Here is NASA’s plan for nuking Gateway and sending it to Mars

Only one US-built nuclear reactor has ever flown in space, and that was more than 60 years ago.

See full article...

 

[eldakka]

Meanwhile in the real world. It's not like a civilian nuclear power plant. Its has the same space constraints as submarine nuclear reactors. They used highly enriche MOX fuel. You do not what that aerosoled landing breathable dust over large areas of Florida.
https://en.wikipedia.org/wiki/Kosmos_954
Musk like hand waving doesn't change facts you don't like

The problem you have here is that you obviously have absolutely no idea what you are talking about. Submarine nuclear plants are rated at hundreds of Mw and are expected to run, unrefueled, for 30 years.

The reactor we are talking about here is on the order of 60kw for a single-digit years duration.

The comparison scale you are making is ludicrous, more than 2 orders of magnitude in power output over timescales that differ by a factor of 3 or 4. The scale difference, and hence fuel type (enrichment levels) and volumes is just silly.

 

[andygates]

Well I do think covering large areas of Florida with Plutonium dust from a NASA built dirty bomb isn't going to be particularly popular with these people called voters.

Oh please, we've been kaboom-securing spicy payloads for decades.

 

[Tactical Finesse]

Oh please, we've been kaboom-securing spicy payloads for decades.

Yes...but...Not very often. The last major RTG launches were Cassini and New Horizons....NH kind of was a non-issue, I vaguely remember people upset about RTGs being used by Cassini during its launch.

EDIT: AFAIK the RTGs that have contaminated people back on Earth...were all terrestrial and not space probes...I thought Lia was one, but it was a Soviet orphan that was always terrestrial

 

[EricM2]

Is it possible to stop giving spacecraft stupid stereotypically USA!USA! rah-rah names like 'Freedom'?

The less actual freedom is provided, the more important those stupid names become. Same thing goes on with "Democracy" in countrie's names. The countries bothering to have this attribute in their official name are usually the least democratic ones.
For example the former eastern Germany/GDR (German Democratic Republic), the Democratic People's Republic of Korea (North Korea), Democratic Republic of the Congo. All are/were basically dictatorships.

 

[AverageDutchGuy]

"NASA isn’t sure what they will do with the SR-1 mothership after reaching Mars."

So they're going to launch a flagship level cost mission and just.... throw it away, basically?
Why? There's probably a lot of cool stuff that that budget could be paying for instead of this basically pointless mission that doesn't need the nuclear reactor.

 

[Tactical Finesse]

So they're going to launch a flagship level cost mission and just.... throw it away, basically?
Why? There's probably a lot of cool stuff that that budget could be paying for instead of this basically pointless mission that doesn't need the nuclear reactor.

Because some billionaire Tech Dude Bros wanted to go to Mars because they say it is the Future. And they bribed POTUS into getting NASA to do it for them.

Honestly....I'm down with paying for it--so long as Musk and Bezos and Pichai and a few others are duct taped to the rocket and space-mailed off and out of here.

 

[zoltan_merc]

you want them to call it Trumpship one?

I think if they did that, the probability of mission failure due to an "accidental" oversight by some non-MAGA technician/technicians would go up significantly.

 

[FranzJoseph]

Honestly, I'd have hoped they might slingshot it to Uranus or Neptune afterwards. Could add one more probe for that. I know there is the planned Uranus Orbiter and Probe mission, but in the current political climate, I see it increasingly unlikely to be funded (imagine the childish jokes Trump would say about it).

Anybody knows if such a mission would be possible with the Gateway bus? I don't even know where the ice giants currently are in relation to Mars.

But the ice giants are horribly under‑researched and it'd be a shame to just dump the Gateway in orbit of Mars after deploying the probes, unless it could serve some other critical function there.

 

[Nalyd]

Honestly, I'd have hoped they might slingshot it to Uranus or Neptune afterwards. Could add one more probe for that. I know there is the planned Uranus Orbiter and Probe mission, but in the current political climate, I see it increasingly unlikely to be funded (imagine the childish jokes Trump would say about it).

Anybody knows if such a mission would be possible with the Gateway bus? I don't even know where the ice giants currently are in relation to Mars.

