The thread for space cadets!

[Estebonrober]

As far as I know, that's the first time in history something like this has been seen by mankind. It's really remarkable.

Background:
SpaceX is launching (no pun intended) a satellite-based internet service. They are going to build a network of around 10,000 satellites in LEO with laser communications crosslinks (means they can route internet traffic between each other without using ground stations) and electronically steered beam antennas to cover the Earth with gigabit-class, low-latency internet.

They launched two demonstration units last year and just this week they launched 60, 200+ kg satellites into LEO. These satellites do not have the laser crosslinks but collectively they generate more power than the ISS and can provide about a terabit of throughput and they all have advanced Krypton electric thrusters they will use to climb to their operational altitude. Here they are, flat-packed in the fairing and being tossed off the rocket:

Spoiler :

This was the heaviest payload the Falcon has ever launched.


SpaceX is not the only would-be provider of space internet. A company called OneWeb is building a similar network and has set up a factory in Florida to build them. They have also launched the first batch of satellites for their constellation as well. Amazon also announced their own satellite internet initiative called Project Kuiper that will be roughly the same size as SpaceX's and OneWeb's efforts and will be launched by Blue Origin - Jeff Bezos's rocket company.

I mean it seems like communications is the most obvious use of LEO space and I support that generally, but we still haven't figured out how to get these things down. I love the idea though.

 

[hobbsyoyo]

There is a huge controversy brewing around the Air Force's launch competition. SpaceX has sued the government over losing Phase 1 of the contest and Blue Origin, ULA and Northrop (the winners) have all joined the lawsuit on the Air Force's side. All sides are also working their Congresscritters with ULA punching well above its weight given how much it and its corporate parents (Boeing and Lockheed) are spread out over the country.

It's weird to talk about ULA punching above their weight now. Just 5 years ago they were the dominate player by a huge margin in the US and now they are standing in SpaceX's shadow on all metrics.

I mean it seems like communications is the most obvious use of LEO space and I support that generally, but we still haven't figured out how to get these things down. I love the idea though.

Yes that is an issue. SpaceX is addressing that in a few ways -

They launch these into a very low, 400ish kilometer orbit. The satellites have to wake up and begin burning within a couple of weeks to stay up there and climb to a higher altitude. That higher altitude has also been reduced from an original ~800 km to just ~550 km. Should the satellites fail in orbit, they will be dragged down by their massive solar arrays within 5 years.

There are some really cool passive and self-contained drag systems that will bring down LEO satellites quickly and several companies are working on service satellites to repair and de-orbit debris. I hope those things catch on but at the same time, if the government begins mandating those things, it would impose a lot of costs and make a burgeoning industry cool down. I don't want that and I think the government should begin paying for R&D and initial deployment and adoption of de-orbiting technology before mandating it and imposing costs.

But absolutely something should be done and all space-fairing countries should sign on to it. It needs to be a UN thing, not just a national thing. Space belongs to everyone and should be governed as such.

 

[Estebonrober]

There is a huge controversy brewing around the Air Force's launch competition. SpaceX has sued the government over losing Phase 1 of the contest and Blue Origin, ULA and Northrop (the winners) have all joined the lawsuit on the Air Force's side. All sides are also working their Congresscritters with ULA punching well above its weight given how much it and its corporate parents (Boeing and Lockheed) are spread out over the country.

It's weird to talk about ULA punching above their weight now. Just 5 years ago they were the dominate player by a huge margin in the US and now they are standing in SpaceX's shadow on all metrics.

How do you feel about this? It looks like classic corruption, but then again in this situation it also appears to be promoting some level of competition since SpaceX has come so far so fast.

Yes that is an issue. SpaceX is addressing that in a few ways -

They launch these into a very low, 400ish kilometer orbit. The satellites have to wake up and begin burning within a couple of weeks to stay up there and climb to a higher altitude. That higher altitude has also been reduced from an original ~800 km to just ~550 km. Should the satellites fail in orbit, they will be dragged down by their massive solar arrays within 5 years.

There are some really cool passive and self-contained drag systems that will bring down LEO satellites quickly and several companies are working on service satellites to repair and de-orbit debris. I hope those things catch on but at the same time, if the government begins mandating those things, it would impose a lot of costs and make a burgeoning industry cool down. I don't want that and I think the government should begin paying for R&D and initial deployment and adoption of de-orbiting technology before mandating it and imposing costs.

But absolutely something should be done and all space-fairing countries should sign on to it. It needs to be a UN thing, not just a national thing. Space belongs to everyone and should be governed as such.

