So in places like U Arizona or CalTech, at least some people must see BFR as an upcoming opportunity, and are thinking about what type of instruments they can orbit. I mean, even it's only academic...
I note the moving part of https://en.wikipedia.org/wiki/Giant_Magellan_Telescope is around a thousand tons, and a billion dollars. ($1000/kg)The 8.4m diameter mirrors would in principle fit in BFR launches, and would be each considerably larger in diameter than JWST.An array of the nominal seven would be a very, very significant improvement over JWST.Note the more ambitious costings for BFR launches (well under $1000/kg) are basically irrelevant to this market at the moment.
The GMT is that massive because gravity. Similarly the mirror. Any space based instrument would be *much* lighter. Also, there is little need for such massive mirrors these days - almost all are segmented.But overall, how BFR helps with orbital (or lunar) telescopes is a good question!
If you're putting something up on BFR, the logical segment size would be around the BFR diameter, all else being equal.
In principle I agree about space based instruments being possibly lighter. But I would be rather surprised if making a large telescope for space use wasn't going to be comparably expensive at least to one on earth.
Fun fact. JWST costs $1000/g.
Bring back ESA Darwin or NASA Terrestrial Planet Finder that were cancelled a decade ago. Or Antoine Labeyrie hypertelescope. BFR is certainly the right rocket for them, but as usual, no buck, no buck rogers.
Quote from: jebbo on 10/26/2017 03:36 pmThe GMT is that massive because gravity. Similarly the mirror. Any space based instrument would be *much* lighter. Also, there is little need for such massive mirrors these days - almost all are segmented.But overall, how BFR helps with orbital (or lunar) telescopes is a good question!If you're putting something up on BFR, the logical segment size would be around the BFR diameter, all else being equal. In principle I agree about space based instruments being possibly lighter. But I would be rather surprised if making a large telescope for space use wasn't going to be comparably expensive at least to one on earth.Yes, some things get easier - gravity and wind loads are notably reduced, and you can throw out a chunk of the adaptive optics.But, lack of maintenance (or considerably harder maintenance), and positioning, comms, vacuum hardening commercial equipment aren't free.Complex 'good' telescopes are still going to be expensive. Single detector relatively small 'light buckets' with limited capabilities might be lots cheaper and compliment the large ones enormously.Fun fact. JWST costs $1000/g.
I bring up the topic of instruments for a BFR type launcher both in cost and capability over lunch breaks occasionally. No one I talked to believes in either. No one could think of designing a sat that heavy. No one believes it can be launched that cheap. No one believes that a funding agency can be convinced to fund a project like that. As a consequence, no one is willing to spend the time in investigating a scientificly relevant instrument and telescope for BFR.
No one wants a second project like JWST. Its just too expensive.
Quote from: Semmel on 10/27/2017 07:10 amI bring up the topic of instruments for a BFR type launcher both in cost and capability over lunch breaks occasionally. No one I talked to believes in either. No one could think of designing a sat that heavy. No one believes it can be launched that cheap. No one believes that a funding agency can be convinced to fund a project like that. As a consequence, no one is willing to spend the time in investigating a scientificly relevant instrument and telescope for BFR.Would there be interest once it's proven?
I work at a scientific institute for ground based astronomy. We did supply an instrument for a space mission but nothing big. I bring up the topic of instruments for a BFR type launcher both in cost and capability over lunch breaks occasionally. No one I talked to believes in either. No one could think of designing a sat that heavy. No one believes it can be launched that cheap. No one believes that a funding agency can be convinced to fund a project like that. As a consequence, no one is willing to spend the time in investigating a scientifically relevant instrument and telescope for BFR.
