请选择 进入手机版 | 继续访问电脑版
四川耍耍网 四川耍耍网首页 科技 查看内容

Mars lander thermal shield reached an important milestone in 2020

2019-5-5 14:49| 发布者: 左二爷| 查看: 263| 评论: 0|来自: 四川耍耍网www.scshua114.com

摘要: According to foreign media reports, an important part of NASA's 2020 Mars program has achieved an important milestone. Its unmanned detector's thermal shield has passed the final static load test in t ...
According to foreign media reports, an important part of NASA's 2020 Mars program has achieved an important milestone. Its unmanned detector's thermal shield has passed the final static load test in the thermal environment it will encounter when entering the Martian atmosphere. The 15-foot(4.5 M) ablation shield, designed and manufactured by Lockheed Martin, is one of the largest components ever.
When the Mars Rover reaches the Red Planet in 2020 on February 18, 2021, it will face the most dangerous stage of the mission -- hitting the atmosphere at interstellar speed. The detector sealed in the protective shell will enter the thin Martian atmosphere at a speed of 12,000 miles per hour(19,300 kilometers per hour), and the shock wave formed in front of it can slow it to supersonic speed.
This is the 10th such shell shield that Lockheed made for NASA missions. Its phenolic plastic structure protects the aircraft by taking heat away from a layer of the shield.

According to Lockheed, the size of the shield makes landing on Mars in 2020 the most challenging mission ever. Even with decades of experience, the company must conduct very detailed tests to ensure that the protective cover can withstand not only high temperatures but also thermal mechanical stresses caused by too hard air.
Late and final static testing of the shield was completed on 25 April. Staff use vacuum pumps to simulate the impact of 140,000 pounds(63500 kilograms) of stress on the shield, which is equivalent to 120 % of the expected flight load. A notable part of the test is that, unlike traditional strain meters and elongators, the effect of this stress is measured in a new form of photogrammetry called Digital image-related technology.
Digital image-related technology involves shielding structures that are sealed in a special, plastered vinyl package and consist of black random spots on a white background. Under the supervision of a digital camera, the stress imposed on the structure causes spots to move, resulting in a 3D map showing how the load produces displacement and surface strain. This allows engineers to assess the stress factors of the entire structure rather than limiting it to a few key locations.
Lockheed said that with the completion of the load test, it will apply the tiles of the phenolic impregnated carbon ablator(PICA) thermal protection system to the structure, followed by the shield and the rest of the aviation housing.

鲜花

握手

雷人

路过

鸡蛋

最新评论

Archiver|小黑屋| 四川耍耍网

GMT+8, 2019-7-17 16:35 , Processed in 0.057644 second(s), 20 queries .

Powered by 成都耍耍论坛

© 2019 成都夜网

返回顶部