原文由美國國家空間學(xué)會（NSS）于2019年出品。?

MILESTONE 2

Continuous Human Occupancy in Low-Earth Orbit

人類在低地球軌道上實(shí)現(xiàn)連續(xù)居住

Construction of continuously occupied pressurized structures in low-Earth orbit.

在低地球軌道上建造連續(xù)居住的「承壓」結(jié)構(gòu)。

DESCRIPTION

From the U.S. Skylab, to the Soviet Salyut and Mir, to the International Space Station (ISS), and China’s Tiangong orbital stations, crewed structures have been placed in orbit and, in the case of the ISS, continuously occupied for almost twenty years.?

從美國的Skylab，到蘇聯(lián)的Salyut和Mir，再到國際空間站，以及中國的天宮軌道站，載人結(jié)構(gòu)已經(jīng)被放置在軌道上，并且就國際空間站而言，連續(xù)占用了近20年。

These space stations are essentially tools, rather than ends in themselves—laboratories where we learn how to construct large structures in orbit, live and work in space, gather biological data, avoid or survive collisions with space debris, and explore scientific principles and technologies that can be developed only in space.

與其說空間站是人類學(xué)習(xí)如何在軌道上建造大型結(jié)構(gòu)，如何在太空中生活和工作，如何收集生物數(shù)據(jù)，如何避免與空間碎片相撞或幸存下來，并探索只有在太空中才能開發(fā)的科學(xué)原理和技術(shù)的實(shí)驗室，倒不如說他們是一種基礎(chǔ)工具。

The International Space Station will be followed in orbit by other human-occupied facilities, which will likely include hotels, laboratories, factories, and storage depots, with many of them commercially owned and operated.?

在國際空間站之后的軌道上將有其他人類居住的設(shè)施，其中可能包括酒店、實(shí)驗室、工廠和儲存庫，其中許多是商業(yè)擁有和經(jīng)營的。

These would support space tourism and recreation, scientific research, low-gravity manufacturing, space solar power infrastructure, refueling and repair operations, and the like. The lessons learned can then be applied to eventual human space settlements.

這些設(shè)施將支持太空旅游和娛樂、科學(xué)研究、低重力制造、太空太陽能基礎(chǔ)設(shè)施、加油和維修作業(yè)等等。然后，學(xué)到的經(jīng)驗可以應(yīng)用于最終的人類空間定居點(diǎn)。

COMPONENTS (needed to create a habitat in space)

先決條件（在太空中創(chuàng)建一個棲息地所需的部件）

No permanent space settlement can be constructed without first accumulating the technical knowledge, industrial tools, unique materials, and techniques necessary to create such a novel habitat, as well as biological data about the ability of humans to survive and thrive for long periods of time outside Earth’s atmosphere and without gravity.

如果不首先積累技術(shù)知識、工業(yè)工具、獨(dú)特的材料和創(chuàng)造這種新的棲息地所需的技術(shù)，以及關(guān)于人類在地球大氣層之外和沒有重力的情況下長期生存和發(fā)展的能力的生物數(shù)據(jù)，就無法建造永久性的太空定居點(diǎn)。

The required knowledge and expertise has been and will continue to be acquired by the launching and assembly of large structures in low-Earth orbit.?

所需的知識和專長已經(jīng)并將繼續(xù)通過在低地球軌道上發(fā)射和組裝大型結(jié)構(gòu)來獲得。

This is the closest location in which research can occur and techniques can be practiced, and from which rapid escape in an emergency is most feasible.

這是可以進(jìn)行研究和練習(xí)技術(shù)的最近的地點(diǎn)，而且在緊急情況下迅速逃離是最可行的。

Over time, newer equipment will be added and critical new experiments conducted onboard these stations.?

隨著時間的推移，將增加更新的設(shè)備，并在這些站點(diǎn)上進(jìn)行關(guān)鍵的新實(shí)驗。

A variable gravity centrifuge, large enough for small mammals, is needed to determine the effects of living in partial gravity environments such as those found on the Moon and Mars.?

需要一個足以容納小型哺乳動物的可變重力離心機(jī)，以確定生活在部分重力環(huán)境中的影響，如在月球和火星上發(fā)現(xiàn)的環(huán)境。

Tests with space solar power wireless energy transmitters and receivers, closed or controlled ecological life support systems, and larger, more efficient electrical power systems are also required.

還需要用空間太陽能無線能量發(fā)射器和接收器、關(guān)閉或控制的生態(tài)生命支持系統(tǒng)以及更大、更有效的電力系統(tǒng)進(jìn)行試驗。

BARRIERS

阻礙

? High launch cost to LEO.

- 到低地軌道的發(fā)射成本高。

? Insufficient focus on non-pressurized docking, external?logistics, and robotic cargo handling for LEO operations.

- 對低地軌道運(yùn)行的非加壓對接、外部物流和機(jī)器人貨物處理關(guān)注不夠。

? Insufficiently developed economic justification for ongoing LEO activities.

- 對正在進(jìn)行的低地軌道活動沒有充分的經(jīng)濟(jì)論證。

? Man-made space debris accumulating in LEO that?pose a hazard to life and property so long as effective international mitigation efforts are lacking.

- 只要缺乏有效的國際緩解努力，在低地軌道上積累的人造空間碎片就會對生命和財產(chǎn)造成危害。

COMPLETION

達(dá)成

The attainment of this milestone will be recognized gradually as inhabited orbital infrastructures become permanent, are supported by sustainable economic activity, and include at least one commercially owned and operated LEO station.

隨著有人居住的軌道基礎(chǔ)設(shè)施成為永久性的，并由可持續(xù)經(jīng)濟(jì)活動支持，且擁有至少一個商業(yè)運(yùn)營的低地軌道站，這一里程碑的實(shí)現(xiàn)將逐漸得到認(rèn)可。