ALTAIR 15A -- 17Nov15This operation was a systems test run from the roof of Wilder. The LX200 was equipped with the focal reducer and images were made of various celestial objects.
ALTAIR 15 -- 24Oct15The purpose of ALTAIR 15 was to provide an engineering test of all the flight and operational systems and to attempt to procure quantitative science imagery of the new LED diffusive light source. The two principle systems under test were the science system including telescope pointing and imaging, and the parafoil recovery system. The plan for ALTAIR 15 was to launch from Thetford Academy before dawn (sunrise at 0714 EDT), capture images while climbing to 7000 m, cut down, capture more images, and then guide the gondola to the science team on Robert Frost Lane for recovery. The sky was clear but there was considerable valley haze that obscured the region around the launch site from the science site. Surface winds were light and the temperature hovered just below freezing.
There was no significant delay in packup, departure, and travel procedures. Upon arrival, the launch team set up, inflated, and rigged the gondola without any serious difficulty. The science team had some difficulty with star alignment, making three attempts before alignment stars appeared good in the camera images. Cross checked stars did not always appear in the camera FoV, however. The science team also experienced some difficulty in obtaining a good focus.
Launch occurred at 0451 EDT. The gondola rose at a steady rate of around 5.9 meters per second. The science protocol ran according to the flight plan, but failed to capture any images of the light source. Winds were less strong than expected, so cutdown was delayed until 8768 meters at 0515 EDT. The parafoil did not deploy correctly and the gondola spiraled on descent, preventing any further science. Steering commands had no effect on descent trajectory. The data shows that the gondola spiraled to the right, indicating that the right side of the parafoil did not deploy fully or correctly. The gondola descended south-eastward over Moose Mountain toward the north end of Goose Pond. Science lost the signal first at 0533 and 2392 meters. Launch lost the signal later at 0539 and 775.9 meters. Landing was estimated to occur a minute after that, at 0541.
The recovery beacon again worked well and was fully readable from Etna. The science team was able to receive the signal without difficulty and recorded coordinates 43.72046, -72.09287, and altitude 326 m. The SPOT also reported as expected, giving coordinates 43.72052, -72.09286. The science and launch team then drove together to Goose Pond and hiked about half a mile into the forest east of Goose Pond where they found the gondola in a very large and long-dead yellow birch tree about 60 feet up. Given the height of the tree and its condition, they declined to attempt a recovery.
Three days later, on the 27 Oct, Asher and Tim returned to the site with the line launcher and retrieved the gondola without incident. There was no significant damage to the gondola or the parafoil.
On teardown, there was a small amount of water inside the gondola, but after drying and recharging the batteries, all systems worked correctly.
The on-board video camera was not activated properly, so there is no on-board video available.
The failure to capture any imagery may be due to a fauty star alignment, but also may be due to a failure of the science protocol to provide accurate enough synchronization between the camera and the payload.
The parafoil deployment issue may be due to an incorrect rigging prior to launch, or may be due to dew which collected on the parafoil before lauch and subsequently froze. There was no indication of any other failure in deployment.
ALTAIR 14 -- 29Jul15(Revised 11Aug15)
This flight was intended as a test of the new gondola with diffusive source with a goal of obtaining low-altitude quantitative imagery. It is also a test of our improved parafoil deployment and navigation systems. Similarly to A13, the plan was to launch from Thetford Academy just before dawn (0400 EDT), climb to 4,000 meters, cut down, and then fly the parafoil to recovery at Robert Frost Lane. The science station was located at Robert Frost. The weather was hazy with some cumulus buildups in the area and considerable valley fog, but clear enough to visualize the flight path from the science station and to get a star alignment.
We had two completely inexperienced team members and a complex new rigging procedure, so packing was a bit slow and setup at the launch site was delayed somewhat. There was also a problem in that the balloon had a hole in it requiring the launch team to deploy the spare.
Launch occurred at 0516 EDT--well into twilight. Climb proceeded smoothly with solid telemetry. The science protocol was activated, and the science team observed the vehicle in the telescope finder. Tracking appeared to be functioning very well. Cutdown ocurred at 0528 at an altitude of 4482 m. The vehicle then entered a rapid descent at about 10 m/s for a full 61 seconds before the parafoil deployed completely and the vehicle stabilized. The vehicle then glided smoothly south-eastward over Moose Mountain with LOS at 0539 while still at an altitude of 1991 m. The on-board video shows landing at 0550 EDT.
