Pipcard

I tried out Dyson Sphere Program in 2021 for about 30 hours (might return to it one day). I don’t hate it, but I wish there was a game like it but with more emphasis on launch and orbital infrastructure, instead of conveyor belt spaghetti and producing energon cubes for research. Like launching components of O’Neill cylinders with mass drivers on the Moon or asteroids, or disassembling Mercury to make a Dyson swarm.

Comparison of interplanetary ships (Mars, Venus, Vesta and Ceres)

Japanese Crewed Ceres Mission "Inari" (2043-2048)

2047-08-16 - The Inari crew transport leaves Ceres 2048-12-20 - Returning to Earth

2047-08-10 - The crew of the Inari mission only stayed six months on Ceres, due to the different launch windows from Vesta. The next launch windows were 4 months from now (requiring an additional 1000 m/s in Delta-v for the Ceres-Earth transfer), or waiting another one-and-a-half years. After docking with the transport, they began their return trip on August 16. 2047-08-16 - Leaving Ceres 2048-12-20 - After over another year in space, Kei Nagase, Takahide Ishikawa, and Hikari Tsuchiyama undocked in the Earth Arrival Vehicle, slowing down by 4900 m/s before entering Earth's atmosphere and splashing down in the Caribbean Sea.

2047-08-06 - The Koujin Vesta crew transport returned to Earth after a journey of over 3 years. The Earth Arrival Vehicle undocked and decelerated by over 4000 m/s using its LE-N engine. After the capsule separated, the nuclear stage boosted out of the way to avoid entering Earth's atmosphere. Heisuke Koishi, Takeshi Kakoi, and Rena Minase splashed down off the western coast of Borneo in Indonesia.

2047-02-07 - Arrival of the Inari crew transport at Ceres 2047-02-10 - Landing in Occator Crater (right to left: Kei Nagase, Takahide Ishikawa, and Hikari Tsuchiyama)

2047-02-07 - After 1 year and 2 months, the Inari crew transport finally arrived at Ceres, slowing down by over 5000 m/s to meet up with the landing module in a 90 km orbit on February 9. On February 10, the powered descent and landing commenced. Kei Nagase, Takahide Ishikawa, and Hikari Tsuchiyama became the first Japanese astronauts to set foot on the largest object in the asteroid belt. Over the next 6 months (a shorter stay due to transfer windows), they would live in the surface base on Occator Crater. On February 15, they explored the crater in the Ceres Cruiser, driving 20 km south and up the central hill. Occator was known for its bright spots, which were made of salt deposits (mostly sodium carbonate) left behind when briny underground water rose to the surface through cryovolcanism. The water had already sublimated into the vacuum of space, and the process could still be happening today.

2045-12-24 - The crew of the Koujin Vesta mission explore Marcia Crater 2046-09-20 - Leaving Vesta 2046-09-26

2045-12-24 - Heisuke Koishi, Rena Minase, and Takeshi Kakoi boarded the Vesta Cruiser and drove over 10 km to the east in Marcia Crater, which was the largest and youngest of the three "snowman craters," the others being Calpurnia and Minucia. The surface of the crater is mostly made of basaltic rock (known as eucrite) and is rich in iron. Due to the low gravity, wheel traction was also lower, and the motor was set to 5% of normal power to avoid excess torque. Cybernetic implants (developed in the 2030s) also assisted the crew physiologically while staying in 2% of Earth's gravity.* *inspired by The Orbital Children 2046-09-20 - After nine months, the three crew members left the surface habitat, using the small landing module to easily launch back into orbit and dock with the interplanetary transport. On September 26, the transport ignited its single LE-N2 engine to return to Earth (~4800 m/s). 2046-09-26 - Departure from Vesta

Not the real-life Mitsubishi.

2045-12-13 - Inari Ceres transport fully assembled, with Kei Nagase, Takahide Ishikawa, and Hikari Tsuchiyama on board 2045-12-22 - Leaving Earth

2045-07-24 - Several months before the Koujin mission landed people on Vesta, construction of the Inari Ceres transport had already begun. 2045-12-13 - After assembly and refueling, the crew of the Inari mission lifted off. Kei Nagase, Takahide Ishikawa, and Hikari Tsuchiyama docked to the massive vessel. On December 21, the spacecraft began its two-part transfer burn to Ceres, to arrive in February 2047.

