Observations

We selected the CaI 6122 Å line to derive the vector magnetograms and the photospheric Doppler maps. With an effective Landè factor of 1.75 this line is only moderately sensitive to Zeeman splitting but is relatively broad and better suited to the 160 mÅ bandpass of our Fabry-Perot etalon

A full set of Stokes images was obtained by sequentially recording six filtergrams at the polarization states I+Q, I-Q, I+U, I-U, I+V, I-V, in both the blue and the red wing of the CaI line. The integration time for each filtergram was 30 ms. Approximately 130 s were needed to acquire and store the full set of vector polarimetric measurements (12 images). A series of 12 chromospheric filtergrams was recorded after recording two vector polarimetric sets. The Fabry-Perot bandpass was positioned at 6562 Å, i.e. 1 Å bluewards off-band of the Ha line core. The integration time for the chromospheric filtergrams was 125 ms. The sequence of two vector polarimetric sets followed by 12 Ha-1 Å filtergrams was completed in approximately 7.5 minutes. It was repeated for four hours, during which a total of 56 vector polarimetric sets and 324 chromospheric filtergrams were recorded

Basic data reduction

First, the raw images were corrected for the CCD dark current offsets and flat fielded to account for the pixel-to-pixel gain variations introduced by the detector electronics and optical system imperfections. To improve the signal to noise the images were resized to 512 × 512 pixels with a scale of 0.18 arcsecs per pixel, corresponding to a field of view of 92.2 × 92.2 arcsecs (66.3 × 66.3 Mm). The images were then carefully co-aligned to account for image motions caused by the residual telescope pointing errors and drifts

The telescope telemetry did not provide a very accurate position in latitude and longitude of the region observed. We determined its exact location by comparing a longitudinal magnetogram acquired by FGE at 16:44 UT on January 25, 2000 with a Kitt Peak synoptic magnetogram recorded between 16:21 UT and 17:16 UT of the same day. The region coordinates for this time were used as reference. We derived the region location for other times by measuring their time difference with respect to the reference time 16:44 UT and subsequently calculating the longitudinal distance from the reference location. We assumed a differential rotation in the photosphere of 13.39° - 2.7° · sin ²(longitude) per day

Vector magnetograms

The Stokes images Q/I, U/I, and V/I were obtained by calculating the normalized difference between measurements of opposite polarization states. For example:

V/I = [(I+V) - (I-V)] / [(I+Q) + (I-Q)]

The magnetic field components longitudinal () and transversal () to the line of sight (LOS) were calculated following Ronan et al. (1987):

where L and T are two constants that depend on the magnetic sensitivity of the spectral line used, on the exact location of the Fabry-Perot passband, and on the instrument polarimetric efficiency. We derived L and T by comparing the FGE data with vector magnetograms obtained with the Imaging Vector Magnetograph (IVM) of Hawaii (see Mickey et al. 1996 for a description of the instrument) that was observing the same active region at the same time. The IVM has a lower spatial resolution but it records full Stokes profiles and the longitudinal and transversal field components are derived by means of an inversion code that fits the Stokes profiles. The FGE vector magnetograms needed to be resized to match the IVM image resolution, and rotated and co-aligned before comparing the two datasets. From the comparison we derived the following calibration factors: L = 26100 ± 450 Gauss, T = 4500 ± 100 Gauss

The magnetic field inclination (or azimuth angle) g(gamma) and azimuth c(chi) were calculated as follows (see Ronan 1987):

c has another possible solution: c₁ = c + 180°, because of the 180° ambiguity introduced by the symmetry properties of the transverse Zeeman effect

The 180° ambiguity is not a straightforward problem to solve. Many techniques have been proposed (see Metcalf 1994 and references therein; Skumanich and Semel 1996). However, most of them work well only for active regions that do not deviate too much from a potential field configuration. Active region AR 8844 has several areas where the field structure appears to be highly complex and non-potential. Therefore, a totally automated algorithm would not be capable to properly resolve the 180° ambiguity for those areas. We adopted an approach that combines a potential field solution with an empiric estimation of the correct field orientation based on simple geometrical considerations

We started by selecting one vector magnetogram out of the 56 recorded, which will be kept as reference, and we solved the 180° ambiguity for it. First, we compared the field vectors with a simple potential filed model derived by the longitudinal magnetograms. In this model we just considered the two main polarities in the active region and neglected the magnetic flux in-between. The field azimuths were chosen such that their angular difference with the model azimuths was the smallest. The resulting vector magnetogram was subsequently filtered with a "smoothing algorithm" that checks for maximum continuity between adjacent vectors to create a smooth azimuthal distribution of vectors across the entire region. The azimuth map was then visually inspected to correct for local geometrical inconsistencies. Finally, the vector field map was transformed from the LOS reference system to the local, heliographic reference system. In it, the zenith angle is expressed with respect to the local vertical and the azimuth with respect to the local N-S / E-W directions. The transformation into the heliographic reference system helps in revealing vectors that were incorrectly chosen due to the non-vertical viewing angle of the region (see Gary and Hagyard 1990 for a discussion on the effects of perspective). Therefore, the vector magnetogram was again visually inspected and corrected for local geometrical inconsistencies

The rest of the vector magnetograms in the time sequence were corrected sequentially by comparison with the preceding vector magnetogram in the time sequence, starting with the reference vector magnetogram. Our assumption was that during the time interval between consecutive vector magnetograms the vector directions changed less than 90°. After this sequential comparison process, a few vector magnetograms still needed some manual correction to account for isolated local errors

The results are two time sequences of 56 vector magnetograms corrected for the 180° ambiguity. One with the vectors expressed in the LOS reference system, and one in the heliographic reference system. The sequences cover a time span of approximately 4 hours, with an average time gap between consecutive vector magnetograms of about 3.5 minutes

Photospheric Doppler maps

The photospheric Dopplergrams were obtained by calculating the difference between filtergrams recorded in the two wings of the CaI 6122 Å line of the vector polarimetric sequences

We averaged all the images recorded in each wing during two consecutive vector polarimetric measurement sets:

,

,

where b,r means blue-,red- wing respectively. This was done to improve the signal to noise ratio, to remove some of the 5 minutes oscillations effects, and to cancel out image to image intensity variations introduced by the vector polarimetric measurements. The Doppler image was then obtained as follows: D = D_b - D_r. A positive value in D corresponds to a red shift

To remove some residual contribution of the 5 minutes oscillation and to reduce image-to-image noise, we applied a space-time Fourier filter. The filter combined a high-pass filter, for the noise, with a bandpass filter, for the intensity oscillations

The Doppler image D in reality is just a map of the intensity difference between the blue and the red wings of the CaI 6122 Å line for a specific location. To obtain an estimation of the effective longitudinal velocities we assumed a linear relationship between the difference maps and the effective Doppler velocity, i.e.: V = c · D, where c is a calibration constant. We derived c by comparing the FGE Doppler images with the velocity maps provided by the inversion of the IVM data: c = 22 ± 1.5 km/s

We want to emphasize that the so derived Doppler velocity maps are just a rough estimation of the effective Doppler velocities. Only a line fit through multiple points across the spectral line can provide accurate velocity values

References

Gary, G. A., & Hagyard, M. J. 1990, Sol. Phys, 126, 21

Metcalf, T. R. 1994, Sol. Phys, 155, 235

Mickey, D. L., Canfield, R. C., Labonte, B. J., Leka, K. D., Waterson, M. F., & Weber, H. M. 1996, Sol. Phys., 168, 229

Ronan, R. S., Mickey, D. L., & Orrall, F. Q. 1987, Sol. Phys., 113, 353

Skumanich A., & Semel, M. 1996, Sol. Phys., 164, 291

Data Acquisition:

• Lines selected: CaI 6122 Å line to derive the vector magnetograms and the photospheric Doppler maps. Ha or Ha-1Å for chromospheric imaging.
• Measurements: Sets of 6 Stokes images I+Q, I-Q, I+U, I-U, I+V, I-V, recorded in both wings of the CaI line. 12 Ha or Ha-1Å filtergrams.

