Well this is bad news. NASA Spaceflight.com is reporting that science operations on Hubble Space Telescope have been shut down by the failure of the “Side A” control system. The telescope is in safe mode but is without any way to run the science instruments. HST’s technical handlers are working to transfer control of science operations to a Side B backup system, but this will take some time. Side B has never been used on orbit, but is assumed to be in working condition. If it works, then science can resume.
However, from what I’m able to glean from several websites, this may affect the servicing mission scheduled for an October 14 launch. If Side B can be activated and used, then the mission may well go on as scheduled. If Side B is not working, the mission could be delayed into 2009 in order to figure out a repair strategy. This is still a developing situation, so stay tuned.
Update: the upcoming repair mission for HST has been delayed until 2009, and the telescope’s handlers will work to bring up Side B to use until the astronauts have been trained on replacing the parts for Side A (and those parts can be put together). For an in-depth look at the issues, check out Phil Plait’s Bad Astronomy Blog.
*********
In other news: I was on travel last week and didn’t get a chance to blog about the Chinese space mission until now. I think it’s very cool and wish their agency the best of luck! In a way it was like watching the U.S.’s own first steps in space in the late 50s and early 60s. Congrats to the Chinese taikonauts!
The history of the solar system is written on the surfaces of planets and moons, but can also be read in dust particles found in the clouds surrounding comet nuclei. How does this work? Think back a few billion years, to when the solar system was first forming. We had a cloud of raw materials-gases, ices, and dust. You could (if you were around back then) take samples of that cloud material and do a chemical analysis on them. You’d determine the mix of elements and also the isotopes of those elements. (Think of isotopes as different forms of the same element. Chemists call them different “species.” So, you could have helium-3 or carbon-12 or carbon-13.) Study those isotopes and they can give you a lot of information about the timeline of history that our solar system experienced.
Comets formed pretty early in the history of the solar system, making them treasure troves of information about the chemical makeup of the gas and dust cloud that eventually birthed the rest of the solar system. So, it’s obvious why scientists send spacecraft (like the Stardust mission) to gather up comet dust: they can use it to fill in the gaps of our knowledge about how the solar system formed and what those early materials were. We know the big picture: that the rocky worlds formed close to the Sun, and that the volatile gases and ices that existed there were melted or driven off to the outer parts of the solar system (an icy deep-freeze that made a great home for gases and icy particles). Now scientists are examining the bits of dust that come flying off comets as they come close to the Sun in their orbits. And, those “bits” have interesting tales to tell.
Tiny crystals from Comet Wild 2 were captured by NASA’s Stardust mission. They resemble these fragments of molten mineral droplets called chondrules. found in primitive meteorites. That similar flash-heated particles were found in Wild 2, a comet formed in the icy fringes of outer space, suggests that solid materials may have been transported outward in the young solar system. Photo by Noriko Kita/Courtesy University of Wisconsin-Madison.
This week, a group of scientists led by Tomoki Nakamura, a professor at Kyushu University in Japan, publicized their analysis of oxygen isotope compositions of three crystals from the halo of Comet Wild 2. Their goal is to the origins of comet materials. Nakamura and University of Wisconsin-Madison scientist Takayuki Ushikubo analyzed the tiny grains – the largest of which is about one-thousandth of an inch across – using a unique ion microprobe in the Wisconsin Secondary Ion Mass Spectrometer (Wisc-SIMS) laboratory.This spectrometer is the most advanced instrument of its kind in the world.
The researchers were surprised to find oxygen isotope ratios in the comet crystals that are similar to asteroids and even the Sun itself. You have to ask yourself: how can this be, if comets formed well away from the Sun (and asteroids)?
Since these samples more closely resemble meteorites than the primitive, low-temperature materials expected in the outer reaches of the solar system, its entirely possible that heat-processed particles may have been transported outward in the young solar system, and eventually embedded in the icy nuclei of comets.
As you might imagine, this is stirring interest among planetary scientists. The findings complicate what used to be a simple view of solar system formation (that I described above). What are these minerals doing in a comet that came to the inner solar system from out past the orbit of Pluto? What sort of migratory patterns did early solar system materials follow? The answers will come from more studies of comet dust, and when they do, these little bits of ancient “stuff” will help revise and clarify the details in the theory of how the solar system grew and evolved. Stay tuned!
