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Quantum astronomy could create telescopes hundreds of kilometers wide

scientificamerican.com

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Re: Quantum astronomy could create telescopes hundreds of kilometers wide

#21

Post by qayxc »

tener wrote: post #9

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.

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.

Re: Quantum astronomy could create telescopes hundreds of kilometers wide

#24

Post by Gravityloss »

qayxc wrote: post #21
tener wrote: post #9

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.

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…

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

One could start a design from something like CHEOPS with a 30 cm mirror. https://sci.esa.int/web/cheops/-/54032-spacecraft

Re: Quantum astronomy could create telescopes hundreds of kilometers wide

#25

Post by macspoofing »

nitrogen wrote: post #19
macspoofing wrote: post #17

Earlier quoted context omitted.

>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 tha…

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?

>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.

Re: Quantum astronomy could create telescopes hundreds of kilometers wide

#26

Post by macspoofing »

ordu wrote: post #20
macspoofing wrote: post #17

Earlier quoted context omitted.

>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 tha…

Oh, we are to get an order of magnitude of cost reduction per kg on an orbit. There are attempts to measure it: https://everydayastronaut.com/raptor-engine/

They need to prove it. Talk is cheap and corporate PR is not very reliable source of information.

SpaceX has been known to talk bullshit ... or more charitably, they have been known to mix aspirational language into their projections. Case in point, I saw a TED talk with the SpaceX CEO claiming that rocket-based passenger travel is just around the corner and will be faster and more efficient than airplane travel... a claim that on face value is just stupid, bordering on insane.

Re: Quantum astronomy could create telescopes hundreds of kilometers wide

#27

Post by mrfusion »

qayxc wrote: post #21
tener wrote: post #9

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.

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…

But how much of that telescope cost is because of high launch costs. Ie using the lightest materials, overbuilding because maintenance is impossible, etc.

Re: Quantum astronomy could create telescopes hundreds of kilometers wide

#28

Post by calvano915 »

macspoofing wrote: post #26
ordu wrote: post #20

Earlier quoted context omitted.

Oh, we are to get an order of magnitude of cost reduction per kg on an orbit. There are attempts to measure it: https://everydayastronaut.com/raptor-engine/

They need to prove it. Talk is cheap and corporate PR is not very reliable source of information. SpaceX has been known to talk bullshit ... or more charitably, they have been known to mix aspirational language into their projections. Case in point, I saw a TED talk with the SpaceX CEO claiming that rocket-based passenger travel is just around the corner and will be faster and more efficient than airplane travel... a…

Coming "Soon"

Re: Quantum astronomy could create telescopes hundreds of kilometers wide

#29

Post by random5634 »

macspoofing wrote: post #26
ordu wrote: post #20

Earlier quoted context omitted.

Oh, we are to get an order of magnitude of cost reduction per kg on an orbit. There are attempts to measure it: https://everydayastronaut.com/raptor-engine/

They need to prove it. Talk is cheap and corporate PR is not very reliable source of information. SpaceX has been known to talk bullshit ... or more charitably, they have been known to mix aspirational language into their projections. Case in point, I saw a TED talk with the SpaceX CEO claiming that rocket-based passenger travel is just around the corner and will be faster and more efficient than airplane travel... a…

And that is why spacex is doing so well. Europe, Russia and old US space contractors said same thing about falcon - and here we are

Re: Quantum astronomy could create telescopes hundreds of kilometers wide

#30

Post by tiborsaas »

macspoofing wrote: post #26
ordu wrote: post #20

Earlier quoted context omitted.

Oh, we are to get an order of magnitude of cost reduction per kg on an orbit. There are attempts to measure it: https://everydayastronaut.com/raptor-engine/

They need to prove it. Talk is cheap and corporate PR is not very reliable source of information. SpaceX has been known to talk bullshit ... or more charitably, they have been known to mix aspirational language into their projections. Case in point, I saw a TED talk with the SpaceX CEO claiming that rocket-based passenger travel is just around the corner and will be faster and more efficient than airplane travel... a…

Investing $100M of your own money into a rocket company and then 18 years later taking NASA astronauts to the ISS is equally crazy.

Most people will remember the achievements and not the bold claims.

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