Preliminary reduction:

• Dark current and flat field correction:
• Computation of Stokes parameters V/I, Q/I, U/I. For example:

Compute LOS vector fields:

Use V/I, Q/I, and U/I images from the red wing of the CaI line

• Calculate Longitudinal () and Transversal () field components:
  
  L, T: calibration parameters. Determined by comparing FGE data with Hawaii IVM vector magnetograms of the same region acquired at the same time.
• Calculate vector field direction:
  
• Transformation from LOS to local coordinate frame:
  • Gamma to local Zenith Angle: 0° ==> vertical UP, 90° ==> horizontal, 180° ==> vertical DOWN.
  • Chi to local Azimuth: counted positive counterclockwise, starting from the local West.
• Solution of the 180° ambiguity:
  1. Comparison of vectorfiled with a simple potential field extrapolation of the observed region. Derived by only considering the main magnetic polarities present in the field of view.
  2. Application of a smoothing filter to ensure continuity in the azimuthal vector field maps.
  3. Visual inspection to manually correct for local, small geometrical inconsistencies.

Compute Doppler velocity maps:

Average filtergrams recorded on both wings (I_blue, I_red) of the CaI line:

V = c × (I_blue - I_red ), c : calibration parameter. Determined by comparing FGE and Hawaii IVM dopplergrams of the same region and recorded simultaneously. Positive values of V denote UP-flows.

We performed a statistical analysis of the errors in the Stokes parameter measurements and derived from that the errors in the inferred magnetic fields. From analysis of the polarization images themselves, we estimate the following rms noise in the polarization measurements: Stokes V/I : ± 0.0023, Stokes Q/I : ± 0.0018; Stokes U/I : ± 0.0018. For Stokes Q and U the rms noise values are slightly smaller, because we applied a weighted running average to the Stokes images. This increases the signal-to-noise ratio in the weak linear polarization signals, although it reduces a little the spatial resolution

From the errors in the Stokes measurements, we estimate the error in longitudinal field at 70 G with 60 G rms noise and a threshold of 55 G, and the error in the transverse field at 85 G with 60 G rms noise and a threshold of 180 G. Here, the rms noise is defined as the error when measuring the same quantity multiple times, without including systematic errors due to uncertainty in estimating the calibration constants. The threshold is the smallest value that can be measured above the zero level noise

The error in measuring the vector field direction is highly dependent upon the strength of the magnetic field for each particular field vector. The stronger the field, the more accurate the direction estimate. From our calculations, it appears that there is a maximum error that can be reached given a specific field strength, but the average error is always between 0° and the maximum value. The following table shows the change in average and maximum errors for the zenith angles and the azimuth angles as a function of field strength:

where |B| is the absolute value of the field strength, and B_trans is just the field vector component transversal to the LOS. From the statistical distribution of the field strength, we estimate that the typical field strength observed was about 1000 G. Therefore, we can say that the typical average error in estimating the zenith angle is about 3° and maximum error is about 6°. For the transversal filed strength the typical value is probably 400 G. Therefore, for the azimuth angle we have typically a 5° error in average and 8° maximum error

These are just the statistical errors derived only from known measurement errors. It is impossible to evaluate the errors in the vector direction that are related to the specific type of observation we made, i.e. measuring the polarization at a single wavelength position with a single and rather broad bandpass. We do not consider magneto-optical effects and we cannot distinguish between weak field and strong field approximation. In addition we cannot evaluate the effects due to Doppler shift of the spectral line and other effects that may change the profile of the spectral line

We estimate the errors in the Doppler velocities of ± 0.17 Km/s with an rms noise of 0.11 Km/s. Here too, we want to emphasize that the so derived Doppler velocity maps are just a rough estimation of the effective Doppler velocities. Only measurements at multiple wavelength points across the spectral line can provide accurate velocity values

Stokes Measurements

This is a typical set of vector polarimetric Stokes images recorded by the FGE vector polarimeter. One full vector polarimetric set was acquired in about 70 seconds, and the measurements were repeated with a cadence of about 3.5 minutes. The Fabry-Perot spectral filter (0.16 Å passband) was positioned at 6122.59 Å, in the red wing of the magnetic sensitive line CaI 6122.5 (Landé factor g = 1.75)

Top right: Light intensity (Stokes I);

Top left: Circular polarization (Stokes V);

Bottom left: Linear polarization "horizontal" ( Stokes Q);

Bottom right: Linear polarization at +45° to Stokes Q ( Stokes U )

The distance between tick marks is 1" (on the Sun about 730 Km or 456 mi)

Click on the image to view the full resolution version

Longitudinal Magnetogram

Map of the longitudinal photospheric magnetic fields (field component parallel to the line of sight). The field strength is indicated by the vertical bar on the left. White, positive polarity indicates field lines pointing towards the observer. The field of view is 90 "× 90", with a spatial resolution of about 0.5". The distance between tick marks is 1" (on the Sun about 730 Km or 456 mi). Below is a "deeper" view of the magnetogram

Deep Longitudinal Magnetogram

In this map the color table has been modifyed to better view the smaller scale LOS magnetic fields. Everything pure white (black) has a field strength bigger (smaller) than +(-)700

Active Region NOAA 8844 observed on January 25 at 17:30 UT

Photospheric filtergram The Fabry-Perot passband (FWHM of 0.16 Å) was centered at 6122.43 Å, on the blue wing of the spectral line CaI 6122.5 Å. The field of view is 90" × 90", with a spatial resolution of about 0.5". The distance between tick marks is 1" (on the Sun about 730 Km or 456 mi)	Longitudinal Magnetogram Map of the longitudinal photospheric magnetic fields (field component parallel to the line of sight). The field strength is indicated by the vertical bar on the left. White, positive polarity indicates field lines pointing towards the observer. The field of view is 90 "× 90", with a spatial resolution of about 0.5". The distance between tick marks is 1" (on the Sun about 730 Km or 456 mi)	Deep Longitudinal Magnetogram In this map the color table has been modifyed to better view the smaller scale LOS magnetic fields. Everything pure white (black) has a field strength bigger (smaller) than +(-)700
LOS Field Lines Orientation (color coded)	LOS Field Lines Orientation (lines) over Longitudinal Magnetogram
The orientation of the transverse field component is indicated by the pixel color according to the color wheel on the lower left corner. Note that there is a 180° ambiguity in the direction, caused by the nature of the linear polarization measurements. Therefore, angles that are 180° apart are shown with the same color code

