Saturday, 26 November 2011

Last test flights in 2011

Today’s flights have been the last test flights of the 2011 test campaign. Equipped with the photochemsitry layout the Zeppelin took off at 12am. The airship headed towards the eastern end of Lake Constance where the City Lindau and the Pfänder Mountain came into sight. After returning to the hangar the flight conditions worsened but still the airship managed to fly one more leg above Lake Constance. An altitude of 4000 ft was reached.

The Zeppelin approaching the air field.

After landing and calibration, the instruments were shut down and the last flight of the 2011 campaign was finished.

Friday, 25 November 2011

Short flight

The sun rose above the fog today, but the sky cleared up. After three days without flights we were glad to fly our instruments today. After a one hour flight the Zeppelin returned to the hangar after a fog warning.
View to the Alps with the inlet of the LOP rack

Wednesday, 23 November 2011

Climbing exercises in the hangar

In the hangar the top platform can be reached by means of an aerial plat form. In the field, the Zeppelin is fixed at a mast truck. If instruments on the top platform fail, they can only be reached via the mast truck.  Unfortunately, bad weather conditions prevented us from flying today so we took the opportunity to exercise climbing on the Zeppelin in the hangar.

Tuesday, 22 November 2011

Cabin layout exchange in the field

Today, we exchanged from cabin layout 9 (Nucleation) to cabin layout 8 (Photochemistry). To get closer to the conditions we are expecting for next year's flights, the airship was moved out of the hangar for this exchange. Using the cabin-mounted crane especially constructed by Zeppelin Luftschifftechnik, lifting the racks into the Zeppelin cabin is unproblematic.

Overall, this first test under tightened field conditions (frost and fog) went really well. A few uncritical points with room for improvement were found, giving us the chance to reduce the necessary time for a complete cabin layout change even further. 

Unfortunately, the weather conditions did not improve throughout the day so we could not fly.

In the late afternoon, the Zeppelin was moved back into the hangar.

Monday, 21 November 2011

Test flights with the nucleation package

After a very misty morning the fog suddenly lifted around noon and we had best weather conditions for the 2nd flight with the top platform installed. The cabin layout for this flight was the nucleation package. This package includes the API-TOF and the NAIS. At 2.45pm the Zeppelin took off, heading to Lake Constance in order to start a vertical flight profile with the lowest altitude of 250ft above ground level.

After slowly ascending to the maximum height of 2350ft above ground level, the airship returned to the airport to exchange the pilot and the cabin crew. The route of the 2nd leg led over woodland where we had the opportunity to pass nearby a transmission mast to check possible interferences of electromagnetic radiation with our very sensitive instrumentation. At around 5pm the Zeppelin returned to the hangar.

While the Zeppelin was in the air, the envelope of the airship which we are going to use in 2012 is prepared in the hangar. The envelope was inflated with air and tested for leaks. On the left-hand side the framework of the Zeppelin is already built up.

Sunday, 20 November 2011

All cabin layouts and Top Platform successfully tested!

Today, the top platform was installed on top of the Zeppelin. Without practicing, it took a little longer than the optimistic estimate of one hour. After the platform was on the Zeppelin, the ground crew and scientists worked together to install power supplies and sample lines.

The airship took off at 3pm, after some minor problems with the power supply. On its first flight leg it reached an altitude of 4000ft above sea level, which was still below the clouds. After flying at constant heights of 3000ft and 1800ft the Zeppelin returned to the air field to exchange the cabin crew.

On the second flight the Zeppelin flew above a forest. Its maximum altitude was 4360ft. The Zeppelin descended to 1800ft to give the operators the chance to test their instrument at different heights. At 5 pm the Zeppelin returned to the hangar. Today's flights were also the first flights for the LOP rack and the FFL rack. By today every instrument has been in the air at least once, so we celebrated with a joint dinner in Friedrichshafen.

Saturday, 19 November 2011

High Above The Clouds Of Lake Constance

The sudden descent of fog yesterday led to the decision to start today's test flights as early as possible.
Good weather conditions in the morning sped up the preparations of the experimenters. Some covers for the instrument racks were attached right before the start.