But the ice giants are horribly under‑researched and it'd be a shame to just dump the Gateway in orbit of Mars after deploying the probes, unless it could serve some other critical function there.

And thus began the scope creep; upon which the mission cost and timeline did shifteth up and to the right, respectively, until cancelled as a boondoggle ten years hence.

 

[Nalyd]

You realize that NASA has spent $60B on SLS/Orion without a moon landing, without even a manned mission.

Now we finally have a NASA administrator who seemingly has the skill to finesse actual moon base through Congress without requiring a massive spending increase, and repurpose existing hardware for a terribly useless project (Gateway) into a legit nuclear electric spacecraft that could be a precursor of faster and far more powerful deep space probes.

We should at least enjoy the glow until a real problem emerges.

Couple more weeks we’ll have spent $60B on bombing Iran.

The cost of this mission, which repurposes parts already in construction to do something novel, is a laughable target for ire about “mah tax dallers”.

 

[Tech-Space-Cars]

A high power engine exists in VASIMR. They just need a 250kW flight certified power source to power it. It’s being developed by former NASA astronaut Dr. Diaz-Chang.

ad Astra Variable Specific Impulse Magnetoplasma Rocket

 

[Speakertoanimals]

Europe should take their module and components back. Screw the unreliable americans.

There you go. First, of course, all the pieces need to be gathered up and put in a pile somewhere since it hasn't ever even been assembled. THEN we can go ahead and ..........

 

[Bill Swallow]

The first manned Lunar surface base will of course be called Trump Station.

Why? It won't exist until after he's gone.

 

[danielravennest]

I’d actually hazard a guess that they intend to have the launch vehicle put the spacecraft on an Earth-escape trajectory before the reactor is even started, to avoid any risk of a hot reactor getting stranded in Earth orbit due to a drive problem.

Since it also is supposed to have solar panels (like the original Gateway PPE has) they can fly solar-electric until it reaches a safe distance/orbit and then start up the reactor.

 

[danielravennest]

The new 'program' seems so completely bass ackwards when the implied goal (and yes, I know it's not) is to establish a permanent human (USican) presence in space. How will human health be affected by long-term 1/6 gee is just for starters.

Presumably less than at 0/6 gee, which has already been tested multiple times for up to a year. We've had a permanent presence in space for 25 years on the ISS. For the Moon you just have to limit stay time to under a year. The bigger concern for people on the Moon is radiation, since you would be outside the Van Allen belts.

There are uncomplicated solutions to radiation - pile a meter or two of Moon dirt over your crew modules, but we don't have dirt-moving equipment yet for the Moon.

For really long-term habitation, artificial gravity by rotation is not a tech barrier. There are centrifuge rides at many theme parks. The unknown is what percentage of time in the centrifuge is needed for human health? Just during daily exercise, full time, or something in-between.

 

[Walker On Earth]

I fully understand that sending a noocular rocketship to Mars is very exciting for a certain type of person/personality, but other than depositing a few Martian helicopters (of questionable value), what's the science payload? Or is it just a tech demo to keep the Chinese in their place?

Trump and the techbros want something cool-looking fast fast fast and what could be cooler than a nuclear-powered rocket? Particularly since at least some of the necessary components are already(?) built. Doing the sludge research stuff that we should have started back in the 70's? That's boring. And the payoff as they see it is too far off, years at best, decades almost certainly.

 

[Rhutanium]

I was hoping they would cancel Gateway, then do a Ship of Theseus thing with it and ISS, but this is a very happy surprise.

Maybe they can dust off some old satellite and strap it on. What about those telescope assemblies that the NRO gave NASA? Is there utility to having one go to Mars? Or even better, to sending it out past Mars, once it drops its kids off?

Those scope assemblies were used for Nancy Grace Roman, IIRC

 

[Walker On Earth]

Presumably less than at 0/6 gee, which has already been tested multiple times for up to a year. We've had a permanent presence in space for 25 years on the ISS. For the Moon you just have to limit stay time to under a year. The bigger concern for people on the Moon is radiation, since you would be outside the Van Allen belts.

