On December 3rd, the NASA astronauts on the Internal Space Station started testing a new Crew Support LAN (CSL). According to the “ISS On-Orbit Status” for December 3rd –











At ~11:05am EST, Jeff Williams conducted a one-hour video-based training session on the exciting new CSL (Crew Support Local Area Network) capabilities and hardware. (Crew Support LAN Phase 1 will provide live Internet access to the ISS crew (initially only USOS crewmembers) as safely, securely and reliably as possible whenever Ku-band is available. The access will be accomplished by connecting to a remote desktop session on a remote server (Citrix server) located on the ground, which hosts the virtual desktops, and the crew sees only an image of the remote desktop which does the Internet surfing. Video and audio can be received (but may be choppy or sometimes out of sync). The CSL, a virtual network completely separate from the station-wide Ops LAN, will use existing IBM A31p laptops and existing network hardware. Initially, there will be only one CSL laptop (Client 1) and one CSL server (CREWLAN SERVER) both set up in Node-2. After the initial testing, the CSL will be expanded to include up to four clients.)

Here is some back ground on the type of Ku-Band link from NASA.



“The Ku-band antenna aboard the space shuttle orbiter is located in the payload bay; thus, Ku-band can be used only when the orbiter is on orbit. The orbiter payload bay doors are opened and the Ku-band antenna is deployed. The Ku-band system operates in the Ku-band portion of the radio frequency spectrum between 15,250 MHz and 17,250 MHz. The Ku-band carrier frequencies are 13.755 GHz from the TDRS to the orbiter and 15.003 GHz from the orbiter to the TDRS. Once the Ku-band antenna is deployed, the Ku-band system can be used as a communication system to transmit information to and receive information from the ground through the TDRSS. The Ku-band antenna aboard the orbiter can also be used as a radar system for target tracking objects in space, but it cannot be used simulta neously for Ku-band communications and radar operations.

Ku-Band has quite a bit of latency. “Since they relay signals off a satellite in geosynchronous orbit 36,000 km (22,300 miles) above the Earth, VSAT links are subject to a minimum latency of approximately 500 milliseconds round-trip. This makes them a poor choice for “chatty” protocols or applications.”

It is great to see that Citrix technology is the choice to deploy virtual desktops over the most extreme network conditions in the world.





Follow me on Twitter.