Search NASA⌕ Search

Engineering topics

Michael Martini

Publications and source records attributed to Michael Martini.

5 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2020

Compass Final Report: Venus Bridge Orbiter and Surface Study (V-BOSS)

The Venus Bridge Orbiter and Surface Study (V-BOSS) Compass concurrent engineering design team study shows that new, high-priority Venus science can be achieved using a linked Orbiter + Surface Element (Lander) mission concept within a $200M cost cap with assumptions. This is feasible through optimizing investment in early technologies and platforms, such as the Long-Lived In-Situ Solar System Explorer (LLISSE), leveraging known and flight-ready technology, and the overall use of simple, small, robust systems in innovative approaches to Venus exploration. This architecture allows a range of science investigations through modification of Orbiter-Lander platforms in this study through choice of other instruments (often sensors), science themes, or operational modes. In particular, a fundamental strength of this approach is to provide science not available in other ways by using simplified architectures including rugged systems operable in-situ on the Venus surface. Such investigations would be pathfinders for more complex, and more expensive, future missions. Additionally, the results of this study can be used to further champion the need, value and return of early investment technology programs for the hard problem of in-situ investigations at Venus.

Venus Bridge↗
NASA NTRSDate not supplied

Mars Opposition Piloted Nuclear Electric Propulsion (NEP)-Chem Vehicle

Many previous studies have examined sending crews to and from Mars. The most economical involved a ‘conjunction’ class whereby the crew spends around 500 days on Mars surface waiting for a ‘cheap’ return. The total mission time results in a mission duration around 3 years. Given the current demonstrated crew maximum of a 1 year stint on ISS, it is interesting to look at reducing that time to only two years, thus reducing risk and minimizing time in the Martian System. In order to meet such a short mission an ‘opposition’ class Mars mission (which includes a Venus flyby) was chosen. The energy required to perform such a mission in only two years (for the 2036 opportunity at least) is about three times that of the 3 year conjunction mission. The rocket equation clearly shows that this mission would then require several times the propellant of the three-year mission unless the Isp of the propulsion system can be increased. Electric propulsion can provide the 3-10x improvement in Isp but even with a nuclear reactor power levels could approach 10 MWe. As an alternative, a smaller reactor (1.5 MWe class) joined together with a chemical stage was found to allow for using each propulsion system to its best advantage: low thrust in interplanetary space and chemical in the gravity wells of Earth and Mars. Indeed, the use of high Isp, low thrust during the interplanetary leg of the journey’s reduced the required capture/departure ∆Vs by 5-10X. Lowering the NEP power also allowed fitting the power system into a single SLS launch – which limited the radiator area to ~ 2500m^2. For the first look a reactor using fuels created by the SP-100 program with a limit of ~1200K was assumed. Starting in the ‘Lunar Gateway’ also allowed for use of commercial tankers to fuel the vehicle in a relative benign place. A top level summary of the mission design, concept of operations, as well as a conceptual point design of the vehicle is described.

Nuclear Electric Propulsion↗
NASA NTRSDate not supplied

Attitude Profile Reference for the Earth Orbit Raising Phase of NASA Gateway’s Co-Manifested Vehicle

As part of NASAs lunar exploration Artemis program, the agency is designing a Gateway to orbit8near the moon and provide long term support of a sustained lunar presence at the moon’s south pole.9The first element launched for the Gateway is the Co-Manifested Vehicle (CMV), comprised of the10Power and Propulsion Element (PPE) and Habitation and Lunar Outpost (HALO). The PPE Mission11Design team of McGuire & et. al (2021) has developed a Design Reference Mission (DRM) trajectory12for CMV’s Earth Orbit Raising (EOR) mission phase, which provides the vehicle’s 3 degrees of freedom13(DoF) trajectory information during the approximately yearlong spiral out from low Earth orbit and14into the lunar near-rectilinear halo orbit (NRHO). In tandem, the PPE GN&C team is developing a15high-fidelity and fine temporal resolution 6DoF model of the CMV spacecrafts GN&C performance16for delivery to the Gateway team; this work acts to bridge the gap between Mission Designs 3DoF17reference and detailed GN&Cs attitude simulation.

Guidance Navigation and Control↗