Date: August 18, 2007

Launch Time: 06:05 AM PST

Objectives:

  1. 1)fly high resolution digital SLR camera. Canon XTi with 10-20mm super-wide angle lens.

  2. 2)introduce new students to the NevadaSat program

  3. 3)test new GPS logger

  4. 4)compare HAM radio and FRS radio systems

  5. 5)test new 8- relay DTMF board

  6. 6)test wind-powered gyroscopic stabilizer

  7. 7)set record for highest LEGO NXT in the world


Balloon Weight: 3000g

Launch location altitude: 3900 feet, N40°8'3.35"  W119°43'41.99

Max Altitude: 96,965' (Above Sea Level)

Burst time: 8:05 AM, N40°33’24.41”    W119°22’17.7

Ascent Rate: 1240 ft/min (average)

Descent Rate (at landing): ~1650 ft/sec (average)

Landing time: 8:28 AM  altitude: 5050 feet,  N40°44'45.22" W119°8'44.08"

Mission Range: no calculated (yet)

Mission Duration: 1 hour, 38 minutes (liftoff to touchdown)

Payloads recovered at 9:39 AM (after very steep hike up Trego Mtn)

Conditions: Very clear, no surface winds, exceptional visibility at altitude.


Payload photos and YouTube video in the photo gallery

 

Summary:

Our sixth launch of 2007. This mission was successful on all accounts. We flew 5 payloads, 3 with cameras, 2 with communication equipment. A radar reflector and 60” Tac-1 parachute were also used. We had exceptionally good weather during the mission, with no clouds, smoke and very low humidity.


The main camera payload contained a high resolution digital SLR with a Sigma 10-20mm lens. The Canon XTi returned the best pictures of any mission to date. Although, many of the photos were over-exposed (half the photo is black, so in hindsight this makes sense), the photos look great. We learned to step down the expose 2 full stops in the future. The main camera payload also contained 2 Aiptek pencams, used to capture VGA quality video during the mission. All 3 cameras were controlled by a LEGO NXT (see below).


The other two camera payloads (UNLV, WNC) contained ‘point and shoot’ cameras (Pentax Optio 33WR and Nikon Coolpix S9). Both cameras functioned perfectly for the entire mission. The Pentax camera was controlled by a timer circuit while the Nikon has built-in auto-timer function. The WNC payload also contained a HOBO datalogger that logged internal and external temperatures.


We had two HAM radios using APRS on board. Our 1.5W Yaesu VX-2R on 433 MHz using a TinyTrak module and a 300mW MicroTrak on 144 MHz (national APRS). Both functioned perfectly for the entire mission. The VX-2R utilizes a fairly omni directional antenna and high power so that we can track the balloon from directly beneath it. The MicroTrak uses a high gain J-Pole antenna so that we can ‘hit’ the repeaters when the payload is close to the ground (increasing our chances of locating the payload if we lose direct contact). The last reported position on FindU.com was at 11,977 feet (6,000 feet above and about 1 mile away the final landing location). We received GPS packets from both systems the entire mission, including after touchdown (making locating the payloads easy).


We also flew our ‘backup’ tracking system, a satellite-based animal tracking system. This system transmits GPS locations to the ARGOS satellite constellation and, therefore, is not dependent on line-of-sight like HAM radios. The unit will continue to transmit for approximately 30 days, allowing us to recover the payloads in the unfortunate event that it lands in a remote area in Nevada. The unit lost GPS lock above 60,000 feet (as expected) but did not reacquire GPS lock when the payload fell below 60k feet. During the previous mission (NBS-07-01) the unit functioned properly. [Also functioned properly on subsequent mission NBS-07-07].


The UNLV payload also contained their standard tracking system - a Rhino GPS that has been ‘hacked’ so that it transmits location every minute. The Rhino doesn’t report altitude data above a certain altitude (not sure but best recollection is 30,000 feet). The Rhino did send GPS packets the entire mission, including while on the ground. In the end, the Rhino system dropped more packets than the HAM radio system, but would have been sufficient to track the payloads during the entire mission. The main disadvantage to relying on the Rhino is that you don’t know when the balloon has popped (since no altitude data at that elevation). The UNLV payload also tested the concept of using a wind-powered gyroscope to stabilize the payload. The reaction moment caused the payloads to spin opposite the rotor. The spin rate of the gyro was unknown.


We also implemented a 8-relay DTMF board. The board was connected to the Yaesu VX-2R radio (using a frequency shift so that send and receive frequencies were different) and uses 8 distinct DTMF codes to activate the relays.  Four of the relays were set up for cut-down (burn) circuits (6V lithium photo battery and NiChrome wire). The other four relays are set up as simple switches that can be sensed by a microprocessor, thus providing the ability for commands to be sent to the payload. The DTMF board functioned perfectly.


The 3 cameras in the main camera payload were controlled by a LEGO NXT programmable brick. Camera relays were activated by the NXT motor ports at regular timed intervals. The timing intervals were set using the DTMF commands, which were sensed on the input sensor ports of the NXT. The NXT logged the DTMF commands received so that we could verify, post mission, whether or not the DTMF board worked. We think this sets the record for the highest flying NXT in the world [subsequent mission NBS-07-07 raised the record to 101,000 feet].