Climb and descent rates were very close to predicted values. For some reason, the on-board computer detected landing while descending through 3770 m and entered Landed Mode, so that it activated the RF recovery beacon and began transmitting telemetry only about once per minute. The science team was able to copy coordinates from the recovery beacon as the vehicle continued its descent and southeastward track. (The last screen image is provided on the images page linked below.) The science team also transmitted a right turn command to put the vehicle into a spiral descent.
The stabilization of the vehicle 61 seconds after cutdown coincides with the issuance of a right turn command. As seen in the video, at the moment of the turn command, the gondola appears to fall and then quickly stabilizes, as if some snag were cleared at that moment. It is unknown whether the turn command caused the the wing to stabilize, or if the timing of these two events was coincidental. The recovery beacon performed very well, with signal clearly readable from Yorke's driveway in Etna. The final coordinates were 43.69246, -72.08444, a point just east of Goose Pond. The SPOT gave almost identical coordinates (43.69248, -72.08444). The recovery team drove to Goose Pond Road and hiked about 1,000 feet east to find the gondola lodged about 50 feet up a dying spruce. The team returned on 6 August and recovered the vehicle. They used a line launcher to put a line through the rigging, and then pulled the vehicle down from the tree. The gondola itself came through this process nearly unscathed; the parafoil, however, was (as expected) badly damaged.
Although the science protocol was activated, and appeared to function correctly, the twilight sky was bright enough to saturate all images.
ALTAIR 13 -- 28Jun14This flight was intended as a medium altitude flight to test all current operational systems with the engineering light source. The plan was to launch from Thetford Academy just before dawn, climb to 6,500 meters, cut down, and then fly the parafoil to recovery at Robert Frost Lane. The science station was located at Robert Frost. The weather was excellent for the planned flight.
Both Launch and Science were on site and set up slightly ahead of schedule. There was some communications confusion that caused Launch to wait until Science had obtained a star alignment before beginning inflation, but all systems were ready for launch by 0445. Release occurred at 0446 EDT. Almost immediately after release, Launch stopped receiveing telemetry. As the vehicle rose above the hills, Science acquired the telemetry stream, but only for five seconds from 1256 m to 1286 m. Despite efforts to aim the antenna, no further telemetry was received.
As the vehicle flew over the science site, Paul scanned the sky in binoculars and located the balloon. We pointed the antenna at the vehicle, but still received no telemetry. The balloon burst at about 0600 at an estimated altitude of 27,000 m. Yorke observed the burst in binoculars.
After packing, Justin and Yorke estimated the burst position as being just west of Newport and the most probably landing site (assuming no gliding) as around Crescent Lake near Unity. We drove to that area and while seeking high ground by road listened for an RF Beacon signal, but heard nothing.
The previous two telemetry tests clearly indicated that there was a problem with the telemetry antenna. In early testing we demonstrated a solid connection between Mt Ascutney and Etna, even with duckie antennas on both gondola and ground station. In A12B, we had no data with the duckie, and good data with the yagi pointed in the opposite direction. GreenCube has reported intermittent antenna connection failures due to the female pin in the antenna wearing out with repeated making and unmaking of the connection. We proceeded with flight 13 on the assumption that the problem was multi-path interference, but clearly that was not the case. Most likely our antenna--a veteran of all previous flights--was defective.
ALTAIR 12B -- 23Jun14After the difficulties with A12A, we constructed a collapsible pole to elevate the gondola above the ground by about 10 feet. The pole will also mount a yagi antenna to improve telemetry over a challenging path. Using this apparatus we conducted a ground test with the gondola on the observation tower on Gile Mt and the science station at Robert Frost. The Gile Mt tower extends above the trees at the summit of Gile Mt and Robert Frost has a clear view of it. The path range is 16.8 km.
After setup at both ends, no telemetry was received from the gondola using the omni antenna. With the yagi installed, however, telemetry was reliable, and the test was able to proceed. Telemetry even worked with the Science antenna pointed in the opposite direction from the gondola.
Just before and after sunset we were able to obtain fair pointing even without a star alignment, and we obtained imagery without a dark background. The optical beacon was clearly visible in the finder scope. The science lights were visible as well, although not obvious.
