Perseverance’s Parachute Secret Message Encoder

Posted on March 18, 2021 by Administrator Posted in Computer Science, Computing Concepts, Cryptography, Solved Challenges

On February 18, 2020, NASA successfully landed its rover “Perseverance” on planet Mars. To slow down its descent the rover deployed a parachute. The whole operation was filmed and relayed on the Internet. You can watch the official NASA video on youtube.

The internet community quickly noticed the unusual red and white pattern on the parachute resembling the pattern of a barcode:

Source: NASA/JPL-Caltech

In just a few hours, internauts successfully decoded the “secret message” encoded on the parachute. The message read:

“Dare Mighty Things – 34° 11’58” N 118° 10’31 W”

The numbers in this message correspond to the GPS coordinates of the JPL centre (NASA’s Jet Propulsion Laboratory in located in California), whereas “Dare Mighty Things” is the moto used by JPL.

The encoding process is fairly basic:

The 3 concentric inner rings of the parachute represent one word per ring.
Each character of a given word is represented by a number between 1 and 26 corresponding to its position in the alphabet (A is 1, B is 2, up to Z is 26). These numbers are then converted in binary using 7 bits per character followed by “000” as a delimiter between each character.
E.g. The word DARE is encoded in the inner circle. D=4 A=1 R=18 E=5 becomes in binary:
000-0000100-000-0000001-000-0010010-000-0000101-000
The pattern consists of red and white stripes. A white stripe represent a 0, a red stripe a 1. e.g.

Character	Value	64	32	16	8	4	2	1
D	4	0	0	0	0	1	0	0
A	1	0	0	0	0	0	0	1
R	18	0	0	1	0	0	1	0
E	5	0	0	0	0	1	0	1

The message is encoded clockwise.
A ring consists of 80 stripes (to encode a word of a maximum of 8 characters. All unused stripes appear as a large red block.
Using a similar approach, the outer ring of the parachute is used to encore the GPS coordinates in DMS (Degrees, Minutes, Seconds) format. Each coordinate being encoded in binary using 7-bits.

Let’s apply this to decode NASA’s Perseverance Secret Message:

“Dare Mighty Things – 34° 11’58” N 118° 10’31 W”

Online Encoder

You can use our online secret message encoder to design your own parachute. To do so you will need to:

Choose 3 words of maximum 8 letters each.
Identify the GPS coordinates (using the DMS format: Degrees, Minutes, Seconds) of a given location on planet earth. (You can use this website (www.gps-coordinates.net) to retrieve the required coordinates)
Input this information below to generate your parachute. You can then print or take a screenshot of your parachute.

Decoding Tasks

We have encoded a few messages using the same approach. Well you be able to decode these messages and identify the exact location using the following parachutes?