NASA to launch space observatory that will map 450M galaxies • Hacker News Board

Re: NASA to launch space observatory that will map 450M galaxies

#91

Post by numpad0 » Wed, Mar 12, 2025, 9:00 AM UTC

indoordin0saur wrote: post #37

connicpu wrote: post #25

Earlier quoted context omitted.

This one is planned to launch on Falcon so I wouldn't be too surprised if it's one project the administration spares.

Everything launches on a Falcon these days. No one else can catch up in terms of safety cost or speed.

I'm not sure how to make out of comments like this. Is SpaceX actually launching customer payloads under $50m or whatever? Because, unless they are, it won't be long before JAXA/MHI starts selling H3 at half the cost of H-IIA, which is already like 15t to LEO for $67m at 150 JPY/USD, which leaves F9 reusable barely competitive in price. I don't know what India or China charge for foreign customers, but is it really reasonable to expect worse deal than Mitsubishi from them? ...

Superheavy-Starship reusable launches at F9 price would completely destroy everything in space space, but so far the only things it had disrupted are itself and airline services under its flightpath. And even F9 is starting to show increasingly clear signs of repetitive "old space" scrubs as NASA gets more disrupted.

Is that really a meaningful statement that stands, or it that just hand wavy glance away one now?

Re: NASA to launch space observatory that will map 450M galaxies

#92

Post by perihelions » Wed, Mar 12, 2025, 9:20 AM UTC

https://blogs.nasa.gov/spherex/2025/03/12/signal-acquired-na... ("Signal Acquired: NASA’s SPHEREx Begins Science Mission")

Success!

Re: NASA to launch space observatory that will map 450M galaxies

#93

Post by jajko » Wed, Mar 12, 2025, 9:27 AM UTC

Tepix wrote: post #87

eleveriven wrote: post #83

It's pretty incredible to think that we're at a point in human history where we can map 450 million galaxies and probe the origins of the universe

The Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Survey has recorded more than one billion galaxies. But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion

> But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion

A bit less officially, need to remove one zero [1]

[1] https://en.wikipedia.org/wiki/Galaxy#:~:text=It%20is%20estim...

Re: NASA to launch space observatory that will map 450M galaxies

#94

Post by perihelions » Wed, Mar 12, 2025, 9:45 AM UTC

perihelions wrote: post #13

Sanzig wrote: post #12

Earlier quoted context omitted.

Why would coolant be a consumable? These things are usually cooled with Stirling cryocoolers which are closed systems.

I did a quick search and it seems there is neither? - "SPHEREx relies on an entirely passive cooling system — no electricity or coolants are used during normal operations" https://www.jpl.nasa.gov/news/6-things-to-know-about-spherex... edit to add: - "The telescope is passively cooled to below 80 K in low-Earth orbit by three nested V-groove radiators. An additional radiator cools the long wavelength focal plane temp…

I found an explanation of the "v-groove" radiator geometry, if anyone else was curious about it:

(.pdf) https://ttu-ir.tdl.org/server/api/core/bitstreams/71aee1e9-3...

Re: NASA to launch space observatory that will map 450M galaxies

#95

Post by [deleted] » Wed, Mar 12, 2025, 9:59 AM UTC

numpad0 wrote: post #91

indoordin0saur wrote: post #37

Earlier quoted context omitted.

Everything launches on a Falcon these days. No one else can catch up in terms of safety cost or speed.

I'm not sure how to make out of comments like this. Is SpaceX actually launching customer payloads under $50m or whatever? Because, unless they are, it won't be long before JAXA/MHI starts selling H3 at half the cost of H-IIA, which is already like 15t to LEO for $67m at 150 JPY/USD, which leaves F9 reusable barely competitive in price. I don't know what India or China charge for foreign customers, but is it really r…

[deleted]

Re: NASA to launch space observatory that will map 450M galaxies

#96

Post by jajko » Wed, Mar 12, 2025, 10:01 AM UTC

indoordin0saur wrote: post #37

connicpu wrote: post #25

Earlier quoted context omitted.

This one is planned to launch on Falcon so I wouldn't be too surprised if it's one project the administration spares.

Everything launches on a Falcon these days. No one else can catch up in terms of safety cost or speed.

Costs are largely meaningless when talking about global situation and other nations and their strategic interests. Europe will move fully to ESA for anything actually important, China and India have their own stuff too. Private satellites, sure why not if companies are OK with risking of getting their payload removed at last minute because somebody again bruised musk's ego.

Business can't be done in an environment with zero trust, doesn't matter how much better the offer looks on paper. That trust with spacex is gone for good.

Re: NASA to launch space observatory that will map 450M galaxies

#97

Post by jimkleiber » Wed, Mar 12, 2025, 10:37 AM UTC

eleveriven wrote: post #83

It's pretty incredible to think that we're at a point in human history where we can map 450 million galaxies and probe the origins of the universe

I feel infinitesimally small.

Re: NASA to launch space observatory that will map 450M galaxies

#98

Post by Tepix » Wed, Mar 12, 2025, 10:44 AM UTC

jajko wrote: post #93

Tepix wrote: post #87

Earlier quoted context omitted.

The Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Survey has recorded more than one billion galaxies. But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion

> But there are many more galaxies in the observable universe … somewhere between 2 and 20 trillion A bit less officially, need to remove one zero [1] [1] https://en.wikipedia.org/wiki/Galaxy#:~:text=It%20is%20estim...

There are more recent estimates going from 6-20 trillion now: https://bigthink.com/starts-with-a-bang/galaxies-in-universe...

Re: NASA to launch space observatory that will map 450M galaxies

#99

Post by JKCalhoun » Wed, Mar 12, 2025, 10:50 AM UTC

eleveriven wrote: post #83

It's pretty incredible to think that we're at a point in human history where we can map 450 million galaxies and probe the origins of the universe

And to think I assumed Astronomy was a stagnant field some decades ago. I have no idea why I thought that. Maybe that optical resolution from ground-based telescopes was not going to advance orders of magnitudes? Maybe I didn't think the sciences would continue to get money for space telescopes?

Re: NASA to launch space observatory that will map 450M galaxies

#100

Post by JKCalhoun » Wed, Mar 12, 2025, 10:53 AM UTC

tiborsaas wrote: post #82

ChuckMcM wrote: post #27

It always surprises me how my enthusiasm for scientific discovery is affected by fears of a dystopian future. My understanding is that with red shift calibration here we'll get a much better idea of the 'when' in terms of various galactic structures emerged, that might give us an interesting idea of where we are in the life-cycle of the Milky Way. But the observation of water signatures will be the most interesting t…

I can't really get what you meant by "dystopian future" in this context. In my understanding that is a human caused concept.

Hard for me to parse as well — but I think OP is talking broadly about humans being able to keep our shit together long enough to be able to reach other solar systems before we outgrow our own.