Ok I remember reading about them falling naturally now, that is a good idea. Obviously being a person who wants to see humanity hit a Type 1 civilization I support the entirety of this statement and the nature of its cooperation.

 

[hobbsyoyo]

I wish there were more synonyms for the word corruption because I think there a few distinct types of corruption at play.

There is overt corruption, wherein ULA has served as an open door for retiring Air Force decision makers looking for a sweet, cushy private sector gig. That's been going on since ULA was founded and is a long-standing practice in the industry that predates them. A particularly eggregious example of this was when the Air Force rammed through a contract to buy something like 30 rockets from ULA without a competitive bid process just as SpaceX was suing the Air Force to stop it. SpaceX won the lawsuit weeks after the deal was inked and one of the principal negotiators from the Air Force immediately retired and took a high-paying VP position at ULA. On top of the contract to buy the rockets, the government also agreed to pay ULA over a billion dollars a year just to keep their doors open. Even though SpaceX won the lawsuit, the contract was not modified or overturned.

Part of SpaceX's complaint about losing the Phase 1 contract is that they lost it partially on the grounds that they don't have certain facilities for vertical integration - the very same facilities that the government is paying ULA a billion a year to build and maintain.

There is also 'systematic' corruption - corporate lobbying of Congress has gotten out of hand and we have the equivalent of 'captured' Senators and Congressmen. A good example of how this process is corrupt is when Senator Shelby (R-AL, a key ULA state) single-handedly cut funds from NASA's budget to pay for rides to the ISS with American vehicles because that program benefited SpaceX. There was no other reason to cut that program's budget and it resulted in the US having to continue to buy seats from the Russians for at least 3 years longer than the original schedule called for.

Then there is 'background' corruption - cost-plus contracting from the government has created a bunch of fat, lazy, handout-seeking corporations in aerospace. It's so bad that even newer startups can fall into the mindset that the government writes blank checks if you ask nicely enough.

There is some hope though; cost-plus is slowly going away and being replaced with firm-fixed price contracts which have flaws but are overall smarter. The government - and especially NASA - have also been extremely supportive and savvy about supporting business and technology development in this field. So far, while government coffers have been open to business with generous contracts that support R&D, there hasn't been a ton of outright fraud, waste and abuse. Meanwhile, the strategy to support these companies is paying off as the industry is advancing by leaps and bounds. Weather forecasting for 5 days out is now as accurate as 2-day forecasts from the 90's, in large part thanks to advances in computing and data collection from satellites. Pretty soon every corner of the Earth will have high-speed internet, just as it already has global sat-phone coverage. Businesses have improved efficiencies by purchasing satellite photography from CubeSats that shows how many tankers are at port, how many shipping containers are at docks, how many factories are running and so on.


Sorry that is a lot. I have opinions about space.

 

[hobbsyoyo]

Oh and Congress has proposed giving NASA about $125 million to research nuclear-powered rockets for deep space exploration. Apparently NASA didn't even ask for it and they didn't ask for when they got like $100 million last year. Oh and they have to do a flight demonstration by 2024!

https://spacenews.com/momentum-grows-for-nuclear-thermal-propulsion/





When I was in college, I led up a design team that was in a NASA sponsored design competition. We proposed two propulsion solutions for the mission - one based on tried and true hydrazine and the other on a miniature nuclear reactor designed in partnership with the college's nuclear engineering team. NASA said in no uncertain terms they wouldn't fly hydrazine from us but wanted to know how many grad students wey had to put on the nuclear effort. We lost the competition so nothing came of it but it was interesting to see where their interests rested on the issue.

The design was pretty neat - it was a hollow sphere covered in Americium. It was sub-critical until we injected a blob of water into the core, at which point it went something called prompt critical and the water would be flashed to steam and ejected through the nozzle at high velocity. It was a pulsed cycle so it would go in bursts as when the water was ejected the process would start over again.

We abandoned the idea when calculations showed the necessary volume to do the reaction was too large for the competition rules. Looking back, we weren't doping the water which could have helped lower the size of the reactor. Also, Americium is like a bajillion dollars an ounce because it's so rare.

 

[uppi]

SpaceX is launching (no pun intended) a satellite-based internet service. They are going to build a network of around 10,000 satellites in LEO with laser communications crosslinks (means they can route internet traffic between each other without using ground stations) and electronically steered beam antennas to cover the Earth with gigabit-class, low-latency internet.

