Elon Musk, who founded SpaceX, first presented his goal of enabling Mars colonization in 2001 as a member of the
Mars Society's board of directors. In the 2000s and early 2010s, SpaceX made many concepts for Mars, including
space tugs,
heavy-lift launch vehicles, and
Red Dragon capsules. The company's current plan was first formally proposed at the 2016
International Astronautical Congress alongside a fully-reusable launch vehicle, the
Interplanetary Transport System. Since then, the launch vehicle was renamed to "Starship", and has been in development since. The development program reached multiple milestones in 2024 such as on its
third test flight, it reached its desired trajectory for the first time and on its
fourth flight test, both stages of the vehicle achieved controlled splashdown after launch for the first time. The company has given many estimates of dates of the first human landing on Mars; the most recent discussion of which occurred during a company all hands meeting in April 2024.[2]
SpaceX's early missions to Mars will involve small fleets of
Starship spacecraft, funded by
public–private partnerships.[3]The company hopes that once infrastructure is established on Mars and launch cost is reduced, colonization can begin. The program has been criticized by some people as far-fetched, because of uncertainties regarding its financing[4] and because it primarily addresses transportation to Mars and not the steps that follow.
George Dvorsky writing for Gizmodo characterized Musk's timeline for Martian colonization as "stupendously unreasonable".[5] For reference, Musk's timeline for the colonization of Mars involves a crewed mission as early as 2029 and the development of a self-sustaining colony by 2050.[6]
Some experts, like
Robert Zubrin, support the concept due to the prevalence of water ice in the form of
permafrost and
glaciers on Mars, as well as other
resources like
carbon dioxide and
nitrogen;[7] some are opposed to the concept, believing the planet's lack of both breathable air and protective
magnetosphere to be unacceptable problems.[8] A common sentiment among those opposed to expanding the scope of human civilization to Mars is that humans should focus on solving the problems on Earth before advancing to
extraplanetary colonization.[9]
In October 2012, the company made the first public articulation of plans to develop a fully reusable rocket system with substantially greater capabilities than SpaceX's existing Falcon 9.[10] Later in 2012,[11] the company first mentioned the Mars Colonial Transporter rocket concept in public. It was going to be able to carry 100 people or 100 t (220,000 lb) of cargo to Mars and powered by methane-fueled Raptor engines.[12] Musk referred to this new launch vehicle under the unspecified acronym "MCT",[10] revealed to stand for "Mars Colonial Transporter" in 2013,[13] which would serve
the company's Mars system architecture.[14] SpaceX COO
Gwynne Shotwell gave a potential payload range between 150-200 tons to
low Earth orbit for the planned rocket.[10] For mars missions, the spacecraft would carry up to 100 tonnes (220,000 lb) of passengers and cargo.[15] According to SpaceX engine development head
Tom Mueller, SpaceX could use nine
Raptor engines on a single MCT booster or spacecraft.[16][17] The preliminary design would be at least 10 meters (33 ft) in diameter, and was expected to have up to three cores totaling at least 27 booster engines.[14]
In 2011, SpaceX planned on proposing Red Dragon for the Discovery Mission #13, which would launch in 2022,[20][21][22] but it was not submitted. It was then proposed in 2014 as a low-cost way for NASA to achieve a
Mars sample return by 2021. In the concept, the Red Dragon capsule would be equipped with the system needed to return samples gathered on Mars. NASA did not fund this concept.
