Vlad Podolsky

Mechanisms of argon plasma decay between high voltage, high repetition rate nanosecond pulses

Plasmas generated by high repetition rate nanosecond pulses have shown potential for many applications due to their efficient ionization, low power cost, and efficient production of excited species. Of interest is their utility for reconfigurable plasma antennas, which require good electrical conductivity (i.e. good electron density) and low Johnson-Nyquist noise (i.e. low electron temperature). In this presentation, experimental studies of plasmas generated by 800 V, 2 ns, 10-100 kHz pulses in argon are described. To study these plasmas, time-resolved microwave interferometry measurements of the spatially-averaged electron number density were conducted. To interpret these experimental results, a kinetic model was developed to describe the behavior of the measured electron number density decay between pulses. The processes considered include ion conversion, ionization in collisions of metastables, dissociative recombination of Ar2+, and ambipolar diffusion. The reaction rates of these processes all depend on the temperature of electrons; therefore, the temporal electron temperature decay is also modeled. The Ramsauer-Townsend minimum of electron scattering cross sections and the presence of a small amount of molecular impurities are shown to play an important role in the plasma decay. The results indicate that between the pulses, the electron density is substantial while the electron temperature quickly drops.

Siddhant Tandon

DOSO: Demonstration of self-organized SmallSats

Smallsats are the frames for agile and sophisticated spacecraft technology, but their applications have been limited to single-unit missions in Low Earth Orbit (LEO). A swarm of SmallSats is a self-organized and synchronized network of spacecrafts that can empower missions for space debris removal, planetary defense and space colonization. Swarm can provide a more economical approach to the same mission that would otherwise use SatComs and deep space probes. Research projects like AAReST have simulated the use of a cooperative centralized system to mobilize Smallsat docking and assembly in space. The Demonstration Of Self-Organized SmallSat systems (DOSO) is an undergraduate-run project which aims to demonstrate that a decentralized SmallSat swarm can rendezvous, dock and maneuver as a single entity with the use of precise adaptive control and robust communication systems. The control system consists of a small thruster that helps each individual system in guidance and navigation while in orbit. The robust communication system will consist of Ka-Band transmitters with high data rates which allow dynamic communications between the SmallSat and to the Ground Station (GS). DOSO provides the basis for improvements in communication and autonomy in space.

Srianish Vutukuri

Spacecraft trajectory design techniques using resonant orbits

The natural motion of a spacecraft in the presence of a single gravitational force is either circular, elliptical or hyperbolic geometry and is referred as Two-Body conic solutions. Incorporating an additional gravitational force, referred to as the Three-Body problem, results in a plethora of natural motions for the spacecraft which have interesting non-conical geometries. In the recent times, spacecraft trajectory design techniques are incorporating these natural motions due to multiple gravitational fields to design novel, low-cost pathways to a variety of destinations within the solar system. One such natural motion occurring in a multi-body gravitational system which is ubiquitous in the solar system are resonant orbits. Historically, resonances have been studied to understand the formation of the solar system. However, they have not been explored as a means for designing spacecraft trajectories. This investigation will examine the use of resonant orbits as an efficient transfer mechanism to move between two dynamically challenging stable regions within an Earth-Moon Three-Body system. Non-linear numerical techniques such as Poincaré maps and Differential Correction Algorithms will be implemented to achieve the goal. As a result, connecting the two regions, a variety of spacecraft transfer trajectories incorporating different resonant orbits will be generated.

What is the Research Symposium Series?

The Research Symposium Series is a department-sponsored forum for graduate students and advanced-level undergraduates to present their research to a general audience.

The Research Symposium Series is designed to: 

• Facilitate the exchange of ideas and knowledge among faculty and graduate students.
• Provide opportunities for students to develop their technical presentation skills.
• Promote the research activities of the department to undergraduates and other interested individuals.

2018 Prizes

• $500, $300, $200 for best three presentations
• $150 for best undergraduate presentation
• $150 for best abstract

Questions about the Research Symposium Series may be directed to:
aaerss@ecn.purdue.edu
https://engineering.purdue.edu/AAE/Academics/StudentOrgs/aaerss
*Winners in the presentation category cannot compete in that category the following year. The same applies for winners in the abstract category.