Childhood dream becomes NASA reality


Debra Levey Larson

Daniel Engel wearing an astronaut flight suit when he was a child.
Daniel Engel wearing an astronaut flight suit when he was a child.

Like many eight-year-olds, Daniel Engel wanted to be an astronaut—transforming a large, empty cardboard box into a make-believe spaceship. Although still as passionate about space, his interests are much more refined, now focused on improving the entry performance of vehicles landing on Mars.

“I believe that the human exploration of space is extremely important, for both the advancement of scientific knowledge and the long-term survival of humans,” Engel said. “Filling the role of a mission designer or flight mechanics engineer for crewed deep space expeditions, I will have the opportunity to play a key part in enabling the success of these monumental missions. Not only will I be contributing to a program that I believe is salient, but I will also be fulfilling my personal passion for space exploration.”

Engel earned his B.S. in aerospace engineering in the spring of 2020 from the University of Illinois Urbana-Champaign. He began a master’s degree program in aerospace engineering that same fall at UIUC working with Professor Zachary Putnam and this past fall received a NASA Space Technology Graduate Research Opportunities award.

One of the benefits of this particular NASA award is the opportunity for visiting technologist experiences.

Engel working remotely for NASA Langley during the summer of 2020.
Engel working remotely for NASA Langley during the summer of 2020.

“Nothing is set in stone yet, but I plan to do an in-person visiting technologist experience this summer at the NASA Langley Research Center, where I interned the past two summers,” he said. “My research collaborator for the fellowship is Dr. Soumyo Dutta at NASA Langley. I have already been collaborating with him throughout the semester. I hope to also visit many of the key NASA Centers for entry, descent, and landing technology, including the NASA Johnson Space Center, NASA Jet Propulsion Laboratory, and NASA Ames Research Center.”

Engel began conducting research for the Putnam Research Group when he was an undergrad. “I was studying steering for planetary entry vehicles using aerodynamic flaps,” he said. “This initial research was the inspiration for my master’s degree and Ph.D. research.”

In Putnam’s research group, Engel said they found changing hypersonic flap configurations affected the shape and size of the vehicle’s aerodynamic control authority capability and the associated landing footprint-both of which differ greatly from the current state-of-the-art of angle-angle modulation. Although the method of bank-angle modulation might be fine for landing small unoccupied rovers, it is unlikely to be sufficient for NASA’s crewed missions of the future.

“I’m studying the performance of Mars entry vehicles using direct force control, a promising alternative to bank-angle steering. The aerodynamic flaps I am currently investigating are one possible implementation of direct force control. The direct force control steering scheme involves modulating a vehicle’s angle of attack and sideslip angle independently, giving it better flight performance, including precision landings on planetary bodies, which is a crucial capability for human exploration. Many studies on blunt body entry vehicles utilizing direct force control have not included realistic vehicle behavior and limitations,” he said.

As the need increases to accurately land higher mass payloads on Mars, including more advanced robotic explorers and human landing infrastructure, new trajectory control methods will need to be developed, Engel said. “Direct force control, along with advanced guidance and control algorithms are a potential solution for steering future Mars entry vehicles.”

Engel with the Illinois Space Society at the Intercollegiate Rocket Engineering Competition
Engel with the Illinois Space Society at the Intercollegiate Rocket Engineering Competition when he was an undergrad at UIUC.

In addition to working in Putnam’s research group, as an undergrad, Engel was an active member of the student group Illinois Space Society. In ISS, Engel participated in two high-power rocketry competitions, including the Intercollegiate Rocket Engineering Competition. He also did mission design work for both a conceptual crewed lunar lander and a short stay Mars mission.

Engel with an F-1 rocket engine at Aerojet Rocketdyne
While doing on internship at Aerojet Rocketdyne, Engel posed with an F-1 rocket engine.

During the summers of 2018 and 2019, he interned for Aerojet Rocketdyne at their Los Angeles location, working on tasks related to the RS-25 rocket engine. Over the summers of 2020 and 2021, he interned at the NASA Langley Research Center as part of the Atmospheric Flight and Entry Systems Branch.