NASA build a centaur upper stage to launch planetary probes from the space shuttle. Was this a good thing, or was it a ticket to disaster?
References
Taming Liquid Hydrogen: www.nasa.gov/wp-content/uploa...
Centaur G Technical Description: forum.nasaspaceflight.com/ind...
Study of upper stage alternatives: play.google.com/books/reader?...
Upper stage alternatives for the shuttle era: ntrs.nasa.gov/citations/19820...
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Because of the Challenger disaster the Galileo probe sat in storage for four years. It was held in the exact same position on its mounting stand, and due to this the lubricants around the folded dish array deteriorated. This was why once launched the main dish array never deployed properly. During the Galileo mission they had to rely on the much smaller backup array to send and receive data which greatly degraded the amount of data that the probe was able to return to Earth
Yes -- the problem with the high gain antenna not properly unfurling was a real shame and significantly compromised the mission. As I recall, an additional factor was believed to be that fact that Galileo was shipped via truck 3 times across the country (it was sent back to the factory after the Challenger disaster, and then back to KSC for the eventual launch). The theory was that the vibrations from the additional shipping caused the lubricants migrate away from where they were most needed.
Always a good night when Eager Space uploads.
The Challenger disaster caused a three-year delay in the launch of Galileo. On 11April 1991 Galileo's computer commanded the umbrella-shaped main communications antenna to deploy, a three-minute procedure similar to opening an umbrella. Data from the spacecraft indicated that the deployment was only partially successful, and the 16-foot diameter mesh antenna was lopsided, i.e. it was more fully deployed on one side than on the other. NASA quickly determined that the dry film lubricant used on the deployment mechanism probably had degraded during the long storage period following the Challenger disaster. Over the next several years NASA used mechanical force and differential solar heating to free the stuck antenna without success. Galileo's high gain antenna was completely useless. NASA had to use the low gain antennas at 10 bits per second data rate and faced the possibility of losing much of the data initially planned for the mission. NASA had no choice but to carefully control the propellant usage and extend the mission as long as possible. On 21 Sep 2003 NASA ended the Galileo by sending it into the Jovian atmosphere at an entry speed of 48 km/sec.
I think part of the reason they changed the I in IUS from "interim" to "inertial" was to differentiate that it was a guided stage from the spin-stabilized PAM (Payload Assist Module) that was used on other shuttle-borne satellites. They had phenomenally accurate guidance. One problem associated with it was that the 2nd stage required an extendable exit cone for the engine bell to give it the specific impulse required. It was mechanically complex and failed on the first IUS/Titan mission, although they recovered it because the TDRS had enough fuel onboard to recover. There was another concern at JSC on the Planetary missions of possible radioactive debris falling on the launch area if a shuttle exploded on the pad while a radioisotope thermionic generator was onboard Ulysses/Galileo. With all the difficulties presented by carrying a cryogenic stage on a crewed vehicle at the time, it is interesting how today everybody's talking about cryogenic refueling of crewed vehicles in space as if it's no problem.
honestly the acronym change almost sounds like cope on the part of NASA to me.
@@kargaroc386 It was definitely copium.
You seriously enlight us all with your knowledge on the american space program, thank you again for sharing!
One big thing limiting the shuttle’s payload to farther orbits (without an upper stage) is the fact that it needs to return. This makes interplanetary missions especially infeasible as the shuttle will have burn more fuel to get back into an Earth orbit after payload deploy. Once that’s done the shuttle will still have much more speed than normal, which will have to scrubbed off with even more engine burns or having the heat shield work overtime.
So glad I found your channel🎉🎉🎉
A road not taken. When you started listing the masses, I kept thinking it;s getting more and more dodgy.
The mission design limited the flight crew to 4 crew members and 4 days. They would have loaded certain consumables and RCS/OMS fuel to just enough to do this mission with emergency reserves. I'd love to see one of the full Crew Activity Plans to see mid-deck payloads they might try to get in with the weight limit, if any. Likely they would have revoved a couple rows of mid-deck lockers and possibly the galley to save weight (a Cabin-config document would be very telling here.) Obviously, they would not fly the RMS. I know they also needed to vent the cryogenics gases on the pad and going uphill as well. I still think they could have done it and the odds would have been with them, but by far it would have been the riskiest set of missions ever proposed.
Starship centaur would be lit tho.
So would New Glenn…
Instead of wide centaur, Starship would need *fat* centaur.
Starship Helios
If starship is ever going to launch interplanetary missions, it will need something like it.
@@whingebot When the old guard of US rocketry falls, I'm sure someone will scrape up the Centaur design and repackage it for Starship in competition with Helios
Very educational, thank you! - Your 4000th subscriber, congratulations!
Thanks.
