OPALS

OPALS

Artists rendering of an OPALS downlink Image credit JPL/Caltech
Operator	Jet Propulsion Laboratory
Manufacturer	Jet Propulsion Laboratory
Instrument Type	Communications
Function	Laser Communications
Mission duration	90 days
Began operations	18 April 2014
Website	http://phaeton.jpl.nasa.gov
Properties
Mass	159 kilograms
Number launched	1
Data rate	50 Mb/s
Host Spacecraft
Spacecraft	International Space Station
Launch date	18 April 2014
Rocket	Falcon 9 Dragon Capsule
Launch Site	Cape Canaveral
COSPAR ID	1998-067A
Orbit	Low Earth Orbit

Optical PAyload for Lasercomm Science (OPALS) is a spacecraft communication instrument developed at the Jet Propulsion Laboratory that was tested on the International Space Station (ISS) from 18 April 2014 to 17 July 2014 to demonstrate the technology for laser communications systems between spacecraft and ground stations.

The purpose of OPALS is to do research into replacing traditional radio-frequency (RF) communications which are currently used on spacecraft. This will allow spacecraft to increase the rate at which data is downlinked by 10 to 100 times. It also will have less error than RF communication.

It launched from Cape Canaveral to the ISS on 18 April 2014 on a Falcon 9 SpaceX CRS-3 Dragon capsule resupply.

The goal of the OPALS mission was to demonstrate a downlink of a short video from space using laser communication. In doing so, the following was learned:

Communications and commands were sent to the flight system via the Mission Operations System (MOS), which is a process developed by the OPALS team. When the team wanted to execute a laser downlink, it went as follows

This process is executed in a matter of seconds. In the case of communications that are not laser transmission (e.g. system health checks), the architecture is much the same. The uplink is the same, following steps 1-3. The downlink instead of going down to the OCTL goes through the same path as the uplink, except backwards. Just like the uplink, all the communications are via RF.

Although most downlinks went through the OCTL, some went through other ground stations, including the German Aerospace Center's (DLR) optical ground station in Oberpfaffenhofen, Germany and the European Space Agency's ground station in Mount Teide, Tenerife, Canary Islands.