Tencent science and technology news on March 16, the prototype sn11 of SpaceX, an American space exploration technology company, will try its static ignition test on Tuesday, followed by the company’s fourth high altitude test flight. Sn11 may represent the final test of this phase of the iteration of the starship, and the program is about to enter the next phase of the test, namely the orbital flight test.
After the flight test of sn11, SpaceX will jump directly to sn15, sn16 and sn17 for testing, and test the super heavy rocket prototype bn1 and BN2, and then use SN20 and bn3 for the first orbit launch test. SpaceX’s internal documents show that the company plans to launch in orbit as early as July 1, 2021.
Sn11 is about to launch
Sn11 will be the fourth high altitude test flight of the Starship prototype. While continuing to improve the landing elements of the flight profile, the aircraft has achieved many milestones, including proving the long-term performance and controllability of the Raptor engine in the ascent process, and the stable “belly flip” under the control of its flight surface, which is a very important test flight goal.
At the same time, SpaceX’s facility in boccachica, Texas, is building starship prototypes at a very fast pace to move quickly after each launch and make design adjustments to the prototypes before the next flight. Although SN8 exploded during landing, it completed the rollover maneuver, sn9 did not complete the rollover due to engine problems, Sn10 completed all actions before hard landing, but exploded a few minutes after landing. The solutions to these problems mainly focus on the last few seconds of flight.
It is not clear what improvements SpaceX has made to the flight of sn11, and musk previously said that a number of repair work is in progress. A possible change during sn11 landing is the use of two engines to combat potential thrust losses and to increase redundancy during a trouble free landing. No matter how the flight changes, so far, the ground test activities of sn11 are proceeding as planned, and the verification tests have been completed under normal and low temperature conditions.
Over three tests
After sn11 is launched, SpaceX will bypass sn12, sn13 and sn14 for three tests and start sn15 test directly. Sn15 includes a new thrust hockey design and other improvements, such as the possibility of an additional thermal protection system (TPS) as part of the insulation test plan.
The prototype is currently in mid Bay, waiting to enter the high cabin to install the nose cone. At present, the high cabin is occupied by two large tanks of bn1, the first super heavy rocket prototype. Bn1 is not expected to conduct flight tests, but will be stacked and installed on the sub orbital platform of the Starship for ground tests, including potential static ignition tests. This will provide vital data prior to the BN2 flight test, which has so far found parts waiting to stack.
Bn1 test activities are expected to take place before sn15 enters the launch pad for test flight. Once sn15 is ready, this will mark the beginning of a new test activity that may involve three starship prototypes, followed by sn16 and sn17. SpaceX may no longer produce sn18 and sn19, because these vehicles are no longer necessary. This will match the way that sn12, sn13 and sn14 are scrapped when SpaceX chooses to upgrade from sn11 to sn15.
It is reported that bn1, BN2 and the new starship represent “an iteration of the launch vehicle to improve the design and act as the Pathfinder of production” to help improve the pace of production.
First orbit test
It is worth noting that SpaceX also mentioned the details of its first orbital flight, which is said to involve bn3 and SN20, with the goal of entering orbit as early as July 1. Although this date seems ambitious, less than four months away, it proves SpaceX’s determination to put the spaceship into orbit this year.
However, this is only the internal goal set by SpaceX, and it is very likely that the first orbital launch of the Starship will not be achieved in July. After all, to achieve the above goals, SpaceX needs to overcome many arduous challenges, including completing the initial test of the super heavy rocket booster (possibly including multiple test flights), verifying the upgraded starship design (above sn15), roughly completing the construction of the orbital launch facility, and delivering about 24 Raptor engines that can operate in orbit.
In fact, it’s very difficult to complete any of these major engineering feats alone, and it’s normal to have months of delays in completing all of them. This means that the starship is likely to go into orbit by the end of 2021, meeting the goals repeatedly repeated by SpaceX CEO Elon Musk and President Gwynne shotwell in the past few months.
Even if SN20 is successfully put into orbit, SpaceX may continue to maintain the Starship development mode, just regard the orbit test as another sandbox to continue to test and improve the Starship prototype. Given all the challenges that SpaceX has to address to put the SN20 into orbit, the first orbital launch attempt of the prototype or super heavy rocket is likely to end in failure. Among them, the super heavy rocket is likely to fail in the first hypersonic launch and landing attempt.
Even if the SN20 itself can reach the orbit intact, there are still numerous problems that may lead to its damage. For example, after a 90 minute orbital flight, SN20 can be easily destroyed when entering the atmosphere at orbital speed. In addition, even if the Starship may try to re-enter the atmosphere successfully in some way for the first time, the orbital space flight and re-entry pressure may prevent the Raptor engine from playing a role in the so-called “power flip” and landing process.
That is to say, although SpaceX is focusing on the orbital flight of the starship, it is still a continuation of its ongoing test plan and iterative development process. Although the cost of spaceships that can fly in orbit may be much higher than that of the same kind in orbit, the difference is not big. SpaceX will undoubtedly continue to challenge the limit, even if it loses its prototype, in order to find and repair errors and design defects as soon as possible. (Tencent technology reviser / Jinlu)