The Zeppelin was equipped yesterday with the SOA (secondary organic aerosol) package. Today it flew to the forest Altdorf Wald to measure at different heights. Afterwards the airship returned to the hangar where the pilot and the accompanying experimentalists were exchanged, to give other experimentalists the chance to observe their instruments on the flight. The instruments mostly performed well at different heights and different speed.  NOx, O3 and CO showed interesting changes during profile measurements. 

The second flight leg led the Zeppelin to the Lake Constance, which was completely covered with fog. Here the maximum flight altitude of 4700ft was reached, and the Zeppelin descended until it dipped into the mist. At 3.30 pm the airship returned in the Hangar just before the fog descended again.

Until late in the evening the airship was tooled to change from the SOA package to the photochemistry package.

Friday, 18 November 2011

First Test Flight

Today we had our first Test flight of the 2011 campaign. The Zeppelin,equipped with the Nucleation Package (Cabin Layout 9), took off at 3:45 pm. The airship flew to the forest Altendorfer Wald where it reached its maximum altitude of 3200 ft.
After a fog warning from the tower at Friedrichshafen Airport the airship had to return and reached the hangar at 5 pm.
An important test today was the switching from the ground power supply to the generator power supply of the Zeppelin. After some tests the switching went well. All the instruments measured during the flight.
Beforehand it was considered that the APi-TOF and NAIS might not see any ions due to static charge forming on the surface of the Zeppelin. Both instruments measured ion concentrations within the expected range.

In the evening, the cabin layout was changed from the nucleation package (CL 9) to the SOA (Secondary Organic Aerosol) package (CL5). During campaign, the cabin layout will be changed to address different scientific questions or simply to safe weight on transfer flights.
Racks with a weight of up to 135 kg can be lifted into the cabin by means of a winch constructed by ZLT. As we found out yesterday, removing an instrument from the gondola takes about 10 minutes, installation lasts about 20 minutes (including electrical connection).

Thursday, 17 November 2011

Press conference

Today we held a press conference to introduce the PEGASOS project and the Zeppelin mission to journalists. The main objectives of PEGASOS were discussed and the Zeppelin mission was introduced both from the perspective of the scientists and the pilots. A tour through the hangar gave impressions of the ongoing test campaign. Also the Zeppelin NT that is currently built up in the hangar and will be used for our campaigns in 2012 and 2013 was shown to the journalists.
Some media coverage can be found at:,-Zeppelin-NT-fliegt-fuer-den-Klimaschutz-_arid,5163772.html,1319148000,1321802230,%5B%223%22%5D.html

Cabin layouts

There are three constellations ("cabin layouts") of instruments used for the Zeppelin flights.
Please find the details of the instruments by clicking on their names.
Some of the instruments are in every cabin layout:

CL5 is the cabin layout for Secondary Organic Aerosol measurements. For this cabin layout, the following instruments are added:
  • AMS (Forschungszentrum Jülich)
    • Size resolved mass spectra of PM1
  • PSI (Paul Scherrer Institute)
    • Mass black carbon
    • Aerosol hygroscopicity
  • HGC (Forschungszentrum Jülich)
    • Fast GC-MS system for VOC measurements

CL8 is the photochemistry layout, which has these instruments:
  • LOP (Forschungszentrum Jülich)
    • HONO
  • FFL (University of Wisconsin)
    • Formaldehyde
  • HGC (Forschungszentrum Jülich)

CL9 is the nucleation layout:
  • API (Forschungszentrum Jülich)
    • Atmospheric pressure interface ToF mass spectrometer
    • Mass spectrometry of naturally charged ions
  • NAS (Airel Ltd., Sander Mirme, Aadu Mirme)
    • Nanometer aerosol and Air Ion Spectrometer (NAIS)

Wednesday, 16 November 2011

The test campaign is starting

The test campaign for the Zeppelin flights in 2012 and 2013 has started.
Months of hard work have been spent on the instruments that are going to fly.
The instruments arrived in Friedrichshafen on November 7th.
One by one, they received their "EASA Form One", which for us means that they are allowed to fly on the Zeppelin. The consequence is, that whenever a single screw or cable of the instrument is replaced, the Form One needs to be renewed by an inspector.

Saturday, 5 November 2011

New Blog for PEGASOS

This is a new blog for the EU project PEGASOS (

Postings will follow the new results and in particular the Zeppelin flight campaign