Do you know what upstream bandwidth can be expected? Upstream is always the problem with existing satellite-based internet. Nevertheless, being able to provide 100 Mbit/s downstream for 30-50 dollars/month (+cost of the ground station, whatever that is going to be) could be very interesting for rural areas, no matter the upstream.

 

[hobbsyoyo]

No I don't, unfortunately

I'd argue that a bigger problem this network will have will be with ground equipment. With GEO satellites, simple and cheap parabolic, non-tracking antennas can be used. With Starlink birds whizzing around in LEO, you need either a mechanically tracking array or an electronically steered flat-panel array. Both options are expensive, while mechanical antennas are unreliable and electronically steered antennas are relatively untried in commercial applications. Designing and mass producing a cheap anenna or finding someway to finance a loss on each antenna leased or sold is a major engineering and business hurdle.

They did just announce they raised another billion dollars in private capital markets with private stock sales, so I think this is achievable. Musk says they need 200-400 satellites to begin service in the US and 1,000 for an economically viable but not truly global network.

I would also like to point out that producing 60 satellites of this sophistication and launching them all in one go is really unprecedented in history. It is to me as earth-shaking as reusing rocket stages even if it's less flashy.

 

[uppi]

I'd argue that a bigger problem this network will have will be with ground equipment. With GEO satellites, simple and cheap parabolic, non-tracking antennas can be used. With Starlink birds whizzing around in LEO, you need either a mechanically tracking array or an electronically steered flat-panel array. Both options are expensive, while mechanical antennas are unreliable and electronically steered antennas are relatively untried in commercial applications. Designing and mass producing a cheap anenna or finding someway to finance a loss on each antenna leased or sold is a major engineering and business hurdle.

I think they are going to use electronically steered, flat-panel phased-array antennas. Mechanical steering would probably be a very bad idea, because you would want to switch quickly from one satellite to the next. These kind of antennas will have a large design and manufacturing setup cost, but the actual cost per unit could get very low, because in the end it is just an array of wires with some electronics added on and computational power is cheap these days. So in the end, the cost will very much depend on the number of stations made. If they can establish this network with many customers, this could be very viable. But this isn't something you can do with just a few customers.

One problem I see, is that the companies that sell this stuff usually make you sign an ITAR form before even talking to you. And I suspect that the ground equipment would make very good radar equipment with some modifications. So world-wide marketing might be hobbled by US arms control regulations. And without world-wide marketing, the business case becomes a lot worse. I suspect that a non-American competitor might fare much better, should they manage to get the required launch capacity. The way the current administration is behaving, people will soon start paying a premium for technology being non-American, but that is a different discussion.

I would also like to point out that producing 60 satellites of this sophistication and launching them all in one go is really unprecedented in history. It is to me as earth-shaking as reusing rocket stages even if it's less flashy.

Now I remember you telling me that sticking a bunch of cubesats into a rocket would be quite complicated. I suppose it can be done, if you work hard enough

 

[hobbsyoyo]

I forgot to mention that they are confirmed to be working on an electrically steered antenna; I brought up the mechanical antennas as an example of their options. Computing cost is easy but unfortunately, these require specialized hardware and unique designs. I agree it can scale but it's not clear it can scale at a truly attractive cost. This is a big point of contention in the industry with the entire scheme right now.


60 CubeSats from 60 different manufacturers is very difficult and complicated. One of the leading providers of integration services for CubeSats coincidentally completed a mission with SpaceX recently where they deployed around 60 CubeSats and they have said they won't ever do it again. It's too complicated technically but more importantly programmatically. Trying to herd 20 or 30 or even 60 different cats (companies) to get their schedules aligned was not cost effective for anyone involved and delayed the whole project by 3 calendar years. SpaceX's design is quite a bit different as there are no deployers - they are flat-packed and each one in the stack carries the load of the one above it. It's really quite brilliant.

 

[Berzerker]

Hyperactive comets, whose water vapour is partially derived from icy grains expelled into their atmosphere thus have a D/H ratio similar to that of terrestrial water, unlike comets whose gas halo is produced only by surface ice. The researchers suggest that the D/H ratios measured in the atmosphere of the latter are not necessarily indicative of the ice present in their nucleus. If this hypothesis is correct, the water in all cometary nuclei may in fact be very similar to terrestrial water, reopening the debate on the origin of Earth's oceans.

https://phys.org/news/2019-05-family-comets-reopens-debate-earth.html

So comets zip around the solar system gathering up ice at varying distances from the Sun while underneath in the comet's nucleus resides water/ice comparable to the Earth's water. But that would mean comets didn't form in any Oort Cloud, they formed near the Earth and many were expelled onto long, elliptical orbits. Maybe comets were born with the asteroid belt resulting in the late heavy bombardment ~4 bya.