Map of the vectorfield direction in the local reference system, i.e. seen as if looking straight down towards the AR. The background is a map of the longitudinal field strength (white areas denote positive magnetic field, pointing upwards), and the overlayed arrows (of unit length) show the azimuthal direction of the field lines. The field of view is 90 "× 90", with a spatial resolution of about 0.5"

Map of the LOS velocity flows, derived from the Blue and Red wing intensity difference of the CaI 6122.6 Å. Bright areas denote an "upfolw", i.e. plasma motion directed towards the observer. Dark areas denote a "down flow". The field of view is 90 "× 90", with a spatial resolution of about 0.5". The distance between tick marks is 1" (on the Sun about 730 Km or 456 mi)

Filtergram at 6562.4 Å (Ha-1 Å). The several small bright points visible in the region between the two main sunspots are the so called Ellerman Bombs. The field of view is 90 "× 90", with a spatial resolution of about 0.5". The distance between tick marks is 1" (on the Sun about 730 Km or 456 mi)

February 13, 2000 Tapes Recovered!

Today the weather over the area where the payload has touched down was finally clewar from clouds, and we were able to land with a Twin Otter near the telescope. The gondola was still standing upright in perfect conditions. We could recover the pressure vessel containing the tape driver and the data tapes, another pressure vessel with some electronics, and a few more sparse small items. Steven (NSBF), recovered the Support Instrument Package and some other items related to the flight train. We had to leave the gondola frame and the telescope itself on the ice, because they are too big and heavy to be put inside the Twin Otter. Before leaving we wrapped a thick tarp around the telescope tube to provide some protection for the winter. We spent about two hours on the landing site. Pietro is leaving Antarctica on February 16. We will recover the rest of the instrument probably next October.

February 11, 2000 Waiting for the recovery

We still haven't been able to reach the payload landing site, yet! We made an attempt on February 5 but it was impossible to see how the snow surface was looking like, because of the thick cloud cover above the landing site. We had to turn around and head back to McMurdo without being able to land. Since then the weather has been bad over the Ross ice Shelf. We will have air support until February 15th. After that date we will be forced to leave Antarctica without the data tapes! But we still have a few days, and there is still hope for an opening in the cloud cover, so that we will be able to land next to the telescope and retrieve the tapes.

January 27th, 2000 Mission terminated!

This morning at about 5 am local time (13 hours ahead to UT) we regained line of sight contact with the payload. The full telemetry revealed that all the systems were working nominally. We were able to turn on the live video camera on board and we could check that the telescope was properly pointing at the last selected target (active region 8844). After considering many factors like airplane availability, balloon trajectory, and weather conditions we decided to terminate the flight today. At 3:30pm LT (02:30 UT) we commanded the main computer to interrupt the observations and to stow the telescope, immediately thereafter we commanded the master power to be switched off. At 4pm Steven Peterzen (NSBF), Ty Sigler (NSBF), and Pietro Bernasconi, jumped on a Hercules C130 and headed towards the balloon that at that moment was flying over the Ross Ice Shelf about 230 miles (360 Km) Sout/East from McMurdo and at an altitude of about 124500 ft (37500 m). Approximately one hour later we were flying underneath the balloon that was clearly visible high in the sky above us. Before termination, we flew around for thirty minutes to inspect the snow surface conditions where the telescope was expected to land. At 4:35 pm (03:35 UT) Steven communicated via radio to the NSBF crew left at Willy Field giving them the go for the flight termination. A command was transmitted to the payload to fire the explosive bolts that will cause the detachment of the balloon from the flight train. The gondola fell free for several thousand of feet, before the air density was thick enough to inflate the parachute. The deceleration was very sharp and at this point the payload experienced a pull of about 10 G. Flying in circles we followed the slow descent of the payload for about 30 minutes. We could see the telescope swinging back and forth with angles as high as 35/40 degrees. At about 5:15 pm (04:15 UT) the payload gently touched down on the snow surface. Steven ordered Ty to send the command to detach the parachute from the payload, It slowly deflated and gently landed next to the gondola . The landing was perfect, we noticed that the payload didn't tip over and crash on the hard snow surface! It was standing upright as it was standing on the barn deck a few weeks ago! From the airplane we could tell that the payload was in excellent conditions: the NSBF solar panels were crushed, since they were sticking a little under the gondola frame, but the Flare Genesis solar panels were in pristine conditions, they never touched the ground! After several passes close to the landing site at low altitude to inspect the gondola conditions and the snow surface around it, we left heading towards Siple Dome to get some equipment to be transported back to McMurdo. At the beginning of the next week we will reach the gondola with a small airplan e (a Twin Otter) to recover the tapes, the SIP, the solar panels and other miscellaneous small components. At this point is unsure wheter we will be able to recover the gondola and the telescope this season, or we will have to leave it on the ice for the winter and recover it next October or November. The second alternative seems to be the most likely.

January 25th, 2000 Heading towards the end of the mission

Communications with the payload are more reliable now. All the systems on board are working nominally. On January 24 at 22:00 UT we will change the target from active region 8831 to a small, growing region that on January 23 crossed the central meridian at about +6 degrees latitude North. No AR number has been assigned to that region yet. The new Flare Genesis target coordinates are: N6 W5 referring to January 23 at 19:05 UT. Sometimes on January 26th we expect to regain Line of Sight contact with the payload, and about 24 to 30 hours later the flight will be terminated.

January 24th, 2000 Flare Genesis is working again!

On January 22 at 00:15 UT, we finally succeded to establish an uplink with the payload. We sent a reboot command to the main computer, and it restarted properly. Immediately thereafter we send two more commands to update the target coordinates, which were several days old. At 03:00 UT the observations were resumed and the new target is region 8831, coordinates S18 deg. E12 deg. referring to January 18 at 03:01 UT. n January 22 at about 23:00 UT we lost again the uplink communication. Probably in two days the balloon will be back again in line of sight, and we will regain our full communication capability until flight termination, which will probably be 24 to 30 hours later. Up to now(January 24 01:20 UT) all the systems have been working nominally.

January 21th, 2000 Still offline!

The main computer has not resumed the observations yet. A reboot command from the ground is needed, but all attempts to send commands to the payload during the last two days have failed. One of the reasons for that is the too high latitude at which the balloon is currently flying (>79 degrees S). At those latitudes INMARSAT is almost behind the horizon, therefore communications between satellite and balloon are very difficult. Another problem is that the HF frequencies are too noisy and the commands sed via this channel are not properly received by the payload. The option to fly with an airplane underneath the balloon in order to regain Line of Sight communication has been considered. No decision in that regard has been made yet. With the exception of the lack off communication and the main FGE computer waiting for a reset, all the systems onboard seem to be in good health.

