Stanford’s Student Space Initiative Group Sets Up Shop in HEPL South/End Station III

There's a Beehive of Activity in the 3rd Floor Northeast Corner of HEPL South/End Station III

Recently, I got word that a group of Stanford students comprising the Student Space Initiative (SSI) group had moved into a small warren of rooms behind the loading dock on the third floor of the HEPL South/End Station III building, and that I might want to write a story about them for this website.So, one afternoon I set out to find out about the Stanford SSI group and what they were up to in HEPL South/End Station III.

HEPL South’s End Station III — The Perfect Home for a Group of Space Explorers

End Station III Loading Dock

The loading dock outside
the End Station III section of
HEPL South

Door to End Station III

The door to End Station III

Standing on the main floor of End Station III, looking northeast

Standing on the main floor,
looking towards the north-
east end of End Station III

Looking up at the 3rd floor SSI offices from the main floor

Looking up at the third floor
SSI offices from the ground
floor of End Station III

The pair of concrete, mostly subterranean, blockhouse bunkers—now called “HEPL South”— on Panama Street, across from the old Roble Gym, is the last visible remnant of Stanford’s 1940s-1960s pioneering work in linear atomic particle accelerators that in 1967 led to the development and construction of the current 2-mile Stanford Linear Accelerator (SLAC).

The HEPL South buildings were originally named End Station II and End Station III, because they were the target rooms at the end of the concrete-shielded, 300-foot tunnel beneath the original High Energy Physics Lab building—later renamed the Hansen Experimental Physics Lab (HEPL)—where beams of particles were accelerated to as much as a billion electron volts (GeV) by the time they reached the End Stations. The HEPL building was demolished in 2007 to make room for the current Stanford Science and Engineering Quad, but the two end stations remain as a testament to Stanford’s extraordinary research and development in high-energy particle physics during the latter half of the 20th century.

Imagine what it would be like walking into a space station—or perhaps, a four-story tall, underground Costco warehouse. That’s the feeling I get stepping into End Station III. It’s a cavernous space, with six-foot thick concrete walls, extending three stories underground. The building has numerous nooks, crannies and tunnels, along with offices on two mezzanines on one wall.

Nowadays, End Station III is home to a number of physics/engineering research project workspaces, including a small clean room. It’s also home to some priceless equipment from previous research projects, such as the lapping and polishing machine and the roundness-measuring machine used to create the perfectly spherical gyroscopes for the 50-year Stanford/NASA Gravity Probe B experiment/space mission.

April 2017 — A Visit to the SSI Quarters in End Station III

Sandip Roy photol

Sandip Roy, a new SSI

SSI Mural

The SSI mural next to the
elevator on the 3rd floor,
northeast wall of ES-III

SSI logo and bannner

Logo on SSI door and
banner on the wall outside
the group's offices


SSI workspace montage

Photo montage of the SSI
workbenches, storage
shelves and nooks, and a
conference table

Access to End Station III is controlled by key card, so I contact Dorrene Ross, manager of the building, and she puts me in touch with Sandip Roy, a new member of SSI who eagerly agrees to meet me at the loading dock and show me around the SSI quarters.

Upon exiting the elevator on the third floor of End Station III, outside the SSI workspace, the first thing I notice is an in-progress, floor-to-ceiling space mural on the hallway wall. The mural depicts outer space, with stars and the Milky Way, the Earth in one corner, a raccoon in a space suit floating near a meteor or asteroid and a spaceship nearby. Clearly, the SSI group includes some budding artists.

The door to the SSI quarters is decorated with a three-foot circular rocket logo, fashioned out of a reddish-bronze metallic coated substance. And, on the wall next to the door hangs a large banner declaring the rooms within to be the home of the Stanford Student Space Initiative.

Sandip opens the door, and I enter a warren of small rooms filled with lab benches, shelves of electronic equipment, tools, books, laptop computers—even an alcove containing rocket hulls and nose cones. This place has the look and feel of a high school FIRST Robotics team workspace…however, moving beyond terrestrial robots, these Stanford students’ interests are clearly “out of this world.”


