July

On July 20, 1969, man first set foot on another planet. This "giant leap for man-

kind" represented one of the greatest engineering achievements of all time. This ar- ticle and the others in this document describe and discuss some of the varied tasks

behind this achievement.

NASA

planning,

design

Manned

flight

principles,

Spacecraft Center:

crew operations,

the all-important

spacecraft

and flight

spacecraft

development,

operations. We

test activities,

mission design and mission

will describe spacecraft

and the discipline that

We will limit ourselves to those tasks that were the direct responsibility of the

evolved in the control of spacecraft changes and the closeout of spacecraft anomalies; and we will discuss how we determined the best series of flights to lead to a lunar

landing at the earliest possible time, how these flights were planned in detail, the

techniques used in establishing flight procedures and carrying out flight operations,

and, finally, crew training and simulation activities -- the activities that led to a per-

fect flight execution by the astronauts.

In short, we will describe three of the basic ingredients of the success of Apollo:

spacecraft hardware that is most reliable, flight missions that are extremely well

planned and executed, and flight crews that are superbly trained and skilled. (We will

not discuss two equally important aspects of Apollo -- the launch vehicles and launch

operations. These elements, the responsibility of the NASA Marshall Space Flight

Center and the NASA Kennedy Space Center, go beyond the scope of this series of

articles. )

changes,

Four

The

aspects of

and interpretation

principles of

SPACECRAFT DEVELOPMENT

spacecraft development stand out: design, test,

of discrepancies. We can begin with them.

A new in-space economy is emerging, with the nascent industries including orbital transfer vehicles, commercial space stations, in-space manufacturing, satellite servicing, commercial rovers, and many more.

Factories in Space is the most extensive online database of commercial entities operating in the in-space economy, space resources, and in-space manufacturing sectors. Launched in 2018, the directory includes 825 entries, more than double from the previous version presented at IAC in 2021. Seraphim recently published their version of the in-space economy ecosystem map, further indicating growth and interest in this field

Graphene nanoelectronics potential was limited by the lack of an intrinsic bandgap[1] and attempts to tailor a bandgap either by quantum confinement or by chemical functionalization failed to produce a semiconductor with a large enough band gap and a sufficient mobility. It is well known that by evaporating silicon from commercial electronics grade silicon carbide crystals an epitaxial graphene layer forms on the surfaces [2]. The first epigraphene layer to form on the silicon terminated face, known as the buffer layer, is insulating. It is chemically bonded to the SiC and spectroscopic measurements [3] have identified semiconducting signatures on the microscopic domains. However, the bonding to the SiC is disordered and the mobilities are small. Here we demonstrate a quasi-equilibrium annealing method that produces macroscopic atomically flat terraces covered with a well ordered epigraphene buffer layer that has a 0.6 eV bandgap. Room temperature mobilities exceed 5000 cm2/Vs which is much larger than silicon and 20 times larger than the phonon scattering imposed limit of current 2D semiconductors. Critical for nanotechnology, its lattice is aligned with the SiC substrate, it is chemically, mechanically, and thermally robust, and it can be conventionally patterned and seamlessly connected to semimetallic epigraphene making semiconducting epigraphene ideally suited for nanoelectronics.