SCIENTIFIC FLIGHT 2
Daily reports of December 2001/January 2002
Local contact: ESRANGE, Po Box 802, 3981-28
Kiruna, Suède Tel 46 980 72000, Fax 46 980
Archeops balloon Hall telephone number: +46 980 72 267
Latest news from the Archeops team
One day, we'll fly for a
Thursday 3rd, January 2002
We closed the cryostat, checked for leaks and noise measurements. We started to cool down the cryostat (thanks to the Mipas helium), more helium should be here tomorow to continue the cooling. Xavier and Juan are coming tonight.
Friday 4th, January 2002
- Xavier and juan arrived last night. We are now 5 here.
- The overexpected liquid Helium has arrived just in time, the cryostat was almost empty !
- The cryostat is cooling down normally, we are already at 2K.
- The bolometers exhibit a satisfactory level of noise.
- A brainstorming about alternative destriping methods is in progress.
Saturday 5th, January 2002
- the cryostat is cooling down (600 mK this morning).
- a new pre-amplifier has not restored the deficient 545 GHz channel : the bolometer is definitely dead.
- the weather is warm : +3 deg.C and even some rain !
- the cryostat should be re-installed on the gondola tonight.
Tuesday 8th, January 2002
Shaul Hanany arrived last sunday, Alain arrived yesterday night and Cyrille is leaving at noon. The cryostat is below 100mK ! The vortex is moving in the right direction but roughly predicted trajectory is still towards New Zemble. It might be OK by the end of the week. We are preparing for a flight Thursday or Friday.
Wednesday 9th, January 2002
The vortex stopped moving towards east and therefore there is no possible flight before sunday. (Suggestion of a simple winter activity before the flight ...)
Thursday 10th, January 2002
The meteorological conditions in the statosphere are still bad. The vortex would send us directly towards the Spitzberg up in the North. (although in a 24 hours flight). No flight is to be expected in the next four days.
The on-board recorder has a small problem but it does not really affect its capabilities. We however send it back to Paris in order to fix the problem, it will be back in Kiruna during next week.
Alain and JC are temporarily going back to France. Shaul left us early this morning after many fruitful discussions. Frederic Mayet arrived today.
Friday 11th, January 2002
The vortex seems to be slowly moving, a flight at lower altitude may be possible on Wednesday. We still haven't seen the sun but it looks very close (see picture)... The day is spent working on particle physics on Archeops and talking about the vortex !
Saturday 12th, January 2002
See in pictures a typical day spent to work, waiting for better winds ...
Sunday 13th, January 2002
Big change in the vortex, a possible flight for Tuesday morning (very early unless the ground weather doesn't change to snow storm later). We are getting prepared ! Alain, Jean-Christophe and the on-board recorder are coming back tonight. We are ready !
Monday 14th, January 2002
Following meteo briefing, it seems that the ground conditions are ok until the end of the week (1-3 m/s wind speed at ground level). No data at high altitude are available, so no flight trajectory estimation can be done. Next meteo briefing at 16h, with perhaps high altitude data. It is heavily snowing. However, a flight seems to be still possible for tomorrow.
After the 4pm meeting, flight conditions are steadily improving, but the flight window is now between Wednesday and Friday, with the best day probably on Thursday. There will be less snow fall and we expect a rather long duration flight at 5 hPa (about 35 km). So far so good...
Tuesday 15th, January 2002
A flight is possible tomorrow with a 150Z balloon for a duration of at least 24 hours and an altitude of 7hPa (32Km) !!! Final preparation is in progress. The 3He and 4He bottles are filled. The gondola will be moved to the launch pad this afternoon. Next meteo briefing tomorrow at 11h00 a.m. for the final decision and the possible countdown for flight.
Wednesday 16th, January 2002
pour Sophie ...
The weather is beautiful and cold now (-15 C): no snow. The large blue cover has been removed, liquid He transfert is done and the gondola is back to the horizontal position. Waiting for the 11:00 meteo briefing ...
It is decided to fly tomorrow with a ballasted 400Z balloon (~38 km), highly preferable to a fly with a 150Z balloon (~32 km) today. The next meteo briefing is scheduled at 8:00 AM for a take-off around 12:00 AM.
Thursday 17th, January 2002
After a very early awakening, the large blue cover has been removed once again, liquid He transfert is done, cryostat at 90 mK ! Waiting for the 8:00 meteo briefing.
Flight confirmed; altitude of 3.8 hPa with a 400Z balloon. A 24 hour flight is possible, regarding the nominal trajectory. Take-off scheduled at 11:15 UT (12:15 AM Paris time).
The gondola is ready for take-off, correctly positionned on the launchpad. The pivot is connected to the flight chain. Last prepation of the balloon.
Ballon filling started: so far, so good ... 12:31 AM local time
Archeops launch has been sucessful. Experiment is working fine and expecting ceiling time within 3 hours.
02:19 PM Valve gate is open, photons are collected !
03:30 PM 0.1K stage at 97 mK
06:30 PM Due to a balloon problem, the flight must be interrupted. The recovery will be done tomorrow by helicopter. The instrument worked perfectly, with very clean signal at 34.5 km.
|go to the 01-17-2002 ARCHEOPS FLIGHT's page|
Friday 18th, January 2002
JCH and Alain will bring back the gondola by helicoptere as soon as possible (if the weather agrees ...). Jean and Frederic stay in Kiruna, to start refurbishment; Karine, Juan and FXavier are flying back home, to have some well deserved rest, after long staying and working in Kiruna. Have fun and come back soon ! Some more news soon about the gondola status.
Saturday 19th, January 2002
Alain, Fred and JC leave Kiruna to Finland in order to find the gondola in the deep finish forest tomorrow morning ... Jean stays in Kiruna.
Sunday 20th, January 2002
The gondola was found on 4 four of its 6 crashpads, in the bed of a small river. It was an heroic recovery at ski by -20C !! The front baffle has been dismounted for the transportation. People and the gondola are once again in the hall. Jean-Charles and Cecile arrived this night.
Monday 21st, January 2002
(+ new pictures "on the launch pad" and January, 16th)
The gondola itself is in good shape. The focal plane, including bolometers, filters, horns and even the "little strings" are perfectly OK. But it seems that during friday, when the battery turned off, the valve re-oppened by itself. This rapid change of pressure caused some damages in the isolation screens (see pictures). Even difficult, it should be recoverable. Refurbishment is on its way.
Discussion with CNES authorities to continue the campaign in February are in progress. A flight in February is not yet granted.
The CNES team has fully understood the problem which occured during our flight. The balloon valve failed: once opened to release some helium in order to fit with the optimal trajectory, it never closed.
Tuesday 22th, January 2002
The Archeops campaign is officially extended from the 2nd to the 18th of February.
We have done good job (c'est Alain qui l'a dit !): the cryostat is closed and is cooling down perfectly, the broken foot is repaired and the front baffle is almost finished.
Wednesday 23rd, January 2002
The cryostat is perfectly OK : the 1.6K is cold and dilution is cooling down. We stop there cryo-tests, everything is fine. The front baffle is finished and the mirror position has been checked. Batteries have been prepared for both the motor and the electronics.
Everybody will go home tomorrow, the "cooling-down team" will arrive next Tuesday.
Go to the February page !
Predicted trajectories (Jan 2002) Celestial infomation (Jan 2002)
Kiruna 2001/2002 Home Page