NASA's JPL (Jet Propulsion Laboratory) recently announced testing of what they've termed a Mars Helicopter Scout (MHS). The scout may be included on the upcoming Mars 2020 mission, a collaborative project led by NASA with a primary mission of determining if life once existed on Mars. The idea is that a helicopter-style drone could help provide better mapping and guidance that will give mission controllers more information to help with path planning and hazard avoidance, as well as identifying points of interest.
How else could we eventually see drone technology used in space exploration? Here's a look at the MHS, other NASA drones, and what kind of challenges engineers face when trying to design a space-ready drone.
Why Send a Drone to Space?
The Mars Helicopter Scout is a payload intended to be part of the Mars 2020 mission. One of its duties, beyond scouting points of interest and potential hazards (say, storms), is to help plan travel routes for the main rover. Despite how this technology could help advance Mars exploration, this use of the MHS would mainly be a demonstration since the drone would have severely limited flight capabilities. However, this proof of concept use is important because adoption of helicopters and drones into space exploration could greatly help achieve operational objectives.
Some of the known specs of the MHS:
Weight: 2.2 lbs
Blade span (co-axial): 3.6 ft
Dimensions of Chasis: 5.5 in x 5.5 in x 5.5 in
Power: 220 W
The MHS is expected to have a range of just under 657 yards and a maximum flight altitude of 130 feet. It will carry a high resolution, downward facing camera and be designed to be able to land on the Martian surface with shock absorbing feet. The helicopter would get about three minutes of flight time every Sol (a Martian day that's equivalent to one Earth day plus 40 minutes). It would use autonomous control and communicate with the rover directly.
In 2016, NASA determined that an additional $15 million in funding would be required to keep the progress of the MHS on track. As recently as February 2017, the MHS was potentially on the list for exclusion from the Mars 2020 mission as there were concerns that the project may go over its mass budget.
So far, the project still seems to be in the running for going to Mars: NASA's Mars Institute is reported to be conducting UAV tests in the Canadian Arctic at the Haughton-Mars Project Research Station this fall. The site, Devon Island, is sometimes called "Mars on Earth" and can help determine whether the devices can withstand Martian-esque conditions.
The Horizon of Space Drones
The MHS isn’t the only drone project in the works, however. There is also research going into prospecting drones that may eventually be used for space mining, multi-planetary colonization, as well as path planning/hazard avoidance.
One such project is "Extreme Access Flyers" which look much closer to the typical quadcopter style drone often used here on Earth. The Swamp Works Laboratory has been working on drones ranging from five feet in diameter, to ones that are small enough to fit in your palm.
They hope the drones can eventually be used for everything from imaging to sample collection, though there is particular interest in resource gathering.
The lab has produced multiple prototypes over the years. One of the major differentiators of these vehicles from our earthly drones is the lack of rotors. Each is designed to utilize whatever gas or even water vapor is available to propel itself, depending on whether it's located on Mars or an asteroid.
Space Environment Challenges
There are certainly unique considerations to take into account when designing a space exploration drone. Particularly relevant to space drone development is the fact that the atmosphere on other planets or celestial objects can be much thinner than what's found on Earth—or non-existent. Mars, for example, has 1% of the atmospheric density of Earth. This is important when determining the mass of the drones, since they will not be able to get the lift required to fly if they're too heavy. On the other hand, if they're too light, they might be difficult to control.
Control is also another challenge. Such drones and UAVs would probably need to be fairly autonomous, since real-time control would not be possible like it is on Earth. It takes approximately 20 hours to send 250 megabits of data to Earth, so live video streams are certainly out of the question.
Finally, there are the daunting challenges of battery capacity and charging. There are a few ways that spacecraft can be powered—the Voyager probes, for example, use RTGs or radioisotope thermoelectric generators. But for small drones that aren't currently being recruited for deep-space missions, the most practical method is likely a solar battery power. Trying to find the balance between mass, battery capacity, and charging time is another element that will need to be considered.
The MHS is an interesting step for UAVs and drones in space exploration. If it succeeds, we may see more missions using drones.
Feature image courtesy of NASA JPL.