The mainland's future manned moon landing and landing on Mars mainly rely on the Long March 9 and the new 921 rocket, and the Long March 9 has now exposed two schemes, one is the bundled 2011 version, and the other is the 2021 version that uses multiple engines in parallel with the N1 rocket and the lower half of the "starship". In addition, like the "Starship", our Long March 9 carrier rocket can also be recycled and reused, but in the way of recycling, there may be some differences.
Two versions of the Long March 9 rocket
The recovery of the first stage of the "Starship", that is, the "Super Heavy", in Musk's words, is the aerial capture of the "Mech Kusla", that is, through the two mechanical arms on the launch tower, holding the returning rocket. More graphically, it is like holding french fries with chopsticks, but this "french fries" weighs 200 tons, and even after running out of fuel, it is a huge weight.
Musk's "Mecha Kusla"
The robotic arm captures a super Heavy rocket in the descending
In fact, it is more like chopsticks sandwiching eggs
There are many technical difficulties in this, such as how to ensure that the "Super Heavy" falls back to the launch platform accurately after completing the launch task? The vector control and positioning technology involved is more difficult than the hundred steps through yang. In addition, when the capture robot arm comes into contact with the rocket arrow body, how to ensure that the strength is just right? Proportionally speaking, the rocket arrow body is "thinner" than the can, and the slightly larger strength of the capture robot arm may "pinch" it.
A capture robotic arm that has been installed in place
Starship recovery method
In addition, Musk's scheme is to achieve the stability of the rocket through the grid wing at the top of the "super heavy", which is on the capture robot arm, which requires that the four grid wings can withstand all the weight of the "super heavy", all the pressure, at the junction of the grid wing and the arrow body, which puts forward extremely high requirements for their material and structural strength.
All the pressure is on the grid wing
Can the little grid wing hold up?
After the Super Heavy rocket stops and turns off, the accuracy is certainly not guaranteed to be 100% aligned with the launch pad. Musk's plan is to attach tracks to the launch tower and capture robotic arm, just like the vertical transfer before the rocket launch, which is completely theoretically and technically feasible. However, the premise is that it can really "catch" the rocket in the landing.
Both the tower and the robotic arm are moved through the tracks
And our Long March 9, in the recovery program can be further than the "super heavy", such as on the basis of capturing the mechanical arm, add a sling and connector driven by a small rocket, capture the mechanical arm to grasp the sling and connector, rather than the arrow body itself, so that you can reduce the probability of force control is not accurate, "pinching" the arrow body.
This recycling scheme is interesting enough
In addition, it can also be used in the form of a double tyre, and the small rocket pulls it to the sides, holds a mechanical arm, and then slowly lowers until the arrow body lands safely. This design is more stable than the landing gear type. When Musk's "Falcon" rocket was recovered, there were many skidding and dumping accidents, because it was not stable enough.
Is this more stable?
Falcon rocket recovery failed
The recycling of the 2011 version of the bundled Long March 9, the outside world is estimated to be the same as the Long March 8R, using the booster and the core level of the overall recovery, the technical details will wait until after the first flight of the Long March 8R to see. Unlike the Long March 8R, whether it is a "super heavy" or a Long March 9, the parts that need to be recovered are too big and too heavy, how to offset their gravitational potential energy? It is several orders of magnitude more difficult than the Long March 8R and the Falcon, so it is necessary to sacrifice such a trick as capturing the mechanical arm.
Long March 8R's overall recycling solution
However, such a toss may only recover part of the cost, and the fuel left for recovery, the lost load, more than worth the loss, perhaps not all rockets need to be recycled and reused, there is a threshold and boundary, involving more complex economic problems outside the technology, need to try out a little.
Are recyclable rockets really the future?