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Top > Astro-E2 > What's New > 2000-04-11


By Hideyo Kunieda (ISAS)
APRIL 11, 2000

Already two months have past after the failure of Astro-E launch, though I can clearly remember the TV image of the rocket. Here I would like to report the current understandings of the M-V-4 launch and the our plan to recover from this great loss.

1. What happened to the M-V-4 launcher?

The failure of the first stage motor is summarized in the ISAS home page. A series of reports there explain:

  1. The graphite insulator of the nozzle throat on the first stage rocket was broken.
  2. The electric wiring of the nozzle actuator was burn out due to the flame, which came out from a hole of the nozzle.
  3. The first stage rocket lost control and tumbled with a deviation of more than 60 degrees.
  4. Though the second and the third motors recovered the control, the loss of the power in the first stage caused the deficit of the final velocity for the satellite orbit.
The rocket team at ISAS is continuing the search for the reasons why the graphite was broken, even though the same type of insulator has been used in 54 rocket launches in Japan without failure.

2. What are we going to do?

Astro-E has been aiming at following science:

  1. With XRS+XRT: the high resolution spectroscopy at high energies, especially for the iron K lines, in order to examine the dynamics and physical state of the most active region in the universe, such as cluster of galaxies and the vicinity of blackholes.
  2. With XIS+XRT: X-ray imaging spectroscopy in wider field of view with large effective area and with medium energy resolution to find the distribution of emission and the abundance.
  3. With HXD: spectral observations in broad energy band up to 600 keV to cover the emission from non-thermal mechanisms.
With the combination of these instruments, Astro-E was expected to provide us with unique information from high energy phenomena in the universe. It was to be a complementary mission among the three giant X-ray missions in the 21st Century.

Since we believe the science, which Astro-E was trying to explore will be left as the major area to be studies even a few years from now, we propose to re-fly Astro-E or a similar mission as soon as possible. Therefore, on both US and Japanese sides, various possibilities are being pursued.

(1) In Japan

The first action taken in Japan was a proposal of Astro-E-II or similar type mission in Japan to the science board of ISAS on March 23. As the first option, it requested a full Astro-E mission with an M-V rocket to be launched in the Japanese fiscal year of 2003.

It is motivated by the facts that the science with three instruments is unique, and that the rocket team members are eager to re-fly Astro-E with an M-V rocket. The launch time is chosen in January-February season in 2004 because it will take three years for us to prepare and test the satellite. In addition, all other launch windows are already booked between 2002-2004.

However, the full Astro-E-II mission with the launcher costs more than $140M (US), which requires about a $50M budget increase for three years from April 2001. It is more than 20 % of the average year budget of ISAS. We need an emergency funding from larger pot of budget.

In the general assembly of the Astronomical Society of Japan, Dr. Inoue(ISAS) explained our status. As a result, it was proposed to issue a statement to support our plan to launch Astro-E-II or an Astro-E-like mission as soon as possible. We are going to look into this approach as well as other options.

(2) In the US

Just after the failure of Astro-E launch, NASA/GSFC people on the Astro-E team submitted a SMEX proposal, named Joule. It is a small satellite to be launched by a Pegasus rocket in 2003. Because of the limited volume and the weight, it is necessary to introduce a new technology such as a hydrogen dewar and a high ratio extensible optical bench. The system consists of one XRT (Astro-E spare) telescope with one XRS detector.

Various options are allowed in the phase A study from June 2000 through April 2001 in the SMEX projects. Large contribution from abroad is welcome, if it is less than the US partner's budget. For example, it is possible to upgrade from a Pegasus rocket to a Taurus to get more volume and weight. If the Japanese side can make a contribution on the order of $15M, then the dewar lifetime will be much longer than a year. At the same time, it may be allowed to convert current SMEX mission to a mission of opportunity to join foreign missions like Astro-E-II.

(3) Schedule

From ISAS, budget requests for 2001 will be submitted to the Ministry of Education in June. Taking into account the response of the Ministry, we need to decide which option we will take. The budget plan of the Ministry of Education will be sent to the Ministry of Finance (MOF) in September. The MOF will tell us their decision in December 2000. In the earliest case, we will be are to use the budget from April 2001. In the US, 6-8 SMEX proposals will be selected for phase-A study in June 2000. Two phase B proposals will be announced in April 2001.

In any case, we plan to work together to get a new version of Astro-E flying as soon as possible.

ISAS/JAXA Department of High Energy Astrophysics

Last Modified: Sunday, 05-Oct-2003 20:02:02 JST