There are uncomplicated solutions to radiation - pile a meter or two of Moon dirt over your crew modules, but we don't have dirt-moving equipment yet for the Moon.

For really long-term habitation, artificial gravity by rotation is not a tech barrier. There are centrifuge rides at many theme parks. The unknown is what percentage of time in the centrifuge is needed for human health? Just during daily exercise, full time, or something in-between.

'Just', 'uncomplicated', and 'not a tech barrier' are doing some heavy lifting here. Why not do the necessary research first to make sure all of that is just as uncomplicated and easy as you say it is?

 

[JerryLove]

We can't do any of the other space things that scientists want to do with ISS updates and telescopes and probes because we are going to go to Mars instead, something that no one expects results from during my administration - Bush

It's actually a point where we should see movement on getting to Mars? Mars is a dumb first goal, we are going to build a lunar gateway. No one expects results in the next 6 years - Trump

OK. Looks like I'm president again and we should be seeing results on the gateway. Gateways are a dumb first step. We are going to build on the lunar surface instead. No one expects results from this during my administration - Also Trump

 

[azazel1024]

Technically, all nuclear reactors ever placed into space (mostly Soviet designs) have also used systems identical to those or like those employed on RTGs to convert thermal energy into electricity.

This means that, while they still generate a lot more thermal energy per given kilogram of fuel (their chain reactions allowing for such over simple decay), you still have very poor conversion of said energy into electricity.

Obtaining greater efficiency requires the use of more mechanically complex and thus more expensive alternatives. While boiling water into steam to spin turbines is the most common means of generating electricity from nuclear reactors on Earth, they have properties that make them too heavy and complex for use in space where non-payload and non-propellant masses have a more deleterious effect than they do compared to more terrestrial forms of propulsion.

Instead, it's generally preferred to use a number of alternative engines (or cycles) that employ gas as a working medium in lieu of water.

Coincidentally, such cycles can use a variety of energy sources, including decaying radioisotopes, nuclear reactors, and even concentrated Sunlight. Stirling engines (among others) have in fact been seriously investigated as a way to generate more electricity per given amount of Plutonium-238 than is obtained with extant RTGs.

While there has been a lot of work done on nuclear power systems for space applications in recent years, completing even the most barebones nuclear vehicle in two years is astronomically unlikely under any condition. I also doubt that the White House is going to request a realistic budget for such a mission, let alone get that budget approved by Congress.

It appears this will use a brayton cycle engine. Basically, a jet engine or gas turbine engine. Though in this case, it'll use a closed cycle, not open cycle. So basically, the heated medium (not sure what, I assume not water, though I also assume they want it fairly high temperature*, but water steam seems unlikely) gets compressed, energy gets added somehow (I assume a heat exchanger from the fission core), and is allowed to expand through the outlet of the turbine, the exhaust medium is then cooled and returned to the intake.

A regular gas turbine or jet engine would use fuel and combusted with atmospheric oxygen in the "add heat" stage, normally called the combustion stage, of the engine, before it enters the expansion stage of the turbine and then exits.

Regular steam turbine engines have the heat added prior to intake to the turbine and work on a pressure differential between the inlet side where the heat is added and the outlet side where the heat is extracted via cooling.

20KWe isn't all that much power, though compared to deep space probes it is pretty substantial. IIRC, most started out around 800-1000We or so and of course diminish overtime. They have to reject about 10x that in heat, as RTGs are only around 10% efficient. So for 1KWe, they'd need to dissipate 10KWt. This will need to dissipate around 60KWt as Brayton cycle are typically 30-40% efficient. I am a bit surprised they aren't going with a Stirling cycle engine, as those are a fair amount more efficient (around 50%). But I am assuming a durability concern, or it may have to do with how they are planning to do heat rejection that is a limitation, or it could be vibration concerns.

IMHO, let's avoid massive scope creep, but it would be really cool if it doesn't add to scheduling concerns or massively to cost, frankly slap a small number of science packages to it and aim it at Uranus or Neptune and put it in orbit around one of them after Mars.

*I assume high temperature as it'll need to radiate the heat and that functions as a 4th power function, so doubling the temperature increases the heat radiated by 16.

