SpaceX
There are many challenges involved in a mission to Mars. What are they and what technology is SpaceX working on to address them?
The concept of sending humans to Mars has been an exciting idea for decades, and the direction of space travel in the 21st century is finally presenting the possibility of actually making that happen. Of course, once everyone let the seriousness of such a journey sink in, the question of feasibility has inevitably come to the table for open discussion with the goal of finding realistic solutions.
It’s interesting enough to simply review the missions of all the Mars hopefuls (Part 1), but now that the reviews are in, it’s the details that are driving the discussion. After all, even the casual observer knows that deep space travel presents challenges such as long-term zero gravity and the ever-popular doom-and-gloom danger of cosmic radiation.
[Say that last one in a loud, booming voice for extra effect.]
Before breaking down any specifics, I want to acknowledge that there’s more than just a twelve-step program to getting to Mars (twelve being the obligatory “go-to” number). It requires an entire infrastructure of capabilities that build upon and support one another. However, I’m taking a leap of faith by assuming that inevitably anyone making a successful trip to Mars will have partnerships in place to tap into such an infrastructure. It’s the larger components of the specific missions that I’m focusing on here.
Outlining the Challenges for a Mission to Mars
Credit: NASA
NASA has a dedicated “Space Technology Mission Directorate” (STMD) charged with developing the capabilities needed to achieve the missions and goals NASA is given.
With the red planet as one of the big missions of the day (meaning Mars obviously, although Pluto has also been determined to be red), there’s no shortage of PowerPoints, panels, and interviews to source for what’s being worked on. I’ll follow their lead for discussion.
Transportation
Falcon 9 launch | Credit: SpaceX
First and foremost, in order to explore Mars, we’ve got to get there and (arguably) back. Depending on the length of stay and mission purpose, the cargo needs are going to play a part in the “how” part of this puzzle piece. Small stuff, no sweat (relative to general space traveler sweat levels). Big stuff? Now we’ve got issues.
Propulsion
Propulsion has been an interesting discussion to watch from the sidelines, mainly due to the debate over the types of systems available versus the types of systems thought to be needed. General mission discussions tend towards a six to eight month flight time each way plus a year and a half or so on the surface, but there are those advocating for shorter flight times to mitigate hazard exposure and reduce cargo needs.
Current rocket fuels can speed things along, but only at the expense of high fuel consumption. Nuclear fusion (and fission) systems are in the works which would theoretically reduce the flight time to Mars to approximately three months, but the timeframe needed to fully develop and test such new technologies isn’t a big crowd pleaser.
The methane-based nature of SpaceX’s Raptor engine for their speculated Mars Colonial Transport doesn’t really lend either way to this debate because using methane is a choice surrounding resource availability rather than power levels. Since methane can be harvested and manufactured on Mars, it reduces the need to carry as much fuel from Earth on missions, thus lowering costs. Methane-based fuel generation is also one of the key parts of the Mars Society’s “Mars Direct” proposal.
Entry, Descent, and Landing
Given the fact that we’ve sent several rovers to Mars already, it might be surprising that getting a craft from orbit to the Martian surface is actually a huge challenge. A quick survey of our recent history certainly makes the case for landing to be a non-issue, so what’s the deal?
Apollo landing module | Credit: NASA
Yes, we land heavy things on Earth all the time, but we do so with an atmosphere about 99% thicker than the one on Mars. The lack of air pressure and wind on Mars means that there isn’t any real air resistance to aid in slowing down a massive descending craft nor is there any wind to tap into for a glider or parachute to be very effective.
What about the moon?
There’s virtually no atmosphere there, either, yet we landed quite a bit of cargo during the Apollo program. That explanation would be gravity. The moon has less than half the gravity that Mars does, which is less than 20% that of Earth. The difference in power required to land a crew module on the moon vs. Mars could maybe be compared to landing a mini Falcon 9 with a micro drone onto a piece of plywood in the middle of a swimming pool versus dropping, say, a child-sized Tesla Model S. Maybe not, but it’s fun to think about. So cute…
In 2012, NASA landed the rover “Curiosity” on the Martian surface using a very complicated parachute-plus-propulsion crane system. The existence of such technology somewhat gives the impression that landing things on Mars is already a solved problem. If what we’re landing is about the mass of a small car, this impression is true, but if we are landing anything significantly larger, such as a capsule carrying humans for example, then the problem is still a problem as larger masses require greater counterforce to slow down their descent.
