Timeline for Starting refueled in LEO, how much payload could a heat-protected Starship softly land on Mercury after a gravity assist from Venus?
Current License: CC BY-SA 4.0
10 events
| when toggle format | what | by | license | comment | |
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| Jan 22, 2022 at 16:19 | vote | accept | Cornelis | ||
| Jan 21, 2022 at 14:53 | comment | added | BrendanLuke15 | @Cornelis I will put this into an answer to this question where it can be digested better (and maybe some pictures / examples) | |
| Jan 21, 2022 at 14:52 | comment | added | BrendanLuke15 | @Cornelis .... You can use the Venus inbound (leg 1) & outbound (leg 2) $v_{\infty}$ vectors to determine the hyperbolic deflection angle ($2\nu$ in Wikipedia) for the flyby. Using that Wikipedia equation you can then determine the $r_p$ value necessary for the gravity assist flyby to work. Obviously if the $r_p$ is below the planet's surface or in the atmosphere then the gravity assist flyby is not possible. | |
| Jan 21, 2022 at 14:47 | comment | added | BrendanLuke15 | @Cornelis ... If I search in those two matrices for a date when the $v_{\infty}$ are equal then a hyperbolic flyby of Venus could be possible for that set of 3 dates (the chosen Venus flyby date that matches $v_{\infty}$ at Venus for leg 1 & leg 2 will determine the Earth departure & Mercury arrival dates). Most Lambert solvers will give you a $v_{\infty}$ vector (x,y,z components)..... | |
| Jan 21, 2022 at 14:39 | comment | added | BrendanLuke15 | @Cornelis no. For verifying & quantifying the possible gravity assists from Venus I used a Lambert's problem solver to create two 2D matrices containing departure and arrival $v_{\infty}$ values for each 'leg' of the proposed trajectory. In my answer Leg 1 is Earth to Venus and Leg 2 is Venus to Mercury for a total of four 2D matrices. However, two of these matrices contain the same metric, the $v_{\infty}$ at Venus.... | |
| Jan 21, 2022 at 14:19 | comment | added | Cornelis | Did you use the equation v1 = -u1 + 2u2 that's mentioned on en.wikipedia.org/wiki/Gravity_assist#Derivation , and if so, can you give the values of v1,u1 and u2 ? | |
| Jan 21, 2022 at 12:23 | history | edited | BrendanLuke15 | CC BY-SA 4.0 |
clarity in "Launch" costs
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| Jan 21, 2022 at 12:20 | comment | added | BrendanLuke15 | @Cornelis total for MESSENGER is from LEO for an equal comparison with Starship, I will make that clearer (launch probably isn't the right word!) | |
| Jan 21, 2022 at 9:13 | comment | added | Cornelis | Impressive work ! I will need some time to check it, as far as it's possible for me. | |
| Jan 20, 2022 at 23:25 | history | answered | BrendanLuke15 | CC BY-SA 4.0 |