James Webb Space Telescope to Earth: It Can Now Connect!
Once it launches in 2013, the James Webb Space Telescope will be able to communicate and connect with the Earth thanks to a modified "off-the-shelf" computer software system that has been recently and successfully tested.
The customized off-the-shelf computer system, the Raytheon Corporation’s ECLIPSE product, will be used to send commands to the Webb telescope and collect its telemetry data.
Image right: Artist's conception of the James Webb Space Telescope in orbit. Click image for higher resolution. Credit: Canadian Space Agency
Telemetry means that a spacecraft in orbit makes automatic measurements and transmits them to the Earth using a radio signal. The information sent also includes information describing the health of the spacecraft. It's important for the engineers on the ground receiving the information, to know that the James Webb Space Telescope is working well. If it isn't, they need to try and fix it from the ground, sending commands to the spacecraft's computer system using a radio signal, so it can repair its software.
Two companies worked together to modify the telemetry system: Northrop Grumman and the Raytheon Corporation. Recently, they completed the tests that made sure it worked properly and specifically for the James Webb Space Telescope. It turns out that the same modifications they made for the Webb telescope can be used in another upcoming space satellite called "NPOESS."
This is the first time a team included engineers from two different spacecraft programs, the Webb telescope and the NPOESS satellite. Alexis Livanos, Corporate Vice President and President of Northrop Grumman’s Space Technology sector said "Two customers with two separate programs were willing to trust our collaboration and teamwork to align schedules so that the same system could be used."
The key for the success was testing the telemetry system. So, Northrop Grumman and Raytheon increased test requirements to bring together the way two different satellites communicate and the needs of their users. Software requirements were checked on the spacecraft and ground equipment simulators at Northrop Grumman over a four-week period that ended in August.
Image right: The Webb telescope sends data to ground stations on Earth, which route the data to the Space Telescope Science Institute for processing and distribution. Click image for higher resolution. Credit: STScI
That testing was the last step in a process that took four years of development at Raytheon. Raytheon was responsible for developing this system for Northrop Grumman. Engineers and scientists at Northrop are actually building the spacecraft. During the tests, 1300 requirements were met. The tests checked the ability to send commands from equipment to equipment, receive telemetry (or communications), and to control and monitor the test hardware.
Recently, the modified telemetry software was delivered to scientists and engineers at the Goddard Space Flight Center who will use it to develop, test, and add it into their instruments for the James Webb Space Telescope.
The James Webb Space Telescope, designed to succeed the Hubble Space Telescope, will be NASA's premier space observatory. Northrop Grumman is the prime contractor, leading a team in the telescope’s design and development under contract to NASA Goddard. NPOESS is the nation's next-generation low-Earth orbiting remote sensing system and will provide environmental data to military and civilian users. Both are scheduled for launch in 2013.
+ The James Webb Space Telescope mission page
+ Northrop Grumman's news release about the system
NASA Goddard Space Flight Center