Flight Recap EOSS-40

LAUNCH DATE: April 16, 2000 
LAUNCH TIME: 09:03:21 MDT, 15:03:21 UTC
LAUNCH SITE: Windsor Colorado (Gene Fatton's Ranch See Map)

  • 40 deg 28.493' North Latitude
  • 104deg 57.756' West Longitude

Predicted Landing Site
Landing Point: 40.368� lat. -103.6513� long.
Altitude: 4199 feet
Flight Time: 117 Minutes
Bearing: 95.7� True
Range: 69.3 Mi.

Actual Landing Site
Landing Point: 40.2317� lat. -103.5613� long.
Bearing: 102.3� True
Range: 75.6 Mi.

Difference from Predicted to Actual Landing Site
Bearing: 153.3� True
Range: 10.5 Mi.


  • Operational training for Colorado University - Boulder Students.


  • Launch Site:
    • Simplex 146.550 MHz
  • Telemetry: (operational)
    • 144.340 MHz FM (1 Watt output) - The Packet telemetry stream is in ax.25 format at 1200 baud and is readable in plain English for the most part. Included in each telemetry frame is an APRS position string (APRS users see note below). Every few minutes a CW ID is transmitted on this frequency.
  • APRS Package - (failed, no antenna found at recovery site)
    • 144.390 MHz
  • X-Band Repeater and Beacon: (input failed, output beacon worked fine)
    • 445.975 MHz input
    • 147.555 MHz output This is the primary beacon for the Tracking and recovery teams and the constant output of the RMRL cross band repeater.
  • ATV: worked fine
    • EOSS Shuttle Video - 426.250 MHz AM (1 Watt output) - NTSC video
  • Foxhunters:
    • 449.450 MHz 103.5 Hz PL Toned Rocky Mountain Radio League Repeater WA0GEH Field Coordinator
    • 146.58 MHz Simplex Field Frequency
  • HF Net:
    • 7.235 MHz NO HF net was held

Flight Map

Map by Street Atlas V 7.0

Balloon Track by APRS-Plus

Predicted Track by Balloon Track

I received only incomplete packets due to my local horizon and the distance to the payload.

This screen shot was composed using Street Atlas 7, APRS-Plus beta 1.99 and Balloon Track 1.5.8 and a hand entry for the final touchdown.

The almost solid blue line composed of blue squares is the actual flight path. The blue and red diamonds north of the actual path represent the predicted flight path from the winds data. Blue is ascent, red descent. The plot of the landing site was obtained indirectly from the payload on the ground. After landing it was still beaconing out aprs and telemetry data. Larry, K0ANI, cross banded the signal into the RMRL 449.450 repeater, and I was able to copy those packets to a log file. The landing GPS data was corroborated as described below by Rob, N2ZVV.

General and from the Landing Site:

Via K0ANI, Larry on site at the landing.

Ranchers Bob and Jim (contacted on site by N0PUF) gave permission to enter the property.

The jpole antenna for the APRS 144.390 MHz package was totally missing at recovery. 

The jpole antenna for the RMRL Cross band repeater was severely damaged thus rendering receive on 445.975 deaf.

Rod, N2ZVV, took a walkup GPS reading of the payload on the ground of :

  • 40� 13.906' N
  • 103� 33.670' W

Lonnie N0PCZ was taking digital video at the landing site and extracted the following (and more but no room) snaps for me. I clobbered them with Photoshop to make them look "better" but that's a matter of interpretation. 


The hunters gather.

Approaching the payload on the ground, that orange thing is the parachute. It's tough here in Colorado to spot a payload on the ground.:-)

Surface winds kept the 'chute inflated making for an easy eyeball target

Shuttle II lying on its side

As seen above the shuttle is lying on it's side. If rotated 90� counter clockwise it would be right side up. The circular object is a rotatable mirror allowing ATV viewing angles from straight down to straight up.

From the Ground Station:

The ground station for EOSS 40 was set up in comfort in Gene's sun room, with the antenna array set up immediately outside. 

The help of the CU students in setting up and breaking down the antennas was greatly appreciated. Both Yagis were set up for horizontal polarization and provided good results. 

We had solid video and telemetry from launch to 6800 feet on the descent. We actually had some video after the last packet.

There was a brief problem with the shuttle GPS but Larry was able to get it reset with a hard reboot. 

We did turn the ATV off a few times to see if it was the reason for the lack of receive on the cross band repeater but there was no effect. The reason for the deafness of the repeater is now known; broken receive antenna. 

The students were set up to monitor the VSI package on 144.39. Unfortunately reception of the package was lost at launch, another broken antenna. The students and Bill, K0UT were able to switch to 144.34 to monitor the shuttle telemetry, which gave them enough data, altitude, time and temperature to work with. However, both groups apparently suffered from poor antennas and possibly receive sensitivity. They were using vertically polarized multi band monitor antennas and scanners and did not get good telemetry, particularly during the descent phase of the flight. 

A copy was made of the ground station log and given to them and I will work with Mike to e-mail them the data when he can download it to a more intelligent computer. 

I suggest that we advise all of our "customers" that, if they want to collect their own telemetry, they will need a gain antenna, even if it is omnidirectional. Even a fixed Yagi, four elements or so, would work. From the adjustments I made on the long Yagis, I would bet that a wider beam antenna, set at around 15 degrees elevation and pointed down the predicted track bearing would provide good copy for most flights. At the least, they should be using a Ringo, Isopole, or 5/8 wave. 

The video was recorded on Merle's recorder and the tape given to the customer. I did not have time to reconnect the monitor to the recorder and so would like to hear how the tape came out. We had P5 video throughout the flight except for some fading during the initial descent. We could easily identify lakes, rivers, roads and crop circles and the students were able to place the balloon's position on a map by identifying the landmarks. 

73 Dave KB0LP

Telemetry and Misc. Files

EOS40TLM.ZIP contains:

  • A log file in ASCII text

  • A Street Atlas 7 overlay of the Pre-Flight situation

  • A Street Atlas 7 overlay after touchdown

  • An APRS-PLUS Position log file for the flight as captured at my QTH 30K on the way up to 26K or so on the way down.