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I sincerely hope that thanks to SpaceX the cost of launching telescopes to space will become small enough to allow multiple space-based telescopes (and radio te

by tener 5y ago

I sincerely hope that thanks to SpaceX the cost of launching telescopes to space will become small enough to allow multiple space-based telescopes (and radio telescopes). We are obviously some ways from that, but not that far away that we cannot start planning for when it happens.

Cthulhu_ 5y ago
Yeah that would be cool, the Hubble telescope has been massively successful but I would have thought there would be much more projects like that. The James Webb one will be next, but I feel like that one's really risky; they took years to develop and build it, and it's going out to a point of space where it's infeasible to send someone up there to fix it if there is a problem. A ring of radio telescopes in high orbit would be neat.
- _Microft 5y ago
  I like the ideas of "solar gravitational lensing telescopes" and "lunar crater radio telescopes". The former would place a telescope extremely far from the sun and use its gravitational lensing effect, the latter would turn a crater on the moon into a giant radio dish. Here is a link for the latter. https://www.nasa.gov/directorates/spacetech/niac/2020_Phase_I_Phase_II/lunar_crater_radio_telescope/ https://www.nasa.gov/directorates/spacetech/niac/2020_Phase_...
  - rbanffy 5y ago
    The Moon could be good place for optical interference - on Earth you need to use fiber (or QHD's) to carry photons from one place to the other, but on the Moon you have a reasonable vacuum so you may be able to get a large base with only mirrors or line-of-sight communications.
lou1306 5y ago
Indeed, lower satellite costs open up lots of possibilities. Another project is LISA [0], a gravitational wave observatory made of 3 heliocentric satellites. Pretty wild idea. [0]: https://en.m.wikipedia.org/wiki/Laser_Interferometer_Space_Antenna https://en.m.wikipedia.org/wiki/Laser_Interferometer_Space_A...
kwyjobojoe 5y ago
Yeah would be nice after they had ruined ground based telescopes for the whole planet.
- corporateshil1 5y ago
  Mhm, now we get to hear how some great future philanthropists donate/launch telescopes for society, making them forever great in mankinds eyes. 'cus some entitled folks had to leave a legacy of trash in our orbit since they can't leave anything useful.
macspoofing 5y ago
>I sincerely hope that thanks to SpaceX the cost of launching telescopes to space will become small enough to allow multiple space-based telescopes (and radio telescopes). I think people have unreasonable expectations as to what SpaceX can do. I'm sure there are efficiencies to squeeze out of the business, but it's largely from the ops, and infrastructure around the rocket, not the rocket design itself ... design that has not changed significantly in 50 years. Rockets themselves are as simple as you can get. It's fuel and exhaust and cargo . That's it. Reusability is fraught with issues and no guarantees it's cost effective (maintenance is expensive, reliability suffers, and decreased cargo/revenue due to needing to carry extra fuel for return). But even if reusability pans out, you're not going to get one (or more) orders of magnitude reduction in launch costs from where we are today. You'll get a few percentage points, maybe a few tens of percentage points and that's it.
- nitrogen 5y ago
  Using the same rocket ten times instead of once is an order of magnitude improvement. Why shouldn't it be possible to do even better than that?
  - macspoofing 5y ago
    >Using the same rocket ten times instead of once is an order of magnitude improvement. Reusability is not a panacea. Space Shuttle was reusable but it was not cost-effective and there were no cost savings. Also, reliability suffered and maintenance became prohibitive. In fact, I think the consensus is that the entire program was a mistake. >Why shouldn't it be possible to do even better than that? Because reusability has to contend with factors like: 1) Turn around time. How quickly can you refurbish a rocket. 2) Maintenance costs. How expensive is it to recover and refurbish the rocket. 3) How many times can you reuse a rocket. 4) Failure rates. Does reusing a rocket compromise quality. 5) Decreased revenue per launch. Reusable rockets need to carry spare fuel meaning, that your cargo space is cut (and cargo is revenue), and your costs are higher, because you have to still 'pay' to ship that spare fuel along with cargo. Factors like those may make it that even if there are cost-savings, that those cost savings are not orders of magnitude lower, but maybe something on the order of 10%-50% - which is nice, and you can disrupt the market and make a good business out of it, but it's not anywhere close to the claims that are made. And again, SpaceX has not shown in practice that they can get ANY savings from reusability.
qayxc 5y ago
Launch costs are only a fraction of the total cost of orbital telescopes, so don't get your hopes up. For reference, the WFIRST telescope came with satellite bus and 2.4m mirror for free yet already has a 3.2 billion dollar price tag attached to it. Even the most expensive launch provider would be less than 10% of that cost. It only weighs about 4 metric tons by the way, so there's that. Just a quick reality check on the unrealistic assumptions some people have.
- Gravityloss 5y ago
  I wonder, if you know you were launching one every six months for the next 20 years, what would the unit cost be? You might be able to use a commercial satellite bus for example. It would be fine if some would experience failures, as there would be the next one already lined up. Just put different instrument(s) at the end of the optical path in each. As example, Hubble has five instruments. https://hubblesite.org/mission-and-telescope/instruments https://hubblesite.org/mission-and-telescope/instruments One could start a design from something like CHEOPS with a 30 cm mirror. https://sci.esa.int/web/cheops/-/54032-spacecraft https://sci.esa.int/web/cheops/-/54032-spacecraft
  - HDMI_Cable 5y ago
    Do we need that many telescopes though? It seems like one only needs many 5 at any given time.
    - Gravityloss 5y ago
      One can already see that the existing terrestrial and space telescopes have long queues for observing time. Maybe more experimental instruments would be nice as well.
    - jjk166 5y ago
      There are currently 35 space-based telescopes in active service with 6 planned to launch in the next 12 months. [0] https://en.wikipedia.org/wiki/List_of_space_telescopes https://en.wikipedia.org/wiki/List_of_space_telescopes

by tener 5y ago

Cthulhu_ 5y ago

Yeah that would be cool, the Hubble telescope has been massively successful but I would have thought there would be much more projects like that. The James Webb one will be next, but I feel like that one's really risky; they took years to develop and build it, and it's going out to a point of space where it's infeasible to send someone up there to fix it if there is a problem. A ring of radio telescopes in high orbit would be neat.

