NASA a and Musk's Plan to Mars (and Back)

choi

You know English grammar: "A's and B's books: means differently from "A and B's books." The latter means that A and B co-owns the books.

I. Kenneth Chang, Mars Will Be the Top Mission, Trump's Nominee to Lead NASA Says. New York Times, Apr 10, 2025, at page A19
(Jared Isaacman)

choi

II. Space exploration | Don't Stop Him Now.  Musk will not get humans to Mars before Donald Trump leaves office. But he may reshape America's space programme in profound and long-lasting ways.  The Economist, Mar 29, 2025, at page 72.

Note:
(1) spacecraft
https://en.wikipedia.org/wiki/Spacecraft
(introduction: "Humanity has achieved space flight, but only a few nations have the technology for orbital launches: Russia (Roscosmos[2]), the United States (NASA[3]), the member states of the European Space Agency,[4] Japan (JAXA[5]), China (CNSA[6]), India (ISRO[7]), Taiwan (TSA[8][9][10]), Israel (ISA), Iran (ISA), and North Korea (NADA). In addition, several private companies have developed or are developing the technology for orbital launches independently from government agencies. Two prominent examples of such companies are SpaceX and Blue Origin")


(2) Newton's Third Law of Motion applies in vacuum.
(a) in weightless vacuum in general:
(i) Learning to Live with the Laws of Motion. European Space Agency, undated
https://www.esa.int/Science_Expl ... _the_laws_of_motion
("if you can accelerate your bullet -- or more usefully, your spacecraft -- to a speed of around 8 km/s, it will never finish its trajectory. Instead, it will orbit the Earth in a state of perpetual free fall. Its velocity exactly cancels the pull of the Earth's gravity" and the object -- bullet or apacecraft -- is in earth's orbit)
(A) "8 km/s is significantly less than the 11.2 from earth (imagine the earth is stationary, not rotating) is 11.2 km/s. This is because at the earth's orbit, the gravity is less than on the sea level. See
escape velocity
https://en.wikipedia.org/wiki/Escape_velocity
([more correctly:] escape speed; "with the definitional value for standard gravity of 9.80665 m/s2 (32.1740 ft/s2),[6] the escape velocity from Earth is 11.186 km/s" / section 2 Scenarios, section 2.2 From a rotating body: this is why ESA launches in French Guiana (see next) + section 2.3 Practical considerations)
(B) European Space Agency
https://en.wikipedia.org/wiki/European_Space_Agency
(1975- ; acronym: ESA; table: Headquarters  Paris)
, whose latest launch vehicle is Ariane 6: "First Ariane 6 launched: 9 July 2024 from Europe's Spaceport in French Guiana," per ESA website.
(C) Ariane
https://www.collinsdictionary.com/us/dictionary/english/ariane
(pronunciation)
is French spelling of a princess in Greek mythology.
(b) in rocket propulsion:
(i) thrust
https://en.wikipedia.org/wiki/Thrust
("Thrust is a reaction force described quantitatively by Newton's third law")
Heed both "reaction" and "force."
(ii)
(A) Rocket Thrust, Glenn Research Center, NASA, undated
https://www.grc.nasa.gov/www/k-1 ... irplane/rockth.html
("This thrust equation works for both liquid and solid rocket engines [on earth and in space]. * * * Since the oxidizer is carried on board the rocket, rockets can generate thrust in a vacuum where there is no other source of oxygen. That's why a rocket will work in space, where there is no surrounding air, and a gas turbine or propeller will not work. Jets and propellers rely on the atmosphere to provide the oxygen")
(B) Glenn Research Center
https://en.wikipedia.org/wiki/Glenn_Research_Center

(3)
(a)
(i) spacecraft propulsion
https://en.wikipedia.org/wiki/Spacecraft_propulsion
("Spacecraft propulsion is any method used to accelerate spacecraft and artificial satellites. In-space propulsion exclusively deals with propulsion systems used in the vacuum of space and should not be confused with space launch or atmospheric entry")
(ii) But there is an additional term to contend with: deep space propulsion.

Salgado  MCV, Belderrain  MCN, Devezas  TC, Space  Propulsion: a Survey Study About Actual and Future Technologies. J Aerosp Tecnol Manag, 10: e111 (2018; review).
https://jatm.com.br/jatm/article/view/829/687

(A) The publisher of Journal of Aerospace Technology and Management (JATM; 2009- ) is Instituto de Aeronáutica e Espaço (IAE), Brazil.
(B) Quote:

• Abstract: Current Space Launch Vehicles use chemical reactions (solid and liquid propellants) to achieve sufficient thrust to launch artifacts and humans into space. Propulsion technologies can be framed in three different categories: 'escape propulsion,' 'in-space propulsion,' and 'deep space propulsion.' The launch vehicles currently used for “escape propulsion” rely on mature technologies, which experienced only small incremental improvements over the last five decades, and breakthroughs for this kind of propulsion are not foreseen for the next two decades.