 

[adam.i]

“SR-1 Freedom primarily has that one new system, the reactor, on a spacecraft bus that already exists,”

Oh just one new system, is that all? Well with the DOGE bros handling safety regulations I'm sure they'll get something radioactive ready in a couple years.
https://meincmagazine.com/science/202...valley-into-americas-nuclear-power-regulator/

Seems like a more realistic, cheaper, and more scientifically interesting plan would be to add capture hardware so PPE could do its original ARM mission.

Put a reactor up in an escape orbit when it's ready without a big EP bus rather than put a ticking clock on development so it can get to Mars in the next window.

One thorny problem that cursed the DRACO mission was the question of how to test a nuclear thermal rocket engine on Earth while adhering to nuclear safety protocols. This would require engine exhaust to be scrubbed of radiological material. Managers found there’s no easy, inexpensive way of doing that.

Maybe not inexpensive, but really cool.

https://ntrs.nasa.gov/api/citations/20180004502/downloads/20180004502.pdf

Since the exhaust is hydrogen, you can burn it with oxygen downstream and condense the resulting steam for testing/processing.

 

[RoryEjinn]

So they're going to launch a flagship level cost mission and just.... throw it away, basically?
Why? There's probably a lot of cool stuff that that budget could be paying for instead of this basically pointless mission that doesn't need the nuclear reactor.

My understanding of this is that it's a proof of concept. So it would prove that Fission Electric Engines work in space and that NASA can actually put one in space. It's confusing because TOPAZ-I was a nuclear based fission electric engine as far as I understand, so I'm not sure why they're acting like it would be the first one in space.

 

[carldjennings]

Well I do think covering large areas of Florida with Plutonium dust from a NASA built dirty bomb isn't going to be particularly popular with these people called voters.

If it includes Mar-A-Lago they might be okay with it.

 

[bobbalaram]

Comments from a retired engineer:

• having a launch date driven by the planets is a wonderful forcing function. Can't kick the can down interplanetary roads. It will be the best thing that happens to the propulsion, spacecraft and reactor teams
• please, let science take a back seat for a change. Being held hostage to always needing to have "science" has held back technology development for years. We need to fly something and check it out, for real, and not in PowerPoint visuals
• build a reasonably robust "nose" for the spacecraft. After the Mars drop-off, rendezvous withvan asteroid, and nudge it off course in a deliberate, controlled way
• I wont comment on the Ingenuity class helicopters. Just glad to see them!!

 

[Deranged]

It's pointed out in the article, basically all parts are paid for already.

Isn’t that the sort of the mentality that got us the SLS though? I mean, it’s different because a lot of components are already very mostly built in this case but there’s a non trivial integration of the various systems to a functional space craft remaining, no? Even then, there’s a lot riding on the “all components are mostly built” being thrown about in the comments. Is mostly built 99.5% and only final adjustments remain? Or is it the “the final 10% of construction takes 90% of the time” situation?

 

[SinclairZX81]

Is the nuclear power KILOpower (eg. 2x 10kW) or something else?

My question (one of two) as well. There's a quote in the article saying the reactor is "almost built," and the fuel is "almost paid for," but Steven didn't really make clear exactly which reactor program they're building from.

Question 2: The helicopters are "Ingenuity class." Ingenuity communicated with Earth via a relay on Perseverance. These won't have that option, and adding a relay transceiver to the orbital relays is quite the mass hit. Maybe these are "Ingenuity class" in terms of overall configuration, but larger to accommodate a larger transceiver to the orbital relays?

 

[Tactical Finesse]

My question (one of two) as well. There's a quote in the article saying the reactor is "almost built," and the fuel is "almost paid for," but Steven didn't really make clear exactly which reactor program they're building from.

Question 2: The helicopters are "Ingenuity class." Ingenuity communicated with Earth via a relay on Perseverance. These won't have that option, and adding a relay transceiver to the orbital relays is quite the mass hit. Maybe these are "Ingenuity class" in terms of overall configuration, but larger to accommodate a larger transceiver to the orbital relays?

