SRADio Skyline Test

Late Saturday evening on January 13th, SSI conducted a long-range test of its SRADio (Student Researched And Designed Radio) system. One team drove to a vista point on Skyline Boulevard, while another team went to the Stanford Radio Shack, which is positioned along The Dish trail. The Skyline team transmitted packets while the Stanford team received them. Under various settings, the number of packets dropped out of a benchmark of 20 was counted.

The radio system performed well at an effective distance of 31 kilometers at a data transmission rate of 5 and 50 kilobits per second, which proved it successful for the applications it is designed for.

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The SRADio system was built by Sasha Maldonado, Sharon Platt, Aria Tedjarati, Joan Creus-Costa, and Tim Vrakas. The system will be used by the IREC team to downlink live telemetry from the rocket. It will also be used by the ValBal and Buzz projects to set up a continental US-wide high altitude balloon communication network.

To simulate the environment of a rocket, the Skyline team placed the transmitter inside a rocket airframe. The carbon fiber of the rocket’s airframe can affect radio wave propagation because it is conductive. While the team was planning on building a carbon fiber rocket at the time of the test, the team has since decided to switch entirely to fiberglass.

 The large distance between the two points, which is about ten kilometers, ensured that the radio would function at great distances. A shorter range test can be conducted with attenuation in place of a long range test, however there is the risk that the signal bypasses the attenuation by being transmitted or picked up by the traces on the transmitter or receiver board. As a result, short range tests are not always reliable indicators of whether or not a system will function at great distance.

Halfway through the test drag racers showed up at the vista point parking lot the Skyline team was positioned at. The San Mateo Police Department and California Highway Patrol swiftly arrived to stop the dangerous activity, and permitted the Skyline team to finish the test. We would like to thank the San Mateo Police Department and California Highway Patrol for their support during the test. Without them the test could not have been fully completed.

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SSI 63 Shatters World Record (Again)

On December 9th, 2017, the Stanford Student Space Initiative (SSI) Balloons Team soared to new heights for high altitude latex balloons research with the launch of ValBal Mk VIII. Our high altitude balloon ValBal, short for “Valve-Ballast”, is a novel platform that uses a valve to vent helium gas and releases biodegradable BB pellets as ballast to maintain altitude stability. Additionally, the new ValBal design introduced essential innovations for space technology, including flexible 3D printed parts and a new control algorithm. 

SSI-63 was the first ValBal launch of the 2017-2018 school year, a wondrous experience for new balloons members and veterans alike. Early Saturday morning we all set off to Hollister to launch our balloon, and although we had planned to fly SSI-63 in tandem with its SSI-64 Carbon copy (pun intended), we ultimately made the decision to launch only SSI-63 while reserving SSI-64 to break the transatlantic record.

This flight incorporated several new elements, from cost-effective and simple-to-assemble 3D printed structures, an autonomous altitude controller that improved our self-equilibrating latex balloon, a new avionics breakout board, and more. 

Throughout the 5 long days of nonstop flight control monitoring via the High Altitude Balloon Mission Control Suite, or HABMC, our balloon made several loops through California, journeyed across Nevada, Arizona, and even Mexico before finally descending in southeast New Mexico after exhausting all of its ballast. 

With an astounding 121 hours and 34 minutes, the results of the SSI-63 flight surpassed the previous world record of 88 hours and 40 minutes for the longest duration flight by a latex balloon.  

Balloon recovery was very successful, with minimal damage to the payload structure overall. The amazing feats of SSI-63 confirmed several predictions, as ValBal is an inexpensive alternative to launching satellites or flying planes for many applications. In the future, ValBal may be used to fly an ice radar to track global warming progress in Greenland, monitor natural disasters such as the wildfires in southern California, and as an aircraft testing telemetry relay.

As 2018 descends upon us, the SSI Balloons team is excited and working harder than ever to revolutionize high altitude balloons research. Our goal is to circumnavigate the world within the next year, and the launch of SSI-64 in January will mark the beginning of a new era.

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John Grunsfeld: NASA Astronaut and Former Chief Scientist Comes to Stanford

Wednesday November 8th in Durand 450, at 7pm. Food provided; RSVP at

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John M. Grunsfeld was named Associate Administrator for the Science Mission Directorate at NASA Headquarters in Washington, D.C. in January 2012. He previously served as the Deputy Director of the Space Telescope Science Institute in Baltimore, managing the science program for the Hubble Space Telescope and the forthcoming James Webb Space Telescope. Grunsfeld's background includes research in high energy astrophysics, cosmic ray physics and in the emerging field of exoplanet studies with specific interest in future astronomical instrumentation.

He will be speaking in Durand 450 on Wednesday at 7pm.

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Gwynne Shotwell: Road to Mars

Tickets at

As President and COO of SpaceX, Gwynne Shotwell is responsible for the company’s day-to-day operations and for managing all customer and strategic relations. She joined SpaceX in 2002 as Vice President of Business Development and the company’s seventh employee. Since that time she has helped SpaceX secure over 100 missions to its manifest, representing over $12 billion in contracts.

In addition to building the Falcon vehicle family of launches, Shotwell is also driving efforts to fly people on SpaceX’s Dragon spacecraft, send private passengers around the Moon, and land the first private spacecraft on Mars.

On Wednesday, October 11th, Shotwell will share SpaceX's story on the road to Mars. After the talk, there will be a Q&A session hosted by Steve Jurvetson from DFJ Venture Capital.
Doors open at 6:30pm.

If you'd like to donate to SSI for hosting this event, please visit Thanks!

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Launching Balloons at Total Solar Eclipse

This August 21st, SSI had the wonderful opportunity to view and launch some balloons from Central Oregon during the Great American Eclipse.
Photo Credits to Anjali Roychowdhury
In order to launch in the band of full totality, we endured a 12-hour drive up to Oregon, braving traffic, supply shortages, and the hoards of people also vying to catch a glimpse of this incredible sight.
The SSI Family
Once we arrived, we prepared to launch two payloads; a live ATV video stream and sun tracking photography payload, and ValBal Mk VIII-A.
The ATV and photography payload included a DSLR, a drone camera attached to the ATV live stream video transmission system, and three Go-Pro cameras, one of which was modified with a motor system and magnetometer to track the sun during flight.
This ValBal flight was a test of a brand new mechanical system made of three 3D printed modules: a ballast module which controlled the release of the biodegradable BB pellets we use as ballast, a payload support, and a valve module which opened or closed to control the release of helium from the balloon during flight control. This new design is a monumental step forward in our technology, not only making ValBal much easier to assemble, but also reducing weight by over 40%, giving us longer flight times and a greater capacity for cool scientific experiments.
About to launch ValBal Mk VIII-A
We launched our photography payload from Ochoco state park just in time to catch the eclipse, and our photography payload captured some amazing images of the total eclipse from thousands of feet in the atmosphere! We launched ValBal right after the eclipse.
The total eclipse from thousands of feet in elevation
We watched our balloon disappear into the sky as darkness set down upon us. From our launch location, high on a cliff, we could see all around us for miles. The shadow of the moon rushed towards us and then everything went dark. The horizon glowed all around, like a 360-degree sunset. The sun itself was replaced by a black circle surrounded by a bright ring, the suns corona. We stared up at it for a minute in awe, and then the moon moved on and the sun came back into view. The light flooded back over the landscape and it looked like a time lapse of a sunrise.
A full minute of darkness
It was a breath taking experience, and wouldn't have been possible without everyone who helped contribute.
SSI-58 mission patchFinally, we would like to thank the Platt family for generously hosting us at their home.

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