NASA Sounding Rocket Experiment: Effects of Ionizing Radiation in Space on Commercial Off-The Shelf Technologies (COTS)

Artash Nath

Orion Terrier Rocket — NASA Terrier-Improved Orion Sounding Rocket

My experiment on “Effects of Ionizing Radiation in Space” has been selected for a sub-orbital space flight on a sounding rocket during Rocket Week (June 14-21, 2019) at NASA’s Wallops Flight Facility in Virginia. The experiment was submitted as a part of the Cubes in Space competition. Cubes in Space is an idoodledu inc., a program in collaboration with NASA Goddard Space Flight Center’s Wallops Flight Facility, NASA Langley Research Center, and the Colorado Space Grant Consortium.

The experiment is due to fly on 20 June 2019 on a NASA Terrier-Improved Orion suborbital sounding rocket that is 36 feet long and has a payload weight of 667 pounds. The rocket will fly to nearly 73-miles (117 kms) altitude. The experiments will land via parachute in the Atlantic Ocean where they will be recovered by boat.

The Rationale behind the Experiment

Earth is continuously being irradiated from all directions by high-energy charged particles (ionizing radiation). As we climb up the sea level towards outer space this radiation increases and can cause damage.

A key reason for failure or shorter mission life of satellites is that electronic components are not able to handle increased levels of radiation. Many important missions have failed because of it, including the 2011 Phobos-Grunt Mission to Phobos, one of Mars’s moons where non-space hardened electronics was used. (http://www.planetary.org/blogs/guest-blogs/2018/0417-space-grade-electronics.html). The ongoing NASA Juno mission has a Juno Radiation Vault – a 1 cm thick titanium compartment inside which most of the electronics and computers are enclosed to offer increased protection against radiation.

Commercial Off-The-Shelf Technologies (COTS) for Space

testing1 — Measuring values of COTS component – resistors for my payload

As more youths and students get interested in space and want to launch their CubeSats, BalloonSats and other experiments into space, it is important that the radiation risks are well understood to protect the satellites and their payloads. But procuring and using space grade electronics is not easy and drives up the costs. The other option is to use Commercial Off-the-Shelf Technologies (COTS). But these are not space hardened hardware. For instance, it can cause electronic components to malfunction by breaking down their material. And yet use of COTS is essential in student-led space projects as they are easily available in all countries, are inexpensive, have ample documentation and libraries available, and are tried and tested technologies.

If we could find ways to make some of the existing Commercial Off-The-Shelf Technologies (COTS) that are not space hardened, more tolerant to space radiation we could bring down the costs of space projects and make them more accessible to the student community. The purpose of my space project is to understand ionizing radiation tolerance of some of the COTS, and how we can lower the risks of these COTS electronic components failure through different protective coatings.

A black object absorbs all wavelengths of light and reflects none. This is why it appears black. A white object reflects all wavelengths of light and therefore appears white. Hence COTS components wrapped in a white coating should reflect back more ionizing radiation and should have a lesser chance of damage than those wrapped in black material.

My NASA / CubesinSpace Sounding Rocket Experiment

I have been making space and electronics projects for the last 5 year. I use many commercial off-the-shelf technologies (COTS) such as Arduino, LEDs, and capacitors. A component I use the most is a Resistor (to provide voltage difference in the circuits). To build low-cost projects, I want to understand the performance of COTS, in particular, resistors, in high-altitude, space projects. Here the independent variable is ionization radiation which increases with altitude.

payload packed — Payload integrated into the canister and ready to launch from @NASAWallops on June 20th!

At an elevation of 5 km, the levels of ionization radiation in millisieverts (mSv) are several times that at the ground level (around 2.4 mSV). The radiation can lead to the ejection of orbital electrons which break the bonds that combine atoms as molecules in the COTS as they are not space hardened. The Experiment will analyze if the dependent variable: the ohms value of the “Resistor” will change when it goes in space where it is exposed to increased dosage of ionization radiation and how it can be protected against it. The breakdown because if ionizing radiation should permanently change the ohms value of the resistor sent to space, and should be easy to measure using an ohms/multimeter.

Components that will stay on Earth to provide comparison data

Experiment Procedure

Step 1: I purchased 30 off-the-shelf Resistors of 1 kilo-ohm value. The Resistors are very small, lightweight and take up very little space.

Step 2: I labeled each of them and measure their resistance values to 2 decimal places using a digital ohms meter and input the readings into Excel.

Step 3: I wrapped 5 of the Resistors in Aluminium Kitchen foil to reflect the radiation. The other 5 Resistors were wrapped in a black plastic sheet to absorb radiation. The remaining 5 were put unwrapped in the Cube.

Step 4: I prepared the remaining 15 Resistors under similar protection (5 in aluminum foil, 5 in black material and 5 wrapped) on Earth (in my home) to provide comparison data and to eliminate changes in resistance values that may occur because of other factors.

Step 5: When I receive my Cube back from space, I am going to take out the 15 resistors and measure their resistance values and record them to 2 decimal places. I will do for the same for the 15 resistors kept at my home.

Analysis

I am looking forward to launching my experiment into space. After I get back the box, I will use the same digital Ohms meter to measure the resistance values of these Resistors to 2 decimal places. I will then record before and after resistance values of each of the Resistors. My project will then determine the percentage change and standard deviation in resistance values for all the Resistors. I will compare the data sets of resistors that went in space to those that stayed in the ground. This will help me analyze the impacts of radiation on COTS components that traveled to space and which protection fared the best. The project findings will provide information about the performance of COTS in space and which protections work the best. The results of the study could help lower down the cost of student space projects if they are able to use COTS components with very small chances of failure.

Space Exploration: Building Rockets, Reaching Higher

I have been building and flying model rockets as a part of the Cambridge Rocket Club. It allows me to test new rocket models, payloads and parachute systems. However, the best part is collecting data from these rockets by using sensors and having the data transmitted over the radio to our base station.

I am passionate about seeing my payloads reaching a higher altitude. My model rockets can go up to 500 meters. Last year my payload on the balloon went up 25 km. This year I am looking forward to crossing the 100km altitude (the Karman line).