# The Great Ongoing Space Exploration Thread **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Tags:** science-math\ **Created:** [November 16, 2020, 12:18pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703 "2020-11-16T12:18:17Z")\ **Posts on this page:** 20\ **Page:** 53
**Author:** ![Fiendish\_Astronaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiendish_astronaut/32/3295_2.png) [@Fiendish\_Astronaut](https://boards.straightdope.com/u/Fiendish_Astronaut)\ **Post date:** [November 29, 2023, 10:12pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1042 "2023-11-29T22:12:01Z")
I think they also look at the wobble of the star due to the gravitational pull of the planets. Of course that also makes it harder to detect small planets but would that not make planets easier to detect using this method if they are above the plane from our perspective? ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [November 29, 2023, 10:59pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1043 "2023-11-29T22:59:45Z")
> [@Stranger\_On\_A\_Train](#): > > Because they are smaller, so the chance that they will significantly occlude a significant chord across the face of the star is lower (especially at longer distances where the star may only be a few dozen pixels), as is the amount of light that is blocked. Yes, of course. I was taking issue with the statement, “They are less likely to transit the face of the star as seen from Earth”. That’s not true, so far as I know. Earthlike planets are exactly as likely to transit in front of their star as seen by us as any other planet in their system. It’s just that they are small and their stars are dim, which means separating the transit signal from the noise may be extremely difficult or impossible, and if they truly are Earth-like around a Sun-like star, it will take 2-4 years to get three transits, which makes finding them even more tedious. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [November 29, 2023, 11:28pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1044 "2023-11-29T23:28:00Z")
> [@Fiendish\_Astronaut](#): > > I think they also look at the wobble of the star due to the gravitational pull of the planets. There are several different methods here. By far the most common method for detecting exoplanets prior to getting data from the Kepler Space Telescope was Doppler spectroscopy, in essence measuring the difference in relatively radial velocity of the light from the star between the planet pulling the star toward versus away from Earth. This works best when the orbital plane of the planet is close to alignment with the view vector. There is also the detection of ellipsoidal variation in the star which is observed best when the viewing angle is close to aligned with the axis of rotation; however, this only works for very extremely large planets that are in very close orbit to their parent star. The use of astrometry (direct observation of the movement of the star in-plane) is limited to observations of very large planets in more distant orbits around bright stars, and because of limits in optical resolution through the atmosphere and the need for a long baseline of good observations has only reliably been done with orbiting telescope, and has not been especially fruitful compared to other methods (although it offers the potential for opening up a lot more potentially detectable planetary systems). Stranger ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [December 1, 2023, 9:39pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1045 "2023-12-01T21:39:38Z")
In the completely unsurprising news department: > **[Amazon buys SpaceX rocket launches for Kuiper satellite internet project](https://www.cnbc.com/2023/12/01/amazon-buys-spacex-rocket-launches-for-kuiper-satellite-internet-project.html)** > > The move is a surprise from Amazon, given the company's Kuiper system aims to compete with Elon Musk's Starlink in the satellite broadband market. I guess ordering a bunch of launches on rockets that do not exist yet (New Glenn, Vulcan, and Ariane 6) turned out to be a bad idea. Also, they’re facing a shareholder lawsuit for not considering SpaceX in the first place. I wonder if this helps or hurts that cause, legally speaking. Is it good for Amazon because it demonstrates they’ll consider SpaceX after all? Or is it bad because it shows there was no technical or economic reason for avoiding SpaceX, and therefore the original decision was harmful to shareholders? I also vaguely wonder if they have private information that the other rocket programs are running a little behind. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [December 1, 2023, 9:53pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1046 "2023-12-01T21:53:33Z")
Huh. I thought I had already read about Amazon planning on putting Kuiper satellites on SpaceX rockets some months ago. I don’t think this hurts them. Or rather, the delay of New Glenn hurts because it’s Bezos’ company, but I doubt the shareholders will be able to sue over a decision like this, because they actually thought the other rocket programs would make the deadline. And there is a valid reason not to launch on your competitor’s rockets - you send money to them to be used to develop products that compete with yours. So it might not have been a crazy decision to go elsewhere - it just didn’t pan out. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [December 2, 2023, 1:04am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1047 "2023-12-02T01:04:01Z")