The Stanford SSI in a Nutshell

So, what is the Stanford Student Space Initiative? According to the SSI brochure and website, SSI is:

…a completely student-run organization founded in 2013 with the mission of giving future leaders of the space industry the hands-on experience and broader insight they need to realize the next era of space development.
SSI Balloons Team photo

High Altitude Balloons team

SSI Rockets Team-Night Launch photo

Rockets team

SSI Communications team-10km optical communications test

Satellites team

SSI Biology Team-2017 DNA Processing workshop

Space Biology team

Their website notes that SSI is Stanford’s largest project-based student group, with approximately 200 dues-paying members. SSI comprises six space-related project teams:

  1. High Altitude Balloons Team. (Faculty Advisor: Professor John Pauly, Electrical Engineering & Biomedical Imaging). The Balloons Team has launched and recovered over 50 high altitude balloons carrying scientific payloads to over 100,000 feet. They've set the world record for latex balloon flight duration and are aiming to circumnavigate the globe.
  2. Rockets Team. (Faculty Advisor: Professor  Hai Wang, Mechanical Engineering). Making aerodynamic objects propel unique payloads to high altitudes since 2013, the Rockets team has certified over 35 members of SSI for high powered rocketry. In addition to a bid for IREC 2017, the team will continue work on Project Daedalus, a series of smaller projects to increase expertise in all aspects of rocketry.
  3. Satellites Team. (Faculty Advisor: Professor Simone D’Amico, Aeronautics and Astronautics). The Satellites team builds imaging and scientific instruments, sensors, distributed networks, and optical communication systems. They're currently working on a CubeSat to test long range optical communication in space.
  4. Space Biology Team. (Faculty Advisor: Associate Professor Drew Endy, Bioengineering). The Biology team is building devices to sustain life in space, and to use life to accomplish missions in space. They’re currently working on building a DNA synthesizer for microgravity, which will be the first device to synthesize DNA in space.
  5. Operations Team. In addition to facilitating events among members, the Operations team brings speakers to Stanford and sends members to see centers of aerospace innovation. They recently brought Gwynne Shotwell, President and COO of SpaceX, for a talk on campus, and have a long list of space industry stars they’ll be bringing to campus later this year.
  6. Policy Team. The Policy team researches the legislation, market trends, history, and philosophy that has affected the development of the space industry. They're teaching their third iteration of a class on space policy and will be travelling to Washington, DC this year for direct engagement with lawmakers on space policy.

As noted above, each SSI technical team works with a faculty advisor. The faculty advisors play an active role in helping their teams define and achieve their goals.

Each team elects two co-leads. In addition, SSI members hold various management positions, including co-presidents, financial officers, community manager, operations manager, marketing manager, alumni coordinator, education and public outreach coordinator, diversity and inclusion coordinator, space manager and webmaster.

The group has enlisted support from more than 20 corporate sponsors, representing a variety of industries. In addition to project-based events such as balloon and rocket launches, SSI has hosted speakers and led the student-initiated class, “Why Go To Space?” in the Stanford Aeronautics and Astronautics Department.

The SSI Satellite Group’s Inter-Satellite Laser Communication Project

Back in the SSI quarters on the third floor of End Station III, Sandip introduces me to Sasha Maldonado, one of the Co-Presidents of the Stanford SSI.

Sasha Maldonado photo

Sasha Maldonado,
SSI Co-President

Michael Taylor photo

Michael Taylor, SSI
Satellites Team

In response to my question about what goes on here in the SSI quarters, Sasha brings me to a workbench and introduces me to Michael Taylor, a graduate student in Electrical Engineering, who tells me about a CubeSat-to-CubeSat space laser communications project that the SSI Satellites Team has been working on.

Michael explains that initially, the team investigated a couple of CubeSat scale (miniaturized satellites for space research, comprised of multiples of 10×10×10 cm cubic units) space-to-ground communication projects—one at MIT, and another at Aerospace Corporation—both creating a high-speed, laser downlink from a satellite to Earth.

