totient | Entries tagged with space

Way back in 2011 I made a post about how SpaceX's engine out capability worked with their plans to reuse rockets. Since that time they have had 110 launches, 75 booster landings and, as far as anyone knows, three engine out events. The first of these was shortly after I made my post and before they were even trying to land boosters. The second was near the end of the boost phase and supposedly wasn't the cause of the subsequent landing failure, though now I have to wonder. The third was a couple of weeks ago and only in the last few days have we learned that it happened and was the cause of the first SpaceX landing failure since the previous engine out event.

Before these last two engine outs, landing failures were much more common. I suspect that going forward, engine outs are going to be the primary cause of booster loss for SpaceX.

One fascinating tidbit is that SpaceX isn't slowing down their launch cadence any after engine outs. They're no big deal! It's one thing to say they'll be no big deal before they've happened but quite another to keep your customers from thinking otherwise once they do.

Crossposts: https://totient.livejournal.com/179240.html

SpaceX just officially unveiled a ridiculously large rocket. Rockets are usually made out of fancy, expensive aluminum alloys because these have the best strength to weight ratios at room temperature, but at cryogenic temperatures it turns out that stainless steel is better, so they're making it out of that.

I've heard a lot of crazy ideas from SpaceX of course, and it's always nice to calibrate just how crazy Elon is being. So, I ran some numbers. To give you some idea how large a rocket we are talking about: during the time that it took to build Starship Mk.1, it accounted for 1% of world stainless steel production.

Crossposts: https://totient.livejournal.com/170441.html

NASA isn't interested in building big rockets, but Congress is interested in them spending a lot of money in Utah, so they're developing some Shuttle-derived solid rocket boosters there. The boosters behave differently at different temperatures, so they test them once at 40 degrees and once at 90 degrees. It was 90 degrees out for today's cold-temperature-limit test, requiring lots of expensive airconditioning to get the motor down to temp. And it was 40 degrees out for the hot-temperature-limit test in early March of 2015, likewise requiring lots of expensive heating equipment. I'd say this is why private space can operate so much more efficiently than NASA, except actually NASA is being super efficient at its mandated task: spending as much money as possible. Maybe the equipment can even be put to some useful purpose now that this test is over.

Crossposts: http://totient.livejournal.com/164023.html

Saw 2001: A Space Odyssey last night, and noticed that the lunar monolith is indicated on a shuttlecraft glass cockpit as 'TMA-1' which apparently stands for Tycho Magnetic Anomaly. I don't think it's a coincidence that the fifth generation Soyuz manned space vehicle, first launched in the early 2000s and the first expendable space vehicle with a glass cockpit, bears the designation транспортный модифицированный антропометрический.

Crossposts: http://totient.livejournal.com/162814.html

Today's news includes a big reveal about Lockheed Martin's bid for the next space station resupply contract. They propose to build a tug that stays in orbit and has a robot arm. Then they'll launch unpowered pods of supplies and have the tug head out from the space station to fetch them, instead of giving each one a docking/propulsion system that has to be launched every time. The tug is built on the platform we're using for most of our Mars orbiters, can be refueled from the pods, and can haul things around between orbits generally. This is the sort of thing that appears early in most 1970s future-histories (complete with ion drive) and it looks like it'd have nice synergy with some of the other interesting work that's going on in the space business these days.

That's not the cool part.

They're calling the tug Jupiter, after the Central Pacific locomotive that participated in the Golden Spike ceremony. But that's not the cool part either.

The cool part is that the guy in charge of this project is named Jim Crocker. I wonder what relation he is to Charles.

Crossposts: http://totient.livejournal.com/160432.html

Which way is ( this ship ) facing?

Answer in the DW comments (meaning you won't see it by expanding the cut on LJ).

Crossposts: http://totient.livejournal.com/158686.html

Some years ago, SpaceX came up with an audacious plan to return the first stage of their launcher to the launch site for reuse. They made an amazing looking video featuring, at 0:40-0:50, a first stage turnaround and relight. This was widely dismissed as science fiction and even when they did it on the Cassiope mission in September the belief was that it was only possible because Cassiope was a lightweight mission to an easy orbit. And publicly, SpaceX has been saying they were not going to try this on the SES mission that launched yesterday.