Great video! It brings back some memories: after space tug project was cancelled, I was quite concerned that shuttle would not be a good platform for interplanetary missions, and was elated once Centaur G got approved. I remember a lot of naysayers within NASA that thought the Shuttle Centaur was too risky, but personally thought the added capabilities were worth the risk. After the Challenger disaster happened, the naysayers had the ammunition to get Shuttle Centaur cancelled. I still think that with some additional effort, Centaur could have been made sufficiently safe for Shuttle, but I guess NASA didn't have the stomach to see the program through in the post Challenger era. As the video pointed out, one of the big challenges of the program was the complex management structure, which didn't do the program any favors.
great video, thank you for sharing
The more I learn about the Shuttle program, the more disenchanted I am by it. The Apollo program seems so much more straightforward, where everyone was driven by the same ultimate goal: getting astronauts to the Moon. But from day one, Shuttle was a solution in search of a problem, with no clear goal and way too many cooks in the kitchen, driven by bureaucratic career ambitions and political fiefdoms rather than by any overarching shared goals. It makes me realize what a phenomenal job NASA PR has done over the past half century that people still think of the agency as an exemplar of noble scientific pursuit and cutting edge technology, rather than the dysfunctional government bureaucracy of middle-management-lifers that it's been for decades.
The goal of shuttle was to keep NASA centers open, NASA managers employed, money flowing to contractors, and votes going to congresspeople, and it was very successful at that. It's not what most of us want in a space program, but I would argue that most large businesses are also run to further the careers of management over producing useful results.
If you want to truely feel how cursed the shuttle was then I recommend building one in kerbal space program
@@EagerSpace While the Shuttle program as it was implemented had plenty of problems, I kind of think it get's too much of a bum wrap based on 20/20 hindsight. The Shuttle as initially conceived to be fully re-usable with internal hydrolox tanks, flyback booster, and high temperature metal composite heat shield could have been a capable and cost effective launcher. Unfortunately, a series of compromises driven by the Nixon administration's desire to halve the development cost resulted in the flawed design that we got. The shuttle program was not conceived as a jobs program, but rather from a desire to radically lower the cost of access to space for a more economically sustainable space program in the post-Apollo era. It certainly required political support, which very often ends up being justified by the jobs that it creates, but this was not at the time a prime driver for the existence of the program. The SLS, on the other hand, was most definitely driven by powerful politicians wanting to keep aerospace jobs in their states/districts and thus could be fairly characterized as a jobs program.
You cannot like the shuttle if you want although nothing else could’ve fixed the Hubble space telescope, but NASA hasn’t accomplished anything is forgetting Juno and Cassini and the Mars rovers and the Mars helicopter, and the voyager and the pioneers
@@mcamp9445 shuttle is good, shuttle is the spacecraft of my generation so I always have a sentimental place in my heart but it is a badly designed object
Great video 🎉
Great work as always. Appreciate the research this video musty taken.
Thanks. I knew very little about shuttle centaur at the beginning and it's learning what is going on and figuring out the story that is the fun part.
Appreciate the video. I do want to point out though that the Kibo module shown on STS-123 is technically not the 'lab module' but the pressurized logistics module (PLM) that sits on top of the "pressurized module" (PM) launched on STS-124 that contains all the science hardware. The PLM still serves your point about showing the need to balance shuttle payloads in the bay, but the PM was presumably even more of a headache - it was 3x longer (11.19m) and twice as heavy (15,900kg), and I don't know how they balanced that out (or if they even tried). Was there ever any discussion about ditching the payload prior to reentry? The payload's uncontrolled reentry would pose a potential threat on the ground, but it certainly seems like a better risk to take than trying to land the already brick-like shuttle with tons of extra weight in the back.
Thanks for the clarification... STS-83 landed with about 11,000 kg of payload, and the orbiter was overweight because they landed early with extra consumables. Any payload is supposed to be safe for TAL or AOA aborts (I'm not sure about RTLS as I don't know if anybody has high confidence there) The number of scenarios where you would have the time to ditch the payload before reentry seems pretty small. NASA hates unpracticed tasks and if you take too long you may kill the crew, plus you are probably busy trying to work the problem that's causing you to return, so my guess is 0% chance NASA does that. Maybe if it's like Columbia but with less damage you might do what you can to lighten the orbiter...
Galileo was not any sort of driver for shuttle-centaur - it was trying to launch large national security payloads using the shuttle, like MILSTAR. This stems back to Carter's directive to *only* use the shuttle for any mission. This killed the various Titan derivatives and Saturn 1B was long dead at that time. When shuttle-Centaur was cancelled, they turned the Centaur Gs around to use in the new Titan IV program, because both the IUS and a potentially reborn Titan transtage were nowhere near powerful enough. As mentioned, there also wasn't enough space for, again, the nearly 35 foot tall (stowed) MILSTAR with a stock skinny-tank Centaur. Almost everything NASA did with regard to upper stages, etc, were driven by national security payloads, not the relatively trivial science programs that, as noted, could be done with lesser capabilities or, frankly, not at all.