January 19th, 2000 Some good days of observations, and then a lot of troubles

From January 16th until January 18th at 06:00 UT the Flare Genesis telescope carried on its observations of the active region 8824 withought a glitch. On January 17 INMARSAT was available again for about 24 hours. On January 18 at about 06:00 UT a VME-bus reset caused both on board computers to reboot. The command interpreter computer, responsible to interface the main compuetr with all the payload subsystems, restarted normally. The main compuetr instead didn't restart, failing to command the command interpreter compuer to turn on the pointing. For about 13 hours (until 19:00 UT of the same day) the gondola drifted without pointing at the Sun. Finally Pietro was able to first send a command to turn on the pointng and then to restart the main compuetr. The Sun was aquired again, and observations of the active region 8824 were resumed at about 20:00 UT. At about 00:00 UT on January 19 INMARSAT telemetry and commanding capability was lost again. Since then all attempts to send commands to the gondola through INMARSAT, as well as through HF failed. We still have telemetry via ARGOS about once every hour. Since we are not able to communicate with the payload, we could't send the commands needed to switch the observing target to the active region 8831 at 07:15 UT as it was planned. The telescope is still pointing at AR 8824. At about 09:30 UT January 19 the main computer stopped again. Since so far we are incapable to communicate with the payload, we cannot send a command to manually restart the main computer. Two days ago we crossed the half way line, and we expect that the flight will last for another 6-7 days. We are confident that soon we will be able to resume the observations, leaving us at least 5 more days worth of observations.

January 16th, 2000 Another problem with the main computer

The FGE telescope is currently observing the active region 8824 located at about 12 degrees S in latitude. At around 1100 UT on January 15 the main computer stopped again. Pietro was able to send a reboot command at 2030 UT of the same day, and the main computer resumed the observations about 10 minutes later. Since January 16 0000 UT the balloon has entered in another occlusion zone for INMARSAT, with the consequence that all communications to and from the payload have been drastically reduced. It is not known yet when INMARSAT will be available again.

January 14th, 2000 A quiet day

The FGE telescope is in an excellent health. All the systems are working nominally. Today the observation program has been switched to H-alpha observations in a filament that at 03:00 UT of January 14 is located at S13 deg, W26.2 deg. FGE will aquire 1 measurement in the red and blue wing of H-alpha and one vectormagnetogram at 6122A every 10 minutes. This program will continue until 08:15 UT. After that the telescope will point at the active region AR8824 and resume the vectormagnetogram program.

January 13th, 2000 Main on board computer hung for several hours

Between January 12 09:00 UT and January 13 04:00 UT the telescope stopped its observing program. The main computer hung up for reasons not weel understood yet. For the entire morning and until mid afternoon local time, Pietro attempted without success to send a command to reboot the computer. The balloon was in an occlusion zone where it was impossible to send commands using INMARSAT. The only other mean to communicate with the payload was to use the High Frequency antenna, which uses ionosferic reflection, but no signal went through. At about 5 pm local time (04:00 UT) it was finally possible to send again commands through INMARSAT. Pietro succeded to send a reeboot command and the hung computer restarted without problems and resumed the observations of the active region AR8821. Today, Dave Rust and Harry Eaton left Antarctica to return to Maryland (USA). Pietro Bernasconi remains in Antarctica to survey the telescope operation and to recover the telescope at the end of its flight.

January 12th, 2000 The first two days of flight

Since the successfull launch on January 10 at 0314 UT (4:14 pm local time at McMurdo Station, Antarctica), all the systems have been operating normally. Although, we had a few hair-raising hours just after reaching float altitude when it seemed that an electronic component of the pointing system had failed due to the cold. During the ascent the payload goes through the tropopause where it is subjected to very cold temperatures, down to -50 degrees celsius. The problem was instead caused by a software error that was fixed by power cycling the entire payload (turn off the power and switch it on again). Now we are especially happy about the performance of the pointing system, which is holding the telescope firmly on its targets despite the fact that it is bucking a 20 knots wind. We lost the line of sight contact with the payload at 4:05 pm local time on January 11 (03:05 UT), 23 hours after launch. Since then we rely on satellite link through INMARSAT and ARGOS, which is very sporadic at high latitudes. Telemetry and commanding are very limited now, and the telescope operates in a fully autonomous mode. It is possible though to update or change our targets on the Sun, as well as the observing program. During the line of sight period we have recieved hundreds of images by telemetry, Now the images are written on tapes carried with the telescope. These tapes will have to be recovered for the mission to be a complete success. The initial data are extremely exciting and the mission is a complete success so far. We are especially grateful to the NSBF launch crew and to our many scientific colleagues who have undertaken collaborative observations and have emailed their support and encouragement. The balloon is expected to circle the globe in 10-20 days. After this period it will be, hopefully, above the McMurdo area again and the telescope and its precious tapes will be retrieved by letting the payload gently drop from its float altitude of 120'000 with a parachute.

January 10th, 2000 We have a lift off!!

The Flare Genesis Experiment was successfully launched January 10 at 0314 UT. All systems are operating normally. It will reach float altitude about 0500 UT and initial observations of AR 8821, which was at N27 E47 at 0831 UT on January 9, will begin at approximately 0700 UT and continue until 0314 UT on January 13.

January 8th, 2000 Launch missed by not much!

The Flare Genesis Experiment almost got launched yesterday, but the winds returned just as we were starting for the launch pad. Current conditions are 20 knot winds with some snow. The forecast is for more of the same tomorrow. First possible launch date is Monday, January 10.

January 3rd, 2000 Flight ready and waiting ...

Today, we mounted the solar panels, put on the last of the the rmal blankets, and rechecked readiness for a launch. We checked payload weight with the NSBF equipment mounted. Dave won a slice of pizza for making the closest guess to the actual weight: 3560 pounds. The skies were sunny for about two hours and we confirmed that we can point well and run with the solar panels and everything else in flight configuration. Pietro took a moment to admire the telescope. Then the winds returned.

January 2nd, 2000 Happy New Year (We will be launching soon!)

The weather at McMurdo on Christmas was wonderful and yesterday was pretty good, too. Sunday, the balloon experimenters and the NSBF crew had a big dinner prepared out here at Willy field with lots of appetizers, ham, veggies, home made pie, cheesecake, etc. Robyn Millan and Damien Chua of the MAXIS experiment team; and Harry and Pietro did much of the cooking. Afterward we relaxed in the sun outside, enjoyi ng the newest issue of the Antarctic Sun. Tough life here in Antarctica. But the news from the stratosphere is not good. We are watching a pattern unlike any seen before in this hemisphere. The polar vortex has wandered back and forth from Marie Byrd Land to Roosevelt Island with no determined motion toward the south. There is some concern that the vorex will never reach the pole. A stable high pressure area at the 10 mb level on the opposite side of the continent seems to be holding it off. Stay tuned.

December 25th, 1999 Merry Christmas!

The skies cleared to a pristine blue everywhere for Christmas Day at Willy Field. We are planning more rehearsals of the observing sequences and another test of pointing precision. The problem with the tape drive seems to have been resolved by switching to another drive. It has passed all tests in for a 24 h period. There has been a significant change in the stratospheric anticyclone in the 5 - 3 mb range over the past 24 hours. The center of the system is now again moving south. Steven Peterzen, leader of the NSBF group in McMurdo, anticipates 2 - 3 days for the center to be in position to support a circumpolar flight. If the local weather conditions allow, a launch on Monday/Tuesday is feasible.

December 22nd, 1999 Good Bye Brigitte!

