the U2.
U2 with experiment payload Photograph taken the night it was
being repaired.
U2 being fueled
George Smoot and Phil Lubin checking out experiment in U2
the next day prior to flight. 
U2 with experiment inside outside the hanger in preparation
for flight. Part of the preflight checkout required going outside
both to run on the U2 flight systems and to see the sky with the equipment. 
U2 taxis out to the runway in preparation for take off.
This photograph shows the U2, our experiment, and a commerical
(Iberia) aircraft for scale. You can also get a hint of how dry,
i.e. lack of rain, it is in south, coastal Peru.
U2 takes off from Lima.
The rate of ascent is so dramatic, that we usually called it a launch.
You will note that during preflight preparations
the pilot wears a "space suit" and prebreaths
oxygen to avoid getting the bends on the rapid ascent.
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