So the thing with this administration is that they really care about the press release much more than the product. The goal is being first to print the news and shape it, rather than the actual policy or goal.

They learned from the Boeing 787. All you need is an airplane shaped object to show and not let anyone get close to look at it and the stock price goes up.

 

[bobbalaram]

My question (one of two) as well. There's a quote in the article saying the reactor is "almost built," and the fuel is "almost paid for," but Steven didn't really make clear exactly which reactor program they're building from.

Question 2: The helicopters are "Ingenuity class." Ingenuity communicated with Earth via a relay on Perseverance. These won't have that option, and adding a relay transceiver to the orbital relays is quite the mass hit. Maybe these are "Ingenuity class" in terms of overall configuration, but larger to accommodate a larger transceiver to the orbital relays?

Jpl has a small to/from orbit radio that fits within the mass capabilities of an ingenuity class helicopters. It was developed subsequent to the Ingenuity effort. If i am not wrong, it may have been in the sample retrieval helicopter design

 

[EllPeaTea]

Yes...but...Not very often. The last major RTG launches were Cassini and New Horizons....NH kind of was a non-issue, I vaguely remember people upset about RTGs being used by Cassini during its launch.

EDIT: AFAIK the RTGs that have contaminated people back on Earth...were all terrestrial and not space probes...I thought Lia was one, but it was a Soviet orphan that was always terrestrial

Curiosity and Perseverance rovers use RTGs and were launched after New Horizons.

One of the issues with Cassini (and before that, Galileo) was that they had Earth flybys for gravity assists, and people were worried a trajectory error could result in an RTG burning up in the earth’s atmosphere.

 

[Argent Claim]

Comments from a retired engineer:

• having a launch date driven by the planets is a wonderful forcing function. Can't kick the can down interplanetary roads. It will be the best thing that happens to the propulsion, spacecraft and reactor teams

Launch dates for interplanetary missions have always had this restriction. Rushing to meet the nearest window is simply reckless, especially since you can't always diagnose (let alone fix) problems experienced on an interplanetary probe. A failure with a nuclear reactor before leaving Earth orbit is also a huge public relations nightmare to best be avoided.

• please, let science take a back seat for a change. Being held hostage to always needing to have "science" has held back technology development for years. We need to fly something and check it out, for real, and not in PowerPoint visuals

You aren't going to, "check it out" without scientists who utilize and typically design the very instruments needed for just that. There is also very little point in sending anything into space unless it does something besides simply get there. Without the demands of scientists providing a reason to go out and explore, there's no reason to develop proverbial bridges to nowhere. The demands of scientists are in fact what often drive engineering advancements in the first place simply to fulfill them.

• build a reasonably robust "nose" for the spacecraft. After the Mars drop-off, rendezvous withvan asteroid, and nudge it off course in a deliberate, controlled way

Why?

• I wont comment on the Ingenuity class helicopters. Just glad to see them!!

Deploying them is a lot easier said than done. Their inclusion alone makes meeting the next launch window unrealistic as Ingenuity was not meant to be deployed and operated alone. You will need entirely new equipment to deploy them to the Martian surface and allow them to communicate with NASA.

To be blunt, even if we assume this proposal gets approved by Congress with a realistic budget, there is simply no chance of it launching in two years even if it's just a bunch of off the shelf electric thrusters on a miniscule nuclear power plant.

 

[_crane]

Meanwhile in the real world. It's not like a civilian nuclear power plant. Its has the same space constraints as submarine nuclear reactors. They used highly enriche MOX fuel. You do not what that aerosoled landing breathable dust over large areas of Florida.
https://en.wikipedia.org/wiki/Kosmos_954
Musk like hand waving doesn't change facts you don't like

I'm curious as to why you think NASA plans to fit explosives to the reactor to properly aerosolize the fuel. Even an unplanned re-entry or a large scale first stage kaboom will tend more towards chunks than dust.

 

[Star Stuff]

Once it drops copters on Mars, it's going to head back to Earth for next load.

Thas is exactly what needs to happen.

