A worthy COS

University helped design and build now-orbiting Cosmic Origins Spectrograph

Feb. 1, 2003, changed everything. Not only was it a disastrous loss for the friends and family of the astronauts aboard the space shuttle Columbia, which disintegrated as it re-entered Earth’s atmosphere, but it also dramatically changed the course of NASA for several years. One of the major projects postponed by the crash was the Cosmic Origins Spectrograph, or COS, one of a pair of replacement instruments slated for delivery to Hubble Space Telescope by shuttle.

More than six years later, the mission was a go, and scientists at the University of Colorado had cause to celebrate.

On May 11, space shuttle Atlantis lifted COS into space. To mark the occasion, CU’s Center for Astrophysics and Space Astronomy held a launch party at the Astrophysical Research Lab on the Boulder east campus. It was CASA, led by Principal Investigator Prof. James Green, that designed and built COS, in collaboration with Ball Aerospace and Technologies Corp.

“This marks the rebirth of UV spectroscopy astronomy here at CASA,” said Tom Ayres, associate director of the lab. “But the installation of COS is only part of the STS-125 Mission,” he explained.

The Space Telescope Imaging Spectrograph, or STIS, which has been damaged for several years, will also be repaired. “It will be like having a whole new Hubble,” he said.

According to the CU-Boulder COS web site, “Ultraviolet spectroscopy provides some of the most fundamental diagnostic data necessary for discerning the physical characteristics of the planets, stars, galaxies, and interstellar and intergalactic matter.”

Charles Danforth, a COS research scientist, explained that COS is 30 times more sensitive than STIS and will help provide clues to the early evolution of the universe. Danforth, who was brought on initially to help analyze COS data as a grad student in 2003, prior to the project’s postponement, now finally will have that opportunity: each COS team member will get a share of 550 orbits of Hubble time. Each orbit takes about 90 minutes, but you can usually only use about 50 for observations as the Earth will obstruct your view for part of that time.

After the successful launch of Altantis, there was a collective sigh of relief and a building excitement for the pending mission. “This is the first step in a long chain of events,” said Ayres, “We are really pleased for everybody here at CU.”

The whole STS-125 Mission ultimately was a great success. The Cosmic Origins Spectrograph was installed, and successfully tested on May 16. STIS was repaired, as was another damaged instrument, the Advanced Camera for Surveys. A new camera – WFC3 – also was installed, and a number of key spacecraft subsystems were replaced. The lifetime of the observatory has been extended to around 2014.

Now, there is a month-long start-up and verification period before COS will begin delivering data. “First light” observations are scheduled for mid-June, and the science program will begin in July.

It also was announced that mission specialist Dr. John Grunsfeld, the astronaut who personally installed COS, will join CU’s astrophysical and planetary sciences department as an adjoint professor.