My Little Pony: My Little Pony The Martian

"Sorry for being late," Teddy placed the briefcase next to his desk. After sitting down, he looked around at everyone in the room and said, "There is still one week left before the launch day. Please walk me through the process."

"Phoenix will be launched at dawn local time on Sol 551," Venkat began to explain. "At that time, Hermes' orbit will be just past the periphery."

"Just after?" Anne asked, "Wouldn't it be better to rendezvous when Hermes is closest to Mars?"

Venkat shook his head and explained, "Relative to the movement of Mars, Hermes will fly in front of and inside its orbit; the gravity of Mars will slow down Hermes slightly - not enough to enter orbit, but enough to change Hermes' orbit. Cutting into Earth's orbit in the shortest possible time. This part is crucial in the entire maneuver. The remaining propellant of the VASIMR engine carried by Hermes is still enough for Hermes to adjust its orbit to rendezvous with the Phoenix and then change its orbit to fly to the Earth, but the prerequisite for success is that it must After passing the closest point, if they deviate from the original flight plan, they will not be able to return home."

"Unless they can use the Shiny Engine," Mitch muttered, "and we don't want to count on that then."

"Indeed," Venkat agreed, "the twilight corresponding to Schiaparelli's local time is 6:44 pm Houston time. When the MAV takes off, its trajectory will be slightly to the west to offset the rotation of Mars, which is expected to cause us to lose about A speed increase of four hundred meters per second. We calculated that even if seven of the fifteen magic boosters failed during launch, the Phoenix could still successfully complete the rendezvous. The increase to eight would be too much. range.”

"The propulsion time of the magic booster and the first-stage engine is about six minutes. During take-off, the booster will provide an acceleration of three times the G force. After the first-stage engine intervenes, it will increase by 2G. The main engine will reduce thrust and launch. The maximum G value is controlled at 8G. We expected Mark, Dragonfly, and possibly Starlight to faint under this kind of pressure, but Cherry Berry assured us that she, Spitfire, and possibly Fireball. We can all stay awake and stick to our posts under this kind of load. In this way, we will lose some speed gain, but considering the many uncertainties of this launch, we hope that there will be crew members on board who can stay awake to deal with emergencies. ”

"Have you considered the lost speed increment in the calculations related to the magic booster?" Teddy asked, taking notes.

"Yes. We can't be sure when the magic booster will stop. Pony said that they have adjusted the boost spell to run for six minutes under battery power, but this number is not accurate. When the energy is exhausted After that, they will not start the second-stage engine immediately; the Hermes crew will review the Phoenix's flight trajectory at this time and verify that the Phoenix's onboard computer estimates the second-stage propulsion parameters required to establish an orbital rendezvous with Hermes. Only They will ignite after getting confirmation. If everything goes well, the two spacecraft should be in position for docking about fifteen minutes after the Phoenix is ​​launched. Of course, any problems encountered during this process will mean a delay in the rendezvous and docking. ”

"It is also possible that there will be no chance." Bruce Wu's voice came from the loudspeaker. "In the event that the launch accident is serious enough to completely lose the possibility of rendezvous with Hermes, the Phoenix crew will start the flash engine and escape directly back to Earth. If the speed The standard is met, but the flight orbit error is too large to allow normal rendezvous. At this time, the Shining engine can also be used to move the Phoenix with its momentum and regain the opportunity to rendezvous with Hermes."

"Escape from the Earth is a last resort." Venkat took over, "We don't know whether the Shining Engine is reliable for long-term operation, and we only have a very rough estimate of the flight time. Send the Phoenix into a certain The available earth orbit would make us very nervous, and landing would be unthinkable. Moreover, the Phoenix would only carry food for them to last for seven days, and no matter how smooth the journey was, it would normally cost us. For four months, the food reserves on the Hermes plane will definitely last for several months, so we hope they can go to Hermes if possible."

Annie was also busy taking notes on her mobile phone, her fingers flying on the touch screen, "It seems that so many reporters who want to hear a horse say 'warp speed' will be disappointed." She then asked, "What about after the docking? What will happen?”

"The Phoenix will dock with the vehicle docking port of Hermes on its nose." Venkat continued to explain, "Normally the MAV will be abandoned after the crew transfer is completed, but this time we will keep it. Even if Hermes It can still rotate when docked with other vehicles, so we do not need to transfer the Twinkle engine to Hermes. The Twinkle engine control software can adjust the parameters to adapt to the amount of available energy and the mass change of the spacecraft complex. We will try to use the Twinkle engine to accelerate Hermes back to Earth faster and always maintain an effective return orbit, so that even if the Twinkle engine fails midway, Hermes can still return to the original orbit at a low speed."

"The arrival time depends entirely on the performance of the Sparkling engine. If it fails completely, Hermes will continue to fly on the Rich Purnell orbit and return in seven months from now; if it is completely successful, the seven-month time can be shortened To about a little over a month.”

"Wait a minute," Annie interrupted, "Can you explain why the Phoenix only takes a week to reach Earth, but the Hermes takes a whole month, both using the Shining Engine?"

"Mass." Venkat replied, "It seems that even if the Shining Engine is indeed powered by magic, it does not mean that it can ignore all laws of physics. Hermes is larger than the Phoenix, so each micro-jump consumes more energy. To compensate for this difference, the Blink engine can only significantly reduce the number of actions per second, so the overall speed is slower.”

Teddy and Annie both took note of this. "Well," Teddy changed the subject, "I want to go back a little bit. From my understanding, every time they used their boost system, they had to rely on someone on the ground. Pulling a rope triggers some kind of simple switch. However, it is impossible for anyone to stay outside the cabin to pull the rope. Have we found any solution?

"We don't need to think of a solution," Venkat replied, "They figured it out three days ago."

"What is it?"

"It was Tingting's idea. The Sojourner will stay in Schiaparelli. A backup radio from the MAV has been installed on the rover, so that the Sojourner can continue to investigate Schiaparelli after Phoenix leaves. Take advantage of the environment around the station site, take photos and send them back to Earth.”

"So we have to rely on Sojourner to pull the rope?"

"No. Tingting felt that Sojourner's traction was not enough, and she originally did not want to permanently tie the robot to the booster system. They actually used the control panel removed from the Phoenix to build a seesaw. "The sojourner will climb up the panel until it falls to the other side." Venkat gestured at the flipping of the seesaw. "When the end of the panel touches the ground, the two connecting rods will be connected. The metal spikes for the wires, so that the circuit from the battery part of the booster system to the booster itself is all closed at once. The Sojourner's placement is adjusted so that it takes no more than two minutes to drive past the equilibrium point; This means that when the boost force arrives, the first stage engine has already completed ignition, and the thrust can be increased immediately to take off. "