Roman Launches: A Telescope's Countdown Ends

0:00 Anna: Hey, everyone. Welcome back to Astronomy daily. It's Monday, August 31st, series five, episode 181. Avery: And, um, this is the good kind of Monday, Anna, because we finally get to talk about a launch that actually happened. Anna: Finally, after a full week of. It's coming, it's coming. Roman is up. Avery: The Nancy Grace Roman Space Telescope launched yesterday morning, right on time. And it went about as clean as a launch can go. We'll walk through the whole thing. Anna: Then SpaceX drops a pretty big hint about Falcon 9's eventual retirement.

0:36 Two Nobel laureates weigh in on whether the universe's expansion is actually still speeding up. One very old asteroid strike explains two separate mysteries on a tiny Martian moon. And we'll get you sorted for what's actually worth looking up at tonight, wherever you are. Avery: Lots to get through, let's go. Anna: But start with the, uh, Nancy Grace Roman Space Telescope launch then. Avery: Okay. I've been waiting all week to say this. Tell me it went well. Anna: It went about as well as a launch possibly can.

1:08 Liftoff was 7:26 yesterday morning, Eastern Time. That's Sunday, August 30th, right on the primary window. No scrubs, no holds. SpaceX's Falcon Heavy took the Nancy Grace Roman Space Telescope up From Launch Complex 39A at Kennedy Space Centre. Avery: The same pad Apollo flew from. Anna: The very same. And More recently, Artemis 1 side boosters peeled away about 2 1/2 minutes in and flew themselves home to landing zones at Cape Canaveral. Textbook boost back and landing on both. Main engine cutoff on the core stage came around the four minute mark and, um, Roman itself deployed clean 31 minutes after liftoff.

1:51 No anomalies reported at any stage of the flight. By NASA's own account, about as tidy a run as you could hope for. Avery: I love it when they get to actually say that. Anna: There was a nice moment in the post launch press conference too. President Trump called in live to congratulate the team, which made for a slightly surreal watch alongside all the mission control. Avery: CHEERING okay, it's up, it's safely away from the rocket. What's next for it? And, um, remind everyone what it's actually for, because we've built this thing up all week without it existing in orbit.

2:22 Anna: Yet right now it's real. Romans on a 90 day cruise out to the sun. Earth L2 point, about a million and a half kilometres from Earth, same neighbourhood as Webb. The first 40 days or so are instrument activation and status cheques. Then science commissioning kicks in from around day 45. First images are expected in early 2027. Avery: And there's an actual local link to this one too, isn't there? Not just an American storey. Anna: There is, and it's worth saying out loud, part of Roman's data is going to come down through a brand new ESA antenna in New Norcia in Western Australia.

3:02 Roman's a formal ESA partnership, so that antenna's already built into how this mission gets its data home. Avery: I like that a lot. Okay. Remind people why this telescope is such a big deal. Because similar mirror size to Hubble undersells it badly. Anna: It does. Same 2.4 metre primary mirror as Hubble. But Roman's wide Field instrument gives it a view roughly a hundred times wider at basically the same sharpness. Where Hubble gives you a postage stamp, Roman gives you a poster. Programme scientist Dominic Benford put it nicely before launch.

3:38 The smallest Roman images will be a billion pixels. There isn't a screen on Earth big enough to display all of them at once. Avery: Billion pixels in the smallest image. Anna: The smallest. And that scale is entirely the point. The flagship project is the High Latitude Wide area survey. Roughly 2 billion galaxies imaged to map dark matter and chart how dark energy is pulling the universe apart faster over time. There's a companion supernova time domain survey chasing the same question from a different angle.

4:13 And funnily enough, that's relevant to our next storey today too. Avery: And um, the exoplanet hunt, that's the one I always want. Anna: More detail on the galactic bulge. Time domain survey, a completely different technique to Kepler or tess. It watches for a foreground star's gravity, briefly magnifying light from something behind it. With a planet adding its own little blip to that signal, it catches things. Transit surveys can't wide orbit planets. Even free floating rogue planets with no star at all bear expecting on the order of 100,000 new detections from that survey alone.

4:52 Avery: 100,000 new worlds from one survey. Anna: From one survey. And there's a fourth instrument riding along the coronagraph, a technology demonstration for directly imaging exoplanets by blocking out the glare of their host star rather than just inferring they're there. If it works as hoped, it's a real stepping stone toward NASA's future flagship missions. Doing that a, uh, standard. Avery: So walk me back through the week because this has actually been a four part storey and I don't think we've said that out loud yet.

