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from the sudden-outbreak-of-common-sense? dept.
https://arstechnica.com/science/2019/03/what-is-going-on-with-nasas-space-launch-system-rocket/
In a remarkable turnaround, NASA Administrator Jim Bridenstine on Wednesday said the space agency would consider launching its first Orion mission to the Moon on commercial rockets instead of NASA's own Space Launch System. This caught virtually the entire aerospace world off guard, and represents a bold change from the status quo of Orion as America's spacecraft, and the SLS as America's powerful rocket that will launch it.
[...] During a hearing of the Senate Commerce committee to assess America's future in space, committee chairman Sen. Roger Wicker opened by asking Bridenstine about Exploration Mission-1's ongoing delays. The EM-1 test flight involves sending an uncrewed Orion spacecraft on a three-week mission into lunar orbit, and is regarded as NASA's first step toward returning humans to the Moon. This mission was originally scheduled for late 2017, but it has slipped multiple times, most recently to June 2020. It has also come to light that this date, too, is no longer tenable.
"SLS is struggling to meet its schedule," Bridenstine replied to Wicker's question. "We are now understanding better how difficult this project is, and it's going to take some additional time. I want to be really clear. I think we as an agency need to stick to our commitment. If we tell you, and others, that we're going to launch in June of 2020 around the Moon, I think we should launch around the Moon in June of 2020. And I think it can be done. We should consider, as an agency, all options to accomplish that objective."
The only other option at this point is using two large, privately developed heavy lift rockets instead of a single SLS booster. While they are not as powerful as the SLS rocket, these commercial launch vehicles could allow for the mission to happen on schedule.
[...] One heavy-lift rocket would launch a fully fueled upper stage—most likely a Delta Cryogenic Second Stage or the Centaur upper stage currently used on United Launch Alliance rockets. Then, a second heavy-lift rocket would launch an Orion capsule and its service module into orbit, and these two vehicles would dock. The fueled upper stage would then inject Orion into a lunar orbit.
Bridenstine did not name rockets during the hearing, but it seems almost certain that at least one of them would be a Delta IV Heavy, built by United Launch Alliance. NASA used this rocket to launch a version of the Orion spacecraft to an altitude of 3,600km in 2014. Both United Launch Alliance and SpaceX—with its Falcon Heavy rocket—would be invited to bid on the second launch.
The SLS is the Space Launch System. It's a heavy launch vehicle that's been funded by NASA and contracted out to Boeing with more than $14 billion spent on it so far. It's been in development since 2010. If and when it's completed launches are expected to run $500 million. It's designed to be mostly an incremental improvement over the Apollo program from 50 years ago which includes no reusability as well as reliance on solid rocket boosters; A solid rocket booster uses solid fuel that—once ignited— cannot be stopped.
SpaceX's alternatives are fully reusable and rely on liquid fuel engines which can be throttled on or off at will. The Falcon Heavy is operational today and runs $90-$150 million for a launch. Their development has been almost entirely privately funded as well.
(Score: 2) by takyon on Thursday October 24 2019, @09:25PM (10 children)
The Starship era could make up for it with:
...and more.
The ongoing waste is a tragedy, but there is pretty much nothing we can do to stop it.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Immerman on Friday October 25 2019, @12:07AM (9 children)
I mostly agree, and am really rooting for Starship to come to fruition quickly and with a minimum of pain (Though I do kind of want to see at least one Super Heavy explode spectacularly...just because)
I think you're asking for trouble with modular telescopes though. Modular means it must be assembled in orbit, which means people in clumsy space suits (or even clumsier robots) performing ultra-precise assembly. It could be done - I'm sure it will be done eventually, but we've got a long way to go before it's anywhere near as easy as designing an origami folding mirror array.
(Score: 3, Interesting) by ElizabethGreene on Friday October 25 2019, @12:41AM (4 children)
I do kind of want to see at least one Super Heavy explode...
AFAIK Starship doesn't have a launch escape system. I do not want to see the consequences of that decision.
(Score: 2) by takyon on Friday October 25 2019, @01:04AM
Pad abort with explosive Super Heavy could be tested sooner than you think™: https://www.teslarati.com/spacex-elon-musk-starship-pad-abort-capability/ [teslarati.com]
Starship escape system nowhere to be found: https://space.stackexchange.com/questions/33837/what-are-spacex-starship-bfr-proposed-abort-modes [stackexchange.com]
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(Score: 2) by Immerman on Friday October 25 2019, @02:43PM (2 children)
Starship *is* the launch escape system. Super Heavy is the high-power launch system (first stage). In event of problems Starship jets away in front of the (potential) fireball, just as the Dragon capsule would from the Falcon 9.
Now, if Starship itself blows up during a non-test flight (especially with passengers) that'd be a tragedy - but launch aborts during the second stage are generally pretty dicey on any current rocket - if they're even possible.