I work at a scientific institute for ground based astronomy. We did supply an instrument for a space mission but nothing big. I bring up the topic of instruments for a BFR type launcher both in cost and capability over lunch breaks occasionally. No one I talked to believes in either. No one could think of designing a sat that heavy. No one believes it can be launched that cheap. No one believes that a funding agency can be convinced to fund a project like that. As a consequence, no one is willing to spend the time in investigating a scientificly relevant instrument and telescope for BFR.By the way, the major advantage of space is, that there is no (dif-)fraking atmosphere. No extinction, no background, no emission lines, no seeing. Ground based telescopes are limited by these things. Adaptive optics can only correct a tiny field, so you can't get wide field with it. And even that not perfectly. In my opinion, a sat would be best for very large mirrors because it would be diffraction limited. Instruments can range from far UV to IR which doesn't work on earth. But such a project is expensive and takes at least 20 years from start to launch. A good alternative would be a swarm of small, wide field telescopes to observe the entire sky continously. Could be cheaper than LSST with better results. Also other high energy telescopes for x-ray astronomy would be great. But there is a new generation coming online in the near future, so probably not a project to get funding in the next decade. Radio astronomy on the moon or in space would be brilliant, not for the interference shielding but for base length with Earth. For comparison, I am not convinced that EELT, GMT and TMT will deliver the science return that justifies the cost. The adaptive optics is much harder due to the size and segmentation of the primary mirror. All three will be a marvel of engineering when it works, but I think space would have been easier and cheaper. We will see. I am pretty sure that the three giant telescopes above are the last class of large telescopes ever built on the ground. For radio, the SKA already covers the entire earth in size. There is no physical way to make it better than to go to space. And then there is gravitational waves telescopes. That doesn't need BFR but it doesn't hurt either. In all, the cost for a space telescope does not come from the launch but from the army of engineers designing and building a one off special device. And once you have a telescope like that, operations costs even more than building it. Thats because a good space telescope is so rare, everyone wants observation time. Many, cheap space telescopes of identical design would be my guess for the first serious application of BFR for astronomy. But I would not count on any telescope being build within the next 20 years that require BFR. It will take around 10 years to get BFR/BFS flying often enough so that science institute consider it as a reliable launcher. It will then take at least 10 more years to design and build a space telescope or a swarm that requires BFR capabilities. If its not a swarm but a giant telescope, it will take 30 years instead of 20. No one wants a second project like JWST. Its just too expensive.
Quote from: Semmel on 10/27/2017 07:10 amI work at a scientific institute for ground based astronomy. We did supply an instrument for a space mission but nothing big. I bring up the topic of instruments for a BFR type launcher both in cost and capability over lunch breaks occasionally. No one I talked to believes in either. No one could think of designing a sat that heavy. No one believes it can be launched that cheap. No one believes that a funding agency can be convinced to fund a project like that. As a consequence, no one is willing to spend the time in investigating a scientificly relevant instrument and telescope for BFR.The first part of your post - that's exactly what I suspected. In some ways, scientists are both very imaginative but also very conservative...We'll see how this plays out. Someone is going to be "first", and it might not be one of the first-tier players.
I work at a scientific institute for ground based astronomy. We did supply an instrument for a space mission but nothing big. I bring up the topic of instruments for a BFR type launcher both in cost and capability over lunch breaks occasionally. No one I talked to believes in either. No one could think of designing a sat that heavy. No one believes it can be launched that cheap. No one believes that a funding agency can be convinced to fund a project like that. As a consequence, no one is willing to spend the time in investigating a scientificly relevant instrument and telescope for BFR.
but i'm sure there are lots of universities around the world that would like to have their own Hubble if one could be had for the cost of a new dorm building or campus stadium.
Expect dramatic shifts in opinion every time SpaceX actually accomplishes a step on the path. Flying Falcon Heavy, Flying Crew, It’s own private manned lunar Flyby, The first reveal of a test full scale BFS. It will come as a shock that they’re serious.
A good first proposal would be to work with an existing design like Hubble. Update the design and cram as many as possible into a cargo BFS. maybe six per launch?There's no funding at the NASA level for "just another Hubble" since it doesn't show any advancement, but i'm sure there are lots of universities around the world that would like to have their own Hubble if one could be had for the cost of a new dorm building or campus stadium.