• Introduction:

at page 02/23: page number is at upper left or right corner): "Space propulsion technologies can be framed in three different categories: “escape propulsion” (from Earth surface to orbit), “in-space propulsion” (in orbit), and “deep space propulsion” (from orbit to outer space). The launch vehicles currently used for 'escape propulsion' rely on very mature technologies, but for 'in-space' and 'deep space' vehicles, there are prospects of significant technological advances. According to Long (2012), chemical fuels are clearly inadequate for interstellar missions and new methods of propelling a vehicle through space should be invented. * * * Recently, Johnson (2012) noted that 'in-space' propulsion begins where the launch vehicle upper stage leaves off ['leaves off' meaning 'ends'] * * *

at page 04/23: Figure 2 on "propulsion technologies"

• Deep Space Propulsion:
at page 09/23: "For 'deep space' missions, such as missions to the outer planets of our solar system, the propellant energy and mass requirements tend to be higher than for missions closer to Earth due to the higher spacecraft speed required to reduce mission duration, lower solar intensity, maneuvers involved and the generally heavier spacecraft. In many missions, natural orbits around the sun, called Hohmann trajectories, are used to send the spacecrafts from Earth orbit to target orbit with a minimum expenditure of energy. Planet movement and gravity are also used to accelerate the spacecraft without consuming energy. However, these missions last a long time. Future manned mission duration must be kept to a minimum and the most direct path is to be adopted. This requires higher energy consumption and propellant quantity. With chemical rockets and existing technologies, these missions are almost impossible.

(b) Hohmann transfer orbit
https://en.wikipedia.org/wiki/Hohmann_transfer_orbit
(i) How to view the top figure: The red and green arcs are orbits of two planets The yellow arc is that of a spacecraft.
(ii) Quote:

"The Hohmann maneuver often uses the lowest possible amount of impulse (which consumes a proportional amount of delta-v, and hence propellant) to accomplish the transfer, but requires a relatively longer travel time than higher-impulse transfers [to achieve direct. or beeline, move from earth to Mars, say].

"Space missions using a Hohmann transfer must wait for this required alignment to occur, which opens a launch window. For a mission between Earth and Mars, for example, these launch windows occur every 26 months. A Hohmann transfer orbit also determines a fixed time required to travel between the starting and destination points; for an Earth-Mars journey this travel time is about 9 months.

"Due to the reversibility of orbits, a similar Hohmann transfer orbit can be used to bring a spacecraft from a higher orbit into a lower one; in this case, the spacecraft's engine is fired in the opposite direction to its current path, slowing the spacecraft and lowering the periapsis of the elliptical transfer orbit to the altitude of the lower target orbit [or destination]. The engine is then fired again at the lower distance to slow the spacecraft into the lower circular orbit  [or destination].


(4) from the Economist article: "In October the company [SpaceX] astonished the world by catching a returning Super Heavy booster in mid-air. The following month it brought down a Starship from its suborbital passage through space, and the fires of atmospheric re-entry, to a precisely controlled splashdown in the Indian Ocean.
(a) "In October the company astonished the world by catching a returning Super Heavy booster in mid-air.  The following month it brought down a Starship from its suborbital passage * * *"

SpaceX Super Heavy
https://en.wikipedia.org/wiki/SpaceX_Super_Heavy
("Super Heavy is the reusable first stage of the SpaceX Starship"/ top photo whose caption reads: "Super Heavy Booster 12 approaching the tower during Starship flight test 5 on October 13, 2024."
with a pair of chopsticks (at the top, the pair of similar-looking arms at the bottom, or close to the ground, are "stabilizers") we had seen. SpaceX called this a "catch."

section 4 Development, section 4.3 Integrated flight tests (2023- ): Compare section 4.3.5 Fifth flight test (catch of B12 where B stands for "booster" or first stage; "ship" is MORE than booster) AND section 4.3.6 Sixth flight test: "Flight 6 was flown on 19 November 2024, with a water landing of the booster [Booster 13] rather than a catch")
HOWEVER, if you click the link for 6th flight test, you will learn that Ship 31 upper stage and Booster 13 both landed in Oceans. the former in Indian Ocean (far away from home) and the latter in Gulf of Mexico closer to home or launch pad. See next.
(b) Starship flight test 6
https://en.wikipedia.org/wiki/Starship_flight_test_6
(section 2 Mission profile, section 2.1 Flight timeline is a table: +00:06:56: on yellow background is the text: "Partial failure[:] Catch aborted due to failed tower health check, booster diverted to splashdown in Gulf of Mexico

To the right of the table is the bottom photo showing Booster 13 into the ocean (and can not be reused).

(5) At last, the fuel tank contemplated in the second illustration of this article is not explained, as to the nature of the fuel: chemical or something else )and therefore under development, not ready).