In 2016, SpaceX planned on launching two Red Dragon vehicles[23] in 2018,[24][25] with NASA providing technical support instead of funding.[26] However, in 2017, Red Dragon was cancelled, in favor of the much larger
Starship spacecraft.[27]
Program manifest
SpaceX has stated on several occasions aspirational plans to build a crewed base on Mars for an extended surface presence, which it hopes will grow into a self-sufficient
colony.[28][29] A successful colonization, meaning an established human presence on Mars growing over many decades, would ultimately involve many more economic actors than SpaceX.[30][31][32]
Before any people are transported to Mars, a number of cargo missions would be undertaken first in order to transport the requisite
equipment,
habitats and supplies.[33] Equipment that would accompany the early groups would include "machines to produce fertilizer, methane and oxygen from Mars' atmospheric nitrogen and carbon dioxide and the planet's subsurface water ice" as well as construction materials to build transparent domes for crop growth.[34][35]
Musk has made statements on several occasions about aspirational dates for Starship's earliest possible Mars landing,[36] including in 2022, that a mission to Mars could be no earlier than 2029.[37]
Exploration
Musk plans for the first crewed Mars missions to have approximately 12 people, with goals to "build out and troubleshoot the propellant plant and Mars Base Alpha power system" and establish a "rudimentary base." The company plans to
process resources on Mars into fuel for return journeys,[38] and use similar technologies on Earth to create
carbon-neutral propellant.[39]
As early as 2007, Elon Musk stated a personal goal of eventually enabling human exploration and settlement of Mars,[40] although his personal public interest in Mars goes back at least to 2001 at the
Mars Society.[41]: 30–31 SpaceX has stated its goal is to
colonize Mars to ensure the
long-term survival of the human species.[4]
Methane was chosen for the Raptor engines because it is relatively inexpensive, produces a low amount of
soot as compared to other hydrocarbons,[46] and can be
created on Mars from
carbon dioxide from the atmosphere and hydrogen via the
Sabatier reaction.[47] The engine family uses a new
alloy for the main combustion chamber, allowing it to contain 300 bar (4,400 psi) of pressure, the highest of all current engines.[46] In the future, it may be mass-produced[46] and cost about $230,000 per engine or $100 per
kilonewton.[48]
Starship's reusability is expected to reduce launch costs, expanding space access to more payloads and entities.[49] According to
Robert Zubrin,
aerospace engineer and advocate for
human exploration of Mars, Starship's planned lower launch cost could make
space-based economy,
colonization, and
mining practical.[41]: 25, 26 According to Zubrin, lower cost to space may potentially make
space research profitable, allowing major advancements in
medicine,
computers,
material science, and more.[41]: 47, 48 Musk has stated that a Starship orbital launch could eventually cost $2 million, starting at $10 million within 2–3 years and dropping with time.[50]
Colonization
The program aims to send a million people to Mars, using a thousand Starships sent during a
Mars launch window, which occurs approximately every 26 months.[51] Proposed journeys would require 80 to 150 days of transit time,[32] averaging approximately 115 days (for the nine
synodic periods occurring between 2020 and 2037).[52] This plan has been described as 'pure delusion' by
George Dvorsky, writing for Gizmodo,[5] and as a 'dangerous delusion' by Lord
Martin Rees, a British cosmologist/astrophysicist and the
Astronomer Royal of the
United Kingdom.[53] Others like Saul Zimet have expressed strong support for the concept, suggesting the possibility that the technological advancements that could be developed on Mars will come to benefit the whole of Earth.[54]
After the first few windows of crewed Mars landings, Musk has suggested that the number of people who are sent to Mars could be ramped up rapidly. He has stated that
in-situ resource utilization will be critical for establishing a self-sustaining colony, and that SpaceX plans to begin its efforts in advancing that field in "seven to nine years".[55] Current theories for in-situ resource utilization involve harvesting CO2 from the atmosphere and splitting into its raw components. This will involve using the O2 as well as CH4 for fuel production, and specifically the O2 in addition to Nitrogen (the second-most common gas in the Martian atmosphere) for breathing air within habitats.[56]
Reception and feasibility
As of July 2024, SpaceX has not publicly detailed plans for the spacecraft's life-support systems, radiation protection, and in situ resource utilization, which are essential for space colonization.[57]
Law
SpaceX intneds to base the colony governing laws on
self-determination. With a diverse population accommodating everyone legally is thought to be challenging. Altogether international
space law does not see space as free, but rather as the "
province of all mankind".[58]
^
Gwynne Shotwell (March 21, 2014).
Broadcast 2212: Special Edition, interview with Gwynne Shotwell (audio file). The Space Show. Event occurs at 29:45–30:40. 2212. Archived from
the original(mp3) on March 22, 2014. Retrieved March 22, 2014. would have to throw a bunch of stuff before you start putting people there. ... It is a transportation system between Earth and Mars.