SpaceX Gives Back
Falcon 9 first stage landing | Credit: SpaceX
SpaceX’s focus on developing propulsive landing systems is aiming to solve the problem of counterforce. This is actually an area where SpaceX is supporting NASA’s Journey to Mars (instead of the other way around) via the data obtained from their Falcon 9 landings to date. One of NASA’s proposed solutions is a “supersonic retropropulsion” system, meaning periodic firing of the engines on a craft to counter the speed resulting from a trip through the (small) Martian atmosphere. To date, NASA hasn’t been able to test this type of technology in an environment similar to what would be encountered on Mars whereas SpaceX has. By studying the results of SpaceX’s Falcon 9 first stage landings, NASA can use the information gathered for their retropropulsive system designs.
Back scratchers, unite!
Crew Systems
Apollo capsule in clean room | Credit: SDASM Archives
The crew ships under development for taking astronauts to Mars have a number of requirements to meet to be successful transports, and from the information available thus far, their progress seems to be moving along swimmingly. SpaceX’s Crew Dragon has been announced with photos and basic details provided, and NASA’s Orion capsule has enjoyed a marketing campaign providing numerous details for quite some time now.
Dragon capsule during hover test | Credit: SpaceX
The primary improvements in both capsule designs over the Apollo age seem to be more room, better heat shields, better software, and glass cockpits (i.e., touch screens). Crew Dragon can also hover (eventually landing) and blast off from its rocket transport in an emergency event. The aesthetics are pretty swank as well. Why isn’t there anything vastly different from what we’ve already done?
If it ain’t broke, don’t fix it.
Crew Cargo & Environmental Systems
Environmental systems and supplies to keep human travelers alive and (mostly) happy have been generally worked out via prior orbital missions, especially on the long-term International Space Station (ISS) ones. However, there are a few added “catches” that a mission to Mars throws in.
ISS | Credit: NASA on The Commons
First, the ISS is able to maintain long-term human crews due to regular cargo resupply missions. The travel distance for Mars-bound astronauts will render such types of delivery schedules unavailable. No cargo deliveries mean carrying all the cargo required for the entire trip, something that generally demands multiple rocket launches for supply assembly before heading out.
Other than the higher expense of multiple launches, this seems to just be a matter of logistics and cost effectiveness rather than capability. SpaceX’s Falcon Heavy was certainly designed with these cargo requirements in mind considering the power packed into its engines.
Second, life support system technology has been developed and advanced over the years on the ISS, but it requires a lot of maintenance to upkeep. Perhaps the life support systems on the new crew capsules will endure for longer than the systems on the ISS as they have the data available to design around, but in the event that upkeep is just a fact of life that can’t be prevented, crews will surely undergo the training to perform repairs as needed as they are now.
As development in the space industry continues, these issues may become minimal. For instance, short-term resupply missions could eventually become available as travel time to Mars decreases with more efficient and powerful propulsion systems. The development of photon propulsion via lasers is ongoing, the goal being to accelerate around 220 pounds of unmanned spacecraft to 25% the speed of light for a three-day trip to Mars. That could almost translate into a sort of Mars-based Amazon Prime. I see what you’re up to, Jeff Bezos!
SpaceX also plans on making regular cargo missions to Mars a bi-annual affair, so as long as supplies and equipment can last for the 26-month(ish) window between launches, it’s Mars-certified.
Zero Gravity Impacts
Astronaut Ed White on a spacewalk | Credit: NASA on The Commons
When astronauts return from long-term zero gravity, their bodies have to acclimate after changes despite attempts to mitigate the effects through exercise regimens. If you’re just going from Earth to space and then Earth again, no big deal really. But going from Earth to space and then Mars? There won’t be a team of medical professionals ready to drag the astronauts out of the capsule and tell them to take it easy for a while.
That’s kind of an amusing image, actually. The Red Dragon capsule lands but everyone inside is all laid out looking like they are badly hungover from the prior night’s club hopping. Throw in some glitter for Instagram? Sorry, I’m digressing…
What exactly are the effects of long-term zero gravity on the human body? According to NASA, muscles (including the heart) can atrophy at a rate of 5% per week, bones at 1% per month, and about 22% of blood volume is lost. These are generally recoverable, but it takes about as long to recover a muscle as it did to lose it, and bone can take two to three years to grow back if it does at all. The lower Mars gravity would probably mean an easier recovery process, but there’s still a process involved and the entire crew is affected. Not even regular exercise can mimic all of the (needed) effects that gravity has on the body.
