Like many innovative engineers, Colton Smith and Kyle Smith and their team members are inspired by something that doesn’t exist. They are developing a vehicle that is ahead of its time for a “highway” that hasn’t been built yet to transport payloads that are still only a gleam in the corporate eye.
It’s just another day in NASA’s RASC-AL Forum aerospace competition, and the Drexel team is ramping up for nationals.
Together with engineering students from three international universities, Drexel RASC-AL is designing a “cis-lunar tug”—something along the lines of a flying tugboat—that could someday ferry payloads between a lightly manned outpost orbiting the moon and low-Lunar orbit.
“Who doesn’t look up at the stars and the moon and think, man, it would be cool to send something up there?” asked Colton, vice president this year of the RASC-AL club and a junior in the College of Engineering Department of Mechanical Engineering and Mechanics (MEM). “That’s also where the aerospace industry is going. If you want to be a part of it, you better just go ahead and get involved now.
“Especially with all the private companies getting into aerospace, the whole domain is progressing a lot faster,” said Colton. “Ultimately, we’d probably all like to end up in aerospace somehow. This RASC-AL competition is a good way to do that.”
The Drexel team chose the theoretical project theme last summer from among four RASC-AL categories drawn up by NASA for the 2019 competition. They are among a handful of universities to reach finals under the mission to develop a “Gateway-based Cis-Lunar Tug.” Rather than build a mini-prototype, team members will draft a “fully realized” paper that details their entry’s structure, power requirements, propulsion, payload transfer modes, and financial specs in a system that should have the capability to be deployed by 2025.
RASC-AL is short for Revolutionary Aerospace Systems Concepts–Academic Linkage. It is a full mission architecture engineering design forum open to undergraduate and graduate students in disciplines with applications to human space exploration. Drexel is partnered with students at RMIT University in Australia; the Korea Advanced Institute of Science & Technology in South Korea; and the Hong Kong University of Science and Technology in Hong Kong.
Nationals will be held in Cocoa Beach, Florida June 18-20. The competition will be publicly live-streamed. The Drexel team of two representatives can be viewed on Wednesday, June 19 from 10:30 to 11 a.m., presenting to NASA officials from the Johnson Space Center and the Langley Research Center, as well industry leaders from Boeing, SpaceX, Blue Origin, and others.
The Drexel entry is named APID, for Autonomous Payload Intermediary and Deployer. APID will go up against entries from Embry-Riddle Aeronautical University, the Stevens Institute of Technology, and Virginia Polytechnic Institute in the cis-lunar tug category.
This is the sixth year in a row that Drexel will field a team for this prestigious aerospace competition. Their team Advisor is Dr. Ajmal Yousuff, associate professor of MEM.
“Participating in this Forum provides the students networking opportunities and helps build skills in project management, public speaking and professional communication,” said Yousuff.
“Their APID is an innovative concept in harvesting the moon’s resources from NASA’s Gateway. The autonomously adaptive variable engine system reduces risk and cost significantly.”
What’s a cis-lunar tug?
Last year, NASA announced that it had teamed up with private international partners to develop a visionary spacecraft called the “Gateway,” an orbiting lunar outpost, solar-powered communications hub, and science lab all in one that will be deployed into a regular orbit and will remain there, much like the International Space Station does. The Gateway will support lunar missions even when there is no crew inhabiting it, according to a NASA website. The cis-lunar tug—the phrase “cis-lunar” signifies a tight, regular lunar orbit—theorized by Drexel would act as a shuttle for equipment between the Gateway and the moon.
“We looked at a lot of designs from Jeff Bezos’ company, which is proposing to make a lunar lander that weighs about 45K kilograms,” said Colton. “If that’s what’s proposed, our tug needs to be able to handle something like that. So that was our upper limit—be able to carry one of those from the Gateway and deliver it. So everything from there on was trying to make our design as modular as possible.”
Kyle Smith, a sophomore pursuing a degree in Biomedical Engineering, is president of RASC-AL this year. He’ll be one of two team reps making the presentation in Florida. “Our system now uses a type of rocket engine called a hybrid engine, solid ABS plastic and liquid oxygen fuel as the oxidizer. Also, we used a different type of docking mechanism for our spacecraft, so we will show that design, too.
“Then, for attaching to things, APID uses a system we designed with a peg interface that’s like slot with two pegs that inflate to stop the payload from detaching again.
“We’re also working on figuring out exactly what our spacecraft would be capable of—to define specific masses and orbits, and then doing some more research fleshing out topics like the power system and the propulsion system,” Kyle added.
One of the biggest challenges in this year’s competition was designing a fully automated system that can operate without human intervention. NASA is proposing that Gateway will be manned only 60 days out of the year. So the Drexel team incorporated a design with a central computer and smaller drones that have the peg interface; the drones will pick up landers, satellites and other equipment delivered to the Gateway and then attach them to the tug—all while being monitored by the central computer.
“We use a lot of ‘bee’ references here,” said Colton. “It’s much like the queen bee orchestrating the smaller worker bees. Hybrid rockets will take the payload down to whatever altitude is desired, and then it detaches before coming back for the next group of equipment.”
Researching a wild idea
In the 2015 drama “The Martian,” a character describes how the Jet Propulsion Laboratory in Pasadena, CA was inspired by a group of Cal-Tech students who were experimenting with recipes for jet fuel in their campus lab. So, it’s not inconceivable that a group of students working in a dorm room somewhere in the United States would stumble across creative solutions to aerospace challenges that more seasoned professionals would overlook. In essence, that is the reason for the RASC-AL competition.
To prime their creativity and meet mission objectives, the RASC-AL team pored over the last nine months through current research, articles, papers, and proposals from the aerospace industry to see what’s out there and to give some structure to their conceptual meetings. They held numerous Skype sessions with team members at RMIT, KAIST, and HKUST early in the morning and late at night to accommodate time differences. And they held regular meetings over Slack once a week every week since last August.
“It all comes down to brainstorming and research,” said Kyle. “We look up as much about the topic as we can and try to find information that will help in any way. When you have a decent-sized group of like-minded people thinking about this stuff, you’re going to come up with something.”
The final paper entry has a limit—just 15 pages in which to describe the entire cis-lunar tug proposal. But team members are nonplussed. They will leave out descriptions of capabilities that are already assumed in the aerospace industry and concentrate instead on the novel details of their APID design.
“You just try to frame the design as tightly as you can. But at some point you have to realize, it is all theoretical,” said Colton. “We’re obviously not going to be able to build this whole thing and send it up there, so there is some forgiveness in the design. We are just going to keep going until we get to that point where we know we would feel comfortable answering any reasonable question the judges could ask.
“NASA has definitely organized the competition to provide for a lot of creativity and novel solutions for the missions statements,” he added. “Because they don’t throw a lot of restrictions on the way the paper is submitted, you can focus on things that are a little more innovative.”
Drexel Interstellar, of which RASC-AL is one component group, invites participation from students across all majors at Drexel. Meetings are meant to be fun, and are often no more technical than watching a sci-fi film and discussing the possibilities it raises—how to put a base on the moon, or how to colonize Mars, or how to design a set of smaller, more compact satellites, for instance.
“No matter what major you are, as long as you’re interested in space, RASC-AL will provide something for you,” said Kyle. “It’s fun, and we’re a good group to hang out with. We’re very welcoming, I think.”
Potential members can access the RASC-AL team through firstname.lastname@example.org.