2045-12-14 - Arrival of the Koujin crew transport at Vesta 2045-12-18 - Landing in Marcia Crater (right to left: Heisuke Koishi, Takeshi Kakoi, and Rena Minase)

2045-12-14 - The Koujin crew transport arrived at Vesta. The last of the Earth Departure Stage's fuel was used to brake about 200 m/s, then detached. The Asteroid Orbit Stage burned for over 4500 m/s of Delta-v, making several maneuvers to intercept the Landing Module in low Vesta orbit (90 km) on December 17. Once it got close, the lander performed an automated docking with the transport. Heisuke Koishi, Takeshi Kakoi, and Rena Minase boarded the lander, which undocked and de-orbited using five LEROS-4 engines (1.3 kN each) to land in Marcia Crater on December 18. After planting the flag, the crew made long, floating strides in the low gravity to the Habitation Module (over 100 m away), which they would stay in for over 9 months. At the same time, the Inari mission was getting ready to send another three astronauts to Ceres.

2044-01-18 - The Inari habitat module arrives at Ceres

2045-01-12 - Three relay satellites (DRTS-X13 to15) inserted into a 9-hour stationary orbit over 720 km above Ceres. They arrived in their final positions on January 15. [Due to underestimations of fuel by MechJeb during orbital insertion at Ceres (it assumed that the satellites would detach prior to insertion), the mission was redesigned / retconned. The core diameter is now 6 m instead of 5, with a total mass of 68 t, and is launched by an H-Z 102L rocket instead of a Zeta.] 2045-01-18 - The Inari habitat and landing modules arrived at Ceres, entering a low orbit between 80 and 90 km on the next day and using up a total of 5900 m/s of Delta-v. The habitat landed in Occator Crater on January 20 while the crew lander would remain in orbit until 2047.

2044-06-15 - Koujin Vesta crew transport in Earth orbit 2044-06-21 - Leaving for Vesta

2044-02-14 - An H-Z 122XL rocket takes off with the first components of the Koujin Vesta crew transport, the Earth Return Stage and Asteroid Orbit Stage, to a 400 km parking orbit. The stages have a diameter of 13.9 m and are launched partially fueled. 2044-03-09 - (H-Z 122XL) The central Earth Departure Stage launches and docks to the rear of the AOS using a new annular docking ring. 2044-04-02 - (H-Z 122XL) The first Earth Departure Stage Booster, which docks to the side of the EDS. Two pairs of docking ports are used for stability. 2044-04-27 - (H-Z 122XL) The second Earth Departure Stage Booster, which docks to the other side. The boosters are designed to remain attached to the central EDS (and not separate). 2044-05-20 - (H-Z 122XL) The Tanker-L, which mostly refuels the transport vehicle with liquid hydrogen but not completely [as I discovered]. 2044-06-01 - (H-Z 104XL) The Tanker-S, a shorter version which does the rest of the refueling. Undocking of the tankers is performed shortly after. 2044-06-14 - (H-Z 102L) The transport habitat (with 50 tonnes of radiation shielding) and Earth Arrival Vehicle launch with three astronauts: Heisuke Koishi, Rena Minase, and Takeshi Kakoi. Over a day later, it docks to the front of the ERS and inflates the 25 m centrifugal gravity ring. 2044-06-21 - Starting with a mass of 3650 tonnes, the Koujin Vesta transport leaves Earth over a series of two burns (total ~4800 m/s). It will reach Vesta in December 2045, coinciding with the Inari crew transport's departure for Ceres.

2044-01-09 - Relay satellites and the Koujin habitat module arrive at Vesta

2044-01-09 - Three DRTS relay satellites arrived at Vesta. The LE-N transfer stage braked into an elliptical orbit before transferring to a semi-synchronous equatorial orbit (almost 11 hours) with an altitude of 600 km and jettisoning the satellites, which moved into their triangular positions by January 12. Vesta took just over 5 hours to rotate, but a synchronous orbit of 280 km could not have line-of-sight communications for a trio of satellites. Vesta capture burn Delta-v (in 2044): 5200-5300 m/s 2044-01-11 - The Koujin surface habitat and lander module arrived at Vesta. From an elliptical orbit, it lowered itself down to an 90 km orbit (36 degree inclination), aligned in such a way for the crew to depart to Earth with a minimal change in velocity. The habitat and lander modules deployed their solar panels and were released from the transfer stage. The lander module would remain in orbit for the crew to arrive by the end of 2045, while the habitat made its descent using two RL10 engines, touching down in the middle of Marcia Crater on January 13 (JST) and deploying drills to mine regolith for radiation shielding.