Space colony concept art | Credit: NASA on The Commons
The concept of using a rotating space craft to mitigate this problem is seen so often in movies and space habitat designs that one might think it’s a “given” that some version of it will be used for Mars travel. In fact, The Mars Society’s “Mars Direct” plan even advocates for a rotating craft which uses the spent upper stage of the rocket as an anchor to spin the crew capsule around for artificial gravity simulation.
Since nothing looked like it would “spin” on the Dragon and Falcon Heavy media releases nor did there seem to be much room for a treadmill, I was really curious about what SpaceX’s answer to long term zero gravity was. From what I’ve read, it isn’t seen as a real problem or “show stopper”, if you will. Again, I’m missing a direct source to cite for any Elon or SpaceX comment on the issue, but from commentary around the web, it seems that the issue has surfaced in public discussions with no particular technology addressed to overcome it.
Perhaps this is one more thing we will see come September when SpaceX’s Mars Colonial Transporter plans are revealed. I can’t imagine that one hundred body-worn, space-traveling colonists wouldn’t be a problem needing to be addressed.
Surface Power
When it comes to any sort of space travel, solar seems to be one of the “go to” choices for power sourcing outside of propulsion. Unfortunately, when it comes to Mars exploration, solar power alone may not be enough. For one thing, Mars receives less than half the sunlight that Earth does, and most of that sunlight is only available in certain regions of the planet such as around the equator. Frequent light-blocking dust storms are also a problem. NASA’s STMD has outlined advanced batteries, regenerative fuel cells, fission nuclear systems, and solar arrays as the choice technologies for development in the area of surface power.
Nuclear power plant | Credit: US National Archives
Now, I admit that I don’t have all the time in the world to watch every Elon Musk video in existence (although I do enjoy the convenience of a YouTube channel with nearly all of them compiled), but I haven’t had much luck finding original sources of either Elon or a SpaceX executive directly commenting on the subject of surface power. I’m sure something is out there either eluding me or that I’ve forgotten I’ve seen.
Crew Dragon uses solar arrays attached to its trunk during flight for power, but the trunk is jettisoned prior to reentry (or entry when talking about Mars). I could make an educated guess based on the connections between Elon Musk and Solar City, Tesla, and the methane-based Raptor engines to presuppose that solar power, advanced batteries, and methane fuel generation are part of SpaceX’s surface power plans, but in the end it’s just a guess. Also, if Raptor is using a methane-based fuel because it can be resourced outside of Earth, I’d imagine that surface power would tie into that same manufacturing capability.
ISS solar panels | Credit: NASA on The Commons
Mars One plans to utilize solar power for its surface power needs, specifically “thin film solar photovoltaic panels”. There isn’t much detail about their required panel size available, only that they should have the ability to be rolled up and transported elsewhere if need be. Finally, as I mentioned previously, the “Mars Direct” plan advocates tapping into fuel generation structures that manufactures a Methane-Oxygen bi-propellant.
Overall, it seems everyone is likely on a similar page regarding power sources – nothing crazy or unheard of, unless you think nuclear anything is too risky.
Coming Up on Countdown to Mars…
Wernher von Braun and Walt Disney | Credit: NASA on The Commons
Cosmic space radiation! There’s so much on this topic, it’s worth an entire piece on its own. Spoiler alert: Elon doesn’t seem to be worried about that issue. Why not?
Also, stay tuned for a (theoretical) discussion on future Martian government…
Did you know that Werner von Braun had a fictional tale of a Martian society wherein the elected Martian leader was called “The Elon”? It’s almost as though he really did take a trip on that Nazi time traveling bell thing…
News
SpaceX’s Starfall just went from secret to storefront
SpaceX now pitches Starfall missions with 1,000 kg payloads, weeks of microgravity, and Starlink connectivity.
SpaceX has put up a dedicated commercial page for Starfall, its disk shaped reentry capsule, laying out for the first time what customers actually get when they book a flight. The page, live at spacex.com/starfall, pitches “affordable, routine access to microgravity” and invites companies to get in touch about flying manufacturing, research or testing payloads.
The specs are short and specific. Each Starfall mission carries up to 1,000 kg of payload, supplies 1 kW of power and connects through an Ethernet interface. Mission length is tailored to the customer, and the payload stays online the entire time through Starlink, which means researchers can pull data from an experiment while it is still in orbit instead of waiting for splashdown.
