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It is not 500mbps but 500Mbps. https://science.nasa.gov/mission/roman-space-telescope/commu...

"mbps" is a meaningless abbreviation. You need to consistently and correctly use capital letters when communicating technical terms. You cannot "e e cummings" your way into effective writing.

500 megabits per second works out to 5.4 terabytes per day. No idea where you get 1.5, unless you were thinking of 500Mb/hour!

60 × 60 × 24 × 500 × 1000000 ÷ 8

my brain is not what it used to be due to long-covid so it's very possible I made a mistake

but 500 megabits per second to me is 500mbps?

ie. my cablemodem is 100mbps which is 100 megabits per second?

and that would [make Roman] 5.4 Terrabytes aka 5.4TB per day

but the transmitter is not at full speed full power 24/7

so it is 1.5TB per day in documentation that I do not have handy but vaguely remember

to repeat the more amazing part is that is from a MILLION MILES away, wow

(JWST "only" does 23mbps, 23 megabits per second)

The GP is alluding to the fact that the prefix "m" means milli-, not mega-. But that's pointless pedantry. Nobody would ever think that you meant 0.5 bits per second, and bit isn't a SI unit anyway.

No, your cable modem would be 1.08 terabytes per day.

Does it stop making sense when your calculations for the Roman telescope indicate slower speeds than your connection, which you say is 1/5th the speed?

Now, since the Roman telescope will be at an L2 point, signal acquisition will always be subject to the Earth's rotation. So there will be multiple ground stations involved across the globe.

https://en.wikipedia.org/wiki/NASA_Deep_Space_Network

If the quoted rate by NASA of 1.5 terabytes per day is accurate, then it will not be downlinking 24/7, but in bursts. 500Mbps is also the max, where the actual range will be 250-500. We'll need to account for RFI and packet loss, etc.

Is it really 500 Mbps of data headed to Earth 24x7? I'd be very interested to see any available public info about the earth station infrastructure being set up for that.

> * https://nextspaceflight.com/launches/details/6983/

06:25 AM Window Open

06:26 AM Window Close

Is it really just a 1 minute launch window? That seems incredibly tight. If there's any hitch in the countdown, that would pretty much mean a scrubbed launch. Not being well versed in orbital mechanics, why would the window be so short?

There's some discussion about a similar launch ~10 years ago (in that case going to L1) https://www.reddit.com/r/spacex/comments/2vb5kv/1second_laun...

Based on that, I guess the one upside would be that you have the window available every day as the L1/L2 positions never move relatively. Unlike a launch to Mars or other solar system body where you definitely want everything to be lined up efficiently.

Not unusual, and there are likely a number of contributing factors.

Falcon launches to the ISS typically have an instantaneous launch window (roughly, when the plane of the ISS's orbit sweeps over the launch site). If they miss it, they try again about a day later.

Falcon (both Heavy and its little sibling Falcon 9) uses subcooled densified propellants which limit how long it can sit waiting for launch while fueled before the LOX warms and expands too much.

A short window means they only have to compute and verify and program one trajectory.

It is important to point out, since you did not note the timezone with that quote, that the launch is actually scheduled for NET 07:26am EDT or 11:26:00 UTC.

You can get live countdowns and updates at https://www.spacex.com/launches which will link to first-party livestream coverage during the launch.

No need to go through third-party and advertising-laden dot-com sites.

The Falcon 9 and Falcon Heavy are intolerant to countdown holds late in the sequence. In particular, after propellant has been loaded, there must be no delay in launch. Any countdown holds will necessarily turn into a scrub for the day, as the propellant must be completely unloaded and the process restarted to prepare for launch. With the instantaneous window, it'll either be "go/no-go" at 07:26am EDT, or they'll go-around to another opportunity on Monday morning, around 07:22am.

The timezone has no bearing on the the one minute wide window. This was not posted as an advertisement of launch time. I provided the link the info was taken. If you click on it, it shows you the localized time. Not really sure why you feel like this was the important part of the question.

> but Musk still needs to send it out of orbit without explosions, so here's hoping

The Falcon Heavy has made 12 launches and all of them have been successful. It's built using the same engines as the Falcon 9, which has become the boringly reliable workhorse of space launch, and the rocket cores are very similar in design. I'd bet on a successful launch, and probably on a successful landing of the side boosters.

(Do we really need to politicize launch vehicles, of all things?)

> except The Habitale Worlds Observatory Space Telescope HWO was scheduled for 2040 and now will not happen in my lifetime because DOGE got that one, Congress awarded it $150 Million and DOGE changed it to $5 Million

I was so excited for this. It was the one thing I really wanted to see happen in my own lifetime.

What a deeply moronic waste.

That's like Hubble funding cuts back in the '70s.

The NASA budget was $5M as a placeholder, but Noel Hinners cut it to zero to light a fire under the community, instead of a bogus pretend-its-still-happening number.

https://en.wikipedia.org/wiki/Hubble_Space_Telescope#Quest_f...

yeah but we don't recover from this one like the 70s

the illegal Iran War costs over $120 BILLION, has used over 1000 Tomahawks at $4 Million each (and 1250 patriot missiles)

a BILLION was stolen from nuclear missile maintenance fund for QatarForceOne

another BILLION was stolen for all the DC renovations so far that no-one asked for

billion diverted to his fake "peace board"

so there is money for war and drapes and gold statues but not science that benefits the world

hell he spends $2 MILLION EVERY WEEKEND for GOLF, first term and this term, half billion before he is gone

we could have had people on Mars for all that (not even a project I support but still would be worthy science)