Introduction Conception, design How it works? The HST launch Scientific results Future of Hubble Conclusion

Conception, design Quest of funding –Success of Orbiting Astronomical Observatory(OAO) encouraged construction of the telescope. –A space telescope is far more costly than any Earth-based telescope.

–The funding issues led to something of a reduction in the scale of the project Construction –Project divided between many institutions: Optical Telescope Assembly Spacecraft …

–Mirror and optical systems were the most crucial part: HST accuracy of 1/20 of wavelength of visible light. Polishing began in 1979 and continued until 1981 –The spacecraft was another major engineering challenge –Challenger disaster In 1986 space program had to halt

How it works?

–Finally the HST was launched on 24 April 1990 –First problem: a flawed mirror Problem with the optical system –Origin of the problem An error from Perkin-Elmer The HST launch

How to correct this mistake? –December 1993 : A servicing mission to save the telescope –New opticals components with the same error in the opposite sens But all the instruments cannot be repair this way –COSTAR: Corrective Optics Space Telescope Axial Replacement

Scientific results –Hubble has helped to resolve some long-standing problems in astronomy. The measure of the rate at which the universe is expanding This expansion is accelerating –The observation of the collision of Comet Shoemaker- Levy 9 with Jupiter in 1994.

Future of Hubble –Equipment failure Estimation of failure rate of gyroscopes by 2008 Hubble eventually require a change of batteries –Orbital decay If not re-boosted by a shuttle, it will re-enter the Earth's atmosphere sometime between 2010 and 2032

Conclusion –A lots of problems to make it work –But a lot of images and an enormous impact on astronomy –A dubious future