But I don't think they'd be working on this unless it could work for real missions too. And with that in mind I took another look at yesterday's launch video. The first thing I noticed is that all nine first stage engines shut off at once, at 3:10 in that video (or about 2:57 after liftoff). This is a departure from past launches (and common practice on other multi-engined rockets) where they've shut two engines down earlier than the others to prevent acceleration from going too high as the tanks empty. The payload is certainly heavier than last time, but this makes me think there was still fuel in the first stage tanks at separation. The first stage goes out of frame briefly but from 3:29 to 3:34 it can be seen firing turnaround thrusters. Then the ground telescope video cuts out and from there all we get is onboard video from the second stage.

So, did it relight?

It sure looks like they tried.

Crossposts: http://totient.livejournal.com/157483.html

Last Thursday NASA and SpaceX held a joint news conference about SpaceX's recent mission to the ISS. They covered things you'd expect, like whether SpaceX had solved the power issues for the onboard deep freezer upon splashdown (yes) or whether the thruster problem was a hardware or a software issue (hardware, and not expected to recur). Of course since Elon Musk was on the call reporters asked him a lot of unrelated questions and as usual he served up some pretty wild answers.

The press has covered the stuff about Dragon 2.0, which will contain the integrated launch escape system and which Musk expects to unveil late this summer and perform a pad abort test with shortly after that. Some news outlets are even reporting what Musk said about working towards recovering Falcon 9 first stages (Space Shuttle SRBs were recovered at sea by parachute, so this is not a first). But lost in the noise is that the very next launch of Falcon 9 will include two additional burns by the first stage post separation. I can't wait to see how the reignition goes and what shape the stage is in after it hits the water.

Crossposts: http://totient.livejournal.com/156086.html

If you're a space nut, you already know that Elon Musk (who seems to be in a one-man space race against China) is going to build a rocket whose first couple of stages fly back to their launch sites and land propulsively after they're done with the boost phase. This takes a lot less than half of their fuel since they're (a) not carrying upper stages any more, (b) mostly empty at that point, and (c) able to take advantage of aerobraking. But still... chemical rockets are a pretty marginal business. What's the secret?

I think I know, and it relates to another feature of the rocket. The Falcon 9 can make its intended orbit with an engine out -- perhaps even multiple engines out, depending on the failure timing. This is an important safety feature and one that's required to carry people, just as airliners all have enough engines to be able to complete a takeoff if one fails. But engine out capability means you have to carry some extra fuel, to make up for the less optimal flight profile. If boost goes nominally, the boosters can use this extra fuel for the return phase. If it doesn't, and if the payload is more valuable than the booster, then an engine out now costs you a rocket. Which is still better than the current regime in which most rockets are entirely expendable and the best case is that the booster has to be mostly remanufactured after a salt water splashdown.

Wow, Palm chose the $300 price point for their long-rumored TX instead of the $400 price point.
That makes it quite a good deal indeed.
That's less expensive than either the TC or the T5, and the specs are far superior.
Curious that they're still bothering to list either of those other devices on their web site.
I do wish they had a device with the new multi-connector at a $150 price point.
Though they do finally seem to have changed their open-box prices to reflect the recently lowered price of the E2, so that's something.
A friend told me that Sleepytime Gorilla Museum was like a cross between Einsturzende Neuebaten and The Residents.
But they were a lot quieter than that.
miss_chance and I thought they were more like a cross between The Dresden Dolls and Devo.
Sleepytime Gorilla Musuem had a lot of interesting instruments.
Some were recognizable: guitar, bass, xylophone, wa-wa pedal, circular saw blade.
But there was a woman who played something almost but not entirely unlike a hurdy-gurdy, and something that wasn't a dobro, and something that might have been somewhat inspired by a sitar.
It wasn't the show I was expecting.
But neither were Einsturzende Neuebaten, when I saw them.
I put a business card in a fishbowl and won a free lunch.
But proverbially, it's not really free: There's a 5-minute pitch for some financial services at the beginning.
It's also in Davis Square, rather than anywhere convenient to my office, since that's where I put the business card in.
I'm not sure if I want to take them up on the lunch or not.
China just launched two more astronauts, bringing their total to three.
What's interesting about that is they showed it on live TV, not tape delay.

Today was the running of the DARPA Grand Challenge. This event, if you haven't heard of it, combines two ideas near to my heart: AI and road rally. Teams are handed a set of instructions shortly before the start, and their vehicle has to make it to the end of a challenging course within a time limit. The catch: It has to do this all by itself, without human intervention. This is the first year that anyone has actually made it. A team from Stanford has the best time, with two CMU teams close behind. As I write this, two more teams (out of about 30) are still on the course, though both of them have already taken more time than the Stanford team. One of those still has a chance of finishing inside the 10-hour limit, if they can avoid driving off a cliff. I'm rooting for them, partly because they're the only hybrid on the course, and partly because they're from New Orleans.

