How Draper's Multi

The system will help to position a spacecraft as it approaches the lunar surface, and it could form an important part of NASA's plans to establish a permanent presence on the Moon with its upcoming Artemis missions.

Last year, DMEN flew aboard Blue Origin's 23rd New Shepard suborbital rocket mission, called NS-23. That mission experienced a catastrophic launch failure, causing the FAA to ground Blue Origin launches for the foreseeable future.

However, the company's capsule escape system worked as intended and Draper was able to recover its payload. The company has since released a paper on the high-altitude test of DMEN.

During that flight, DMEN was tested at altitudes ranging from 4.5-33 kilometers (2.7-20.5 miles) and at speeds of up to 880 km per hour (550 mph). We spoke with Dominic Maggio, the lead author of the DMEN study, who is also a Draper scholar and a master’s of science degree candidate at MIT, to get some insight into the novel navigation system.

The following conversation has been lightly edited for clarity and flow.

Interesting Engineering: How did you collect the data from the failed NS-23 launch? Was it collected live during the mission? Otherwise, was Draper's payload in good condition inside New Shepard's capsule escape system? 

Dominic Maggio: "The data was recorded live during the flight by the DMEN computer inside the capsule. However, we didn't stream telemetry off the rocket during flight (so we couldn't see our data live).

"We received our payload after the flight and then extracted data from the DMEN computer when it arrived back in Cambridge. There was no damage to the Draper payload and all our hardware functioned as it should have, despite the abort."

IE: What were the main takeaways from the recent high-altitude test aboard New Shepard?

"On New Shepard, we recorded data at an altitude up to about 8km (4.9 miles) and at speeds up to about 880 km/h (546 mph). The flight test showed that our vision navigation solution could track the trajectory of the rocket with errors of less than 55 meters. To improve the system’s accuracy, Draper developed software that fuses data from vision-based and inertial navigation systems and that benefits from the advantages of both sensing approaches."

IE: Broadly speaking, what sets the DMEN system apart from previous lunar lander systems?

"As exploration reaches farther into our solar system, both human missions and a multitude of smaller craft will need to perform entry, descent, and landing to complete their mission. A small, reliable navigation package, such as Draper's, is a necessary technology. DMEN provides autonomous navigation capability that could be used for planetary landing, relative navigation, and moving about the surface of a planetary body in a remarkably small-sized package."

IE: Why is this new system required for NASA's Artemis operations?

"Future missions to the moon will require more accurate navigation to make missions safer and enable spacecraft to land on sections of the moon that are potentially more hazardous. New landing locations on the lunar surface could have more boulders and craters and less (or no) sunlight. But that variety also means navigation systems like Draper’s DMEN will need to be more accurate.

"Draper’s recent test flights gave us an opportunity to test the DMEN system in ways that hadn’t been done with previous landers. For instance, we demonstrated DMEN’s ability to use a camera-based navigation solution at higher altitudes during the descent. This is important because frequent return trips to the moon will require vision solutions to begin tracking the lunar surface during descent at over 20km to the surface. In contrast, Mars landers typically don't employ vision methods until less than around 4,200m to the surface."

IE: Could you explain, in simple terms, how DMEN combines both vision-based and inertial navigation data to perform the safest landing possible?

"Weighing just 3 kg (6.6 lbs), DMEN consists of a suite of sensors (camera and inertial measurement unit), along with sensor circuitry, a computer, and a powerful set of algorithms to process the sensor data for navigation. The algorithms include tightly coupled visual-inertial odometry and visual terrain-based absolute positioning.

"DMEN scans the terrain below, pinpointing landmarks that appear most promising for landing, using satellite imagery, camera images, United States Geological Survey elevation maps, and software developed by Draper called Image-Based Absolute Localization, or IBAL.

"The data from the cameras is combined with data from other sensors and sent to a flight computer running our algorithms. DMEN is designed to give crewed missions accurate wayfaring and location data needed for safe and accurate lunar and planetary landings."

IE: What is the next big upcoming test milestone for the DMEN system?

"We plan to further prove the ability of DMEN and test the system at even higher altitudes and speeds on another flight test onboard New Shepard."

IE: Could the technology developed for DMEN be used for any other type of vessel or vehicle other than a lunar lander? Could it have any applications on Earth?

"Definitely, DMEN can be used for a wide range of applications such as for navigation on long-range drone or aircraft flights and for airdrops. Draper has also tested DMEN as a human wearable package that can track the locations of astronauts as they explore a lunar surface."