- NASA Watch
- March 23, 2023
Moon 2024 Goal Delays SLS Availability For Europa Clipper
NASA OIG Follow-up to May 2019 Audit of Europa Mission: Congressional Launch Vehicle Mandate, NASA OIG
“NASA’s renewed focus on returning humans to the Moon on an accelerated timetable means that an SLS will not be available to launch the Clipper mission to Europa before 2025 at the earliest. Given all of the foregoing factors, we urge Congress to consider removing the requirement that NASA launch the Europa Clipper on an SLS and allow the Agency to decide whether to use an SLS or a commercial vehicle based on cost, schedule, vehicle availability, and impact on science requirements.”
“However, because of developmental delays and, more significantly, NASA’s plans to use the first three SLS rockets produced for its Artemis lunar program, an SLS will not be available until 2025 at the earliest. Consequently, if completed on its projected schedule, the approximately $3 billion dollar Europa spacecraft (known as “Europa Clipper”) will need to be stored for at least 2 years at a cost of $3 to $5 million per month until an SLS becomes available. NASA recently added $250 million in Headquarters-held reserves to the project to address these storage and related personnel costs. Congress could reduce risks to both the Europa mission and Artemis program while potentially saving taxpayers up to $1 billion by providing NASA the flexibility in forthcoming fiscal year (FY) 2020 appropriations legislation to determine the most cost effective and timely vehicle to launch the Europa Clipper mission in 2023 or whenever the satellite is completed.”
NASA OIG Audit: Management Of NASA’s Europa Mission, NASA OIG, earlier post
“In addition, although Congress directed NASA to use the SLS to launch the Clipper, it is unlikely to be available by the congressionally mandated 2023 date and therefore the Agency continues to maintain spacecraft capabilities to accommodate both the SLS and two commercial launch vehicles, the Delta IV Heavy and Falcon Heavy.”
It would be a real loss to lose the SLS, since that would avoid the need for years of gravitational flybys to pick up velocity. Another reminder that we could really use in-orbit refueling for upper stages.
I don’t really see this as a loss. They’re talking about saving $700 million by not using SLS. The extra time during cruise will cost some, in terms of salaries for the usual JPL standing army. But I expect it’s still going to be a $500 million or so less. That’s an entire Discovery mission. Of course, there’s no way to be sure that’s where the money would go, but that does illustrate the magnitude of the savings.
I’ve also worried that the saved time would not materialize. SLS only gets Clipper to Jupiter sooner if it stays on schedule. A Falcon Heavy launch in 2023 gets the mission to Jupiter sooner than a SLS launch in 2026. And, honestly, some of us have been waiting long enough for those data to have learned patience. Plans and studies for such a mission have been going on for two decades. The formal start of Clipper was in early 2015. Another three years isn’t making us wait all that much longer.
But it would be best to make it a Falcon Heavy. I don’t think there’s anything else available which avoids a Venus flyby. And that’s a real pain when it comes to the spacecraft’s thermal design (which, by the way, should have been frozen already, if it weren’t for being in launch vehicle limbo.)
If it weighs less than a Tesla convertible, it should be fine on a Falcon Heavy.
That’s not how orbital mechanics works. The Tesla only went out to about the orbital distance of Mars. You really need to add a solid kick stage to Falcon Heavy to get Europa Clipper to Europa.
Understood. I was thinking mainly about how much thrust would be required to get the whole package off the ground.
You can get it to Jupiter on a FH without a kick stage, but it would need additional gravity assists.
How about the Starship/Super Heavy? It should give it a bigger boost then SLS, especially with orbital refueling.
I think NASA is too used too long design cycles. They aren’t going to bet a $3 billion mission on a launch vehicle which hasn’t flow yet. And yes, I know SLS hasn’t flown yet. But NASA is in charge of developing it. So they have control of it’s schedule and schedule risks. Having written that, I realize that’s a bad joke. But I just can’t see NASA accepting a “trust me” from Mr. Musk about Starship/Super Heavy flying on time and with the currently claimed capabilities. I’m not even convinced SpaceX has the planned capabilities defined firmly for NASA to use for a project in phase C.
True, but if SpaceX is anywhere close to its development schedule it will be putting payloads in orbit before SLS Block I even flies, and many years before the Europa Clipper launches. Compare the mere 90 tons to LEO of the SLS Block I with the 150 tons of the Starship and it should allow a more direct flight, with perhaps a couple smaller satellites added to explore the outer Jupiter Moons which are also interesting.
I can think of a number of things to do at Jupiter with that sort of mass. Planetary science really needs to get away from the idea of single-event measurements (one flyby, one mission, etc.) Mars Reconnaissance Orbiter has done some great things with repeated imaging, like seeing new craters formed in the last year, or seasonal changes. We’ve never really tried to do that right in the outer solar system.
But I think Europa Clipper is stuck with something like a Falcon Heavy. It’s not that SLS won’t be flying before Clipper is ready to launch. I think that’s a real possibility, but not the main obstacle. Details of the final design for Clipper do depend on launch vehicle and the cruise trajectory. That means a decision before the Critical Design Review, and then everything has to be build, assembled and tested. The way NASA develops class A missions, there just isn’t time for SLS to be an option. If they were willing to take a 20% chance of mission failure, that would be different. But people really don’t like taking that sort of risk with a flagship mission.
That’ll work better without (or with a separate launch for) the lander portion.
There is no lander portion for the Europa Clipper mission. An idea for one was floated, but only 250 kg of mass available to go along with Clipper (even launching on SLS and adding gravity assists during cruise.) Everyone familiar with the mission knew that was a no-brainer, but people were told to study that option.