_Microft 5y ago
I like the ideas of "solar gravitational lensing telescopes" and "lunar crater radio telescopes". The former would place a telescope extremely far from the sun and use its gravitational lensing effect, the latter would turn a crater on the moon into a giant radio dish. Here is a link for the latter. https://www.nasa.gov/directorates/spacetech/niac/2020_Phase_I_Phase_II/lunar_crater_radio_telescope/ https://www.nasa.gov/directorates/spacetech/niac/2020_Phase_...
- rbanffy 5y ago
  The Moon could be good place for optical interference - on Earth you need to use fiber (or QHD's) to carry photons from one place to the other, but on the Moon you have a reasonable vacuum so you may be able to get a large base with only mirrors or line-of-sight communications.

lou1306 5y ago

Indeed, lower satellite costs open up lots of possibilities. Another project is LISA [0], a gravitational wave observatory made of 3 heliocentric satellites. Pretty wild idea. [0]: https://en.m.wikipedia.org/wiki/Laser_Interferometer_Space_Antenna https://en.m.wikipedia.org/wiki/Laser_Interferometer_Space_A...

kwyjobojoe 5y ago

Yeah would be nice after they had ruined ground based telescopes for the whole planet.

corporateshil1 5y ago
Mhm, now we get to hear how some great future philanthropists donate/launch telescopes for society, making them forever great in mankinds eyes. 'cus some entitled folks had to leave a legacy of trash in our orbit since they can't leave anything useful.

macspoofing 5y ago

>I sincerely hope that thanks to SpaceX the cost of launching telescopes to space will become small enough to allow multiple space-based telescopes (and radio telescopes). I think people have unreasonable expectations as to what SpaceX can do. I'm sure there are efficiencies to squeeze out of the business, but it's largely from the ops, and infrastructure around the rocket, not the rocket design itself ... design that has not changed significantly in 50 years. Rockets themselves are as simple as you can get. It's fuel and exhaust and cargo . That's it. Reusability is fraught with issues and no guarantees it's cost effective (maintenance is expensive, reliability suffers, and decreased cargo/revenue due to needing to carry extra fuel for return). But even if reusability pans out, you're not going to get one (or more) orders of magnitude reduction in launch costs from where we are today. You'll get a few percentage points, maybe a few tens of percentage points and that's it.

nitrogen 5y ago
Using the same rocket ten times instead of once is an order of magnitude improvement. Why shouldn't it be possible to do even better than that?
- macspoofing 5y ago
  >Using the same rocket ten times instead of once is an order of magnitude improvement. Reusability is not a panacea. Space Shuttle was reusable but it was not cost-effective and there were no cost savings. Also, reliability suffered and maintenance became prohibitive. In fact, I think the consensus is that the entire program was a mistake. >Why shouldn't it be possible to do even better than that? Because reusability has to contend with factors like: 1) Turn around time. How quickly can you refurbish a rocket. 2) Maintenance costs. How expensive is it to recover and refurbish the rocket. 3) How many times can you reuse a rocket. 4) Failure rates. Does reusing a rocket compromise quality. 5) Decreased revenue per launch. Reusable rockets need to carry spare fuel meaning, that your cargo space is cut (and cargo is revenue), and your costs are higher, because you have to still 'pay' to ship that spare fuel along with cargo. Factors like those may make it that even if there are cost-savings, that those cost savings are not orders of magnitude lower, but maybe something on the order of 10%-50% - which is nice, and you can disrupt the market and make a good business out of it, but it's not anywhere close to the claims that are made. And again, SpaceX has not shown in practice that they can get ANY savings from reusability.

qayxc 5y ago

Launch costs are only a fraction of the total cost of orbital telescopes, so don't get your hopes up. For reference, the WFIRST telescope came with satellite bus and 2.4m mirror for free yet already has a 3.2 billion dollar price tag attached to it. Even the most expensive launch provider would be less than 10% of that cost. It only weighs about 4 metric tons by the way, so there's that. Just a quick reality check on the unrealistic assumptions some people have.

Gravityloss 5y ago
I wonder, if you know you were launching one every six months for the next 20 years, what would the unit cost be? You might be able to use a commercial satellite bus for example. It would be fine if some would experience failures, as there would be the next one already lined up. Just put different instrument(s) at the end of the optical path in each. As example, Hubble has five instruments. https://hubblesite.org/mission-and-telescope/instruments https://hubblesite.org/mission-and-telescope/instruments One could start a design from something like CHEOPS with a 30 cm mirror. https://sci.esa.int/web/cheops/-/54032-spacecraft https://sci.esa.int/web/cheops/-/54032-spacecraft
- HDMI_Cable 5y ago
  Do we need that many telescopes though? It seems like one only needs many 5 at any given time.
  - Gravityloss 5y ago
    One can already see that the existing terrestrial and space telescopes have long queues for observing time. Maybe more experimental instruments would be nice as well.
  - jjk166 5y ago
    There are currently 35 space-based telescopes in active service with 6 planned to launch in the next 12 months. [0] https://en.wikipedia.org/wiki/List_of_space_telescopes https://en.wikipedia.org/wiki/List_of_space_telescopes