 

[hobbsyoyo]

There are multiple sources of comets. The outer belt is water-rich and some of the asteroids there get pushed onto elliptical paths that bring them close to the sun which turns them into comets. There is the Kuiper belt and related scattered disk (a small subset of the Kuiper belt gravitationally disturbed by Neptune), then there is the hypothesized Oort cloud and finally there are extra-solar cometary visitors.

 

[Samson]

Curiosity has taken video of clouds on mars. I think they are cool, hauntingly earthlike:

 

[Estebonrober]

Curiosity has taken video of clouds on mars. I think they are cool, huntingly earthlike:

Sometimes you should be able to like twice.

 

[hobbsyoyo]

Very cool!


Something weird is going on over at Stratolaunch, the maker of the gigantic airplane meant to carry rockets aloft of mid-air launches. There was a Reuter's report from 4 sources high up in the company that claimed it was being shut down by Paul Allen's sister, who inherited control of the company. This was both shocking and expected - shocking because Paul Allen poured a ton of money into this project and was fully committed to completing it. IIRC, he had publicly stated that the company would be provided for in his will. On the other hand, the shuttering was not unexpected as almost as soon as he died, the company cancelled their rocket development program meant to give the airplane a payload worth launching. Apparently his sister only went through with the test flight of the airplane to honor her brother and more or less immediately went about trying to sell the company and when that failed, decided to shutter it.

To make things even weirder, Stratolaunch came out with a statement almost immediately stating that the company was not in fact shutting down. Strange.

 

[hobbsyoyo]

Oh yeah -

Northrup Grumman had a static fire on the first stage motor of the new rocket they are developing called OmegA (stylized) and it suffered an anomaly:


The company has characterized this as a successful test and that's almost as dumb as Elon blaming Amos-6 on ULA snipers.

 

[Estebonrober]

Oh yeah -

Northrup Grumman had a static fire on the first stage motor of the new rocket they are developing called OmegA (stylized) and it suffered an anomaly:


The company has characterized this as a successful test and that's almost as dumb as Elon blaming Amos-6 on ULA snipers.

Um boom!

 

[hobbsyoyo]

It is a bit shocking, to be honest. The part of Northrup that ran this test is the old Orbital ATK, which in turn is the old ATK, which is the old Thiokol. These guys have been making solid motors for decades and are good at it. They have had some spectacular failures but are generally quality producers.

 

[hobbsyoyo]

Some astronomers are complaining about SpaceX's new Starlink constellation.

 

[hobbsyoyo]

Big Mood at NASA this week.

They announced selections for a commercial unmanned lunar lander program that may kick start exploration efforts of the moon.

They also announced a plan to begin commercializing the ISS and will allow companies to install their own modules and ferry workers there twice a year. I think this is a good thing as the ISS has had miserable science returns (even before you factor in the exorbitant cost) and something clearly needs to change. I'm support government spending on basic research but there's been so little of it at the ISS that we should be exploring options for making some sort of return on the investment. While the private sector will be more focused on making money than research for research's sake, almost all of that effort to make money will involve a huge amount of R&D just due to the space-based nature of it. So it is not the case that research will go away as they add commercial operations and in fact the pure science work they are doing will continue and will even benefit from the cross-pollination that goes on in multi-discipline facilities.

 

[Estebonrober]

Big Mood at NASA this week.

They announced selections for a commercial unmanned lunar lander program that may kick start exploration efforts of the moon.

They also announced a plan to begin commercializing the ISS and will allow companies to install their own modules and ferry workers there twice a year. I think this is a good thing as the ISS has had miserable science returns (even before you factor in the exorbitant cost) and something clearly needs to change. I'm support government spending on basic research but there's been so little of it at the ISS that we should be exploring options for making some sort of return on the investment. While the private sector will be more focused on making money than research for research's sake, almost all of that effort to make money will involve a huge amount of R&D just due to the space-based nature of it. So it is not the case that research will go away as they add commercial operations and in fact the pure science work they are doing will continue and will even benefit from the cross-pollination that goes on in multi-discipline facilities.

They should use proceeds on building the next station. We are about ten years behind on starting that imo. I get that resources are thin.