About OLHZN-8 :: Rectify
Result: Success!! 109,102 FT.
OLHZN-8 was the eighth high altitude weather balloon flight for Overlook Horizon High Altitude Balloons. This flight launched on August 1, 2017 at exactly 10:00:00am ET (14:00:00 UTC). The focus of this flight was to have a short recovery distance and we were also looking to resolve our radio positioning broadcast issues that occurred on OLHZN-7. We thought we had this resolved once and for all after OLHZN-5 successfully transmitted throughout the entire flight, but this issue returned unexpectedly on the last flight due to some voltage drops that occurred when the radio transmitter began its broadcast. This flight again used a third Lightdow LD4000 Camera upwards facing camera recording the balloon to obtain better footage of the balloon burst than we obtained on OLHZN-7.
Flight Day Story
The launch of this flight was unique in that it was our first completely solo launch that was performed by only 1 member of the team. This was simply because the flight was launching in the middle of the week and in the middle of the day so most of the team had to work. Solo launches are much more difficult to perform, particularly when it comes to inflating and sealing the balloon as well as making sure the launch procedures stay on track for an on time launch. Even with those difficulties, we were able to launch on time with a liftoff of exactly 10:00:00am ET (14:00:00 UTC) – on time down to the second!
Around the T-15 minute mark, prior to launching, we were experiencing some issues with one of our cameras failing to power on. It was determined that one of the battery lines for the camera had a loose / broken connection. We were able to quickly piece it together to get the camera to power on, but it was a very weak solution so we were not confident that it would last for the entire flight. Fortunately, upon landing, we discovered that all three cameras performed perfectly and somehow the loose connection stayed in place and capture the entire flight, including some fantastic footage of the balloon burst!
The radio tracking system changes we made for this flight to rectify that issues on OLHZN-7 work almost perfectly. We were able to track the entire flight all the way to 109,102 FT. when it reached our highest achieved altitude yet! The flight computer remained powered-on and functioning throughout the entire flight and did not power cycle at all during flight. We did experience one minor issue with the flight computer that we’ll be looking to resolve on OLHZN-9, which was that the landing alarm cut-out early and stopped sounding at around 1400 ft. in altitude. When this occurred, the flight computer seemingly locked up and stopped recording data so the last 20 seconds of the flight were not recorded with the onboard systems.
Despite the system failing in the last 20 seconds, the most exciting part of the flight came within those last few seconds when our solo recovery “team” was on-site for the landing. We were so close to the landing site that we were able to literally run to the payload and caught the payload line in our hands before it hit the ground! This was incredibly exciting and a very rare opportunity that we may never see again! This event was captured during the live broadcast and you can see the catch as it happened.
Overall, this was our most successful flight to date and was the closest we’ve come to perfection on one of our flights. It was just short of perfect as we did have some very minor issues, but we’d call this a 99.9999% success and we had some amazing achievements:
- Solo launch by only 1 team member
- Perfect on-time launch to the second!
- New record for maximum altitude achieved at 109,102 FT.
- New record for shortest downrange recovery achieved at 5.01 miles
- Nearly perfect flight computer performance
- Flawless in-flight camera performance for all 3 cameras
- Caught the payload as it landed!
The maximum altitude on this flight was 109,102 ft. which was recorded at 12:05:14 ET over East Bloomfield, NY, just 6.26 miles from our launch site. This burst event occurred only 46 seconds prior to our predicted burst time of 12:06pm ET. This is the highest recorded altitude we’ve achieved up to this point.
This flight again featured a third Lightdow LD4000 Camera as an upwards facing balloon camera to try to capture better footage of the balloon burst event. We also added two sets of capacitors to the power rails to try to smooth out voltage drops that occurred on OLHZN-7 in the colder temperatures, causing the Arduino to power cycle continuously during the flight. The first set of bypass capacitors was on the unregulated battery input to smooth out any voltage drops on the battery that could occur. The second set of bypass capacitors was on the regulated 5V rails for the Arduino’s power output to the components, like our radio transmitter. This set of capacitors drastically improved the flight computer performance and worked well to smooth out ripple effects that could occur when the transmitter needed more power, but the Arduino’s 5V regulator may need a microsecond to catch up to the increased power demand causing an incredibly brief, but significant brown-out / voltage drop and a subsequent power cycle.
This flight again featured a large 1200g balloon to ensure an altitude of over 100,000 ft. Due to the quick turnaround after OLHZN-7, this flight had a much smaller 600g backup balloon that we already had on hand. The 600g balloon size was last used on OLHZN-4. The 1200g balloon performed flawless on this flight.
One of the main perks of this launch date was the possibility of a very short downrange recovery distance. On this flight, we set a new group record for shortest downrange landing of just 5.01 miles from the launch site. Previously, our shortest downrange recovery was 17.6 miles which was achieved on OLHZN-2. Additionally, the payload never traveled more than 8.63 miles away from the launch site at any point during the flight. It reached 8.63 miles away at 6565655 ft. in altitude. Lastly, the payload also passed within 0.56 miles of the launch site at 96,196 ft. in altitude at 1 hour and 52 minutes into the flight which is another interesting and unique note.
The maximum achieved ground speed for this flight was just 48 mph. This is lower than we’ve seen on some flights, but one note that is very interesting is that this maximum speed was achieved at 101,974 feet in altitude. We’ve never seen the maximum ground speed occur at such a high altitude before.
The minimum temperature we recorded on the flight on the outside of the payload package was -55° F which occurred at an altitude of 53,185 ft. This temperature appeared pretty consistently between 40,000 ft. and 55,000 ft. We’ve seen much lower temperatures in the past, but that’s still cold!
After the balloon burst at 109,102 ft., we recorded the fastest freefall vertical drop speed of 129 mph which occurred at 106,890 ft. The payload fell at over 100 mph for the first 10,000 ft. It remained about 50 mph until 68,000 ft. and didn’t reach a gentle 25 mph until it hit 38,000 ft.
The launch time was bumped up significantly in the final hours prior to launch in an attempt to try to achieve the shortest possible downrange landing distance. Wind predictions were looking great for a Tuesday morning launch that would allow us a single digit recovery distance. Unfortunately, our launch team was very slim due to this launch time, but we had to try for the shortest recovery distance possible! This also gave us the opportunity to perform a solo launch procedure. These images were the final flight predictions from the midnight forecast that we operated off of with an on time launch of exactly 10:00:00am ET / 14:00:00 UTC. Another prediction was available around 6:00am ET on launch day, but our FAA notifications had to be completed no later than 6 hours prior to launch time so the launch time couldn’t change after this point.
Launch Time: August 1, 2017 at 10:00:00am ET (14:00:00 UTC)
Launch Location: Canandaigua Academy, Canandaigua, NY, USA
Ascent Rate: 4.20 m/s (Target: 4.35 m/s)
Burst Altitude: 109,102 ft. (Target: 108,000 ft.)
Time to Burst: 125 minutes, 14 seconds (Expected: 126 minutes)
Helium Volume: 122.7 cu ft. (Target: 124.9 cu ft.)
Payload Mass: 1615g (3.56 lbs)
Neck Positive Lift: 751g (Target: 816g)
Landing Speed: 5.45 m/s (Target: 6 m/s)
Descent Time: 38 minutes, 6 seconds (Expected: 37 minutes)
Landing Location: Prosecco Italian Restaurant, Farmington, NY