Spacebridge/NBRL-001: Infinite Improbability Drive

Another thing that got forgotten was the fact that against all probability a sperm whale had suddenly been called into existence several miles above the surface of Tracy, California.

Spacebridge Project: First Launch Report

NBRL-001: Infinite Improbability Drive

NBRL-001 Mission Patch

The Spacebridge project, a revival of an old Noisebridge initiative, aims to explore near-space environments using high-altitude balloons. This report details the first launch of the renewed project, highlighting our achievements, challenges, and future plans.

Date and Time:

2024-06-16 2:30 pm

Vehicle Type:

Unmanned Free Balloon

Launch Location:

McLaren Park, San Francisco, CA

37°43'10.7"N 122°25'10.6"W

Landing Location:

Tracy, CA (Estimated)

37°40'44.0"N 121°27'33.2"W

Objectives:

Pre-launch:

• 🟩Track and recover NWS radiosonde using SDR ground station
• 🟩Repurpose RS41 radiosonde to transmit telemetry on amateur radio band via APRS
• 🟩Identify appropriate launch location
• 🟩Plan safe and recoverable flight trajectory
• 🟩Communicate with FAA to issue NOTAM

Launch:

• 🟩Assemble and integrate payload and balloon subsystems
• 🟩Safely fill and handle balloon
• 🟩Launch!

Post-launch:

• 🟨 Take time-lapse photos with iPod touch
• 🟩 Receive radio signal from radiosonde
• 🟨/🟥 Track balloon position using telemetry data
• 🟨 Recover payload

Predicted flight path and landing locations. The black line indicates the expected flight path for a release at 10:00 AM. The colored dots indicate expected landing locations assuming a release at 10:00 AM and advancing hourly (11:00 AM launch, 12:00 PM etc.)

Launch Specifications

Balloon Details

• Type: 1500g balloon
• Color: Natural
• Neck Diameter: 1.3"
• Uninflated Diameter: 72"
• Standard Inflated Diameter: 22'
• Burst Diameter: 27'
• Hydrogen fill: 125L

Payload

1. RS41 board components:
   • Microcontroller
   • 70cm radio transmitter
   • GPS
   • Humidity sensor
   • Thermometer
   • Barometer
   • Battery pack
2. Two stuffed animals (Whale and Petunia) for future fundraising potential

Predicted Flight Parameters

• Estimated maximum altitude: ~35km
• Estimated time to peak altitude: 130 minutes

Launch Execution

Launch Process

The launch was conducted by the Spacebridge team, consisting of 15-20 participants with 5-10 regular members.

Tracking and Chase

1. A chase car equipped with a ground station followed the balloon's trajectory.
2. Signal reception points included Menlo Park/Redwood City and across the Hayward Bridge.

Challenges Encountered

1. Frequency band issue: Transmitted on 432.500 MHz instead of the national APRS frequency (144.390 MHz).
2. Recovery difficulties: The team was unable to recover the balloon and payload.

Data Collection

Telemetry Data Transmitted (via APRS)

• Callsign
• GPS coordinates (latitude, longitude, altitude)
• Temperature
• Voltage
• Contact email
• In-flight "conversation" between the Whale and Petunia stuffed animals

Communication Method

APRS (Automatic Packet Reporting System) was used for data transmission.

Ground Station Setup and Capabilities

[TO-DO: Add details about the ground station setup once available]

Technical Details

Main Circuit Board

(RS41) Capabilities The team repurposed a recovered RS41 radiosonde, which included various sensors and communication equipment.

Parachute Deployment System

[TO-DO: Add details about the parachute system once available]

Trajectory Prediction and Optimization

[TO-DO: Add information on trajectory prediction methods once available]

Results and Analysis

Maximum Altitude Reached

The balloon reached approximately 35km (to be confirmed with final payload weight).

Flight Duration

The balloon reached peak altitude in approximately 130 minutes.

Data Analysis

[TO-DO: Add detailed data analysis once all collected data is processed]

Lessons Learned

Frequency Band Selection

Future launches will use the national APRS frequency (144.390 MHz) for better integration with existing tracking networks.

Chase Strategy

Improvements needed in chase car deployment and tracking methods.

Ground Station Improvements

Plans to enhance the ground station setup for more reliable data reception.

Additional Lessons

[TO-DO: Add any other lessons identified by the team]

Future Plans

Improvements for Next Launch

1. Payload recovery strategies:
   • Prepare chase team to leave immediately upon launch or stage downwind
   • Improve ground station setup
   • Transmit on national APRS frequency for wider tracking coverage
2. Transmission frequency adjustment to 144.390 MHz
3. Ground station enhancements for better data reception and tracking

Long-term Project Goals

• Regular Sunday evening meetings to discuss progress and plan future launches
• Potential fundraising through auctioning space-flown collectibles

Conclusion

The first Spacebridge launch was a significant step in reviving this exciting project.