5:23 Anna: It has. Tuesday we told you. Roman got cleared for launch nine months ahead of schedule, which is almost unheard of for a NASA flagship mission. Thursday we told the genuinely Strange storey of how its core optics started life inside a, uh, cancelled National Reconnaissance Office spy satellite programme before being donated to NASA back in 2012. Friday we told you it survived a budget draught that would have cancelled it outright, and how the team that saved it responded by pulling the launch forward eight months instead of slipping it.

6:00 And Saturday we previewed the launch itself. Avery: And today the actual thing happened. Anna: The actual thing happened. Clean launch, clean deployment, on its way to L2. First images due early next year. After everything that had to go right just to get it off the ground, it's genuinely satisfying to get to close the loop on this one. Avery: A very good Monday indeed. Next up, sticking with SpaceX for a second because Elon Musk said something last week we haven't gotten to yet worth flagging. Anna: Even though the post itself isn't brand new.

6:35 Musk said on X on August 22 that winding down both Falcon 9 and Falcon Heavy is, in his words, inevitable. Avery: Inevitable. That's a strong word for the rocket that's basically been SpaceX's entire business for a decade. Anna: It is, but the condition he attached matters. Once Starship is flying reliably several times a week, he says it makes sense to shift production resources over to Starship and push its launch rate up to multiple times a day. Avery: So this isn't, um, we're retiring Falcon 9 next quarter?

7:10 Anna: Not remotely. It's a statement of intent, not a timeline. Falcon 9 only just hit its 100th launch of the year back on August 25th, and Booster B1067 set a new single booster reuse record at 37 flights on that very mission. This is still an enormously active fleet. Avery: So what's the actual estimate for when this starts to bite? Anna: Industry reporting points to most Falcon 9 missions winding down from around 2028, with a limited number of flights continuing well past that. NASA's crew and cargo runs to the ISS are expected to keep flying on Falcon 9 through at least 2030.

7:51 Since human rating, a brand new vehicle for those missions isn't something anyone rushes. Avery: There's something almost poetic about this landing. The same week Roman flew on a Falcon Heavy. Anna: Genuinely, Roman rode one of the very rockets Musk is talking about eventually phasing out on what could well end up being one of Falcon Heavy's higher profile flights. And it's not an isolated signal either. We've already told you about Starbase, Louisiana. SpaceX's planned second Starship focused launch complex, and Starship's own Flight 14 is still tracking toward, uh, no earlier than September 15th.

8:29 Avery: So the plan really is get starship flying like Falcon 9 does now, then hand over the keys. Anna: That's the plan. As Musk describes it, whether starship's flight cadence actually gets there on anything like that timeline is very much the open question. Avery: Onto our next storey today. And this one's got some serious star power behind it, literally. Nobel Prize star power. Anna: This is a good one. Back in November last year, a, uh, South Korean research team published a paper suggesting the universe's expansion might actually, actually be slowing down, not speeding up.

9:03 Which, if true, would upend a huge chunk of modern cosmology. Avery: That's the kind of headline that gets a lot of attention. Anna: It did, and it also got a lot of scrutiny. A team led by Phil Wiseman at the University of Southampton, working alongside Adam Reese And Brian Schmidt, two of the three scientists who shared the 2011 Nobel Prize in Physics for discovering the universe's accelerating expansion in the first place, which went back through the analysis and published a rebuttal in the monthly notices of the Royal Astronomical Society this week.

9:36 And their finding, the universe is in fact still speeding up. Nobody's disputing that part. What they found was a specific flaw in the earlier study's method. It had effectively treated the age of a distant galaxy as if it were the age of the individual star inside it that later exploded as a supernova and hadn't properly accounted for the host galaxy's mass either. Avery: Which matters because. Anna: Because the whole technique relies on type 1A supernovae, extremely bright, reliably behaved stellar explosions from white dwarf stars as standardised cosmic candles to measure distance.

10:15 And from that, the universe's expansion rate over time. Get the underlying age or mass assumptions, even subtly wrong, and you can shift your final answer in a way that looks like new physics, when it's actually just an error creeping in upstream. Avery: So this isn't new data, it's a correction to how old data was read. Anna: Exactly. No new telescope, no new survey, just a more careful reanalysis of existing supernova observations. Which, fittingly, is precisely the kind of question Roman was built to help nail down for good with its own dedicated supernova time domain survey.

10:51 Avery: Once it's up and running, dark energy remains undefeated. Anna: Then, for now, nobody's claiming to know what dark energy actually is. Only that, whatever it is, it's still doing what we thought it was doing. Avery: Next up, we're heading to Mars. Well, technically, just passed it to one of its two little moons, Themos, the Anna: smaller and more distant of Mars. Two moons. It's always been a Bit of an odd duck. It's shaped like a lumpy potato. It's got an unexplained depression near its south pole and its surface is oddly smooth and dusty for a body that small.