(Score: 2) by ElizabethGreene on Saturday October 26 2019, @03:15AM (1 child)
I'm skeptical of that. It's very different shooting a fully loaded second stage off in atmosphere than landing an almost empty stage in atmo. The turbopumps are going to be offline, the MVAC engines aren't going to be chilled, etc.
That doesn't make it impossible, just a hard engineering problem. One of the other replies mentioned that they've bandied the idea around, but aren't concrete on it yet.
(Score: 2) by Immerman on Saturday October 26 2019, @08:13PM
How long is the second stage riding inert before separation? A few minutes? I imagine most bits will be primed and waiting to go regardless. Of course - that'd be the vacuum engines, you'd probably want to keep the atmosphere engines primed too for escape. That'd also mean you could fire all six for escape, roughly doubling the available thrust during those critical first seconds, before shutting off the vacuum engines to get better control.
They're designing Starship to be able to fly fully-loaded suborbital (and maybe orbital with only a tiny payload) on its own, so it shouldn't have any problem providing the thrust needed to land safely. Especially since unlike the Falcon 9 (if Starhopper is any indication) it will be able to throttle down low enough to hover, and thus land at an arbitrarily low speed. It's hard to overstate just how huge a safe landing options envelope that creates. It could even just hover to burn off fuel if it really needed to.
And control is actually easier with a heavier vehicle - more rotational inertia means greater stability. A slower response means more time to accurately characterize and correct for any problems.
(Score: 2) by takyon on Friday October 25 2019, @12:54AM (3 children)
IIRC, one of the astronauts who built or serviced Hubble said they were willing to risk death to do it.
Building or upgrading a giant space telescope is arguably one of the most important things an astronaut could do in space. And we apparently insist on having humans traveling to space stations in low Earth orbit or lunar orbit. So while they are there, why not assemble a telescope or two? Or a hundred.
Falling back on "big, dumb, and cheap" is another option. Put docking adapters on big telescope body segments holding frames with sections of segmented mirrors. Link them together. Assembly complete.
https://www.nasa.gov/directorates/spacetech/niac/2018_Phase_I_Phase_II/Modular_Active_Self-Assembling_Space_Telescope_Swarms/ [nasa.gov]
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(Score: 2) by Immerman on Friday October 25 2019, @02:59PM (2 children)
Finding people willing to risk death for a good cause is easy. Heck, in the immediate aftermath of the Fukushima disaster several retired nuclear engineers and technicians came forward to volunteer to go in and stabilize things, knowing full well it would be a death sentence. Better they chop a few years off the end of their life to save their nation from the long-term aftermath.
Finding administrators who will allow them to do so is an altogether different problem. When people die in the line of duty, *especially* volunteers who knew what they were signing up for, it makes the administration look bad. "Working stiffs sacrifice life to fix administrator's screwups" plays well in the media for all the wrong reasons.
There's also the likely blowback - an astronaut may understand why a telescope is worth risking your life over. Joe Sixpack is more likely to just see a man die trying to fix some egghead's science toy. And that jeopardizes funding for future missions - especially once it's spun by political opponents to the program.
(Score: 2) by takyon on Friday October 25 2019, @03:17PM (1 child)
The spacewalks weren't the real risk with the final Hubble servicing mission. It was the use of the Space Shuttle. A vehicle that left 7+7 astronauts dead, not in space, but in Earth's atmosphere.
We are continuing to send people to the ISS, despite risks that can't be entirely minimized, as well as events like the Soyuz MS-10 accident in 2018.
You get a crew on ISS or LOP-G. They can fiddle around with hydroponic planters and mice experiments. But they should also be assembling giant space telescopes. The bigger, the better. The more, the merrier.
But if it can be done autonomously, that's great too. Dragon capsules can autonomously dock with ISS. I'm optimistic that some kind of modular telescope could be assembled autonomously.
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(Score: 2) by Immerman on Saturday October 26 2019, @09:35PM
Hmm, ISS as our preliminary orbital assembly platform? I wouldn't mind seeing that at all.
Of course then you'd need to boost the things into their desired orbit... But that could be an excellent testbed environment for developing and using "orbital tugboats", both chemical and ion drive. Even if you initially use them just to ferry stuff in and out of the exclusion zone, so that you don't have a lot of untrusted propulsion systems firing off nearby.
Be an excellent place to work on telepresence robotics too. Autonomous systems are nice, especially for repetitive tasks - but I suspect we're a long way away from really versatile ones. I really think an upper-torso VR telepresence robot, mounted on a robot arm or whatever else makes sense, will be a great way to put human versatility to work in open space, while human frailty can be kept safe within nearby habitats, or even down on Earth for low-orbit work where the communication lag is relatively low.