AstroAnt

Overview

AstroAnt is a robot about 3 cm across, built by the MIT Media Lab’s Space Exploration Initiative, that drives on the outside of another spacecraft [1], [2]. It rode to the Moon on IM-2 mounted on the top surface of the Lunar Outpost MAPP rover, where its task was to measure the temperature of that rover’s radiator from several positions along it.

The premise is symbiotic rather than independent: a miniature robot that lives on the exterior of a larger vehicle, moves across it, and inspects it. The stated longer-term applications are a team of such robots clearing dust from solar panels and checking structures for damage [1]. Nothing about the vehicle is autonomous or self-sufficient; it carries a sensor to a place on another machine that a fixed sensor could not reach.

IM-2 landed on 6 March 2025 with the lander on its side [2]. MAPP was never deployed and AstroAnt never operated.

Specifications

Parameter	Value	Source
Size	about 3 cm across	[1]
Wheels	4, magnetic	[1], [2]
Attachment	magnetic adhesion to any ferromagnetic surface	[1]
Incline capability	up to 80 degrees
Sensor	thermopile on the underside, contactless temperature
Communications	Bluetooth Low Energy, robot and central station	[2]
Endurance	a few hours before recharge	[1]

Mass, battery capacity, drive speed, processor and thermal limits are not published, and no peer-reviewed or conference publication about the vehicle has appeared.

Mission profile

Parameter	Value	Source
Launch	27 February 2025	[2]
Landing	6 March 2025, Mons Mouton
Host	Lunar Outpost MAPP rover
Task	contactless temperature of the MAPP radiator from several positions
Outcome	host rover not deployed; no operation

Mobility

Four magnetic wheels, which is both the drive and the attachment method: the robot holds itself to a ferromagnetic surface by the same wheels it drives on, so it can work on a vertical or inverted surface as readily as a horizontal one [1], [2]. The published capability figure is an incline of up to 80 degrees. Adhesion has been exercised on rough surfaces, on beta cloth simulant, on steel, and on aluminum coated with magnetic paint, which is what makes a non-ferrous spacecraft surface usable [1].

Drive speed and traction are not published, and the surface it was to work on, a rover radiator, is a manufactured plate rather than regolith, so no terramechanics question arises.

Power and energy

An onboard battery giving a few hours of operation before it must be recharged [1]. Capacity, charging method and the recharge interface are not published.

Thermal

Not published, which is the notable gap for a robot whose task is to sit on a radiator in lunar daylight and whose measurement is a temperature.

Compute and avionics

Not published.

Autonomy

Not described. The robot and a central station on the host vehicle communicate over Bluetooth Low Energy, and the station is the path back to the ground [2].

Communications

Bluetooth Low Energy between the robot and a central station carried on the host rover, with the station relaying through the host [2]. Data rate and range are not published.

Payload and instruments

A single thermopile on the underside of the robot, giving contactless temperature readings of whatever it is standing over [1], [2]. The measurement it was flown to make is the performance of the MAPP rover’s thermal radiator, sampled at several points across the radiator rather than at the one place a fixed sensor would occupy, which is the entire argument for making the sensor mobile.

The sensor payload is modular, so the same chassis can be fitted for a different inspection task [1].

Modes of operation

Not published.

Ground operations

Not published beyond the robot-to-station-to-host communications path [2].

Technologies developed

The design point is the contribution: a mobile, magnetically adhering robot at 3 cm scale with a sensor, a radio and a battery, able to hold and drive on an 80 degree incline, and able to grip an aluminum surface treated with magnetic paint rather than requiring a ferrous one [1]. Reduced gravity behavior was addressed before flight rather than assumed: the Media Lab flew AstroAnt on four parabolic flights with NASA during 2021, including lunar-gravity and zero-gravity segments, and tested adhesion across rough surfaces, beta cloth simulant, steel and painted aluminum [1], [2]. No results from those flights have been published.

References