NASA’s Jet Propulsion Laboratory (JPL) has announced that they are working on a new concept of robot for asteroid exploration that doesn’t need legs, wheels, rocket engines, or any of the sort. This concept is called the Hedgehog which has fully integrated hardware mobility.
Hedgehog Design
The JPL is working on the project together with Stanford University in California and the Massachusetts Institute of Technology in Cambridge. The specific design of the Hedgehog allows it to deal with the challenges of exploring small bodies with reduced gravity. These small bodies in space include asteroids, comets, and small moons.
“Hedgehog is a different kind of robot that would hop and tumble on the surface instead of rolling on wheels. It is shaped like a cube and can operate no matter which side it lands on,” Issa Nesnas, leader of the JPL team, said.
Basically, Hedgehog is a cube with eight spikes that moves by spinning and braking three internal flywheels. During movement, the spikes protect the robot from the adverse effects of the terrain and act as feet during hopping and tumbling. “The spikes could also house instruments such as thermal probes to take the temperature of the surface as the robot tumbles,” Nesnas said.
By itself, the prototype’s weight is about 11 lbs (5 kg). However, the researchers believe that it could weigh more when packed with instruments such as cameras and spectrometers. With instruments, its weight could go up to 20 lbs (9 kg).
How It Works
The Hedgehog had its microgravity testing on parabolic flights. During the testing in June 2015 aboard NASA’s C-9 aircraft for microgravity research, two Hedgehog prototypes demonstrated several types of movements.
Maneuvers found include “yaws” or the device turning in place, and “tornadoes” which launches the device from the surface due to aggressive spins. These maneuvers would be useful for getting around on a range of surfaces such as sand, rocks, and ice with little gravity.
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“We demonstrated for the first time our Hedgehog prototypes performing controlled hopping and tumbling in comet-like environments,” said Robert Reid, lead engineer on the project at JPL.
“By controlling how you brake the flywheels, you can adjust Hedgehog’s hopping angle. The idea was to test the two braking systems and understand their advantages and disadvantages,” said Marco Pavone, leader of the Stanford team, who proposed the Hedgehog idea with Nesnas in 2011.
According to the researchers, the construction of a Hedgehog robot is cheaper than for a traditional rover. Additionally, several of these devices could fly together in the mothership. The mothership could then deploy many robots at once or in stages.
The researchers are also working on Hedgehog’s autonomy. This means that they want to increase how much the robots can do without receiving instructions from Earth. So far, they seem to still be in Phase 2 of its development.
YouTube: How to Explore the Surface of a Comet or Asteroid
Photo credits: All images and graphics used are owned by NASA.
Source: Elizabeth Landau (Jet Propulsion Laboratory)
