MichSpace

by: Scott Granger - Mission Architectures Intern at Aerojet and MEng Student

This summer I had the opportunity to work at Aerojet in Sacramento, CA. Aerojet is a defense contractor mainly for spacecraft, launch vehicle, and missile propulsion systems. Aerojet has two main competitors – Pratt & Whitney Rocketdyne and ATK. What makes Aerojet so unique is they are the only company that have experience in liquid, solid, and electric propulsion.

I spent 13 weeks in Sacramento, CA working on two main projects. I sat in the Mission Architectures Group which performed the up-front feasibility studies for propulsion systems. The work that is done in this group eventually is the basis for determining the requirements of the system – should the customer give us their business. On the job, I was first introduced to a trajectory simulation tool called POST. POST is a FORTRAN based code (though compiled through an executable) that determines the best trajectory for a launch vehicle based on different propulsion systems. You can set different constraints on the problem to limit, for example, dynamic pressure during staging. A large part of my summer was spent running POST simulations for different launch vehicles composed of many different propulsion systems. Second, I was assigned as the head engineer on a small contract with Sierra Nevada that required 2 weeks of engineering design and analysis. Under this contract, I conducted a trade study for a solid rocket grain geometry that incorporated industry tools that I had never used before. I created grain burn backs for complicated grains and the complete ballistics analysis. The design was put into CAD with performance analysis (Isp, Thrust, maximum pressure, etc) and shipped to the customer.

The location of Aerojet – really located in Rancho Cordova, CA – is somewhat less than desirable. The weather approaches 100 degrees F in the summer and located about 3 hours from San Francisco (the water). Aerojet has historically been an “older” person site, however, it has started to hire younger people over the last 5 years. I encourage anybody interested in mechanical or aerospace design, analysis, or modeling to consider Aerojet.

For those of you that haven't seen it yet, the following is an amazing time-lapse video made from pictures taken on the ISS up until sun rise. There is a glow that appears 'inches' above the Earth which is the atmosphere, light from cities as the ISS traverses silently, and even lightning from storms on the surface. I hope you enjoy this as much as I did!

http://www.universetoday.com/88998/amazing-timelapse-video-from-the-space-station/

- Chase

by: Veronica Benitez - Thermal Engineering Intern at Goddard Space Flight Center and MEng Student

This summer I had the opportunity to work at NASA Goddard Space Flight Center. I interned in the Thermal Engineering branch and worked with the thermal team of the Global Precipitation Measurement (GPM) satellite. Working in the Thermal Engineering Branch has been an incredible learning experience. Aside from my primary project, I was able to work on many important tasks that a thermal engineer would complete in a typical work day including both analysis and testing.

On the thermal analysis and modeling side, I gained familiarity with the software used at GSFC mainly Thermal Desktop and SINDA Fluint. I was able to work with Thermal Desktop in tutorials and real thermal problems. I used SINDA Fluint to create the multiple cases of my primary project.

On the integration and testing side, I created multiple Work Order Authorization forms and helped test real flight hardware. I was put in charge of a thermal blanket bakeout for GPM Multilayer Insulation blankets as well as a Chotherm bakeout. I created the Work Order Authorization forms for both, made sure they were approved by the Quality Assurance Engineers as well as the Contamination Engineers. I was able to contribute to the thermal vacuum testing of the solar array drive assembly (SADA) by attending shifts to monitor the temperature of the chamber and the various components of the SADA. I also helped install thermocouples on the avionics module of the GPM satellite and route them to the proper location for connection.

My primary project at GSFC was the statistical analysis of the thermal margins of the GPM spacecraft. The average spacecraft designed at GFSC is proposed to last three to four years; however, the majority of these spacecraft are consistently lasting anywhere from ten to fifteen years. The result of the longer spacecraft life may be due to overdesign by assuming accumulated worst case scenarios. The purpose of my study is to assess the degree of margin and conservatism in the GPM thermal design that may be masked by designing to stacked, worst case conditions. The assessment contains the analysis of how the temperature and heater power of the critical spacecraft components vary over the lifetime of the spacecraft when four different variables are adjusted: power dissipation, optical properties, beta angle, and seasonal flux.

A distribution plot of the temperature ranges was created to analyze what percent of the mission lifetime the spacecraft critical components will spend at various margin ranges from operational. The impact of conservatism on each of the four variables can be studied independently to evaluate how much margin is absorbed or generated by using the extreme variables instead of nominal values. The end result of this study will be a way of quantifying the degree of conservatism in the GPM Observatory thermal design based on the traditional design approach used by the GSFC Thermal Branch.

by: Jimmy Gawron – Systems Engineering Intern at Orbital Sciences Corporation and MEng Student

This summer I had the awesome opportunity of working at Orbital as a systems engineering intern. I worked in the Science and Technology Business Development group where I was responsible for the technical design of spacecraft buses and end-to-end space missions for several NASA proposals. This involved the first order sizing of the spacecraft bus to accommodate payload requirements, the design of the communications architecture, and determination of the mission operations. I was given a lot of responsibility on high profile ventures, which provided for an exciting summer. I found Orbital’s work environment to be very high energy, and the internship helped to enhance my engineering and team working skills.