SpaceX is launching a secret spacecraft that could change how things are made in space
SpaceX is aiming the service at three markets. Biomedical customers are told they can grow stem cell organoids, replacement tissue and layered biomaterials. Pharmaceutical companies are pitched on protein and small molecule drug crystals, which form smaller and more uniform shapes without gravity driven convection. Materials science rounds out the list, with semiconductors and other next generation materials grown in vacuum and microgravity.
The page also makes clear which rocket SpaceX is counting on. “By launching on Starship, Starfall brings a reliable and scalable cadence previously unavailable to the market,” the company wrote, contrasting weeks of continuous microgravity with the seconds offered by drop towers and parabolic flights. No price or first operational flight date is listed.
The commercial push is a sharp turn from how Starfall started. SpaceX said almost nothing about the capsule ahead of its first flight in June, and nearly everything known came from FAA and FCC filings describing a disk about 10.2 feet wide and 2.5 feet tall that can return 2,200 pounds of cargo. By its second flight on the Bandwagon-5 rideshare in October, Starfall was listed by name on the mission page, though SpaceX still did not say what it carried.
Customers appear to be lining up. SpaceX said in its third quarter results that it signed three commercial Starfall missions during the quarter. On the earnings call, President Gwynne Shotwell described the capsule as providing “routine relatively low cost access to microgravity environments for scientific research, including improving our understanding of diseases like cancer and diabetes,” and said the three new missions would fly on Starship.
The branding effort extends past the website. SpaceX added a Starfall T-shirt to its online store on Monday as part of a batch of new merchandise, giving the program a place next to Starship, Starlink and Starshield in the company’s lineup.
The move also puts SpaceX in more direct competition with companies it launches. Varda Space Industries, which has built much of the in-space manufacturing market so far, flew its W-Series 7 capsule on the same Bandwagon-5 mission as Starfall in October. Varda’s capsules are roughly three times smaller than Starfall, and SpaceX controls the ride to orbit for both.
Starfall’s near term cadence depends on Starship. SpaceX is preparing for Flight 15 after completing static fires of Ship 42 and its Super Heavy booster in late October, and is aiming to catch both stages with the launch tower on that flight.
Elon Musk said weeks ago during SpaceX’s third-quarter earnings call that the company’s Grok Bot, its autonomous AI Agent platform, was showing “the fastest growth of a product” that he’d ever seen in his life.
Now, SpaceXSI is scaling back Grok Bot users’ weekly limits, much to the surprise of those who have relied on it to take away monotonous tasks in their lives.
Elon Musk’s terse November 1 reply on X captured a sharp tension in the early days of agentic AI. Responding to a user who asked for a Grok Bot usage reset after hitting 100 percent with four days still left on the weekly cycle, Musk wrote: “The cost of serving Grok Bot was unsustainably high relative to revenue.”
@DogecoinNorway The cost of serving Grok Bot was unsustainably high relative to revenue
— Elon Musk (@elonmusk) November 1, 2026
The post arrived amid a wave of similar complaints from paying subscribers whose meters had jumped unexpectedly toward or to the limit, sometimes overnight and with little corresponding activity. It also stood in clear contrast to statements Musk had made only days and weeks earlier.
On the SpaceX third-quarter earnings call in mid-to-late October, Musk had described Grok Bot in almost the opposite terms. He called it “the fastest growth of a product that I’ve ever seen in my life” and said he had “never seen anything grow this fast.”
Company figures put paid weekly users at roughly 800,000 earlier in the month, more than doubling over the prior period. Daily active users had climbed from under 100,000 in early September to over 600,000 by late October.
Musk emphasized that the product has no free tier and that users appear to be getting real value beyond what they pay. In other remarks, he noted that usage per user was rising rather than declining, the opposite of the usual decay pattern for new software.
Grok Bot, launched around August, functions as an always-available agent with its own persistent cloud computer; it can schedule, research, shop, browse, and execute multi-step workflows even after the user steps away. Access is bundled into X subscription tiers (roughly $30, $100, and $200 per month) and certain Cursor plans, drawing from shared weekly usage pools whose exact sizes have not been publicly detailed.
The economics of that model are what Musk’s November 1 post put in the spotlight. Agentic systems burn far more compute than ordinary chatbot exchanges. Each task can trigger repeated model calls, tool use, web actions, and sustained background work.
