Mars TransferIn 2022, SpaceX intends to land humans on Mars using its new rocket, BFR, and interplanetary spacecraft , BFS. To prepare for this mission, an unmanned BFS will fly to Mars in 2020, validating the life support, EDL and in situ propellant production systems essential to the success of the 2022 manned mission. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get an original essayIn order to simulate the worst-case survival need, BFS will be launched on a longer transfer trajectory than a typical manned BFS mission. This longer trajectory, in addition to ensuring that BFS can withstand a longer period of interplanetary flight than expected, will also reduce delta-V requirements, further saving fuel for Mars EDL. Increasing fuel margins for EDL helps ensure that experiments critical to the 2022 manned mission, such as the Sabatier reactor that will produce liquid methane for BFS's return to Earth, will reach the surface safely. To determine an optimal launch date within the 2020 transfer window, departures starting on 1 April 2020 and extending to [date] and arrivals starting on 28 September 2020 and ending on [date] were considered. Additionally, trajectories were constrained to require no more than 500 and no less than 45 days of transfer time between Earth and Mars. Based on the resulting pork chop plot, shown in Figure 1, a nominal human mission in the 2020 window would depart 100 days after April. 1, on July 10, 2020, and will arrive on Mars 90 days after September 28, on December 27, 2020. These dates were chosen to give a nominal flight duration of 170 days while minimizing the delta-V required for interplanetary transfer . During the 2020 test launch, this trajectory will be modified to arrive 120 days after the start of the transfer window, on January 26, 2021. The launch date of July 10, 2020 will not be modified compared to the nominal inhabited trajectory. This transfer will result in a hyperbolic excess speed of 2.9012 km/s and a C3 of 13.7455 km2/s2. The flight time for this trajectory will be 200 days, which will allow verification of life support systems to an acceptable margin above a nominal trajectory. Table 1 shows these values ​​compared to those for a nominal manned flight in 2020. The Lambert solver returns a tm of 1 for the nominal manned and unmanned test trajectories, indicating that both are short-range transfers . The J2 Disturbance J2 Disturbance is caused by the asphericity of the Earth. The Earth, like most rotating bodies, has a bulge around its equator that creates gravitational effects on orbiting satellites. This effect is manifested by a progressive shift in the longitude of the ascending node and an argument of the periapsis of an orbit. This is shown in the attached Matlab graphs, where the longitude of the ascending node of orbit A1 can be seen decreasing linearly over the course of four days. This is different from a two-body hypothesis, where the longitude of the ascending node would remain constant over time. The rates of change of ascending node longitude and periapsis argument vary depending on other orbital elements. The plots of the two rates of change show that the rate of apsidal and nodal regression approaches zero as the inclination approaches 90°. This is clear in the nodal regression plot, but is obscured in the apsidal rotation plot by a peak. Orbits B3, B4 and B5 cross an argument of 0° of periapsis due to their orbital disturbances – resulting in.