 

[Malmesbury]

Launch dates for interplanetary missions have always had this restriction. Rushing to meet the nearest window is simply reckless, especially since you can't always diagnose (let alone fix) problems experienced on an interplanetary probe. A failure with a nuclear reactor before leaving Earth orbit is also a huge public relations nightmare to best be avoided.


You aren't going to, "check it out" without scientists who utilize and typically design the very instruments needed for just that. There is also very little point in sending anything into space unless it does something besides simply get there. Without the demands of scientists providing a reason to go out and explore, there's no reason to develop proverbial bridges to nowhere. The demands of scientists are in fact what often drive engineering advancements in the first place simply to fulfill them.


Why?


Deploying them is a lot easier said than done. Their inclusion alone makes meeting the next launch window unrealistic as Ingenuity was not meant to be deployed and operated alone. You will need entirely new equipment to deploy them to the Martian surface and allow them to communicate with NASA.

To be blunt, even if we assume this proposal gets approved by Congress with a realistic budget, there is simply no chance of it launching in two years even if it's just a bunch of off the shelf electric thrusters on a miniscule nuclear power plant.

The whole point of this is that for decades, we have had a cycle of

• design nuclear propulsion
• the mission grows to unaffordable
• cancelled
• design nuclear propulsion

….

By flying a mission, you break that cycle.

As part of that, you need to pare down what it is demonstrating to the implementable.

 

[Komarov]

Égalité might sound too French

Liberté it is, then. The correct translation plus close enough to a loanword that English speakers could understand.

 

[Barleyman]

The scale of the reactor seems about right (40 kW) but reading between the lines of the January 2025 announcement it doesn't look like they're close to the TRL required to be integrating this thing with a spacecraft and launching it in less than 2 years time.

If this is the reactor they're planning to use, it will be an impressive accomplishment to manage it on this timeline!

At least they've been working on the approval with NRC for past six years already, so significant effort has been done on the reactor & generator & control design, even although this would be micro-version of already tiny road-portable reactor. I'd imagine the most time-consuming part would be actually the design of a miniature version of the brayton cycle engine as the reactor itself has no moving parts beyond the rotating reflectors that control power output.

 

[Komarov]

The first manned Lunar surface base will of course be called Trump Station.

It will be called Freedom Station because a certain kind of apparatchik comes standard with very limited imagination.

I mean, they could try Diana Station as a wry acknowledgement of the Artemis project, but I suspect the name sounds too female for the fake machos making the decisions.

(P.S.: Please, no-one tell Rump who Artemis is.)

 

[SinclairZX81]

A high power engine exists in VASIMR. They just need a 250kW flight certified power source to power it. It’s being developed by former NASA astronaut Dr. Diaz-Chang.

ad Astra Variable Specific Impulse Magnetoplasma Rocket

Yeah, it's the 250kw flight-certified power source that the fly in that particular ointment. Awesome engine, no juice in the time available.

 

[Barleyman]

So they're going to launch a flagship level cost mission and just.... throw it away, basically?
Why? There's probably a lot of cool stuff that that budget could be paying for instead of this basically pointless mission that doesn't need the nuclear reactor.

Who says it's flagship cost? Okay, it uses the PPE from gateway, which is no doubt hideously expensive like everything else SLS-adjacent, but that's already spent money.

And the probe is the mission, like Isaacman says, the fission reactor coupled with Ion engine is the hard part and they don't want mission creep to balloon schedules and cost out of hand like always. Invading Mars with aerial drones dropship-style is just a bonus. Having said that, the nuclear reactor should let you run nice powerful comms array, which shouldn't take 5 billion and 20 years to develop.

 

[SinclairZX81]

'Just', 'uncomplicated', and 'not a tech barrier' are doing some heavy lifting here. Why not do the necessary research first to make sure all of that is just as uncomplicated and easy as you say it is?

We've known how to mitigate ionizing radiation since the 1950's. With all the necessary research. The radiation (and how to mitigate it) isn't different because it's "in spaaaaaaaaaaace!" For aerospace applications, what's "different" is usually the mass constraints. When you're talking about piling dirt on a hab, that's a wee bit less of a concern.

Low-to-micro-gravity effects have been researched on the ISS for the last 25 years, and on the Shuttle before that.