While waiting for the surface weather and stratospheric weather to cooperate, Pietro and Harry sealed up and pressure tested the tapedrive enclosure and the optics enclosure. A problem is that the Exabyte tapedrive is now responding irratically and we had to reopen the enclosure. Before launch, we will have to correct the problem and renew the seal. We must also test the optical path once again in sunlight, in case the pressurization of the optics enclosure changed something. Pietro and our team from NSBF, Frank Candelaria, Otto Masters, Mike Mayfield, Brian Stilwell, Bill Stracner and David Sullivan, hooked up the SIP (balloon control, telemetry and data logging package) to our gondola. The remaining tasks are relatively minor: pressure testing the batteries, testing SIP-FGE connections and cabling, mounting and testing the solar panels. After helping us greatly to develop solar target selection techniques, Brigitte had to leave for the city of lights. Before she left, we got one last shot with us all together.

December 19th, 1999 Stratospheric Winds

The stratospheric wind pattern hasn't moved in five days, so if we launched today the balloon would just head for the pole and cross the continent and then go out to sea. A pathfinder balloon will go up possibly on Wednesday, December 22,but we won't know how it is doing until Thursday, so that is the earliest possible launch date. Meanwhile Pietro pushes the telescope out each morning for another day of tests in our magnificent sunlight. Yesterday Brigitte again practiced target selection and we ran on the sun all day using all the programs that will be executed in flight. Dave, Pietro and Brigitte took a break from the computer screens for a conference on the veranda of the telescope barn.

December 17th, 1999 Silver Epoxy in a Hurry

The pathfinder balloon is headed straight for the South Pole. Obviously, the stratospheric winds are not ready for our circumpolar flight. The upper atmosphere vortex stalled for two days over Marie Byrd Land. The earliest it could be in place now is December 20. The earliest possible launch opportunity in that case would be December 21. Meanwhile we have been taking advantage of sunny days to make magnetograms and H-alpha pictures and to rehearse the launch sequence and flight programs. Nick completed routines to display compressed data. Pietro completed the flare build-up and filament/sigmoid program command sequences. Harry performed the final checkout of the on-board computers and guiding electronics before sealing them in the pressure vessels. He installed the backup Fabry-Perot etalon, and it is performing well, but we will go ahead and repair the solder on the original flight FP for backup. Many thanks to our friends at CSIRO in Sydney, Australia, especially Chris Freund, who shipped us the needed silver epoxy on a moment's notice.

December 14th, 1999 Pathfinder Balloon Launched

Snow flurries, winds, cold and low clouds kept us in the barn for the past two days but today is sunny and calm again. The NSBF folks took advantage of the improved conditions to launch a pathfinder balloon that will sample the stratospheric winds. The latest wind maps show a vortex moving toward the pole, so prospects for the launch window opening in the next few days are excellent. Meanwhile, Pietro is writing the rather lengthy command sequences that will be needed to carry out the flare build-up and filament/sigmoid programs. Harry calibrated the radio link modulation amplitude, buttened up the pointer telescope, and tested the flight batteries. Dave and Brigitte and Hugh Hudson (in Japan) have been selecting targets. We selected a region in the north, and it had a flare! Today, we plan to recalibrate the filters and again rehearse procedures for pointing at solar target regions. The sun is quiet today but a new active region is coming over the east limb and it will be ideally positioned in 4 - 5 days from now, which is our current best estimate of the launch date.

December 11th, 1999 The Sun is Up!

The weather in McMurdo has been great. The skies have cleared the past few days which has allowed extended testing of all systems. Pietro and Harry worked until 3 AM in order to take full advantage of the opportunity. The ACE and pointing operated continuously for a period of over three hours. Brigitte selected solar targets for study, were the launch to take place within 24 hours, and Harry and Pietro fine-tuned the pointing system. In the meantime, Dave and Nick worked on checking the performance of the backup Fabry-Perot etalon, since fixing the connector on the flight etalon seems to become less likely. The group hopes to inst all the backup etalon tomorrow and install the thermal insulation on the etalon housing.

Friday, December 10th 1999 Solar Targeting, Filter Testing and Loose Connectors

Today we took advantage of full the continuous sunlight to recheck the passbands of the Fabry Perot filter and the two back-up FPs. We also successfully practiced pointing at sunspots, of which are plentiful just now. We practiced target evaluation and selection, using the many resources placed on the web by other solar observatories. We spent a lot of time running down a loose connection in the pointing servo. The upper stratospheric vortex is still off the Antactic coast, but it will likely be in position by December 15. We will probably not launch then, as we had hoped to, but the delay should not be more than a few days. Next task is to verify the response of the polarization modulators.

Friday, December 8th 1999 The Pointing Parameters

Today is sunny and optical alignment is nearly complete! We verified that the sun center find program is working. Then we entered the coordinates for those nice sunspots near disk center, expecting to point right to them. But we forgot that the telescope hasn't been pointed at spots since it left the northern hemisphere. We missed the spots because things are upside down and backwards here. North is down, not up, and as seen from the telescope, East is on the right, not on the left. But after we made the sign changes, the telescope locked right in on the spots. We got the first live video images of spots since arrival here. Launch is still planned for December 15, but it could be delayed by the failure of the polar vortical winds to develop by then. It could also be delayed by unfavorable surface weather conditions. Also by too many cloudy days between now and then. We need to complete the calibrations and flight dry-runs. Activities in the next few days: further testing of the Fabry-Perot filter, which seems to have developed an open circuit. Cloudy day activity: attach the balloon control package and test the interfaces to our experiment.

Monday, December 6th 1999 Test Flight

The principal achievement today was the flight test in a C-130 above McMurdo of radio communications between our equipment on the airplane and the gondola on the ground. We installed an antenna in the sextant port and successfully received signals from the gondola. Unfortunately, we could not check the link through the NSBF equipment, because it wasn't working during the flight. Later tests on the ground were successful, however. Clutter was removed from the FGE web pages and new links were established to the Max Millennium campaign pages. We also refined the observing plans.

Saturday, December 4th 1999 Optical Alignment and Hardware Tweaks

Optical alignment work has been progressing as well as can be expected in the absence of sunlight. With a laser and a theotarted when the radio comm system was turned off for other tests. This bug has been fixed and the on-board computers are running reliably. We tested the LOS and OTH comm systems linking our GSE to the NSBF transmitters to the payload. These comms are working normally. We still have to test communications from our system through the NSBF system during an underflight. The flight test is scheduled for next week, depending on aircraft availability. We will also test direct reception of signals from the payload through a helical antenna to be installed in the C-130's sextant port. There will be an underflight during the mission only if needed to correct a serious problem that cannot be addressed with the limited OTH comm system. All other systems have been checked and are working normally. The principal tasks remaining are final optical alignment, underflight checkout, installation and checkout of the NSBF SIP with our payload, and final observing program specification.

Tuesday, November 30th 1999 (Williams Field) Project PI Arrives, We Hope the Sun Shines Soon

Yesterday at three am, David Rust, Principal Investigator arrived in McMurdo station. Since Thanksgiving, the FGE team has been waiting for sunlight with which to finish aligning the post-focus optics as well as calibrate the filters. During the wait, the liquid crystal modulators were installed, four damaged temperature sensors were repaired, and finally the science instrument package (SIP) was integrated and tested.