Interestingly Falcon 9 had successfully retrofitred to fuel methalox lander inside it. And it worked. You can theoretically change the lander to an upper stage like Impulse, and it can decimate many high energy contracts (Falcon upper stage is already impressive as it's, lowest mass fraction) Another nice bonus: no need to worry about the crew!
Look for that discussion in an coming video.
let's gooooo
The economics of the Space Transportation System were hard to comprehend at the time - the fact that the orbiter was stuck in low earth orbit resulted in hazardous booster solutions which I recall did cause concerns at the time. I watched a documentary on the BBC about it before 51L.
Do you think the Soviet Energia-Buran would've solved this issue since the Enegia booster stage was an independent system. They did launch a massive satelite with it ( though the satelite failed to reach orbit after detaching from the booster)
It didn't have an orbit-only stage like this, so no. If a stage was designed for it, it would benefit from being designed after the vehicle was in service, and thus less susceptible to the payload underperformance issues that drove a lot of the Centaur-Shuttle integration issues, and also from having 80-90 odd tons to play with instead of 22 tons (for a variety of program reasons, just because you can toss 100 tons or something to LEO, and thus 20 tons to whatever random high-energy orbit, it rarely translates to actually having a 20 ton probe, so there's more margin with starting from a heavier lifter--compare how Europa Clipper worked on SLS originally as a ~6 ton probe, and how they were able to restructure the trajectory to fit on expendable Falcon Heavy in the end.
Not really. Energia was a really cool rocket *if* you wanted to launch really big and heavy payloads, but it was reportedly very expensive. Putting payloads in a reusable shuttle to put it on an energiya so you can get the shuttle back costs more than an energiya launch by itself and carries much less useful payload.
@@EagerSpace I didn't get the point. Energia launching payload alone is cheaper than energia-buran launching payloads . Did I get it right ? Why use buran shuttle when energia can function independently?
Ah, another way in which the Space Shuttle was ... ineffectual.
The things I didn't know about the Shuttle Program - or did know once upon a time and were long forgotten. Thanks for another hunk of interesting spaceflight knowledge.
I started writing a video on kick stages in general and their applications to shuttle and another very large rocket that is currently under testing. I had forgotten all about shuttle centaur - if I ever knew about it - but as I read more the story got better, and then I got to the "death star" comment and I knew I had to devote a video to it. I didn't figure out how to fit it in, but Martin Marietta played Star Wars music at the rollout of the Centaur G Prime. The interesting thing to me what the "just run the engines at 109%" was so much like the decisions made elsewhere WRT shuttle. Engineers trying to do the right thing, management walking all over them.
@@EagerSpace "Engineers trying to do the right thing, management walking all over them." Isn't that SOP at some old-line aerospace companies?
@@EagerSpaceif you make that other video, could you discuss an F9 upper stage as a Starship kick stage? Particularly in light of refilling.
The original mistake was launching Galileo on Shuttle at all. Titan IIIE or a 34D with Centaur would have been the prudent option.
It's such a stupid choice. Titan had a good reliability record and you just had to put the probe on it and launch it. But NASA had to show that shuttle was great and useful...
@@EagerSpace And in the process they proved the opposite.
@@EagerSpace No - they and everyone else was required by executive order to only use the shuttle, aside from legacy programs that couldn't be launched any other way, or couldn't be brought to shuttle safety requirements (like 3 physical and 3 electrical safeties for firing a thruster, for example). That's why there was such a scramble after Challenger all single-use boosters were being phased out by fiat. And, again, NASA was hardly a driver for any of these capabilities. If there was a mistake made, it was putting NASA in charge of/as a supplier to everyone else, DoD and other government customers being the 800 lb gorillas with far more critical missions. Just about any NASA program could be cancelled at any time with no important side effects.
Surely the East Coast Shuttle could have been made more effective for special missions if they had used the uprated Graphite-Epoxy SRBs developed to give the West Coast Air Force Shuttles more takeoff thrust ?
Interesting question. I don't know the state of development of those boosters in 1986 but my guess is they weren't ready yet - I didn't see any mention in any of the shuttle centaur stuff I looked at.
@@EagerSpace There isn’t much reported on the “Filament wound” boosters but all Air Force space stuff especially at Vandenburg was pretty secretive back then.
3:18 the External Tank actually has an empty mass of 35,000 kg in the initial Standard Weight configuration
Remember the time (before the Challenger disaster) that NASA wanted to fly the space shuttle from SLC-6 at Vandenberg Space Force Base?