Given that high speed space-to-ground communications had been achieved, the SSI Satellites Team set its sights on the more difficult goal of achieving high speed satellite-to-satellite optical communications.  Specifically, the team wants to launch two CubeSats into orbit, 100+ km apart, communicating with each other via low-powered lasers.

The goal of this SSI Satellites Team project is to achieve a high communications data rate between satellites for applications such as network relays, formation flying, precision timing and ranging, gravity wave detection, and so on. According to Michael, NASA has been working on this problem for years, and the European Space Agency (ESA) and the German Space Agency (DLR) have already launched relatively large sized satellites that are communicating with each other at reasonably high data rates. However, the SSI Satellites Team’s focus is on achieving high data rate optical communications between much smaller CubeSat scale satellites.

To this end, over the past couple years, the Satellites Team members built two prototype laser communications modules, named Rosencranz and Guidlenstern (from Shakespeare’s play, Hamlet), one of which was sitting on the workbench where we were standing.

Optical communications prototype (3 views)

Three views of the SSI Satellites Team prototype laser communications module

It consists of a receiver about the size of a small trash bucket. Its front frame is about 16 inches square, with four trapezoidal-shaped plastic or cardboard sides, tapering to a 3-inch square back plane containing the optical receiver. The front frame is covered with a Fresnel lens that focuses the incoming beam on the receiver. A small, low-powered laser—similar to the kind used by presenters to point at PowerPoint presentations— is attached to one side of this receiver module.

2016 Lake Lag optical communications test

Lake Lag nightime test of a
pair of prototype optical
communications modules

In February 2016, the Satellites Team took these two communications modules, mounted on tripods, to opposite sides of Lake Lag, a few hundred meters apart. There, using differential pulse position modulation at the rate of 10 kilobits per second, team members were successful in sending text from Hamlet from one module to the other and vice versa.

However, the team’s ultimate goal was to communicate across a distance of 10 kilometers or more. So, the team placed one communications module on the hill where the Stanford Dish  [radio telescope] is located and the second module in a line-of-site clearing, 10 kilometers away on Skyline Blvd. Again, team members were successfully able to transmit text from Hamlet, at a rate of 10 kilobits per second, over a distance of ten kilometers.

At the same time, the SSI Satellites Team was writing a proposal to NASA’s Small Satellite Technology Program to obtain funding for their ultimate goal of miniaturizing their satellite-to-satellite laser communication experiment to CubeSat scale. This NASA program had some funds set aside for university teams doing research in this area, partnering with a NASA JPL lab (the center for NASA optical communications research) that would provide engineering support with a 1-2 year time frame for developing a piece of space technology. Ultimately, the SSI Satellites Team was not awarded funding from the NASA SST program, but the team did receive valuable feedback on their proposal, and they are continuing to move ahead on this project.

The SSI High Altitude Balloons Team

Paige Brown photo

Paige Brown, SSI
Balloons Team

After Michael finished describing the work of the Satellites Team, I asked about another project sitting on the workbench—a plastic cone, perhaps 12 inches in diameter, supported by four plastic flanges, spaced 90 degrees apart, each of which had a thin vertical rod extending up from the base, through a connector on the circular edge at the top of the cone and extending vertically another foot or so. A cylindrical tube was mounted in the center of the cone, extending up to the same height as the rods, and capped with a small, red balloon.

Michael explained that this was the payload hardware for one of the experiments of the High Altitude Balloon Team. About that time, a woman entered the SSI offices, and Michael introduced her to me as Paige Brown, Co-Team Leader of the Balloon Team, and suggested that she would be the best person to tell me about their activities.