2043-05-22 - Another trio of relay satellites was launched to Ceres. This time, launching in full daylight. Earth-Ceres transfer burn Delta-v (in 2043): ~5000 m/s [edit: Due to underestimations of fuel by MechJeb during orbital insertion at Ceres (it assumed that the satellites would detach prior to insertion), the mission was redesigned / retconned. The core diameter is now 6 m instead of 5, with a total mass of 68 t, and is launched by an H-Z 102L rocket instead of a Zeta.] 2043-05-28 - The "Inari" mission to Ceres began with the launch of the surface habitat and landing modules. After Trans-Ceres Injection, the first nuclear transfer stage ran of fuel and was jettisoned early. It would arrive at Ceres in January 2045, about 1 year after the arrival of the Koujin habitat at Vesta.

[JAXA+] 2043-01-03 - An H-Z 122XL rocket launches the surface habitat and lander of the "Koujin" mission to Vesta. This will be followed by the "Inari" mission to Ceres.

In the 2040s, JAXA+ planned to send two crewed missions to the Asteroid Belt between Mars and Jupiter. The Koujin mission (named after the Japanese god of the hearth and kitchen) would go to Vesta, while the Inari mission (named after the Japanese god of rice, agriculture, and prosperity) would go to Ceres. Both missions would use identical hardware, the habitats and landers sent first in 2043, followed by the crewed transports in 2044 and 2045. This would be the first use of nuclear thermal propulsion (NTP) on a mission. Nuclear power was considered controversial in Japan after the 2011 Tohoku earthquake and tsunami, leading to the meltdown of the Fukushima power plant . However, by the 2020s, Japan was restarting its nuclear plants. There was still some reluctance to utilize nuclear power* unless it was necessary or practical, such as powering a base for long lunar nights. As JAXA+ started to aim beyond the inner solar system, nuclear energy would be needed for efficient engines (about twice the specific impulse of chemical propulsion) and powering spacecraft where sunlight was weak. Two engines were developed: the small LE-N engine (based on the SNTP-PFE100, 245.2 kN of thrust) and the massive LE-N2 (based on the NERVA II, 867 kN of thrust). The engine designs were modified to use low enriched uranium (LEU)**, which could not be used for nuclear weapons (the mythological deity Koujin also represented "violent forces that are turned toward the betterment of humankind"). *As a side note, sentiment against nuclear power after Fukushima led to the building of more coal plants instead of renewables (which are land-constrained) **I do not know how that would affect performance The NTP engines used pure liquid hydrogen instead of hydrolox, meaning less dense and much larger propellant tanks (from 10 to 13.9 m diameter). Each mission would launch 7 rockets mostly consisting of the H-Z 122XL, a variant using a single extended core stage, two liquid and two solid rocket boosters, and an extra large fairing (19 m diameter) to accommodate the larger stages. It would be able to lift between 750 to 800 tonnes to low Earth orbit. The interplanetary transport habitat launched by the H-Z 102L had a larger 25 m centrifuge ring, able to generate 0.5 Gs. The crew would primarily live in the rigid sections comprising one-fourth of the inflatable ring, surrounded by a total of 50 tonnes of radiation shielding to reduce exposure to cosmic rays. The heavy shielding would result in the transport weighing over 3600 tonnes, while the surface habitat and transfer stages only weighed 760 tonnes. (note: I had to change the Kerbalism config files to make the ring shieldable, and reduce the surface area for shielding) edit 2023-01-23: I underestimated the amount of hydrogen needed for refueling, so I have revised the mission plan with one more tanker launch. 2042-12-29 - A Zeta rocket (with a 9 m wide fairing) launched from Uchinoura Space Center with three relay satellites to Vesta. Each had a mass of about 900 kg. The 5 m nuclear stage used a single LE-N engine and was almost 50 tonnes, and had drop tanks to increase maximum Delta-v. A distant flyby of the Moon occurred less than a day after launch. Earth-Vesta transfer burn Delta-v (c. 2043): ~4300 m/s 2043-01-05 - An H-Z 122XL launched the Koujin surface habitat and lander to Vesta. The first nuclear stage used two LE-N2 engines, followed by a single LE-N2. Both the habitat and relay satellites would reach Vesta in January 2044.

JAXA+ | Japanese Crewed Venus Mission "Ame-no-Uzume" (2037-2040)