After dark we obtained an excellent star alignment, centering alignment stars in the camera field of view rather than using the ocular. We ran the science protocol and obtained imagery including backgrounds for several cycles. For the most part, the ground station and the payload remained synchronized, but there were some anomalies similar to issues seen in the lab. For a period of time, the payload was not transmitting a GPS sentence.
Based on star tests, telescope pointing accuracy is usually within the field of view of the camera, but often at the extreme edge. Given the accuracy limitations of GPS, the gondola will often fall out of the field of view. The pointing offset facility in the sofware works effectively to bring a static target into view.
ALTAIR 12A -- 16Jun14A12A was a ground test with the gondola on the observation tower at the summit of Mt Ascutmey and the science station at Robert Frost. After setup at both ends, no telemetry was received from the gondola, probably due to mulit-path interference from both foliage at Robert Frost and terrain and observation tower structure at Ascutney. Ascutney is visible from Robert Frost, but through a fairly narrow window in the foliage. The range was 33.8 km.
We were able to get a good star alignment and use the telescope pointing system to find Mt Ascutney. The observation tower itself was not visible, but we exchanged laser pointer flashes. Without the ability to control the payload, we imaged Saturn as a test of pointing and focus. The focus difference between the 26 mm ocular and the camera is 1 turn CW.
After the Ascutney team returned to Etna, we attempted a shorter-range test between Dogford Road and Robert Frost. In this test telemetry was received, although with numerous errors. In this case there was considerable foliage around the Dogford Road site. Range was 4.24 km.
ALTAIR 12 -- 18May14Flight completed. Details to be posted soon.
ALTAIR 11 -- 12Oct13After our experience with A10, we decided that the only serious obstacles were keeping the parafoil dry before launch and having the manpower to operate the science station efficiently. Specifically, we needed one person to monitor tracking performance by viewing the vehicle in the finder scope, and another to operate the computer and take images. We assembled a team including new students and GreenCube volunteers to man both the launch station and a science station.
Coordinated by Kristo, the launch team set up on the grounds of Thetford Academy starting at 0400 Saturday. Once the launch setup was underway, Yorke took the science team to Robert Frost Lane in Etna and began setup at about 0445. No problems were encountered with any prelaunch procedures (despite the inexperience of many personnel). Science got a star alignment on the first try, focused on Polaris, and tested pointing on Mizar.
Launch occurred nearly on schedule at 0550. The science team acquired telemetry shortly after launch, and about the same time began observing the target visually in the finder scope. Humidity was high and there was a layer of morning radiation fog in the river valley, so the target was quite faint, but it was bright enough that the green color was quite evident. Tracking appeared dead-on, so no attempt was made to adjust the tracking offset. We began acquiring focus images in order to verify the target was in the field of view of the camera, and then began taking images of the beacon with 90 ms exposures. We also tried taking exposures of 2 s with the source in mux mode, hoping to get two images of different exposure.
Tracking appeared to work very well, with the image frequently occulted by the crosshairs in the finder scope! Yorke observed through the finder while Waad shot exposure on command when the telescope was not in motion and the targer was near centered. Jake monitored vehicle status.
As the vehicle rose above 4,000 m, Jake noticed that the climb rate had gone negative. We immediately cut down on the assumption that the balloon had burst but that there was still hope that the gondola and parafoil could separate from the balloon and we could try steering. Maximum altitude reached was 4489 m at 0602. Cutdown occurred at 0605 at an altitude of 3892 m.
Although the descent rate was nominal at -3 m/s, steering had no effect and it appeared that the vehicle was descending in a slow spiral. It eventually landed at 43.79997, -72.28112. LOS occurred at 0625 at an altitude of 316 m.
After packing up, we met in Norwich and proceeded to Stowell Road. Althogh we were unable to receive telemetry from the road, we reacquired telemetry both from a jeep road, and from the top of the ridge running along the road. The final location was 43.80000, -72.28084. Yorke hiked to this location and found the vehicle in the very top branches of a very tall red maple.
A little more than a week later, on 22Oct, a professional arborist climbed the tree and recovered the vehicle. On shroud line was broken during this operation, but it was easily repaired. The gondola itself appeared in excellent condition. The batteries recharged without a problem, and all systems were functional on test.