I commented to Paige that the red balloon attached to the top of the tube on this payload seemed a bit small. Paige explained that it was just there for testing purposes. The actual balloons used in these experiments are made of latex, and they can expand to 2-3 meters in diameter. She noted that it’s important that these balloons be recovered once they land so that they are not mistaken for food by animals or fish nor that animals or fish become entangled in them. For this reason, the balloon payloads include tracking technology and address labels that enable them to be located or returned if found. Two views of a high-altitude balloon payload

Two views of a high-altitude balloon payload

Play Balloon Launch Video

Video of record-setting 2016
high-altitude SSI balloon
launch from Holister, CA

balloon flight map

Flight path of 2016 record-
setting 79 hour SSI balloon
flight from Hollister Ca to
Quebec Canada

Solar eclipse day balloon launch team

SSI balloon team prepares
to launch a high-altitude
balloon from central
Oregon on August 21, 2017
--the day of the solar eclipse

Paige proudly told me about an SSI balloon that was launched from Hollister, CA—away from airplane traffic routes— about three days before the U.S. election in 2016. That balloon set a world record for the longest duration latex balloon flight, landing in Quebec, Canada, 79 hours later. Paige noted that the balloon crossed into Canada on Election Day, which the team took as an omen of the 2016 election outcome.

The goal of the Balloon team is to tightly control the cruising altitude of their balloons by using a valve and ballast system called “ValBal.” The balloons must fly at a minimum altitude of 12.25 kilometers, with a target altitude of 13 kilometers. If the balloons fly too high, the ozone in the atmosphere disintegrates the balloon’s surface. If they fly too low, they present a potential danger to aircraft and need to terminate their flight. Onboard electronics in the payload enable the team to monitor a balloon’s position and altitude and the ValBal system enables the team to control a balloon’s altitude by releasing ballast to gain altitude or releasing air from the balloon to lose altitude. Also, during an actual flight, the payload hardware currently on the workbench fits into a Styrofoam box, underneath four layers of aerogel blankets. This insulation can produce a 100-degree-Celsius temperature differential between the inside and outside of the box.

The SSI Balloon Team is soon planning to fly a balloon over Greenland, using onboard radar to measure the thickness of the Greenland Ice sheet. A payload that the team is currently working on will use temperature sensors to measure changing temperature inside and outside the balloon. The team is interested in determining how the changing temperature inside and outside the balloon affects the balloon’s flight pattern.


The SSI Rockets Team

Will Koski photo

Will Koski, SSI
Rockets Team

SSI Rockets team at New Mexico competition in June 2017

SSI Rockets team at New
Mexico competition in
June 2017

Official competition rocket launch, June 2017 Photo Credit: Benno Kolland

Official competition rocket
launch, June 2017
Photo Credit: Benno Kolland

As Paige finished describing the Balloon Team’s plans, we were joined by Will Koski, Co-lead of the SSI Rockets Team. So, we transitioned from high altitude balloons to rocket launches.Will explained that members of the Rockets Team are encouraged to build their own rockets, launch them at approved launch sites, and become certified at Level 1, Level 2, and so on. Increasing their certification level enables members to use larger motors, with heavier and more sophisticated payloads. There are many amateur rocket clubs around the country, providing support as well as launch sites—typically farms, cattle ranches and other places with ample acreage for launching and retrieving rockets.

Rockets are made of reinforced cardboard. The motors use solid-state fuel, and the ignition is typically a car battery with a key switch, which sends electrical current to an ignition “sparkplug” that ignites the fuel. Level 1 (L1) rockets have a simple parachute payload. When the rocket reaches a preset altitude, a charge ignites, dislodging the nose cone and deploying a parachute that slows the rocket’s descent back to the ground, some distance away from the launch site.

Moving up to Level 2 (L2) certification enables members to purchase rockets with larger motors, thus increasing the altitude which the rocket can achieve. L2 rockets can reach an altitude of 9,000 feet or more. Also, L2 rockets are larger and can include electronics, such as a barometer to measure pressure and a radio beacon for tracking the rocket. In addition, L2 rockets may contain two parachutes—a small, drogue parachute that deploys first and begins to slow the rocket’s descent. The drogue parachute then helps to pull out a larger parachute, that brings the rocket slowly back to the ground. Onboard electronics control separate charges for deploying the drogue chute and the main chute.

According to Will, the SSI Rockets Team is currently working on a rocket that will compete in an International Rocket Engineering Competition (IREC). The goal is to build a rocket with a 4 kilogram payload that can reach a height of 30,000 feet. While the rocket’s payload can be dead weight, teams receive more points for creating useful payloads. For example, the rocket could deploy two small “satellites” from its nose cone that can measure the distance between them as they fall back to Earth.