Also today was the failed launch of Cryosat, an Earth ice coverage mapper. This is geeky because the failure was presaged by the failed launch of the Planetary Society's solar sail experiment; both used the same Russian IUS, which failed to ignite. The first failure was half-assedly covered up by the Russians, who tried instead to blame it on the experimental use of a sub-launched first stage. I guess that coverup isn't going to work any more; the good news out of this is we might see more sub-to-orbit launchings.

Manned spaceflight is a boondoggle. During the cold war, boondoggles were the weapon of choice: the objective was to get the "enemy" to spend more money on the {space, arms, whatever} race than you. Kennedy may not have understood this explicitly, but Reagan (or someone in his administration) did, and furthermore understood that we were losing the manned spaceflight boondoggle war as the Russians were (and still are) just plain better at making rockets than we¹. I don't think Bush gets this, but after a long hiatus through the '90s, we seem to be in a boondoggle war with China now.

If we're going to be doing it anyway, it seems like maybe we should try to do it right.

NASA has just revealed a $100000000000.00² plan to go to back to the moon³. This is five thousand times as much money as Dick Rutan spent to win the Ansari X prize. Sure, the moon is a lot more than 100km away. But we've been to the moon before, for a lot less money, starting from a much smaller technological base. What's going on here?

Part of it, I think, is what I call the US "culture of life". By this I mean that it has become unacceptable for certain kinds of endeavors to result in fatalities, ever. In the 60's, dead astronauts were heroes. Now they're victims. I say let's make them heroes again. And this is where I think the private sector comes in: heroes are people who took on the risks themselves. And that, these days, means a private sector adventurer, not a government employee⁴.

If we competed against China by announcing (hefty) prizes for private orbiters and moon shots and so on, I think that'd give us an added PR victory as a defeat of centrally planned economic activity, as well. And it seems to me both cheaper and more likely to succeed.

1. Oh, how archaic of me to use grammatical rather than positional declension.
2. Commas intentionally omitted to emphasize the sheer enormity of the number.
3. And Mars too, but that will cost extra.
4. Of course, astronauts (and firefighters, and so on) took their jobs knowing about the risks, and in many cases in order to become heroes. They're just being thwarted by public misconception that the government could keep any of them from dying ever if only it cared enough.

NASA has just spent $1B on the return to flight program, with the result of one very lucky but successful flight and back to square one otherwise. This likely does not include the cost of actually launching Discovery, which probably approaches $1B on its own. I've always thought the Shuttle program was a bad idea anyway: it's an agglomeration of technical decisions made for political reasons, and without going through the litany of reasons they're a mistake technically, let's just say that I've seen enough product development cycles to know that that's not a good way to build something that works.

However, NASA has three orbiters on hand, and the space station is lacking in several capabilities that the orbiters possess.

Why not modify the orbiters so that they could fly attached to the ISS for extended periods of time, and leave one up there to provide boost, environmental, and emergency crew return capabilities to the station?

We could even continue to launch ISS components in the other two orbiters in the face of potentially fatal damage, by flying unmanned, or (if flying unmanned is not practical) by having seats available in a lifeboat orbiter on station so that a second orbiter could be abandoned with no loss of life.

Over the years, I've heard a lot of proposals for what to do with the Hubble as it reaches the end of its design lifetime (which is pretty much now). The latest plan involves an unmanned upgrade mission for $2B. To put this number in perspective, the original cost of the Hubble was $1.5B, and the Next Generation Space Telescope is being projected as costing $1B. Sure, that number would grow if we built it, but so would the cost of the upgrade mission.

One might argue that the whole problem is that we're not willing to fly a shuttle mission, and that it'd be a no-brainer if we were. I'm not sure about that either. One of the parameters of the NGST is for it to fly on an Atlas; if we had a shuttle flight available we'd probably do better to fly a copy of Hubble than to fix the one that's up there. It will be a shame to lose Hubble, but it would be more of one to lose its replacement.

Today is the 47th anniversary of the Sputnik launch.

Flight one completed. Flight two scheduled for next Monday.

phi

Entries tagged with space

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a prediction comes to pass

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which way is this ship facing?

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