Sub-orbital rocket searches for first galaxies

The universe’s very first galaxies may feel a little closer by the weekend, thanks to a planned March 2nd (US time) launch of a sub-orbital Black Brant IX rocket bearing the Cosmic Infrared Background ExpeRiment (CIBER)that hopes to figure out which light comes from the earliest stars.

CIBER bears three instruments, one of which is an imager that probes the infrared spectrum of the Extragalactic Infrared Background in an attempt to find fluctuations that could come from the earliest stars and galaxies.

CIBER boffins say a low resolution spectrometer will conduct “… a search for the redshifted Ly-cutoff feature, a signature of UV photon emission from when the universe was partially ionized,” a useful trick as if a transition from the near-infrared to the optical were confirmed it would “… have a much different spectral shape than either zodiacal light or the integrated counts of galaxies, providing definitive evidence for a first-light galaxy …”

A narrow band spectrometer will help to calibrate results, by measuring dust in the solar system so its ability to reflect light from the sun doesn’t mess up other data.

The launch is CIBER's third rocket mission and the experiment prefers this method as ascending even the few hundred kilometres possible on a sub-orbital rocket means much more light is available for capture and analysis.

The rocket CIBER will use is a sounding rocket, a class of sub-orbital rocket used for experiments and to test components for orbital missions. Dozens are launched each year and the Black Brant vehicle CIBER will use is among the world’s favourite, having chalked up more than 1000 successful launches since its first journey in the early 1960s. Black Brant rockets can carry payloads up to 410kg and can reach altitudes of 1,500km.

The Black Brant IX CIBER will use has a range of up to 550 kilometres, but flight time for this kind of mission is usually under 30 minutes. Sounding rockets are recovered manually by crews who visit the landing site and retrieve the rocket’s remains and any instruments aboard. CIBER’s website shows its boffins rummaging through a grounded rocket.

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