Saturday, November 27th 1999 (Williams Field) Filter Calibration Begins, Telescope is Online!

The FGE team has had a fruitful week past week. On Monday and Tuesday the alignment of the post focus optics, mounting of the heat shields and installation of the pointing telescope was completed. The spectrograph and heliostat were set up for the calibration of the narrow band filters and the Fabry-Perot etalon. The momentum transfer unit was cleaned and reassembled. Optics were installed in the Optical Pressure Vessel (OPV) and on the optical table of the pointing telescope. The ACE Pressure Vessel (APV) was sealed and installed, as well as all computers on the mezzanine, all cables were connected. The instrument was powered on November 26th for the first time in several months. Performance check ongoing.

Monday, November 22nd 1999 (Williams Field) Calibration Complete, OPV Alignment Begins

Pietro, the resident optics expert, has completed the alignment of our secondary mirror. To enable this task, the carpenters built a sturdy platform made of wooden I-Beams. The platform was suspended by two four by four beams which were cushioned by foam padding to provide stability. Stability is fundamentally important -- the secondary was aligned within micrometers of specification. In order to perform the alignment, the telescope was used as an interferometer. One can see the laser and beam splitter here. One beam path went through the optics, bounced off the flat mirror at the end, and came back. The other beam path simply reflected off the flat mirror on the optics table, and bounced back. Both paths end up in the Theodolite, which projects an image of the interference between the two beams into the Black Box. The Black Box had a camera inside which was hooked up to a TV screen next to the secondary. Ultimately, Pietro was responsible for tweaking the secondary until the interferogram looked good. Please look at some more pictures of the alignment process.

Tuesday, November 15th 1999 (Williams Field) Calibration starting any day now

Over the course of the past four days, the FGE team managed to mount the OPV, set up the racks, as well as mount the telescope tube. As most of the optics were mounted, FGE aligned the optical axis. With the successful completion of this first alignment, work began on establishing the interferometer. The small mirror was set to an orthogonal position to the optical axis. The team is waiting for our tertiary mirror to arrive from Christchurch, which will allow us to fully calibrate the instrument.

Thursday, November 11th 1999 (Williams Field) Our first day of work.

Several weeks late, we received our telescope and optics. The telescope was in a big box which filled with sea water, and so we spent several hours cleaning. Harry disassembled and cleaned the Image Motion Compensator (with some help from Nick.) Jeff removed rust from several bolts and cleaned some of the optics to the OPV. Pietro worked on cleaning the cylinder. When finished with the cleaning, work began on mounting the primary mirror. At the end of the day, we had managed to mount the primary mirror, and clean several of our key components.

Tuesday, November 9th 1999 (McMurdo Base) Jeff and Harry arrive in Antarctica

Jeff, Harry and presumably our cargo have arrived in McMurdo. We hope that today's Herc' flight has our optics so that we can begin our calibrations.

Wednesday, November 3rd 1999 (Williams Field) The alignment platform is completed!

Today the carpenter finished build the wooden platform that Pietro will use to align the telescope's main optics. The alignment is a very delicate procedure that uses an interferometer sensitive to micrometric displacements of the optical elements. The slightest vibration or motion of the interferometer or the optics will render vain any attempt to succeed in the task. Therefore, a solid platform was built to prevent unwanted displacements. To reduce the vibrations a series of foam pads was put between the platform and the floor of the barn. To check the solidity of the platform Pietro set the theodolite on the platform and pointed at a distant target, while Nick was wandering and jumping around the platform. The result was positive, since no motion or vibration was observed! Here's what it looked like at the end of the day.

Monday, November 1st 1999 (Williams Field) Good God, this is an awful place (Scott)

Today the weather started off bad, and got worst (compare to a week ago.) Naturally, flight operations were canceled again. In fact, tonight we are sleeping at Williams Field due to bad weather. However, that doesn't stop us from capturing a beautiful moment. According to our weather station, the temperature over the past 8 hours has hovered around -40F (wind chill) with winds peaking at 57 MPH, and not dropping below 15 MPH. Nothing else to say but it's cold.

Sunday, October 31st 1999 (McMurdo Base) Gondola is Up!

After 4 days of various delays, our gondola is set up in our high bay. We had feared damage to it, due to the sea crate crushing it's box, but our fears were unfounded. The weather today got to condition 2, which is not a good sign for flight operations tomorrow. We are still waiting on the majority of our cargo to arrive. We started work in the early afternoon. After opening the box we had a great time unpacking it. Actually, it seems only Steven was having a good time.

Tuesday, October 26th 1999 (McMurdo Base) A day of learning

The first half of today was spent dealing with various administrative issues: Waste Management training, NSF Meeting, and drivers licensees. Everything went as well as it could have. At about 1300 (New Zealand) we drove to the barn at Williams field. The barn is where we will be hanging the gondola for testing. Although it's hard to see from the picture, there are two tracks that go into the barn where an A frame hangs. When the door is open, we can wheel the A frame out with the telescope hanging from it. It is a great facility. Unfortunately, the cargo still has not arrived as of 1900 (New Zealand.) The cargo for the NSBF will arrived today around 2200 (New Zealand) and our cargo is scheduled to arrive tomorrow, same time.

Monday, October 25th 1999 (McMurdo base) Pietro & Nick Arrive in Antarctica

At roughly 1300 Pietro & Nick Arrive in Antarctica (in a C-141D), on the way down, we find out from Steve Peterzen that the box holding the gondola was crushed by a ten ton crate. Because the box is crushed, all Flare Genesis cargo is delayed by one day, in short, none of our equipment (except for the theodolite and theodolite stand) has arrived. Also upsetting, is the fact that the ice cave has not been excavated, which is necessary to calibrate the telescope, however, Steven is getting things moving here at McMurdo to expedite the completion of these tasks.

Click on the images to view a larger picture

All images were taken by Aniko Safran, with the exeption of those marked with a (*)

	Gondola hanging from the launch vehicle outside the barn. The NSBF crew does the last checks before moving to the flight line.
	Moving the gondola to the flight line.
	The launch vehicle reaches the flight pad and the fog arrives.
	Pietro deploys the antennas from the bottom of the gondola.
	Dave and Pietro
	NSBF crew mounts the parachute termination plate.
	Pietro eats something while surveying the gondola.
	NSBF crew is taking a brake, and is having fun! (* By Damien Chua)
	The gondola hanging from the launch vehicle waiting for the take off.
	And again the FGE gondola. (* By Damien Chua)
	Dave proudly standing next to the FGE telescope! On the background the volcano Mt. Erebus.
	NSBF crew deploies the parachute. On the background the helium tank arrives.
	Deploying the balloon.
	A skua looks arround, intersted and maybe amused by what is going on.
	Balloon inflation crew replacing a balloon valve.
	Again working on the installation of the balloon valve.
	Everything is ready! The balloon inflation begins!
	Pietro, Dave, and Rick Sterling (member of the MAXIS project) observe the inflation operation.
	Ready for launch!
	Ready for launch! (* By Damien Chua)
	Launch! The balloon is released ... (* By Tobias Schunck)
	... it pulls first the parachute ... (* By Tobias Schunck)
	... and then the gondola! Good bye! Have a safe flight! See you in a couple of weeks! (* By Tobias Schunck)