> [@Sam\_Stone](#): > > Huh. I thought I had already read about Amazon planning on putting Kuiper satellites on SpaceX rockets some months ago. That was probably OneWeb, which is another LEO constellation. They don’t have their own adjacent rocket program (i.e., Amazon vs. Blue Origin), but they do directly compete with Starlink. They had to fly on SpaceX because they were set to fly on Russian Soyuz rockets and then Ukraine happened. ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [December 3, 2023, 2:21am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1048 "2023-12-03T02:21:48Z")
> **[Richard Branson rules out further investment in Virgin Galactic](https://arstechnica.com/space/2023/12/no-further-investments-in-virgin-galactic-says-richard-branson/)** > > UK entrepreneur says his business empire no longer has ‘the deepest pockets’ So is it going to follow Virgin Orbit in going out of business? If I were rich enough to travel into space, I would at least want to orbit the earth for a day or so–not up and then right down. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 3, 2023, 2:50am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1049 "2023-12-03T02:50:31Z")
They (VG) had their one promo flight w Branson himself aboard (guts move of which I approve) 6 months ago now, and zero revenue flights since. Ref both wiki & the current stock price, the company has a current market cap of roughly 900M which is roughly one _third_ of its speculative peak, nowhere near that much in booked revenue, and non-trivial costs per month just sitting there not flying. If VG had earnings from which to compute a PE ration, it’d be in the triple digits, maybe even 4-digits. I didn’t get into the 10-Ks, but I hear a fat lady doing scales & see her adjusting her prodigious brassiere. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [December 3, 2023, 6:21pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1050 "2023-12-03T18:21:05Z")
Virgin Galactic and Blue Origin’s New Shepard both suffer from the same problem: The enthusiasm they generated when we thought orbital alternatives would cost tens of millions of dollars has waned quite a bit as space access has become somewhat routine. When millionaires apcan buy rides to orbit on Falcon 9, a 15-minute roller coaster ride to the Karman line and back is no longer the pinnacle of adventure. There’s probably a very small market of people who have $100,000 to spend on a short flight but who can’t afford a trip on a Dragon, or who want to take a suborbital ballistic flight even though they could afford a trip into orbit. SpaceX is making space look routine, and that also cuts down on the number of people who are willing to spend a huge sum for a ‘second class’ space trip. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 3, 2023, 8:53pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1051 "2023-12-03T20:53:06Z")
It’s also been in the works for 19 (!) years. _Everything_ is very different than ~20 years ago. SpaceX of course is the elephant in the room for any space-centric conversation. But beyond that, “affordable” space tourism was novel and cool when it was conceived 25 years ago; now not so much, SpaceX or no. Had they gotten flying back around 15 years ago after a 4-year development effort, things would have been very different since, and might well have been different now too. Too little, too late, too expensively. So much of bleeding edge tech entrepreneurialism crashes on that Trifecta of Doom. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [December 4, 2023, 9:33pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1052 "2023-12-04T21:33:19Z")
🤦‍♂️ > **[What happens in Vega didn’t stay in Vega, as key rocket parts went missing](https://arstechnica.com/space/2023/12/italian-rocket-maker-has-a-problem-key-parts-of-final-vega-booster-were-trashed/)** > > There's a valuable payload riding on the final Vega rocket launch. > The [European Spaceflight newsletter reports](https://europeanspaceflight.com/the-case-of-the-missing-vega-avum-propellant-tanks/) that two of the four propellant tanks on the fourth stage of the Vega rocket—the upper stage, which is powered by dimethylhydrazine and nitrogen tetroxide fuel—went missing earlier this year. > > Now, it seems that the propellant tanks have been found. However, the newsletter says, the tanks were recovered in a dismal state, crushed, alongside metal scraps in a landfill. Someone, apparently, had trashed the tanks. This is a rather big problem for Avio, as this was to be the final Vega rocket launched, and the production lines are now closed for this hardware. The Italian engineering jokes just write themselves. ---
**Author:** ![xtenkfarpl](https://avatars.discourse-cdn.com/v4/letter/x/c2a13f/32.png) [@xtenkfarpl](https://boards.straightdope.com/u/xtenkfarpl)\ **Post date:** [December 4, 2023, 9:44pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1053 "2023-12-04T21:44:41Z")
> [@Sam\_Stone](#): > > There’s probably a very small market of people who have $100,000 to spend on a short flight but who can’t afford a trip on a Dragon, or who want to take a suborbital ballistic flight even though they could afford a trip into orbit. Right. If you’re going to get bragging rights for going “to space”, you may as well do it properly. A bit of a pop-up out of the atmosphere doesn’t really count. I wonder how long these tourist gimmicks will last? ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [December 4, 2023, 10:55pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1054 "2023-12-04T22:55:10Z")
