How high can a Spiri Mu fly?

  • Default setting: 100m above launch position.
  • Legal limit: 100m above ground (varies by country and location)
  • Physical operating limit: 8,000m above sea level
  • Radio limit: 10,000m (for a horizontal reach of 9,000m, that's 4,359m in height)

What is the maximum flight time for Spiri Mu?

Assuming a full charge and low wind:

  • 15 minutes at moderate speed (below 4m/s) and no payload
  • 8 minutes at high speed (above 10m/s) or heavy payload (1kg)
  • 4 minutes at giv'er speed (above 25m/s) or huge payload (2.5kg) – risk of igniting the batteries

Note that a battery will lose about 10% of its capacity for every 100 times it is recharged. Using worn batteries will reduce maximum flight time.

How much weight can a Spiri Mu carry?

1kg, assuming low winds and no acrobatic maneuvers.

Is there an academic or educational discount for Spiri Mu?

Is there a start-up, professional or small business discount for Spiri Mu?

Is Spiri Mu compatible with other robots?

Yes, Spiri Mu can exchange information with any robots also using ROS.

What kind of sensors can I connect to Spiri?

You can connect any sensor that uses USB3 or I2C to Spiri.

What kind of batteries does Spiri Mu use?

Spiri Mu uses four Li-ion 21700 style batteries in series, each able to discharge at 30A. We also provide a racing version of the battery with higher amperage. Our instructions on battery handling are here:


Do not mix batteries of unlike type, age, level of charge, chemistry, or capacity. Do nothing with the batteries except what we explicitly advise. Misused batteries can explode, emit noxious psycho-active fumes, kill or seriously injure you and others, as well as cause property damage not limited to your Spiri Mu. Certain cell phone batteries of Li-ion chemistry, but much less powerful than Spiri Mu batteries, have caused motor vehicle and house fires, deaths, and fires on board commercial airliners. Treat Spiri Mu batteries with appropriate care and heed every word in our instructions.

How long does it take to recharge the batteries for Spiri Mu?

Approximately 1 hour.

What is the top ground speed for Spiri Mu?

10m/s is the default ground speed limit. You can change this, but it will void certain provisions of your warranty during flight above that limit. Spiri has been clocked at over 25m/s.

What is ROS and how does it work on the Spiri Mu?

Robot Operating System (ROS) is primarily a system for communicating data between different parts of a robot, or between different robots. On Spiri Mu, ROS is used, among other things, to communicate flight data between the flight control system and the cognitive and vision systems, which enables camera data to support navigation.

What is the operating range of a Spiri Mu?

  • 500m for local Wi-Fi connection, depending on the strength of your router's antenna
  • 10km for radio communication, provided direct line of sight from you to your Spiri Mu
  • infinite, provided both you and your Spiri Mu have access to the cellular network or to Internet

Spiri Cloud and Spiri Net sound dangerous. Is this like Skynet in the Terminator movies?

No. Spiri robots and humans are friends.

How smart is Spiri Mu compared to an animal?

Computers and animals are not smart in the same ways. By rough estimate, a Spiri Mu has a similar ability to process information as a honey bee. How that ability takes shape is in the hands of software developers.

What software is running on the current installer release of Spiri Mu?

  • PX4 1.9
  • BLHeli-32
  • Ubuntu 18.04
  • ROS Melodic
  • CUDA 10
  • OpenCV 4.0
  • Python 3.7

For the complete manifest, see [link]

What happens to a Spiri Mu when it crashes?

Spiri Mu recovers from 90% of in-air collisions with other drones, against simple surfaces such as walls and telephone poles, and when struck by a simple object such as a beachball. It can continue to fly with damage to its propellers, motor spurs, and shell. In an uncontrolled hard crash, Spiri Mu will sustain damage to its landing gears, propellers, and dorsal shell. In a free fall from 100m, damage may be sustained to the interior crux, especially at the interface with the motor spurs. Typically, the electronics and the data records on the SD cards are undamaged and fully recoverable. After a crash, the batteries should be safely discarded. A damaged battery is at risk of fire or failure later.

Can I obtain a courtesy sample or free Spiri Mu loan?

Not usually. That being said, we do provide Spiri Mu drones to researchers at universities and similar institutions as an in-kind contribution to work we are co-developing. We also provide robots for the purpose of developing educational programs for school systems.

I am an Instagram influencer. Will you send me a free sample to review?


If I order a Spiri Mu today, how long will it take for me to get it?

Thirteen weeks. We are working with our factory through a backlog of orders, including orders from our original Kickstarter campaign.

If I order 1,000 Spiri Mus today, how long will it take me to get them?

13 weeks.

Is there any way to expedite delivery of a Spiri Mu? Can I pay an expediting fee to get one faster?


What is isopropanol and why are you telling me to pour it into a cotton pad inside my Spiri Mu?

We recommend a 70% isopropanol mixture with distilled water, commonly known as rubbing alcohol, as a coolant for your Spiri Mu. It evaporates naturally at temperatures between the operating low and high temperatures of the electronics, and allows the computer to run faster than it could otherwise. This mixture, also, will not damage the electronics if it spills – in fact, it is commonly used to clean electronics. You should have a bottle of it in your first aid kit. It is also used to clean wounds on humans.

Can I use a liquid other than isopropanol to cool the computer? Is 100% isopropanol even better than 70%

No and no. Do not pour anything into Spiri Mu that we do not explicitly recommend.

Is Spiri Mu able to use its cameras in low light?

Spiri's cameras are not as sensitive in real time to low light as human eyes, but can take low light photographs using a long exposure. Otherwise, a small LED flashlight is sufficient to light the way for a Spiri Mu in terms of using visual odometry to aid its navigation. A Spiri Mu can easily carry a flashlight powerful enough for it to see by.

Can a Spiri Mu detect human body heat?

That is an edge case for its built in cameras, but Spiri Mu can carry an IR sensitive camera which can detect body heat.

Can a Spiri Mu discern a person in a crowd? In a forest? In the ocean?


Is it true that you keep a list of people who are mean to your robots?

No. We keep a list of friends of our robots.

Can Spiri Mu see and operate in fog?

Spiri Mu has the same trouble seeing as you do in fog. It can continue to use its visual odometry algorithms, but at lower ground speed.