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NASA to launch space observatory that will map 450M galaxies

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21–30 of 134 posts

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

#21
post #12

Earlier quoted context omitted.

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

Every system I'm familiar with that used liquid nitrogen to cool the IR instruments has had a operational lifespan based on the coolant. JWST is one such. "The coolant will slowly vaporize, limiting the lifetime of the instrument from as short as a few months to a few years at most."[0] [0] https://en.wikipedia.org/wiki/James_Webb_Space_Telescope

You've misread your source article—what you've quoted is not a description of Webb.

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

#22
post #15
post #7

"The SPHEREx mission will map the entire sky four times over two years, offering scientists a chance to study how galaxies form and evolve, and providing a window into how the universe came to be." So each object will be scanned ~6 months from the previous scan. How much evolving within the universe will be noticeable within that 2 year run? My gut response is not much, but that's why we do the science to see the cha…

To answer three of your questions: - It is passively cooled rather than using an expendable coolant- "SPHEREx relies on an entirely passive cooling system — no electricity or coolants are used, simplifying the spacecraft’s design and operational needs." - It is a Medium-Class Explorers (MIDEX) mission - Investigations characterized by definition, development, mission operations, and data analysis costs not to exceed…

ah, I misread the Orbital Parameters on the wiki. that day-night orbit is also a LEO which makes it even more possible to do a manned mission for upgrades. Oh, wait, we no longer have a shuttle for those types of missions.

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

#23

Earlier quoted context omitted.

Every system I'm familiar with that used liquid nitrogen to cool the IR instruments has had a operational lifespan based on the coolant. JWST is one such. "The coolant will slowly vaporize, limiting the lifetime of the instrument from as short as a few months to a few years at most."[0] [0] https://en.wikipedia.org/wiki/James_Webb_Space_Telescope

You've misread your source article—what you've quoted is not a description of Webb.

[deleted]

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

#24
post #10

This is so cool, but I did not see a key piece of info in the article: does the ongoing operation of this mission fall under NASA's science budget and therefore at risk of cuts and defunding under Trump [1]? [1] https://arstechnica.com/space/2025/03/white-house-may-seek-t...

Yep, it looks like it will be cut and closed, which is truly unfortunate. It’s disappointing to see that science nor innovation are not a priority for this administration. And this doge cutting of funding or even shutting down important projects will have long-term consequences, impacting research, education, and technological advancements that benefit everyone.

This is a proposal (not final) budget to be sent to congress. What congress eventually allocates is what matters.

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

#25

This is so cool, but I did not see a key piece of info in the article: does the ongoing operation of this mission fall under NASA's science budget and therefore at risk of cuts and defunding under Trump [1]? [1] https://arstechnica.com/space/2025/03/white-house-may-seek-t...

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

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

#26
post #20

> four suitcase-sized satellites Americans will use anything else but the metric system :)

The PUNCH mission features four 140-pound small satellites, each about 1-by-2-by-3 feet in size. Or The PUNCH mission features four 63.5 kg small satellites, each about 0.3048 m × 0.6096 m × 0.9144 m in size. https://blogs.nasa.gov/spherex/2025/03/04/nasas-spherex-punc...

About 30x60x90cm in size.

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

#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 to me. Presumably there is a lot of water tied up in comets and such, but will SPHERE be able to detect those signatures near planets?

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

#28

Earlier quoted context omitted.

Every system I'm familiar with that used liquid nitrogen to cool the IR instruments has had a operational lifespan based on the coolant. JWST is one such. "The coolant will slowly vaporize, limiting the lifetime of the instrument from as short as a few months to a few years at most."[0] [0] https://en.wikipedia.org/wiki/James_Webb_Space_Telescope

You've misread your source article—what you've quoted is not a description of Webb.

Does that really change anything?

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

#29
post #7

"The SPHEREx mission will map the entire sky four times over two years, offering scientists a chance to study how galaxies form and evolve, and providing a window into how the universe came to be." So each object will be scanned ~6 months from the previous scan. How much evolving within the universe will be noticeable within that 2 year run? My gut response is not much, but that's why we do the science to see the cha…

>How much evolving within the universe will be noticeable within that 2 year run?

Anton Petrov had a recent episode about rapid transformations in large supergiant stars, so there are some parts of space that can rapidly evolve.

https://www.youtube.com/watch?v=gHvV9ewPY7s

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

#30
post #7

"The SPHEREx mission will map the entire sky four times over two years, offering scientists a chance to study how galaxies form and evolve, and providing a window into how the universe came to be." So each object will be scanned ~6 months from the previous scan. How much evolving within the universe will be noticeable within that 2 year run? My gut response is not much, but that's why we do the science to see the cha…

They're talking about galaxy evolution in the early universe, over timescales of millions of years. Statistics measured across the (large) sample group, not within one galaxy. Scroll down to "It will classify galaxies according to redshift accuracy..."

Right, at that scale, For a galaxy to move a fraction of a centimeter will take a thousand years. So not much will be missed in a gap of 6 months.
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