Subsequently, there was an idea for a separate Europa Lander mission. The concept study team did a nice job, but the cost was really off the map. Even the revised, descoped version would have preclude things like an Uranus or Neptune mission before 2033. And that just wasn’t in the cards. No submitted NASA budget has included funding for an Europa Lander. Just a little bit of money to study the idea.
Interesting. I read that Sen. Shelby was making the lander a priority, and made funding conditional on it in a last-minute, pre-vote edit to a budget. He allegedly did it to assure that only SLS would have the throw-weight to send it.
What about Starship? Can it fly a small (i.e. Cubesat) Europa lander with only Clipper-relay communications?
I’m sure Senator Shelby is quite interested in the Europa Lander. The concept study ended up with something that required both a SLS launch and gravity assists on the way to Jupiter. The lander is something the President’s budget has consistently left out, except for some preliminary studies and technology development, like the Instrument Concepts for Europa Exploration (ICEE-2) grants. Interested Congressmen have written in somewhat larger appropriations. Only in the form of I didn’t know this year’s Senate bill was that far along, but I’m not shocked.
If Spaceship performs as claimed, I suspect it could get that big lander on a direct trajectory. You’d want a high energy kick stage, rather than sending Spaceship itself, but that should be doable.
In terms of smaller landers, the problem is what they could do once they get there. I can’t find the numbers, but I believe the 2016 concept needed to send 13 tonnes to Jupiter to get a 40 kg payload on the surface. That’s not going to scale down very well. I think they did do things the hard way, in some respects, but a small lander would still be very limited. At one point, they were talking about adding a 250 kg lander to Clipper, but it ended up being too limited to be worth doing.
Only 1 extra year of flight time with one Earth flyby if launch on Falcon Heavy with STAR-48 kick stage.
You need the SLS Block 1B variant to do the direct flight on it’s inaugural launch if the Block 1B come online by 2025.
Actually, they decided a Block 1 would do. As far as I can tell, that was purely a management decision. Someone was asked (by Mr. Culberson) if they could find a way to fly Clipper on a Block 1 instead of a 1B. They always hold mass margin, both on the launch vehicle’s capabilities and on the spacecraft mass. How much is sort of a touchy feely thing about what managers are comfortable with, and it can change. (Yes, there are formal rules and guidelines, but there are also formal rules and guidelines about waiving those formal rules and guidelines.)
Delta IV Heavy and Vulcan would need a VEEGA profile (2 Earth, 1 Venus gravity assists).
But NASA has now determined that adding a Star 48 kick stage to the Clipper on a Falcon Heavy launch would eliminate the need for the Venus flyby and one Earth flyby. Which would also shave years off the flight time.
On another note, the engine section for core stage #1 is complete, checked out, and ready to be mated to the tanks.
Based on experience so far, SLS will never fly. The sooner we move on to something else such as the Starship or Falcon Heavy, the better.
SLS will fly at least three times, or until 2026, or until a little after #DearMoon. Whichever of those three happens first.
It’s first flight will fly on Artemis pressure and just program momentum. Second and third on Congressional willpower.
Starship/Super Heavy will be available, and will give it a good ride.
It took FH three launches and about 18 months after its first launch before NASA would even speak its name in public. It might as well have the name Voltimort. That’s with FH being a very poor capability replacement for SLS and with it probably not even being projected to be in operation at the same time as SLS.
Starship will be a full capacity replacement and then some, and in operation during the same time, a second (third?) total market disruption, and people yet doubt that the concept will work at all. Europa Clipper will be on its way to Europa before NASA certifies Starship.
You might think the name “Voltirmart” is a joke, but some planetary scientists actually use it in published papers. There is a long-standing problem about what to call the boundary between the atmosphere of an unmagnetized planet or a comet and the solar wind. It looks different in the data from different instruments, and those instruments place it at different altitudes. The scientists squabble over terms like “ionopause” and “magnetic pile up boundary.” One scientist, David Brain, introduced the term “Voldimort Boundary”, as the name which can not be spoken without starting an argument.
LOL! Made my morning!
You could free up an SLS sooner if you hold the SLS/Orion being built for em-2 to be used for the 2024 boots on the moon flight. This could free up an SLS from em-3 for Europa clipper. Do we really need a free flight Apollo 8 crewed mission in between em-1 and landing on the moon given how short we are getting on time?
Almost nobody believes the 2024 date is realistic, especially without any extra funding.
well if the FY2020 $1B to kickstart the Appendix H vendors designing the lander systems then maybe the funding will continue subsequent years. if congress doesn’t cough up the amendment money to get things started by December then 2024 seems less likely unless the vendors are willing to use all their contribution portion upfront while NASA and congress work things out.
You could rename SpaceX’s Starship to the Starship Launch System. Then SLS may be ready in time. Easy… ?
IMHO Moon 2024 has nothing to do with a lack of SLS availability – that is purely on Congress and NASA – they own the glacial pace of system development.
The dismal projected SLS flight rate makes this “news” obvious to anyone following SLS and the moon by 2024 push by this Administration.
Yea, but now I get to make a whole bunch of friends and professional colleagues mad at me by saying “I told you so.”
KILL SLS while we still can.
Yet another way for Artemis to annoy me.
Alternatively, we could see Artemis as a launch system accelerant…and say that because of it, SLS will have to fly sooner and thus enable a 2025 launch date for Europa Clipper instead of…oh…I don’t know…let’s say 2030?
I was going to say 2050, but that would have been too sarcastic maybe.
It’s settled then…