CLASP was successfully launched

Sep. 04, 2015

CLASP launch (NASA/MSFC)

The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is a sounding rocket experiment to observe the Sun through Lyman-alpha line emissions. Because the Lyman-alpha line is absorbed by the Earth's atmosphere, the instrument needed to be raised above the atmosphere. CLASP was successfully launched to space from White Sands in the U.S.A. at 11:01 local time on September 3.

What is CLASP?

CLASP aims to infer the nature of the magnetic fields in the chromosphere and the transition region of the Sun, by measuring the polarization of light caused by the Hanle effect. The magnetic fields in the photosphere can be measured through the Zeeman effect. However for the chromosphere and the transition region, where the field strengths are weak, it is difficult to use the Zeeman effect to measure their magnetic fields. The Hanle effect provides an attractive alternative.

The CLASP project has been carried-out through international collaboration between the U.S.A., Spain, France, Norway and Japan. The CLASP flight instrument was assembled in the Advanced Technology Center (ATC) of the National Astronomical Observatory of Japan (NAOJ). Assembly started at the beginning of 2014, and the final performance tests were finished by April of 2015. After that, the electrical functional tests with the flight computer were performed at NASA/Marshall Space Flight Center (MSFC) in the U.S.A. Then the final assembly and tests with the rocket instruments and motor were performed at White Sands in preparation for the launch.

Installation of the primary mirror (in the ATC cleanroom). The cold-mirror coating, which reflects the Lyman-alpha line but transmits visible and infrared light, has already been applied to the primary mirror. (NAOJ, JAXA, NASA/MSFC)

The CLASP instrument installed in the rocket skin is shown below with a composite image. The instrument consists of the telescope and the spectro-polarimeter.

CLASP Launch

CLASP was launched from White Sands, U.S.A. at 11:01 local time on September 3. Once in space, the CLASP instrument was ejected by the rocket motor and observed the Sun for the approximately 5 minutes that CLASP was above 150 km. The instrument used a parachute to land in the White Sands desert, and was carried back to the laboratory. All the data stored in the instrument were recovered successfully. Analyzing the observational data precisely, we will obtain information about the magnetic field of the solar chromosphere.

NAOJ, JAXA, NASA/MSFC

Dr. Kano (CLASP project J-side PI) said, "Everything was the perfect in this sounding rocket experiment: the rocket flight, the instrument's on-flight performances, and the pointing operation. CLASP observed one point on the solar disk without any jitter/drift motion, as if time stopped. Since I saw the excellent data in real time, I am so excited and look forward to the detail analysis from now by ourselves."

Dr. Narukage (Instrument Scientist) said, "The CLASP sounding rocket took a perfect data set as response to our effort at 7-year development!! Though we just starts the detail analysis of the obtained data, I have already confirmed that our data will remain in the solar observation history!!"

Dr. Ishikawa (Project Scientist) said, "I was very excited with the launch of CLASP. When I looked at data from the telemetry, I was very happy that data was excellent. Moreover, I also remembered these seven years which I spend with CLASP and I realized that we finally come here!!!! I am looking forward to performing the detail data analysis very much."