Will Koski standing with one of his rockets (left and right panels) and with Michael, Sandip and Sasha at the workbench

Will Koski standing with one of his rockets (left and right panels) and with Michael, Sandip and Sasha at the workbench

Will noted that there are more than 100 rocket teams worldwide. Some teams construct their own rocket motors, while others use commercially available motors. Some teams even use liquid fuel rockets. Sir Richard Branson (Virgin Galactic), Jeff Bezos ( and Elon Musk (Space X) all have interests in amateur rocket clubs, and their companies often hire student interns with an interest in rocketry.

The SSI Space Biology Team

Will Koski photo

Design for a spaceborne
DNA synthesizer

DNA Synthesizer design presentation

Presenting the MVP DNA
Synthesizer design at the
Uytengsu Teaching Lab
2017 Spring Showcase.

On the day I visited the SSI group, no one from the Biology Team was working on the premises, but Sasha and Michael offered to summarize the current interests of this team. The broad goal of the Space Biology Team is to avoid shipping medication and other organic chemicals into space by synthesizing these chemicals directly from DNA. The team is currently working on a process to synthesize that DNA in space. To accomplish this, the team must first build a small device—miniaturization is critically important—that can operate in space and pioneer a new type of chemical reaction to produce DNA. Currently, DNA synthesis requires the use of hazardous and incendiary chemicals, so the team is investigating ways to use non-toxic, non-flammable enzymes with highly compact equipment to snap base pairs together in a vessel that can be flown in space.

The Audacy CubeSat Project

As we were winding down my interview with members of the SSI team, Sasha and Michael had one final project—perhaps the most important  one—that they wanted to describe to me. Recently, SSI was approached by a representative from a Silicon Valley startup company named Audacy (pronounced “Odyssey”) that is planning to launch its own network of satellites. According to Audacy’s website:

Audacy is a space communications service provider. Our space-based data relay system is going live in 2019, with initial ground-based services launching in 2017. Audacy provides spacecraft and launch operators with continuous space communications access and latency under 1 second.

The model is similar to that of a telecommunications operator, but for customers in space. Integrating Audacy into your operations is as simple as installing a certified radio and purchasing a service plan.

 As a preliminary test of Audacy’s technology, the company is planning to launch a CubeSat in 2017. This CubeSat has an empty module, and Audacy has offered the Stanford SSI group the opportunity to fill this module with an experiment of their choosing. The SSI Satellites Team sees this as a perfect opportunity to test one half of their satellite-to-sastellite laser communications project.

The SSI plan for using this CubeSat module is as follows: Working with NASA JPL, Stanford SSI would fly their CubeSat module over JPL ground station. NASA JPL would shoot a laser beam at the CubeSat module, and the CubeSat module would try to acquire and track the JPL laser signal. This would represent half of problem of satellite-to-satellite high-data rate communications problem.

In other words, this would be half of the project to have two satellites pointing to each other and communicating back and forth via laser beams at cubesat scale. ESA has been doing this well; NASA has demonstrated this technology from ISS to ground station terminal—but not at CubeSat scale.

Prototype circuit of a MEMS circuit that controls the motion of a laser tracking mirror in two axes to 1,000th of a degree accuracy

Prototype circuit of a MEMS circuit that controls the motion of a laser tracking mirror in two axes to 1,000th of a degree accuracy

One of the challenges that the Satellites Team must address in constructing this laser beam tracking CubeSat module is building a microelectromechanical (MEMS) machine to control the angle of a laser tracking mirror in two axes. As proof of concept, the team has bonded a 4.2mm mirror to a MEMS machine made by Mirrorcle Technologies of Richmond, CA that uses voltage and piezoelectric arms to torque the mirror to 1,000th of a degree accuracy in two axes.

Sasha and Michael tell me that SSI members have become quite proficient in making good use of found parts. Their motto: “Build what you can from what you’ve got.”

Story by Bob Kahn, HEPL Communications Consultant & Webmaster

For More Information:

View the Stanford SSI Website:

Play Balloon Launch Video

2015 Stanford SSI Promo Video