ALTAIR 10 -- 11Aug13With confidence in the parafoil and steering system, we attempted in this flight to do a complete end-to-end test including tracking with the LX200 telescope and image capture of the optical beacon with the SBIG camera. Launch was from Garipay Field just before morning twilight with expected fly-to-ground and recovery at Robert Frost Lane in Etna. The launch went smoothly and the beacon was visible naked-eye and in the LX200 finder scope throughout the flight. The position in the finder was about 1 degree off center, however, so despite good tracking performance, this offset put the image outside the field of 0.25-degree view of the SBIG camera. Consequently, we obtained no imagery of the beacon.
Cutdown took place as planned at 3,000 m, but apparently the parachute failed to deploy correctly and the descent proceeded at nearly 6 m/s rather than the proper rate of 3 m/s. Steering commands had no effect. The vehicle overshot the planned landing zone and landed on the top of King Hill in the Morton Farm woods.
Although there was no ELT or other RF beacon on board, we were able to drive close enough to the landing site to receive telemetry and determine the precise location of the vehicle. The vehicle was found that afternoon and recovered undamaged the following day. Once again, we needed to climb a tree in order to retrieve the vehicle, although in this case we were able to expedite the climb a bit by getting a rope over a branch about 20 feet up.
Since we were operating short-handed, the system waited with the balloon fully inflated for more than an hour while the downrange station was set up and prepared for launch. We speculat that during this time the parafoil picked up a substantial amount of dew which froze at altitude making the parafoil too stiff to inflate properly. There were no signs of spinning or instability in the data.
ALTAIR 9 -- 7Aug13ALTAIR 9 was originally intended to be a short-hop night free flight from Thompson's field in Taftsville to Robert Frost Lane in Etna. Clouds prevented this flight, however, so we made several tethered flights at Garipay Field using the new, rectangular planform 3 meter parafoil. All tests with the dummy gondola resulted in smooth deployment and stable, straight flight. We then attempted four flights using the test gondola. These flights all demonstrated stable steering on command. On the last flight, the vehicle snagged on a flagpole at the rugby field.
ALTAIR 8 -- 30Jun13
ALTAIR 7A -- 12Jun13
ALTAIR 7 -- 9Jun13
ALTAIR 6 -- 5Jun13
ALTAIR 5A -- 11Dec12
ALTAIR 5 -- 13Oct12
The LT-6 tracked well enough that the vehicle could be seen using the 25 mm ocular. Unfortunately, the 50 mm video telescope was not properly focused before launch and was unable to procure any imagery. Nevetheless, visual observation confirms tracking effectiveness, even for this fast-moving target.
The only operational problems at launch were the focus failure on the 50 mm telescope and a loose telemetry antenna connection that caused a brief loss of telemetry.
The landing zone was considerably farther downrange than expected, so once again we did not succeed in tracking all the way to the ground--although LOS occurred only 200 m above the surface, so we had a very good fix on the landing site. A ground team drove to the landing zone during the afternoon but received no ELT signal. The following week, on 18 Oct, we conducted an aerial search of the area, but despite our confidence in the landing location, we saw nothing. The week after that, on 24 Oct, a ground team walked to the predicted landing location and found the gondola on the ground. Examination of the gondola revealed no damage except a broken ELT antenna connection, explaining the failure of the ELT.
ALTAIR 4 -- 23Aug12
The optical payload was lost from sight within a few minutes of launch and was never seen either with the tracking telescope or in binoculars. The telescope appeared to track correctly, but this was impossible to verify because the light signal was not visible. All other aspects of the launch operations proceeded smoothly. The launch team consisted of only one experienced person and one inexperienced assistant. The new control software, including "night mode" and map plotting, worked well.
The recovery team lost signal for a brief time because of confusion in the hand pointing of the telemetry antenna. Nevertheless, the recovery team tracked the vehicle to within a few hundred meters of the surface so that eventual recovery was straightforward. The gondola was recovered intact on 31Aug.
ALTAIR 3 -- 14Jul12
Recovery--including tree-climb--was accomplished on 19Jun.
ALTAIR 2 -- 11Apr12
Despite the problems with descent and recovery, this flight demonstrated the effectiveness of the tracking algorithm and the tracking capability of the LT-6 telescope. We obtained imagery of the light source using the piggyback 50 mm telescope and video camera. Thermal management was very successful.
ALTAIR 1 -- 2Sep11