Team members who were in Antarctica during the Summer Season 1999/2000 supporting the second launch were:

	David Rust	JHU/APL	Principal Investigator
	Pietro Bernasconi	JHU/APL	Project Scientist / Co-I
	Harry Eaton	JHU/APL	Project Engineer
	Brigitte Schmieder	Observatoire de Paris	Co-Investigator
	Nicholas Konidaris	CMU	Undergraduate Student
	Jeff Hickinbotham	JHU/APL	Technician

Team members who supported the antarctig group fom the US:

	Graham Murphy	JHU/APL	Computer Systems Engineer
	Christoph Keller	National Solar Observatory	Co-Investigator
	Phil Wiborg	USAF Phillips Lab	Programmer
	Jean-Claude Hénoux	Observatoire de Paris	Co-Investigator

Click on the images to view a larger picture

All images were taken by and are copyright to Tim Meehan

Primary mirror	Payload prior to final integration	Payload leaving balloon barn	NSBF preparations
Moving to the flight line	Moving to the flight line	Helium arriving at the launch field	Testing of the parachute lines
Balloon valve preparation	Balloon inflation	Balloon inflation	Balloon inflation
Balloon inflation crew	Front view on the hook	Mount Erebus	Ready for launch
Ready for launch	Launch		FGE Team

The Flare Genesis Experiment payload returns to the ground.

The payload was stowed and powered off by "over-the-horizon" command at 1996-01-24 21:30UT. Three people from NSBF, one from ASA, and Graham Murphy, flew in an LC-130(#04) to the vicinity of the balloon. At 1996-01-26 03:14UT, the command was sent to terminate. This should set in motion the following sequence:

• 1. Separation of the load bearing joint between the balloon and the parachute.
• 2. Ripping apart the balloon down its side using a rip line connected to the parachute.
• 3. Separation of the rip line from the parachute.
• 4. Deployment of the parachute, once it "feels" enough air.
• 5. Descent.
• 6. Touchdown.
• 7. Separation of the payload and parachute, at the command of NSBF.

All stages of this process were accomplished without problem. The balloon took about a half hour to float down to "earth", and just moments after hitting the ice, the parachute was separated. While not obvious in this photograph, the gondola toppled onto its back with minimal damage to the solar panels. According to the GPS receiver on the LC-130, the gondola's final position was:

 S69d 03.6886m  E141d 29.354m 

This was the last good view of the gondola. Soon after it landed, everyone was told to strap in for a landing attempt. This involved two touch-and-goes, dragging just the rear skiis across the surface, and then seeing what impact (if any) had been made. Unfortunately, the landing area was composed of hard sastrugi: wind-sculptured ice, between one and four feet high, and capable of destroying the LC-130's skiis. This meant that no landing could be made by the LC-130 and recovery of the gondola would have to be made some other way.

The following day, the National Science Foundation Antarctic command declared that it would be too difficult and risky to recover the whole payload so close to the season close-out (February 21). Plan B was to send out a light aircraft, a twin otter, to bring back just the two tape drives. Weather and logistics meant that even this operation was almost cancelled, but luckily, the twin otter was able to reach the payload at about 1996-Jan-31 02:00UT.

The pressure vessels holding the tape drives were extracted, and were returned to JHU/APL. Condition of the payload is believed to be very good - in particular, the primary mirror survived descent and landing.

The Flare Genesis Experiment payload returning from Antarctica.

The gondola has been recovered and should be arriving at APL early in February!

I'll have to rewrite this page soon - if nothing else, the tense must now be changed from future to past! Hopefully, I'll hear from Harry as to exactly what happened, so I can replace all my speculation with fact!

Last week, Harry returned to the United States, after two and a half months away. We have also been notified that the experiment should be in New York by January 30, and, depending upon the time needed to clear customs, should show up at APL the week after.

A clean room in APL's Building 23 has been made available to us, and as soon as practicable, we will unpack the payload, detach the pressure vessels, and carry out a step-by-step test of the systems. As soon as we feel it is safe, we will put everything back together, power up, and check out the pointing etc.

While we know of some damage to the telescope, it will take a more extensive series of tests to know exactly what condition the experiment is in, and how much work must be done to refurbish it for its next flight. While the current schedule calls for a flight at the end of this year, achieving that will clearly depend upon nothing critical being broken.

Distances between various places

	APL	Christchurch	McMurdo	Terra Nova Bay	Dome C II	FGE Gondola	Dumont d'Urville	Hobart
APL	0	14377km	14865km	15040km	15903km	16010km	16213km	16345km
Christchurch	8933mi	0	3834km	3495km	4240km	3352km	3234km	2049km
McMurdo	9237mi	2382mi	0	365km	1146km	1254km	1520km	3995km
Terra Nova Bay	9345mi	2172mi	227mi	0	1159km	994km	1243km	3637km
Dome C II	9881mi	2635mi	712mi	720mi	0	910km	1111km	3775km
FGE Gondola	9948mi	2083mi	779mi	617mi	566mi	0	273km	2929km
Dumont d'Urville	10074mi	2010mi	945mi	772mi	690mi	169mi	0	2682km
Hobart	10156mi	1273mi	2482mi	2260mi	2346mi	1820mi	1666mi	0

As described on another page, the FGE gondola landed in the icy wastes of Antarctica at

 S69d 03.6886m  E141d 29.354m 1980m/6500ft 

and, so far as we know, has had no visitors following the brief operation to recover the FGE's Exabyte tape drives and the NSBF's Support Instrument Package on 1996 February 1. Temperatures at a nearby automated weather station (D-57 q.v. below) ranged from -40C/-40F in February to around -50C/-60F in August, with wind speeds often reaching 20m/s (45 miles/hour), and peaking at 27m/s (60 miles/hour). The conditions at D-57 from February to August (when the station apparently failed) are plotted on this diagram. The abscissa is the day of year for 1996. Note that 1 m/s is equivalent to 2.24 miles/hour.

With the aim of recovering the bulk of the payload i.e. the telescope, computers, mechanisms and the frame, FGE Team Member, Harry Eaton, of APL's TSE group, left the United States for Antarctica on November 16. Harry flew first to Christchurch, New Zealand, and then by RNZAF C-130 to McMurdo, arriving on 1996 November 20, local time.

The recovery plan called first for Harry to attend a two-day survival training camp, referred to as "Happy Camper School", before joining an Italian Twin Otter (based at Terra Nova Bay , (S74.695 E164.123) for a flight from McMurdo to a French-Italian research site at Dome Concordia. (Concordia is a relatively new operation near Dome C II (S75.121 E123.374 3250m/10660ft), which is more likely to be on a map.) Once there Harry was to join a group that is traversing to the French base of Dumont d'Urville, situated on the Adelie coast (S66.665 E140.007 30m), on a route that was first opened up in November, 1993. The traverse, so far as we can ascertain, is now a regular operation carried out in the relative comfort of large (i.e. Antarctic class) tracked vehicles. On this journey, "relative" refers to an outside temperature of below -30C/-20F. Inside, according to Harry's primary source of information, Brooks Montgomery, who did this last year, the brutal beating you receive riding over the hard sastrugi and bashing around in the tractor is like being beat up in a bar brawl every day for 8 hours!