When growth is as rapid as Musk celebrated, the absolute compute bill scales quickly even if average revenue per user stays fixed under flat monthly subscriptions. Industry observers noted the opportunity cost as well: the same GPUs can be rented to other AI labs at higher rates.
A simple back-of-the-envelope comparison circulating after the post illustrated the gap: if every reported daily user paid the top tier, annualized subscription revenue would still be modest relative to the scale of compute infrastructure SpaceX is building and leasing to companies like Anthropic.
Some users also reported possible dashboard anomalies around the same period, though Musk’s framing treated the underlying cost-revenue imbalance as the core issue rather than a pure metering glitch.
The juxtaposition is the core of this exchange. Within roughly two weeks of publicly framing Grok Bot as an unprecedented success with strong unit economics and no free tier, Musk acknowledged that serving the same product had become unsustainable relative to the revenue it generates.
For the broader industry, the episode underscores a structural challenge of the agent era: demand is real and growing faster than many expected, yet the cost of fulfilling that demand through always-on, multi-step agents can outrun subscription pricing before companies can adjust limits, introduce metered billing, or raise prices.
Musk’s reply did not promise an immediate reset or higher allowances; it simply stated the constraint. In doing so, it supplied a rare, explicit public data point on the unit economics of a high-profile AI agent just as adoption numbers were still being celebrated as the fastest in Musk’s experience.
The tension between rapid, paid growth and the compute required to deliver it is now on the record.
Elon Musk
Elon Musk calls Earth’s data centers “peanuts” next to what SpaceX is planning in orbit
Elon Musk says SpaceX capex efficiency is underestimated as orbital data centers loom by 2028.
Elon Musk is pushing back on one of the biggest worries hanging over SpaceX stock. In a reply on X on Sunday, Musk said the company’s capital expenditure efficiency is severely underestimated. He was responding to a Milk Road Stocks post citing analyst Kyle Reidhead, who estimates SpaceX will need to spend roughly $470 billion over the next five quarters.
Reidhead built that figure around the target SpaceX set on its third quarter earnings call: 13 gigawatts or more of compute by the end of 2027. In his breakdown, Nvidia captures 83 to 89 percent of the spending. SpaceX ended the quarter with 1.7 GW of nameplate compute and guided to $35 billion to $40 billion in fourth quarter capex, as Teslarati reported.
Musk did not attach a number to his claim, but the earnings call shows the argument. CFO Bret Johnsen said new compute currently pays for itself in under a year at today’s pricing, and Musk said that window could shrink to six months next year. Using that pace, Reidhead argues about $230 billion of the $470 billion could come from operating cash flow and about $60 billion from SpaceX’s roughly $90 billion cash pile, leaving around $180 billion to borrow. Musk confirmed last week that SpaceX had already closed a new $40 billion debt raise to buy GPUs.
The ground buildout is not the end goal. It is what is meant to pay for the move to orbit. Replying on Friday to charts built from Sequoia partner Shaun Maguire’s SpaceX model, Musk wrote that “Terrestrial compute will be peanuts compared to orbital compute,” adding that orbital compute deployed per month “probably exceeds terrestrial around the end of 2028 and then far exceeds it in 2029.”
Maguire’s model shows how steep that path is. It has capex climbing from $88 billion this year to $290 billion in 2027 and $369 billion in 2028, with SpaceX burning $77.8 billion in cash this year and $122.6 billion next year before turning $114.9 billion cash positive in 2028. Musk’s response to the model was, “I think we can do better.”
The orbital half runs through Starmind. SpaceX plans to operate up to 1 million AI satellites flying in clusters of about 10, linked by roughly 10 terabits of bandwidth, with deployment of thousands of units starting as soon as late 2027 out of its Gigasat factory in Bastrop, Texas, according to SpaceX’s space safety page. Musk has said each Starmind spacecraft will carry more than 250 kW of solar power.
Getting there depends on launch volume. Maguire’s model assumes 250 Starship flights in 2028, up from two this year and 38 next year. The nearer test is financial: SpaceX guided to $33 billion to $37 billion in first quarter 2027 revenue, more than double the $14.58 billion it booked in Q3, and Musk reposted that guidance again on Sunday morning.
SpaceX’s Starfall just went from secret to storefront
Grok Bot users hit with weekly limits early, Elon Musk explains what happened