11:26 Avery: Small. And somebody's finally worked out why. Anna: A team led by Sabina Radican, now at the Vri Universitite Brussels, working with Martin Uzi at the University of Bern, published the answer in Nature Astronomy. And this is the first published study to use actual Flyby Data from ESA's HERA mission, which swung past Deimos on its way out to the asteroid Dimorphos. Avery: What did they find? Anna: A single asteroid impact explains both quirks at once. They're simulations, about a hundred of them, each needing roughly a week of supercomputer time.

12:00 Using a piece of impact modelling software the University of Bern has been developing for two decades, show an asteroid around 320 metres across, hitting at a 45 degree angle is enough to carve out that south polar depression and scatter enough debris around the entire moon to explain the dusty regolith layer everywhere else. Avery: 45 degrees feels oddly specific. Anna: It's the sweet spot. Violent enough to genuinely redistribute material across the whole surface, but not so violent it would have shattered a moon this small entirely.

12:40 Deimos, by the way, is basically a porous rubble pile rather than one solid rock. So getting that balance right mattered a lot in the models. Avery: One impact, two mystery, M solved. Anna: One impact, two mysteries. And a nice example of a spacecraft doing useful science on the way to somewhere else entirely. Hera's primary job is studying what NASA's DART mission did to Dimorphos. This Deimos flyby was almost a bonus stop on the way past. Avery: Alright, let's get everyone sorted for tonight, wherever tonight actually is for you.

13:16 Anna: Venus is the headline act, and it's an easy one to find. Low in the west, west southwest, roughly 45 minutes after sunset from Sydney tonight. Sunsets around 5.32pm, so you're looking from about a quarter past six. Wherever else you are, just use your own local sunset and add the same 45 minutes. Avery: How long do people have before it sets? Anna: Uh, not long. Venus is following the sun down pretty quickly at the moment, setting only 90 minutes after sunset. So don't dawdle. It's sitting close to Spica right now, too.

13:52 Tonight's basically a preview, because the real close pass happens tomorrow night, September 1, when the two will be less than 2 degrees apart. It's heading toward its brightest of the year later in September So this is really just the opening act. Avery: What about Saturn? We've called it the reliable one a lot lately. Anna: Saturn's actually graduated to a better slot. It's now rising close to sunset and staying up for the most of the night, sitting in aquarius at magnitude 0.3, brighter than anything else nearby in that stretch of sky.

14:27 Even a modest telescope will show the rings clearly separated from the disc now that they've opened up to about 7.5 degrees, a big improvement on how flat and hard to read they were last year. It's closing in on opposition on October 4, so it only gets better from here. Great target either hemisphere. Avery: And for the early risers, Jupiter's just Anna: returned to the morning sky after being lost in the Sun's glare, so it's back as a pre dawn target. Low in the east, best windows roughly 4 to 6 in the morning.

15:01 Mars is out there too, fading a uh, bit these days in that same pre dawn eastern sky. And the moon waning gibbous tonight, still bright. It was sitting right next to Saturn the last couple of nights and it'll keep thinning out through the week. Avery: One quick standing reminder before we go. Since we're talking about bright things low Anna: near the horizon, always worth repeating. Whenever you're pointing anything, even just your eyes near the Sun's position in the sky, sunrise, sunset or any direct solar viewing, make sure any filter you're using is certified to ISO 123122.

15:40 Ordinary sunglasses are nowhere near enough protection. Venus and Saturn ah, are perfectly safe to look at anytime. Obviously this one's just a standing habit worth keeping. Sharp. Avery: Good habit to keep sharp indeed. And that's a show for today. The Nancy Grace Roman Space Telescope safely away and headed for deep space. SpaceX uh, signalling the eventual end of the Falcon 9 era. Two Nobel laureates defending an accelerating universe, one very old asteroid strike solving two mysteries on Deimos, and everything you need to get outside tonight.

16:14 Anna: If you enjoyed today's episode, the best thing you can do for us is leave a rating or review wherever you're listening and share it with a fellow space nerd. Full show notes, sources and links for every storey we covered today are @astronomydaily IO and you can find us on social media. We're AstroDaily Pod pretty much everywhere. Avery: We'll be back tomorrow with more space and astronomy news. Until then, keep looking up. Anna: See you next time. Clear skies.

16:50 Avery: Mhm. Anna: The storey.