Those gimmicks won’t last. There was cachet in going to space when only a few dozen people had ever done it. Now? We have private astronauts going up all the time. Millionaires book flights on Dragon or stay at ISS. Another millionaire is booked to fly around the Moon. Compared to that, a pop up to the Karman line and back down again just isn’t all that anymore. But we’ll see even more private astronauts in the future. The difference is that they’ll actually b e doing useful things, and not just tourists. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 4, 2023, 11:39pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1055 "2023-12-04T23:39:28Z")
> [@Dr.Strangelove](#): > > The Italian engineering jokes just write themselves. _Inventory records_? We don’ need no steenkin’ inventory records. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [December 4, 2023, 11:41pm UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1056 "2023-12-04T23:41:48Z")
It’s like that classic joke: > Heaven in Europe is where… > the English are the policemen > the French are the cooks > the German are the mechanics > the Italians are the lovers > and the Swiss organize everything > > Hell in Europe is where… > the German are the policemen > the English are the cooks > the French are the mechanics > the Swiss are the lovers > and the Italians organize everything ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [December 5, 2023, 12:34am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1057 "2023-12-05T00:34:40Z")
I could much more easily imagine this happening in the context of a bankruptcy or merger where the records get chaotic and the new purchasers don’t care about anything except the small subset of the company they intend to keep. Plus of course shoveling lots of borrowed money into their own pockets; they care deeply about that. That these tanks were made by the factory that made the whole rocket and everybody who works there knows they’ve got one more launch to go is just boggling. Or is industrial sabotage by a workforce facing total layoffs. The article mentions there are 4 test articles laying around the factory they’ll now try to repurpose for that final flight. I wonder … As they were pitching unused tooling and downsizing floorspace, etc., as production was winding to a close, maybe someone goofed and they pitched the flight articles thinking they were the now-unneeded test articles, and spared the test articles thinking they were the flight articles. Holy oopsie, Batman! 🤦‍♂️ ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [December 5, 2023, 1:58am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1058 "2023-12-05T01:58:19Z")
> [@Sam\_Stone](#): > > Huh? Why? I would assume they are as likely to transit in front of us as any other planet would. A few days old, but, “Small, rocky worlds like ours, orbiting at a comfortable distance from an old, calm star like our sun, are hard to find. They are less likely to transit the face of the star as seen from Earth” I think the key difference being made is distant planets vs close planets. And the farther a planet orbits from the star, the more perfectly the planet’s orbital plane has to be edge-on from Earth’s point of view, as a tilt puts the transit above or below the disc of the star. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [December 5, 2023, 2:59am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1059 "2023-12-05T02:59:54Z")
That might be a good explanation if small rocky planets tended to be farther out than larger planets, but they aren’t. The real reason is simple, I think: They take a longer time for each orbit, so we have to observe longer to get three transits. They are smaller, so the dip in the light curve is smaller, and their stars are dummer, lowering contrast. Much easier to see a hot Jupiter orbiting every several hours or days. I think we would have found a bunch of earthlike planets had Kepler’s main mission survived. We’ll find them eventually with the new scopes coming online. Right now we have a huge bias in the dataset towards gas giants and super Earths and mini Neptunes, because they are simply the easiest to find. ---
**Author:** ![Zakalwe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zakalwe/32/270_2.png) [@Zakalwe](https://boards.straightdope.com/u/Zakalwe)\ **Post date:** [December 5, 2023, 3:31am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1060 "2023-12-05T03:31:12Z")
> [@Dr.Strangelove](#): > > The Italian engineering jokes just write themselves. All jokes aside, why have they not dumped Avio and called SpaceX for a lift? Based on that article I would say it’s a solid 40% chance the Avio rocket fails at some stage of the flight. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [December 5, 2023, 3:37am UTC](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703/1061 "2023-12-05T03:37:10Z")
I expect that to happen. But they have to pretend otherwise for a while. So they go through the rigamarole of seeing if they can re-certify their old qualification tanks, even if they already know what the answer is going to be. 2000 kg is a little too big for the standard rideshare program, but SpaceX will happily put them on a premium rideshare slot, or at the top of a (slightly reduced) stack of Starlink satellites, for $15m or so. The Vega is $35m. [Previous page](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703.md?page=52) [Next page](https://boards.straightdope.com/t/the-great-ongoing-space-exploration-thread/925703.md?page=54)