That traverse took 14 days, (with one shortened day to celebrate Christmas).

Courtesy of Brooks Montgomery, the map below shows, in orange, the path taken last year. It is likely that Harry's journey will be similar, probably with the diversion to the landing site being made as short as practicable. Once there, the gondola will be excavated from the snow and ice, and placed upon a large sled to continue in the traverse.

Temperatures and wind speeds in the region from November to mid-January are available as graphs here:

• Dome C
• Dumont d'Urville
• McMurdo Region
• South Pole

Upon reaching Dumont d'Urville, Harry must prepare the gondola for shipping, pack it in a box that had been built for the purpose in Christchurch, and ensure that everything is placed aboard the French research support ship, l'Astrolabe.

Harry and the gondola will then journey with l'Astrolabe to Hobart, Australia. The gondola will be unloaded and shipped to Melbourne, from where it will be flown to the United States. Harry will be unloaded and flown to Sydney and then home.

In keeping with the Antarctic experience, Harry only learned of the altitude at Dome C (some 400m/1300ft higher than South Pole) when he was in Christchurch. So upon reaching McMurdo, he prepared as well as he could, immediately attending an altitude survival school and stocking up on the drugs now available to help ward off sickness.

The Italian Twin Otter was originally going to pick Harry up in McMurdo on November 28, and on the day before, we received email from him suggesting that all was well. We didn't hear from him over the next several days and knowing that there would be little opportunity to call or email while "on the road", everyone here concluded that he had departed for the main part of his adventure! No such luck. Email received December 4 EST pronounced that he was still stuck in McMurdo, with the plane expected "any day now". Bad weather had apparently also delayed the traverse team heading to Concordia as well, just to make matters more interesting.

Under the latest schedule, Harry was to leave Wednesday 1996 December 11, with the French-Italian traverse team expected to arrive at Concordia from Dumont d'Urville on December 12. Departure for the return trip was set for December 14.

We have received no email from Harry since Tuesday December 10 EST, when he finally managed to leave McMurdo for Concordia. ASA's Ron Nugent confirmed that Harry arrived safely, as contact was made by HF radio.

Email sent out by Dave Rust summarized the position just before the new year, based upon an Inmarsat phone call and a telex he received from Harry:

The Flare Genesis Experiment was retrieved just before Christmas by Harry and a team from the Institute Francais pour la Recherche et la Technologie Polaires (IFRTP). It is generally in good shape, but one secondary mirror actuator and the heat pipe are broken, and the bottom of the frame is mangled a bit. We expected much worse, and probably there is some internal damage that we won't know about until we get it back to APL.

Harry and all are now at Dumont d'Urville, the French station on the Antarctic coast. He describes it as Willy field (the U.S. station) without the airport. There are cranes etc to use for dismantling the experiment and packing the parts into the boxes, which are on the supply ship from Hobart, Tasmania. A problem is that the ship is trapped in ice 6 km from the shore. Harry plans to take the boat out, but first it must get to the port and unload. Since it will leave as soon as unloading is completed, it is not clear that Harry can get the FGE in the freshly unloaded boxes and get them on the ship in time. Loading the parts into the boxes should take only a half day, so let's be optmistic. (Our chances of a reflight in 1997 will be lost if the FGE does not reach APL in January.)

Harry had planned to clear the snow from the payload inside the garage, but that is being used to refurbish the tractors for the next traverse. Nevertheless, he was able to clear virtually all the snow during a few sunny warm days. Right now the telescope is staked down (upright) on a pallet, with a tarp covering the windward side. Despite wind and snow, very little snow is getting into it.

The miserable flu epidemic in the U.S. seems to have reached Dumont d'Urville. Many of the staff members are ill, even though the boat hasn't reached there yet. Maybe the flu virus can even leap across frozen continents.

Here are two views of Dumont d'Urville taken from a Qantas 747-400 as it flew over the French base on January 18, 1998, at an altitude of about ten thousand feet: (Courtesy P. Murphy, Australia) Dumont d'Urville and again. In both of these views, the runway built in 1993 can be clearly identified. According to one report (the Antarctic Managers Electronic Network link given below), this runway was severely damaged by a storm in January 1994, and with no money for repair, it has been abandoned. Also, note the orange buildings visible in the second picture - the overall colour appears to be the result of some strange interaction between the sunlight reflecting off the ocean and the aircraft's window.

On January 12, Ron Nugent in McMurdo emailed that he had heard from a Twin Otter pilot that Harry and the gondola left Dumont d'Urville onboard l'Astrolabe four days ago! That suggested that Harry should have arrived in Hobart on January 15 or so, which was probably about right. Harry has kept a low profile since then.

Just for reference, Dumont d'Urville, like McMurdo Station, is built on an island, the Ile des Pétrels, Pointe Géologie archipelago. Cap Prud'homme is a staging area on the main land, where the traverse team is based. The only mode of transport between the two places is by helicopter, with a lifting capacity of 1200kg/2700lbs (the gondola weighs around 1500kg/3300lbs).

Once at Dumont d'Urville, Harry will prepare the gondola for shipping, pack it in a box that had been built for the purpose in Christchurch, and ensure that everything is placed aboard the French research support ship, l'Astrolabe.

Harry and the gondola will then journey with l'Astrolabe to Hobart, Australia. The gondola will be unloaded and shipped to Melbourne, from where it will be flown to the United States. Harry will be unloaded and flown to Sydney and then home.

Meanwhile, l'Astrolabe is scheduled to arrive in Dumont d'Urville on December 14, depart on December 28, and reach Hobart, January 3. Based upon our current understanding, it will be very close as to whether the gondola can be retrieved, transported, and prepared before the ship leaves Antarctica.

If Harry misses that opportunity, then he will have to wait in Dumont d'Urville until the ship returns on 1997 January 11, with its next departure slated for January 17, and finally arriving in Hobart on January 24.

The map directly below shows the key points of interest, and in red, a stylized version of Harry's journey. The orange line is the traverse path taken last year from Dome C to near Dumont d'Urville, lasting 14 days. This path is shown in greater detail in the second map - annotations give the day of the journey, altitude in feet, and temperature, where available. D-47, D-57 and D-80 are fuel dump sites and/or ice core drilling sites, where automated weather stations are currently active.

Team members who were in Antarctica during the Summer Season 1995/1996 supporting the first launch were:

David Rust	JHU/APL	Principal Investigator
Kim Strohbehn	JHU/APL	Chief Engineer
Russ Cain	JHU/APL	Electronics Engineer
Harry Eaton	JHU/APL	Electronics Engineer
Ashok Kumar	JHU	Graduate Student
Steve Keil	USAF Phillips Lab	Co-Investigator
Phil Wiborg	USAF Phillips Lab	Programmer
Christoph Keller	National Solar Observatory	Co-Investigator

The full FGE team heading to Antarctica in December 1996 for the recovery operation is:

Harry Eaton

JHU/APL

Chief Payload Recovery Engineer