A NASA .. "what If?" piece.
Kind of sorry this dumps on Centaur as being at the root of the issues, which is a common failing of people telling this story, when it's more about the fear, uncertainty, and doubt Johnson cast over Lewis' work and got the astronauts worried about, while the real risks aren't the venting or anything like that, but Johnson's overselling of Shuttle's payload performance and the need to over-power the engines (though to a level which had decent backing behind it) to compensate for the launch mass Johnson had previously promised. The "death star" line is evocative, but like many evocative lines...fundamentally misrepresents key facts.
I agree that the payload lift was a real driver but I wonder why Lewis ended up taking them at their word - shuttle wasn't going to get lighter during development and that payload number was only going to go down. I suspect that Galileo also got heavier and that was part of the problem, but they didn't have enough margin. It's also certainly true that JSFC seemed fine with shuttle centaur as long as Marshal got the management contract.
Why don't you count the first stage for the calculations at 2:25?
I used second stage because I want to talk about the effect that second stage dry mass has on payload. If you want to look at the whole rocket, Atlas V puts about 3% of its takeoff weight into LEO, shuttle puts about 1%.
The biggest problem of the space shuttle program was that it wasn't canceled before it even started.
Every time I think I know just how crap the SS was, I learn something new that makes me hate it more. The entire SS lineage (including the SLS and Constellation before it) has been just one long series of disasters and bad decisions that have hobbled American space programs since they cancelled Saturn V
@@Joe-xq3zu It was the same for me, the more I learned the more I hated it. Space Shuttle was the greatest disaster of US space program and we are still recovering from it.
The RS 25s on SLS are being run at a standard 109 percent. And these are using the same exact engines that launched the space shuttle. With the engines now being certified up to 113%
Not quite the same exact engines. The engines flying at the time of Challenger were Phase I engines. There were by the RS-25A, B, C, and D. This paper talks a little bit about the changes in the different versions: ntrs.nasa.gov/api/citations/20020022303/downloads/20020022303.pdf All of the shuttle engines on SLS are RS-25D. The new RS-25E engines are planned to run at 111%, though they have been tested above that.
I wonder whether the constellation program would have been able to move faster if they used a traditional shuttle stack like shuttle C, with a hydrogen upper stage like centaur or the S-IVB. It might have actually been able to bear the fruits of being "shuttle derived" to reduce development time, rather than only lining the pockets of existing shuttle contractors.
There was the Direct/Jupiter project that was in that vein. The Wikipedia article is pretty good. en.wikipedia.org/wiki/DIRECT_%26_Jupiter_Rocket_Family
@@EagerSpace I am very skeptical of the efficacy of "in-line" shuttle derived vehicles; Wasn't SLS majorly delayed from redesigning the fuel tank to handle higher structural loads caused by this configuration? A horizontally integrated stack could also provide better main engine reuse options. It seems like one of the lynch pin issues that the DIRECT team had with the constellation program was the use of a five segment booster, but this was already proposed as a shuttle upgrade and has since been demonstrated on SLS.
6:35 Wait, ridiculous KSP style gravity assist chains were real things that were used?
Yes, real things and very common if you want to get to the planets. I talked about Galileo. Cassini did two from venus, one from earth, and another from jupiter to get to Saturn. Voyager 2 did Jupiter, Saturn, and Uranus on its way to Neptune.
@@EagerSpace I know about Voyager style, I just assumed they were all like that and they didn’t do multiple solar orbits to set themselves up for other gravity assists. Thanks!
As an old dude that was 14 years old when they landed on the moon, let me give you my view. 2001 the movie came out about that time and the nimrods in congress saw the movie and said "MAN, WE GOTTA GET US ONE O THEM THERE SPACE AIREOPLANE THINGIES FOR SURE !!!" without a clue how rockets worked. The fact that it worked at all was due to extreme talent and endless money. It really never had a chance to work like the Science Fiction version, and we now know Spacex hardware solution is much better. At least the best so far.
Uhhh... you should verify your dates. Challenger did not fly on May 15, 1986.... it was already destroyed. And Atlantis did not fly 5 days later, in 1986.
That is the point. Those are the dates and missions that Shuttle Centaur was scheduled to fly, and likely would have flown if Challenger didn't happen.
The Space Shuttle was an impressive engineering achievement, but a ridiculously foolish concept. It almost looks like some kind of scam. They spent all that money to put nearly 170 tons into orbit but could barely deliver 20 tons of payload.
Granted, it did more than loft satellites. Negative arguments about shuttle are popular but it also can't be ignored that shuttle taught humans the fundamentals required to utilize LEO.
How about we clean space junk.