My Name is Chris Bellant and I am a first year Ph.D. Student in Aerospace Engineering. I am not much of a blogger but I have been jumping out of my skin since the official announcement of the space Launch System a few days ago. The SLS is to be a Shuttle-Derived heavy launch vehicle that will be capable of delivering around 130 mT into LEO. It is claimed that the SLS will be both affordable and sustainable. I don’t see how either claim is true. The development cost is estimated to be 30 to 60 Billion dollars, depending on your source, and the first launch of the SLS in the final 130 mT configuration is to be no sooner than 2030. From what I have read NASA is expecting to get one or two launches a year for about 15 years. That is two to three billion dollars per launch just in development cost. It will cost at least another half billion dollars to build each one. Assuming an optimistic averaged cost of 2.5 billion dollars per launch, the cost to put 130 mT in LEO 20 years from now would be about $20,000/kg. I am a little confused why this is affordable, or even acceptable to do anything other than laugh at. The question I really want answered is why don’t we just use Space-X’s Falcon Heavy to put these payloads up? It will put 53 mT into LEO at a cost of $2,000/kg. It is also projected to have its first launch in about 2 years. The falcon heavy compared to the SLS will have 1/10th of the development time and 1/10th of the cost. Because the payloads are being sent up on two or three different rockets there would be a little added complexity but I believe the final cost would still be at least a factor 5-7 less than using SLS and we could start missions in a few years instead of a few decades.

I have only been able to find one other article that points out the obvious and long list of flaws with the SLS, and that was by Rick Tumlinson. I realize that several small issues were not addressed here but I would love to hear other’s thoughts on this. Leave a comment on this post or email me directly at bellanck@umich.edu.

There is an interesting article by a guy that did some investigative journalism outlining why the most recent price quote on the JWST ($8.7 billion, up from $6.5) is due to the Government, NOT NASA. He lays everything out in a very nice manner and makes a strong case. Enjoy!

This summer I had the pleasure of working with Prof. Nilton Renno and his electric field sensor both at the University of Michigan and at NASA Glenn Research Center (GRC). The sensor is an electric field mill composed of a conductive rotating cylinder divided into four electrically isolated quadrants. When the cylinder rotates, the charge must redistribute across the quadrants producing a current proportional to the electric field. A picture of the sensor can be found below. An important aspect of this sensor versus other electric field sensors is that the system is not electrically grounded. This allows for the sensor to take measurements even when subjected to the impact of charged particles. The idea behind the sensor is to look at charge build up during dust storms, dust devils, and wind-blown sand and to determine what impact it has on atmospheric chemistry. Our design requirements are being developed with a Martian environment in mind as we are looking at having the sensor flown to Mars on the 2018 MAX-C/ExoMars mission.

In addition to the potential applications in space, Professor Renno has a startup company in the North Campus Research Complex called EngXT. Through EngXT, we are commercializing the sensor for use in the electrostatic discharge industry and other potential industrial applications. The foreseen markets include semiconductor manufacturers, lightning detection, and power line field dispersion. While at U of M, I ran several tests in the Space Physics Research Laboratory’s (SPRL) copper room to characterize the second generation of the sensor. My results were used to demonstrate to potential customers how the sensor performs. My other responsibilities included mentoring two high school interns in our lab. I taught them how to assemble the sensors, allowing them to conduct a field campaign on the El Dorado Dry Lake Bed outside of Boulder City, NV.

The second half of my summer I moved my research to GRC, where I worked on repairing one sensor and writing a proposal to attain funding to develop the sensor’s third generation. Before coming out to Glenn I was tasked to create assembly and disassembly procedures for the second-generation sensors. When first arriving at GRC, my mentor and I spent time repairing some very brittle wires that connect to the motor. Due to strict tolerances, theses wires are fragile and have to be manipulated a lot. I also had the chance to help setup a test with our sensor to diagnose the electric field of a solar panel behind a Faraday cage. A large portion of my time was spent putting together a proposal to combine the benefits of the first two sensor generations into an optimized design. I am receiving my Masters in Space Systems Engineering, so this was right up my alley. I put together a Gantt chart, work breakdown schedule, CAD models of concepts, and combined work from contractors to make a complete proposal. The proposal is due the week after I leave and hopefully GRC will start work on the next version in March 2012. I can be seen working on the motor in the following picture.

I learned a lot of valuable skills this summer. I worked with all age groups- from the high school students at U of M to people on the verge of retiring at GRC. A big takeaway is that prototypes are not meant to be tampered with! This is what lead to the headaches with the latest sensor. I also learned how the government works, which should be a class on its own. With the experience I have attained this summer, I am more confident in my ability as an engineer and am ready to enter the work force this winter.