Originally posted by: Antoneo
I thought the Bush administration was partying about a new space endeavour towards Mars? NASA's budget seems to have always been thin ever since the Cold War fizzled, so I wouldn't just stick this one onto the current Bush administration alone. (correct me if I'm wrong)
Especially because the humans-on-Mars thing is projected to cost close to a trillion dollars in the next 20 years. Now they're worried about a billion dollar investment to repair and upgrade the Hubble?
From one of Bush's speeches:
Returning to the moon is an important step for our space program. Establishing an extended human presence on the moon could vastly reduce the costs of further space exploration, making possible ever more ambitious missions. Lifting heavy spacecraft and fuel out of the Earth's gravity is expensive. Spacecraft assembled and provisioned on the moon could escape its far lower gravity using far less energy, and thus, far less cost. Also, the moon is home to abundant resources. Its soil contains raw materials that might be harvested and processed into rocket fuel or breathable air. We can use our time on the moon to develop and test new approaches and technologies and systems that will allow us to function in other, more challenging environments. The moon is a logical step toward further progress and achievement.
A permanent moon base capable of harvesting and processing materials for constructing anything substantial will be very expensive; making it resistant to micrometeor impacts will also be very difficult, not to mention shielding against radiation present outside of Earth's magnetosphere.
Originally posted by: ElFenix
Originally posted by: Wallydraigle
Originally posted by: raildogg
Originally posted by: Wallydraigle
I read that either currently, or very soon, we will be able to build huge terrestrial telescopes with the technology to cancel out atmospheric disturbances. So Hubble was basically obsolete anyway, and probably wasn't worth fixing anymore.
it is worth fixing.
Why would it be worth it to keep fixing it if we can build better telescopes here on earth for a fraction of the price?
they're not very aimable
Can't do any million-second exposures with an Earth based telescope - that's how long Hubble stayed pointed at one spot in the sky to create its Ultra-Deep Field image. Over several hundred orbits, it was able to point at the same spot. And it can acquire several groups of images a day - 90 minutes per orbit. On Earth, the spot will change place over the seasons - and you'd only get a chance at one imaging session a day. Cost suddenly goes up when it takes 16x longer to get deep-space images from the ground.
Interesting too is this on NASA's site:
Ultimately, a flight mission to Hubble will be required at the end of its time to either to return it to ground, raise it to a higher orbit, or guide it into a controlled re-entry (possibly with the aid of an attached booster).
I guess that a re-entry booster could be done without human intervention. But there's an idea - send the shuttle to service Hubble, AND install the re-entry module on it at the same time. Extended life, and save the money of launching another rocket to get the thing down when its new warranty runs out.