Astronomy. NGST aims for big advance by going back in time.
نویسنده
چکیده
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 standing army of technicians and engineers, plus exhaustive training for the astronauts who carry out the work. And then there’s the $500 million price tag for a shuttle flight. These huge costs led to an agreement in the late 1990s among Congress, NASA, and the White House Office of Management and Budget to halt servicing missions after 2004 and to funnel money into NGST. “If you don’t stop servicing Hubble, then NGST won’t get started,” says Weiler, adding that Hubble’s 15-year lifetime has already been extended to 20 years. By then, he says, even servicing missions won’t be able to keep Hubble’s technology up-to-date. “We could continue to do great science with Hubble,” says Weiler. “But I want to do outstanding science. Without unlimited funding, we’ve got to make tough choices.” Beckwith, however, says the choice isn’t necessarily that stark. NASA could conduct a relatively inexpensive repair mission after 2004 that wouldn’t entail costly instrument upgrades, he says, and technical advances could cut Hubble’s $40 million annual operating costs in half by the end of the decade. Keeping Hubble alive a bit longer would also restore a 1-year overlap between NGST and Hubble that disappeared as the new telescope’s launch date has slipped at least a year, he adds. But Anne Kinney, a senior NASA space science official, says that an overlap is not vital to the agency’s research program. And even reduced annual operating costs—not to mention the cost of another servicing mission—would break NASA’s limited budget, she and Weiler say. Turning off Hubble “is not a scientific question, it’s a political one,” concedes Beckwith.
منابع مشابه
Weak Gravitational Lensing with Ska
I shall outline the basic principles and some observational aspects of weak gravitational lensing, and discuss several applications of this powerful tool in observational cosmology. It will be explained why the applications have been restricted to optical observations up to now, and why SKA is going to change this. I conclude with a few general remarks on a comparison between SKA and the NGST, ...
متن کاملNASA ’ s Goddard Space Flight Center
The Laboratory for Astronomy and Solar Physics ͑LASP͒ continues to conduct a broad program of research and instrument technology development in ultraviolet and infrared astronomy and in optical/UV, X-ray, gamma-ray, and visible-light studies of the Sun. The program encompasses theoretical, observational, and experimental work, using platforms in space such as the Hubble Space Telescope ͑HST͒ Space ...
متن کاملPostpartum Haemorrhage: Still a Big Issue in Maternity Care - What is Going Wrong?
Background and aim: Postpartum haemorrhage remains one of the main leading causes of maternal mortality across the world. This is despite a wide-spread coverage of active third stage of labour care in many countries. Reflecting on emerging evidence in this context, a discussion of associated factors which should be considered in interpretation of the evidence and its implications is presented ...
متن کاملGoing Small for Big Advances Using Nanotechnology to Advance Cancer Diagnosis, Prevention and Treatment
متن کامل
An investigation of using hump in the Cherenkov photon lateral distribution for Gamma-Hadron separation
Simulation of gamma and hadron showers in the energy range 100GeV- 25TeV has been carried out. For a big ideal Cherenkov light array, characteristics of lateral distribution of Cherenkov photon density have been studied. Results from this ideal detector are compared with those simulated for a real TUNKA- like array to investigate experimental potential of using existence of a hump in lateral di...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Science
دوره 295 5559 شماره
صفحات -
تاریخ انتشار 2002