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Title: Missions To Mars With Starship Could Only Take Three Months

Link: https://science.slashdot.org/story/25/06/05/0...

alternative_right shares a report from Phys.Org: Using conventional
propulsion and low-energy trajectories, it takes six to nine months for
crewed spacecraft to reach Mars. These durations complicate mission design
and technology requirements and raise health and safety concerns since crews
will be exposed to extended periods in microgravity and heightened exposure
to cosmic radiation. Traditionally, mission designers have recommended
nuclear-electric or nuclear-thermal propulsion (NEP/NTP), which could shorten
trips to just 3 months. In a recent study, a UCSB physics researcher
identified two trajectories that could reduce transits to Mars using the
Starship to between 90 and 104 days. The study was authored by Jack Kingdon,
a graduate student researcher in the Physics Department at the University of
California, Santa Barbara (UCSB). He is also a member of the UCSB Weld Lab,
an experimental ultracold atomic physics group that uses quantum degenerate
gases to explore quantum mechanical phenomena. [...] As outlined on its
website, conference presentations, and user manual, the SpaceX mission
architecture consists of six Starships traveling to Mars. Four of these
spacecraft will haul 400 metric tons (440 U.S. tons) of cargo while two will
transport 200 passengers. Based on the Block 2 design, which has a 1,500
metric ton (1,650 U.S. ton) propellant capacity, the crewed Starships will
require 15 tankers to fully refuel in low Earth orbit (LEO). The cargo ships
would require only four, since they would be sent on longer low-energy
trajectories. Once the flotilla arrives at Mars, the Starships will refuel
using propellant created in situ using local carbon dioxide and water ice.
When the return window approaches, one of the crew ships and 3-4 cargo ships
will refuel and then launch into a low Mars orbit (LMO). The cargo ships will
then transfer the majority of their propellant to the crew ship and return to
the surface of Mars. The crew ship would then depart for Earth, and the
process could be repeated for the other crew ship. Kingdon calculated
multiple trajectories using a Lambert Solver, which produces the shortest
elliptical arc in two-body problem equations (aka Lambert's problem). The
first would depart Earth on April 30th, 2033, taking advantage of the 26-
month periodic alignment between Earth and Mars. The transit would last 90
days, with the crew returning to Earth after another 90-day transit by July
2nd, 2035. The second would depart Earth on July 15th, 2035, and return to
Earth after a 104-day transit on December 5th, 2037. As Kingdon explained,
the former trajectory is the most likely to succeed: "The optimal trajectory
is the 2033 trajectory -- it has the lowest fuel requirements for the fastest
transit time. A note that may not be obvious to the layreader is that
Starship can very easily reach Mars in ~3 months -- in fact, it can in any
launch window, over a fairly wide range of trajectories. However, Starship
may impact the Martian atmosphere too fast (although we do not know, and
likely SpaceX don't either actually how fast Starship can hit the Martian
atmosphere and survive). The trajectories discussed are ones that I am
confident Starship will survive." The paper describing the work has been
published in the journal Scientific Reports.

Read more of this story at Slashdot.

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